Extraction of tungsten from tailings of processing plants. How is tungsten obtained? Technology of enrichment of wolframite ores

Cassiterite SnO 2– the main industrial mineral of tin, which is present in tin-bearing placers and bedrock ores. The tin content in it is 78.8%. Cassiterite has a density of 6900...7100 kg/t and a hardness of 6...7. The main impurities in cassiterite are iron, tantalum, niobium, as well as titanium, manganese, pigs, silicon, tungsten, etc. The physical and chemical properties of cassiterite, for example, magnetic susceptibility, and its flotation activity depend on these impurities.

Stannin Cu 2 S FeS SnS 4- tin sulfide mineral, although it is the most common mineral after cassiterite, has no industrial significance, firstly, because it has a low tin content (27...29.5%), and secondly, the presence of copper and iron sulfides in it complicates the metallurgical processing of concentrates and, thirdly, the proximity of the flotation properties of the bed to sulfides makes separation during flotation difficult. The composition of tin concentrates obtained at processing plants is different. From rich tin placers, gravity concentrates containing about 60% tin are isolated, and slurry concentrates obtained by both gravity and flotation methods can contain from 15 to 5% tin.

Tin deposits are divided into placer and bedrock deposits. Placer Tin deposits are the main source of world tin production. Placers contain about 75% of the world's tin reserves. Indigenous Tin deposits have a complex material composition, depending on which they are divided into quartz-cassiterite, sulfide-quartz-cassiterite and sulfide-cassiterite.

Quartz-cassiterite ores are usually complex tin-tungsten ores. Cassiterite in these ores is represented by large-, medium- and finely disseminated crystals in quartz (from 0.1 to 1 mm m more). In addition to quartz and cassiterite, these ores typically contain feldspar, tourmaline, micas, wolframite or scheelite, and sulfides. Sulfide-cassiterite ores are dominated by sulfides - pyrite, pyrrhotite, arsenopyrite, galena, sphalerite and stanine. Also contains iron minerals, chlorite and tourmaline.

Tin placers and ores are enriched mainly by gravity methods using jigging machines, concentration tables, screw separators and sluices. Placers are usually much easier to enrich by gravity methods than ores from primary deposits, because they do not require expensive crushing and grinding processes. Finishing of rough gravity concentrates is carried out using magnetic, electrical and other methods.

Enrichment on sluices is used when the cassiterite grain size is more than 0.2 mm, because smaller grains are poorly captured on the sluices and their extraction does not exceed 50...60%. More efficient devices are jigging machines, which are installed for primary enrichment and allow the extraction of up to 90% of cassiterite. Finishing of coarse concentrates is carried out on concentration tables (Fig. 217).

Fig. 217. Scheme of enrichment of tin placers

Primary enrichment of placers is also carried out on dredges, including sea dredges, where drum screens with holes of 6...25 mm in size are installed to wash sand, depending on the distribution of cassiterite according to the classes of sand size and washability. Jigging machines are used to enrich the under-screen product of screens. various designs usually with an artificial bed. Gateways are also installed. Primary concentrates are subjected to cleaning operations on jigging machines. Finishing is usually carried out at onshore finishing installations. The recovery of cassiterite from placers is usually 90...95%.

The enrichment of primary tin ores, characterized by the complexity of their material composition and uneven dissemination of cassiterite, is carried out according to more complex multi-stage schemes using not only gravitational methods, but also flotation gravity, flotation, and magnetic separation.

When preparing tin ores for beneficiation, it is necessary to take into account the ability of cassiterite to sludge due to its size. More than 70% of tin losses during enrichment are due to sludged cassiterite, which is carried away with the drains of gravity devices. Therefore, the grinding of tin ores is carried out in rod mills, which operate in a closed cycle with screens. At some factories, enrichment in heavy suspensions is used at the head of the process, which makes it possible to separate up to 30...35% of the host rock minerals into the tailings, reduce grinding costs and increase tin extraction.

To isolate coarse-grained cossiterite at the head of the process, jigging is used with a feed size ranging from 2...3 to 15...20 mm. Sometimes, instead of jigging machines, when the material size is minus 3+ 0.1 mm, screw separators are installed, and when enriching material with a size of 2...0.1 mm, concentration tables are used.

For ores with uneven dissemination of cassiterite, multi-stage schemes are used with sequential grinding of not only tailings, but also poor concentrates and middlings. In tin ore, which is enriched according to the scheme presented in Fig. 218, cassiterite has a particle size of 0.01 to 3 mm.

Rice. 218. Scheme of gravity enrichment of primary tin ores

The ore also contains iron oxides, sulfides (arsenopyrite, chalcopyrite, pyrite, stanine, galena), and wolframite. The nonmetallic part is represented by quartz, tourmaline, chlorite, sericite and fluorite.

The first stage of enrichment is carried out in jigging machines at an ore size of 90% minus 10 mm with the release of coarse tin concentrate. Then, after additional grinding of the tailings of the first stage of enrichment and hydraulic classification according to equal incidence, enrichment is carried out on concentration tables. The tin concentrate obtained according to this scheme contains 19...20% tin with an extraction of 70...85% and is sent for finishing.

During finishing, sulfide minerals and host rock minerals are removed from coarse tin concentrates, which makes it possible to increase the tin content to standard levels.

Coarsely disseminated sulfide minerals with a particle size of 2...4 mm are removed by flotogravity on concentration tables, before which the concentrates are treated with sulfuric acid (1.2...1.5 kg/t), xanthate (0.5 kg/t) and kerosene (1...2 kg/t). T).

Cassiterite is extracted from gravity enrichment sludge by flotation using selective collecting reagents and depressants. For ores of complex mineral composition containing significant amounts of tourmaline and iron hydroxides, the use of fatty acid collectors makes it possible to obtain poor tin concentrates containing no more than 2...3% tin. Therefore, when flotating cassiterite, selective collectors such as Asparal-F or aerosol -22 (succinamates), phosphonic acids and the IM-50 reagent (alkylhydroxamic acids and their salts) are used. Liquid glass and oxalic acid are used to depress minerals in host rocks.

Before cassiterite flotation, material with a particle size of minus 10...15 microns is removed from the sludge, then sulfide flotation is carried out, from the tails of which at pH 5 when feeding oxalic acid, liquid glass and the Asparal-F reagent (140...150 g/t), supplied as a collector, cassiterite is floated (Fig. 219). The resulting flotation concentrate contains up to 12% tin with extraction from the operation up to 70...75% tin.

Sometimes Bartles-Moseley orbital locks and Bartles-Crosbelt concentrators are used to extract cassiterite from slurries. The rough concentrates obtained on these devices, containing 1...2.5% tin, are sent for finishing to slurry concentration tables to obtain commercial slurry tin concentrates.

Tungsten in ores it is represented by a wider range of minerals of industrial importance than tin. Of the 22 tungsten minerals currently known, four are the main ones: wolframite (Fe,Mn)WO 4(density 6700...7500 kg/m 3), hübnerite MnWO 4(density 7100 kg/m 3), ferberite FeWO 4(density 7500 kg/m 3) and sheelite CaWO 4(density 5800...6200 kg/m3). In addition to these minerals, molybdoscheelite, which is scheelite and an isomorphic admixture of molybdenum (6...16%), is of practical importance. Wolframite, hübnerite and ferberite are weakly magnetic minerals; they contain magnesium, calcium, tantalum and niobium as impurities. Wolframite is often found in ores together with cassiterite, molybdenite and sulfide minerals.

TO industrial types tungsten-containing ores are veined quartz-wolframite and quartz-cassiterite-wolframite, stockwork, skarn and placer. In the deposits vein type contains wolframite, hübnerite and scheelite, as well as molybdenum minerals, pyrite, chalcopyrite, tin, arsenic, bismuth and gold minerals. IN stockwork In deposits, the tungsten content is 5...10 times lower than in vein deposits, but they have large reserves. IN skarn The ores, along with tungsten, represented mainly by scheelite, contain molybdenum and tin. Placer tungsten deposits have small reserves, but play a significant role in tungsten mining. The industrial content of tungsten trioxide in placers (0.03...0.1%) is significantly lower than in bedrock ores, but their development is much simpler and more economically profitable. These placers, along with wolframite and scheelite, also contain cassiterite.

The quality of tungsten concentrates depends on the material composition of the ore being processed and the requirements that are placed on them when used in various industries. So, to produce ferrotungsten, the concentrate must contain at least 63% WO 3, wolframite-huebnerite concentrate for the production of hard alloys must contain at least 60% WO 3. Scheelite concentrates typically contain 55% WO 3. The main harmful impurities in tungsten concentrates are silica, phosphorus, sulfur, arsenic, tin, copper, lead, antimony and bismuth.

Tungsten placers and ores are enriched, like tin ones, in two stages - primary gravity enrichment and finishing of rough concentrates using various methods. With a low content of tungsten trioxide in the ore (0.1...0.8%) and high requirements for the quality of concentrates, the total degree of enrichment ranges from 300 to 600. This degree of enrichment can only be achieved by combining various methods, from gravity to flotation.

In addition, wolframite placers and bedrock ores usually contain other heavy minerals (cassiterite, tantalite-columbite, magnetite, sulfides), therefore, during primary gravitational enrichment, a collective concentrate containing from 5 to 20% WO 3 is released. When finishing these collective concentrates, conditioned monomineral concentrates are obtained, for which flotogravity and sulfide flotation, magnetic separation of magnetite and wolframite are used. It is also possible to use electrical separation, enrichment on concentration tables, and even flotation of minerals from displacement rocks.

The high density of tungsten minerals makes it possible to effectively use gravitational enrichment methods for their extraction: in heavy suspensions, on jigging machines, concentration tables, screw and jet separators. During enrichment and especially during finishing of collective gravity concentrates, magnetic separation is widely used. Wolframite has magnetic properties and therefore separates in a strong magnetic field, for example, from non-magnetic cassiterite.

The original tungsten ore, like tin ore, is crushed to a size of minus 12+ 6 mm and enriched by jigging, where coarse wolframite and part of the tailings with a waste content of tungsten trioxide are isolated. After jigging, the ore is crushed into rod mills, in which it is crushed to a particle size of minus 2+ 0.5 mm. To avoid excessive sludge formation, grinding is carried out in two stages. After grinding, the ore is subjected to hydraulic classification with the separation of sludge and enrichment of sand fractions on concentration tables. The industrial products and tailings obtained on the tables are further crushed and sent to the concentration tables. The tailings are also successively further crushed and enriched on concentration tables. Enrichment practice shows that the extraction of wolframite, hübnerite and ferberite by gravitational methods reaches 85%, while scheelite, inclined to sludge, is extracted by gravitational methods only by 55...70%.

When enriching finely disseminated wolframite ores containing only 0.05...0.1% tungsten trioxide, flotation is used.

Flotation is especially widely used to extract scheelite from skarn ores, which contain calcite, dolomite, fluorite and barite, floated by the same collectors as scheelite.

Collectors during flotation of scheelite ores are fatty acid oleic type, which is used at a temperature of at least 18...20°C in the form of an emulsion prepared in soft water. Oleic acid is often saponified in a hot solution before entering the process. soda ash at a ratio of 1:2. Instead of oleic acid, tall oil, naphthenic acids, etc. are also used.

It is very difficult to separate scheelite from alkaline earth metal minerals containing calcium, barium and iron oxides by flotation. Scheelite, fluorite, apatite and calcite contain calcium cations in the crystal lattice, which provide chemical sorption of the fatty acid collector. Therefore, selective flotation of these minerals from scheelite is possible within narrow pH limits using depressants such as liquid glass, sodium fluorosilicone, soda, sulfuric and hydrofluoric acid.

The depressive effect of liquid glass during flotation of calcium-containing minerals with oleic acid is the desorption of calcium soaps formed on the surface of the minerals. In this case, the floatability of scheelite does not change, but the floatability of other calcium-containing minerals sharply deteriorates. Increasing the temperature to 80...85°C reduces the contact time of the pulp with the liquid glass solution from 16 hours to 30...60 minutes. Liquid glass consumption is about 0.7 kg/t. The process of selective scheelite flotation, shown in Fig. 220, using a steaming process with liquid glass, is called the Petrov method.

Rice. 220. Scheme of flotation of scheelite from tungsten-molybdenum ores using

finishing according to Petrov's method

The concentrate of the main scheelite flotation, which is carried out at a temperature of 20°C in the presence of oleic acid, contains 4...6% tungsten trioxide and 38...45% calcium oxide in the form of calcite, fluorite and apatite. Before steaming, the concentrate is thickened to 50...60% solid. Steaming is carried out sequentially in two vats in a 3% solution of liquid glass at a temperature of 80...85°C for 30...60 minutes. After steaming, cleaning operations are carried out at a temperature of 20...25°C. The resulting scheelite concentrate can contain up to 63...66% tungsten trioxide with its recovery being 82...83%.

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State budgetary professional

educational institution of the Republic of Karelia

"Kostomuksha Polytechnic College"

Deputy Director of OD ___________________ Kubar T.S.

"_____"_________________________________2019

GRADUATE QUALIFYING WORK

Subject: “Maintaining the main method of beneficiation of tungsten ores and the use of auxiliary dehydration processes in the technological scheme of Primorsky GOK”

Group student: Kuzich S.E.

4th year, group OPI-15 (41C)

Specialty 02/21/18

"Beneficiation of mineral resources"

Head of the research and development work: Volkovich O.V.

teacher special disciplines

Kostomuksha

2019

Introduction………………………………………………………………………………...…3

1. Technological part………………………………………………………6

1.1 General characteristics of tungsten ores………………………………….6

1.2 Economic assessment tungsten ores……………………………10

1. Technological scheme for beneficiation of tungsten ores using the example of Primorsky Mining and Processing Plant………………………………………………………..……11

2. Dehydration of enrichment products…………………………………......17

2.1. The essence of dehydration processes…………………………………..….17

2.2. Centrifugation…………………………………………………..…….24

3. Organization of safe working conditions…………………………………….30

3.1. Requirements for creating safe working conditions in the workplace…………………………………………………………..…...30

3.2. Requirements for maintaining safety in the workplace…….…..32

3.3. Safety requirements for enterprise employees…………32

Conclusion………………………………………………………………………………….…..…..34

List of sources and literature used……………………....…...36

Introduction

Mineral beneficiation - This is an industry that processes solid minerals with the intention of obtaining concentrates, i.e. products whose quality is higher than the quality of the original raw materials and meets the requirements for their further use in the national economy.Minerals are the basis of the national economy, and there is not a single industry where minerals or their processing products are not used.

One of these minerals is tungsten, a metal with unique properties. It has the highest boiling and melting points among metals, while having the lowest coefficient of thermal expansion. In addition, it is one of the hardest, heaviest, most stable and dense metals: the density of tungsten is comparable to the density of gold and uranium and 1.7 times higher than that of lead.The main tungsten minerals are scheelite, hübnerite and wolframite. Based on the type of minerals, ores can be classified into two types; scheelite and wolframite. When processing tungsten-containing ores, gravitational, flotation, magnetic, and also electrostatic,hydrometallurgical and other methods.

IN last years Metal-ceramic hard alloys made on the basis of tungsten carbide are widely used. Such alloys are used as cutters, for the manufacture of drill bits, dies for cold wire drawing, dies, springs, parts of pneumatic tools, valves of internal combustion engines, heat-resistant parts of mechanisms operating at high temperatures. Surfacing hard alloys (stellites), consisting of tungsten (3-15%), chromium (25-35%) and cobalt (45-65%) with a small amount of carbon, are used for coating quickly wearing parts of mechanisms (turbine blades, excavator equipment and etc.). Tungsten alloys with nickel and copper are used in the manufacture of protective screens from gamma rays in medicine.

Metal tungsten is used in electrical engineering, radio engineering, X-ray engineering: for the manufacture of filaments in electric lamps, heaters for high-temperature electric furnaces, anticathodes and cathodes of X-ray tubes, electric vacuum equipment and much more. Tungsten compounds are used as dyes, to impart fire and water resistance to fabrics, in chemistry - as a sensitive reagent for alkaloids, nicotine, protein, and as a catalyst in the production of high-octane gasoline.

Tungsten is also widely used in the production of military and space equipment (armor plates, tank turrets, rifle and gun barrels, rocket cores, etc.).

The structure of tungsten consumption in the world is constantly changing. It is being replaced by other materials in some industries, but new areas of its application are emerging. Thus, in the first half of the 20th century, up to 90% of tungsten was spent on alloying steels. Currently, the industry is dominated by the production of tungsten carbide, and increasingly important acquires the use of tungsten metal. Recently, new possibilities for using tungsten as an environmentally friendly material have been opening up. Tungsten can replace lead in the production of various ammunition, and also find use in the manufacture of sports equipment, in particular golf clubs and balls. Developments in these areas are being carried out in the USA. In the future, tungsten should replace depleted uranium in the production of ammunition large caliber. In the 1970s, when tungsten prices were around $170. for 1% WO content 3 per 1 ton of product, the USA, and then some NATO countries, replaced tungsten with depleted uranium in heavy ammunition, which, with the same technical characteristics, was significantly cheaper.

Tungsten, as a chemical element, belongs to the group of heavy metals and, from an environmental point of view, is classified as moderately toxic (Class II-III). Currently, the source of tungsten pollution of the environment is the processes of exploration, mining and processing (beneficiation and metallurgy) of tungsten-containing mineral raw materials. As a result of processing, such sources are unused solid waste, wastewater, and dusty tungsten-containing fine particles. Solid waste in the form of dumps and various tailings is generated during the enrichment of tungsten ores. Wastewater Processing plants are represented by tailings discharges, which are used as recycled water in grinding and flotation processes.

Graduation goal qualifying work : justify the technological scheme for the enrichment of tungsten ores using the example of Primorsky GOK and the essence of dehydration processes in this technological scheme.

Introduction

1 . The importance of technogenic mineral raw materials

1.1. Mineral resources of the ore industry in the Russian Federation and the tungsten sub-industry

1.2. Technogenic mineral formations. Classification. Need for use

1.3. Technogenic mineral formation of the Dzhida VMC

1.4. Goals and objectives of the study. Research methods. Provisions for defense

2. Study of the material composition and technological properties of stale tailings from the Dzhidinsky MMC

2.1. Geological testing and evaluation of tungsten distribution

2.2. Material composition of mineral raw materials

2.3. Technological properties of mineral raw materials

2.3.1. Grading

2.3.2. Study of the possibility of radiometric separation of mineral raw materials in the original size

2.3.3. Gravity analysis

2.3.4. Magnetic analysis

3. Development of a technological scheme

3.1. Technological testing of various gravity devices for the enrichment of stale tailings of various sizes

3.2. Optimization of the general waste processing scheme

3.3. Pilot testing of the developed technological scheme for the enrichment of general waste and an industrial plant

Introduction to the work

The sciences of mineral beneficiation are, first of all, aimed at developing the theoretical foundations of mineral separation processes and the creation of beneficiation apparatuses, at revealing the relationship between the distribution patterns of components and separation conditions in beneficiation products in order to increase the selectivity and speed of separation, its efficiency and economy, and environmental safety.

Despite significant reserves mineral resources and the reduction in resource consumption in recent years, the depletion of mineral resources is one of the most important problems in Russia. Poor use of resource-saving technologies contributes to large losses of minerals during the extraction and enrichment of raw materials.

An analysis of the development of equipment and technology for mineral processing over the past 10-15 years indicates significant achievements of domestic fundamental science in the field of knowledge of the basic phenomena and patterns in the separation of mineral complexes, which makes it possible to create highly efficient processes and technologies for the primary processing of ores of complex composition and, as Consequently, to provide the metallurgical industry with the necessary range and quality of concentrates. At the same time, in our country, in comparison with developed foreign countries, there is still a significant lag in the development of the machine-building base for the production of main and auxiliary enrichment equipment, in its quality, metal intensity, energy intensity and wear resistance.

In addition, due to the departmental affiliation of mining and processing enterprises, complex raw materials were processed only taking into account the necessary industry needs for a specific metal, which led to the irrational use of natural mineral resources and increased costs for waste storage. Currently accumulated

more than 12 billion tons of waste, the content of valuable components in which in some cases exceeds their content in natural deposits.

In addition to the above negative trends, since the 90s, the environmental situation at mining and processing enterprises has sharply worsened (in a number of regions, threatening the existence of not only biota, but also humans), there has been a progressive decline in the production of non-ferrous and ferrous metal ores, mining and chemical raw materials, deterioration in the quality of processed ores and, as a consequence, the involvement in the processing of difficult-to-process ores of complex material composition, characterized by a low content of valuable components, fine dissemination and similar technological properties of minerals. Thus, over the past 20 years, the content of non-ferrous metals in ores has decreased by 1.3-1.5 times, iron by 1.25 times, gold by 1.2 times, the share of difficult ores and coal has increased from 15% to 40% of the total mass of raw materials supplied for enrichment.

Human impact on natural environment in the process of economic activity is now acquiring a global character. In terms of the scale of extracted and transported rocks, transformation of the relief, impact on the redistribution and dynamics of surface and groundwater, activation of geochemical transfer, etc. this activity is comparable to geological processes.

The unprecedented scale of extracted mineral resources leads to their rapid depletion, the accumulation of large amounts of waste on the Earth’s surface, in the atmosphere and hydrosphere, the gradual degradation of natural landscapes, a reduction in biodiversity, and a decrease in the natural potential of territories and their life-supporting functions.

Ore processing waste storage facilities are objects of increased environmental hazard due to their negative impact on the air basin, ground and surface waters, soil cover over vast areas. Along with this, tailings dumps are little-studied technogenic deposits, the use of which will make it possible to obtain additional

sources of ore and mineral raw materials with a significant reduction in the scale of disturbance of the geological environment in the region.

Production of products from technogenic deposits, as a rule, is several times cheaper than from raw materials specially mined for this purpose, and is characterized by a quick return on investment. However, the complex chemical, mineralogical and granulometric composition of tailings, as well as a wide range of minerals contained in them (from main and associated components to the simplest building materials) make it difficult to calculate the total economic effect of their processing and determine individual approach to the assessment of each tailings dump.

Consequently, at the moment a number of insoluble contradictions have emerged between the change in character mineral resource base, i.e. the need to involve difficult-to-process ores and technogenic deposits in the processing, the environmentally aggravated situation in mining regions and the state of technology, technology and organization of primary processing of mineral raw materials.

The issues of using waste from the enrichment of polymetallic, gold-containing and rare metals have both economic and environmental aspects.

In achieving the current level of development of the theory and practice of processing tailings from the enrichment of non-ferrous, rare and precious metal ores, V.A. made a great contribution. Chanturia, V.Z. Kozin, V.M. Avdokhin, SB. Leonov, L.A. Barsky, A.A. Abramov, V.I. Karmazin, SI. Mitrofanov and others.

An important component of the overall strategy of the ore industry, incl. tungsten, is the increased use of ore processing waste as additional sources of ore and mineral raw materials, with a significant reduction in the scale of disturbance of the geological environment in the region and the negative impact on all components of the environment.

In the field of using ore processing waste, the most important thing is a detailed mineralogical and technological study of each specific

individual technogenic deposit, the results of which will allow the development of an effective and environmentally friendly safe technology industrial development of an additional source of ore and mineral raw materials.

The problems considered in the dissertation work were solved in accordance with the scientific direction of the Department of Mineral Processing and Environmental Engineering of the Irkutsk State technical university on the topic “Fundamental and technological research in the field of processing of mineral and technogenic raw materials for the purpose of their integrated use, taking into account environmental problems in complex industrial systems” and x/d topic No. 118 “Research on the beneficiation of stale tailings of the Dzhida VMC.”

Goal of the work- scientifically substantiate, develop and test
rational technological methods for enriching stale

The following tasks were solved in the work:

Evaluate the distribution of tungsten throughout the entire space of the main
technogenic education of the Dzhida VMC;

study the material composition of the stale tailings of the Dzhizhinsky MMC;

study the contrast of stale tailings in the original size in terms of the content of W and S (II);

to study the gravitational enrichment of stale tailings of the Dzhida VMC in various sizes;

determine the feasibility of using magnetic enrichment to improve the quality of rough tungsten-containing concentrates;

optimize the technological scheme for the enrichment of technogenic raw materials from the general waste treatment plant of the Dzhida VMC;

conduct pilot tests of the developed scheme for extracting W from the stale tailings of DVMC;

To develop a circuit diagram of devices for the industrial processing of stale tailings from the Dzhida VMC.

To carry out the research, a representative technological sample of stale tailings from the Dzhida VMC was used.

When solving the formulated problems, the following were used research methods: spectral, optical, chemical, mineralogical, phase, gravitational and magnetic methods for analyzing the material composition and technological properties of initial mineral raw materials and enrichment products.

The following are submitted for defense: basic scientific principles:

The patterns of distribution of initial technogenic mineral raw materials and tungsten by size classes have been established. The need for primary (preliminary) classification by size of 3 mm has been proven.

The quantitative characteristics of the stale ore dressing tailings of the Dzhidinsky VMC in terms of WO3 and sulfide sulfur content have been established. It has been proven that the initial mineral raw materials belong to the category of non-contrasting ores. A reliable and reliable correlation between the contents of WO3 and S (II) was revealed.

Quantitative patterns of gravitational enrichment of stale tailings from the Dzhida VMC have been established. It has been proven that for starting material of any size effective method W extraction is gravity enrichment. Forecast technological indicators of gravitational enrichment of initial mineral raw materials have been determined V of various sizes.

Quantitative patterns of distribution of stale ore dressing tailings of the Dzhida VMC among fractions of different specific magnetic susceptibility have been established. The effectiveness of the sequential use of magnetic and centrifugal separation has been proven to improve the quality of rough W-containing products. The technological modes of magnetic separation have been optimized.

Material composition of mineral raw materials

When examining a secondary tailings dump (emergency discharge tailings dump (EDT)), 35 furrow samples were taken from pits and clearings along the slopes of the dumps; the total length of the furrows is 46 m. ​​The pits and clearings are located in 6 exploration lines, spaced 40-100 m from each other; the distance between pits (clearings) in exploration lines is from 30-40 to 100-150 m. All lithological varieties of sands were tested. Samples were analyzed for W03 and S(II) content. In this area, 13 samples were taken from pits with a depth of 1.0 m. The distance between the lines is about 200 m, between the workings - from 40 to 100 m (depending on the distribution of the same type of lithological layer). The results of sample analyzes for WO3 and sulfur content are given in table. 2.1. Table 2.1 - Content of WO3 and sulfide sulfur in private samples of CAS It can be seen that the content of WO3 ranges from 0.05-0.09%, with the exception of sample M-16, selected from medium-grained gray sands. In the same sample, high concentrations of S (II) were found - 4.23% and 3.67%. For individual samples (M-8, M-18), a high content of S sulfate was noted (20-30% of the total sulfur content). In the upper part of the emergency discharge tailings dump, 11 samples of various lithological varieties were taken. The content of WO3 and S (II), depending on the origin of the sands, varies over a wide range: from 0.09 to 0.29% and from 0.78 to 5.8%, respectively. Elevated WO3 contents are typical for medium-to-coarse-grained sand varieties. The S(VI) content makes up 80 - 82% of the total S content, but in individual samples predominantly with low contents of tungsten trioxide and total sulfur, it decreases to 30%.

The deposit's reserves can be assessed as Pj category resources (see Table 2.2). Along the upper part, the length of the pit varies in a wide range: from 0.7 to 9.0 m, therefore the average content of controlled components is calculated taking into account the parameters of the pits. In our opinion, based on the given characteristics, taking into account the composition of stale tailings, their preservation, conditions of occurrence, contamination with household waste, WO3 content in them and the degree of sulfur oxidation, only the upper part of the emergency discharge tailings with resources of 1.0 million can be of industrial interest . tons of sand and 1330 tons of WO3 with a WO3 content of 0.126%. Their location in close proximity to the designed enrichment plant (250-300 m) is favorable for their transportation. Bottom part The emergency discharge tailings are subject to disposal as part of the environmental rehabilitation program for the city of Zakamensk.

5 samples were taken from the deposit area. The interval between sampling points is 1000-1250 m. Samples were taken over the entire thickness of the layer and analyzed for the content of WO3, Btot and S (II) (see Table 2.3). Table 2.3 - Content of WO3 and sulfur in private ATO samples From the analysis results it is clear that the content of WO3 is low, varying from 0.04 to 0.10%. The average S(II) content is 0.12% and is of no practical interest. The work carried out does not allow us to consider the by-product alluvial tailings dump as a potential industrial facility. However, as a source of environmental pollution, these formations must be disposed of. The main tailings dump (MTD) was explored along parallel exploration lines oriented at azimuth 120 and located 160 - 180 m from each other. The exploration lines are oriented across the strike of the dam and the slurry pipeline, through which the ore tailings were discharged, deposited subparallel to the dam crest. Thus, the exploration lines were also oriented across the bedding of technogenic deposits. Along the exploration lines, a bulldozer drove trenches to a depth of 3-5 m, from which pits were drilled to a depth of 1 to 4 m. The depth of the trenches and pits was limited by the stability of the walls of the workings. The pits in the trenches were made through 20 - 50 m in the central part of the deposit and through 100 m - on the south-eastern flank, on the area of ​​​​the former settling pond (now dried up), from which water was supplied to the processing plants during the operation of the plant.

The area of ​​the OTO along the distribution boundary is 1015 thousand m (101.5 hectares); along the long axis (along the valley of the Barun-Naryn river) it extends for 1580 m, in the transverse direction (near the dam) its width is 1050 m. In this area, 78 pits were made from pre-created trenches in five main exploration lines. Consequently, one pit illuminates an area of ​​12850 m, which is equivalent to an average network of 130x100 m. In the central part of the field, represented by sands of different grains, in the area where slurry pipelines are located on an area of ​​530 thousand m (52% of the TMO area), 58 pits and one well (75% all workings); The exploration network area averaged 90x100 m2. On the extreme south-eastern flank, on the site of a former settling pond in the area of ​​development of fine-grained sediments - silts, 12 pits were made (15% of the total), characterizing an area of ​​​​about 370 thousand m (37% of total area technogenic deposit); the average network area here was 310x100 m2. In the area of ​​transition from heterogeneous sands to silts, composed of silty sands, on an area of ​​about 115 thousand m (11% of the area of ​​the technogenic deposit), 8 pits were drilled (10% of the number of workings in the technogenic deposit) and the average area of ​​the exploration network was 145x100 m. The average length of the tested section at the technogenic deposit is 4.3 m, including for different-grained sands - 5.2 m, silty sands - 2.1 m, silt - 1.3 m. The absolute elevations of the modern surface relief of the technogenic deposit in the tested sections vary from 1110 - 1115 m near the top of the dam, up to 1146 - 148 m in the central part and 1130-1135 m on the southeastern flank. In total, 60 - 65% of the capacity of the technogenic deposit has been tested. Trenches, pits, strippings and burials were documented in M ​​1:50 -1:100 and tested with a furrow with a cross section of 0.1x0.05 m2 (1999) and 0.05x0.05 m2 (2000). The length of the furrow samples was 1 m, the weight was 10 - 12 kg in 1999. and 4 - 6 kg in 2000. The total length of the tested intervals in the exploration lines was 338 m, in general, taking into account the areas of detailing and individual sections outside the network - 459 m. The weight of the samples taken was 5 tons.

The samples, together with a passport (characteristics of the rock, sample number, production and performer) were packaged in plastic and then fabric bags and sent to the RAC of the Republic of Buryatia, where they were weighed, dried, analyzed for the content of W03, and S (II) according to NS AM methods. The accuracy of the analyzes is confirmed by the comparability of the results of ordinary, group (RAC analyses) and technological (TsNIGRI and VIMS analyses) samples. The results of the analysis of private technological samples taken at the OTO are given in Appendix 1. The main (OTO) and two secondary tailings dumps (KhAT and ATO) of the Dzhida VMC were statistically compared in terms of WO3 content using the Student's t test (see Appendix 2). With a confidence probability of 95% it was established: - no significant statistical difference in WO3 content between private samples of side tailings; - average results of OTO testing for WO3 content in 1999 and 2000. belong to the same general population. Consequently, the chemical composition of the main tailings pond changes insignificantly over time under the influence of external influences. All general waste reserves can be processed using a single technology.; - average sampling results of the main and side tailings dumps in terms of WO3 content differ significantly from each other. Consequently, to involve mineral raw materials from side tailings, the development of local enrichment technology is required.

Technological properties of mineral raw materials

Based on their granular composition, sediments are divided into three types of sediments: heterogeneous sands; silty sands (silty); silts There are gradual transitions between these types of sediments. Clearer boundaries are observed in the thickness of the section. They are caused by the alternation of sediments of different grain compositions, different colors (from dark green to light yellow and gray) and different material compositions (quartz-feldspathic nonmetallic part and sulfide with magnetite, hematite, hydroxides of iron and manganese). The entire thickness is layered - from fine to coarsely layered; the latter is more typical for coarse-grained varieties of sediments or layers of significant sulfide mineralization. Fine-grained (silty, silt fractions, or layers composed of dark-colored materials - amphibole, hematite, goethite) usually form thin (a few cm - mm) layers. The occurrence of the entire thickness of sediments is subhorizontal with a predominant fall of 1-5 in the northern directions. Sands of different grains are located in the northwestern and central parts of the OTO, which is due to their sedimentation near the source of discharge - the pulp pipeline. The width of the strip of different-grained sands is 400-500 m; along the strike they occupy the entire width of the valley - 900-1000 m. The color of the sands is gray-yellow, yellow-green. The granular composition is variable - from fine-grained to coarse-grained varieties up to lenses of gravelstones 5-20 cm thick and up to 10-15 m long. Silty (silty) sands stand out in the form of a layer 7-10 m thick (horizontal thickness, outcrop 110-120 m ). They lie under heterogeneous sands. In cross-section they represent a layered formation of gray, greenish-gray color with alternation of fine-grained sands with layers of silt. The volume of silts in the section of silty sands increases in the southeast direction, where silts make up the main part of the section.

Silts make up the southeastern part of the OTO and are represented by finer particles of enrichment waste of dark gray, dark green, bluish-green color with layers of grayish-yellow sand. The main feature of their structure is a more uniform, more massive texture with less frequent and less clearly defined layering. The silts are underlain by silty sands and lie on the base of the bed - alluvial-deluvial deposits. The granulometric characteristics of OTO mineral raw materials with the distribution of gold, tungsten, lead, zinc, copper, fluorite (calcium and fluorine) by size class are given in Table. 2.8. According to granulometric analysis, the bulk of the OTO sample material (about 58%) has a particle size of -1+0.25 mm, 17% each is coarse (-3+1 mm) and small (-0.25+0.1) mm classes. The share of material with a particle size of less than 0.1 mm is about 8%, of which half (4.13%) is of the slurry class - 0.044 + 0 mm. Tungsten is characterized by a slight fluctuation in content in size classes from -3 +1 mm to -0.25+0.1 mm (0.04-0.05%) and a sharp increase (up to 0.38%) in size class -0 .1+0.044 mm. In the slurry class -0.044+0 mm, the tungsten content is reduced to 0.19%. The accumulation of hübnerite occurs only in small-sized material, that is, in the class -0.1 + 0.044 mm. Thus, 25.28% of tungsten is concentrated in the -0.1+0.044 mm class with an output of this class of about 4% and 37.58% in the -0.1+0 mm class with an output of this class of 8.37%. Differential and integral histograms of the distribution of particles of mineral raw materials GTO by size classes and histograms of absolute and relative distribution W by size classes of GTO mineral raw materials are presented in Fig. 2.2. and 2.3. In table Table 2.9 shows data on the dissemination of hübnerite and scheelite in the OTO mineral raw material of the original size and crushed to - 0.5 mm.

In the -5+3 mm class of initial mineral raw materials there are no pobnerite and scheelite grains, as well as intergrowths. In the -3+1 mm class, the content of free scheelite and hübnerite grains is quite large (37.2% and 36.1%, respectively). In the -1+0.5 mm class, both mineral forms of tungsten are present in almost equal quantities, both in the form of free grains and in the form of intergrowths. In thin classes -0.5+0.25, -0.25+0.125, -0.125+0.063, -0.063+0 mm, the content of free grains of scheelite and hübnerite is significantly higher than the content of intergrowths (the content of intergrowths varies from 11.9 to 3. 0%) The size class -1+0.5 mm is limiting and in it the content of free grains of scheelite and hübnerite and their intergrowths is almost the same. Based on the data in table. 2.9, we can conclude that it is necessary to classify delimed mineral raw materials OTO according to a particle size of 0.1 mm and separate enrichment of the resulting classes. From the large class, it is necessary to separate the free grains into a concentrate, and the tailings containing splices must be subjected to further grinding. The crushed and deslimed tailings should be combined with the deslimed class -0.1+0.044 of the initial mineral raw materials and sent to gravity operation II in order to extract fine grains of scheelite and pobnerite into the middling product.

2.3.2 Study of the possibility of radiometric separation of mineral raw materials in the original size Radiometric separation is the process of large-piece separation of ores according to the content of valuable components, based on the selective effect of various types of radiation on the properties of minerals and chemical elements. Over twenty methods of radiometric enrichment are known; the most promising of them are X-ray radiometric, X-ray luminescence, radio resonance, photometric, autoradiometric and neutron absorption. Using radiometric methods, the following are solved: technological challenges: preliminary enrichment with removal of waste rock from ore; selection of technological varieties, varieties with subsequent enrichment according to separate schemes; selection of products suitable for chemical and metallurgical processing. Assessment of radiometric enrichment includes two stages: studying the properties of ores and experimental determination technological indicators enrichment. At the first stage, the following basic properties are studied: the content of valuable and harmful components, particle size distribution, single- and multi-component contrast of ore. At this stage, the fundamental possibility of using radiometric enrichment is established, the maximum separation indices are determined (at the stage of studying contrast), separation methods and characteristics are selected, their effectiveness is assessed, theoretical separation indices are determined, and a basic diagram of radiometric enrichment is developed, taking into account the features of subsequent processing technology. At the second stage, the modes and practical results of separation are determined, large-scale laboratory tests of the radiometric enrichment scheme are carried out, and rational option schemes based on a technical and economic comparison of the combined technology (with radiometric separation at the beginning of the process) with the basic (traditional) technology.

In every specific case the mass, size and number of technological samples are established depending on the properties of the ore, the structural features of the deposit and methods of its exploration. The content of valuable components and the uniformity of their distribution in the ore mass are the determining factors in the use of radiometric enrichment. The choice of radiometric enrichment method is influenced by the presence of trace elements isomorphically associated with useful minerals and in some cases playing the role of indicators, as well as the content of harmful impurities, which can also be used for these purposes.

Optimization of the general waste processing scheme

In connection with the involvement in industrial exploitation of low-grade ores with a tungsten content of 0.3-0.4%, in recent years, multi-stage combined enrichment schemes based on a combination of gravity, flotation, magnetic and electrical separation, chemical finishing of low-grade flotation concentrates, etc. have become widespread. . A special International Congress in 1982 from San Francisco. An analysis of the technological schemes of existing enterprises showed that during ore preparation, various methods of preliminary concentration have become widespread: photometric sorting, preliminary jigging, enrichment in heavy environments, wet and dry magnetic separation. In particular, photometric sorting is effectively used at one of the largest suppliers of tungsten products - at the Mount Corbijn plant in Australia, which processes ores with a tungsten content of 0.09% at large factories in China - Taishan and Xihuashan.

For the preliminary concentration of ore components in heavy media, highly efficient Dinavirpul devices from Sala (Sweden) are used. Using this technology, the material is classified and the +0.5 mm class is enriched in a heavy environment represented by a ferrosilicon mixture. Some factories use dry and wet magnetic separation as pre-concentration. Thus, at the Emerson plant in the USA, wet magnetic separation is used to separate the pyrrhotite and magnetite contained in the ore, and at the Uyudag plant in Turkey, class - 10 mm is subjected to dry grinding and magnetic separation in separators with low magnetic intensity to isolate magnetite, and then enriched in high tension separators to separate the garnet. Further enrichment includes table concentration, flotogravity and scheelite flotation. An example of the use of multi-stage combined schemes for the enrichment of low-grade tungsten ores, ensuring the production of high-quality concentrates, are the technological schemes used in Chinese factories. Thus, at the Taishan factory with a capacity of 3000 tons/day of ore, wolframite-scheelite material with a tungsten content of 0.25% is processed. The original ore is subjected to manual and photometric sorting with 55% of waste rock removed to the dump. Further enrichment is carried out on jigging machines and concentration tables. The resulting rough gravity concentrates are finished using flotogravity and flotation methods. Xihuashan, which processes ore with a wolframite to scheelite ratio of 10:1, uses a similar gravity cycle. The crude gravity concentrate is sent to flotogravity and flotation, through which sulfides are removed. Next, wet magnetic separation of the chamber product is carried out to isolate wolframite and rare earth minerals. The magnetic fraction is sent to electrostatic separation and then flotation of wolframite. The non-magnetic fraction is fed to sulfide flotation, and the flotation tailings are subjected to magnetic separation to produce scheelite and cassiterite-wolframite concentrates. The total WO3 content is 65% with a recovery of 85%.

There has been an increase in the use of the flotation process in combination with chemical finishing of the resulting poor concentrates. In Canada, at the Mount Pleasant plant, flotation technology has been adopted for the beneficiation of complex tungsten-molybdenum ores, including the flotation of sulfides, molybdenite and wolframite. In the main sulfide flotation, copper, molybdenum, lead, and zinc are recovered. The concentrate is cleaned, further crushed, steamed and conditioned with sodium sulfide. The molybdenum concentrate is purified and subjected to acid leaching. Sulfide flotation tailings are treated with sodium fluoride to depress gangue minerals and wolframite is floated with organophosphorus acid, followed by leaching of the resulting wolframite concentrate with sulfuric acid. At the Kantung factory (Canada), the scheelite flotation process is complicated by the presence of talc in the ore, so a primary talc flotation cycle was introduced, then copper minerals and pyrrhotite are floated. The flotation tailings are subjected to gravity enrichment to produce two tungsten concentrates. Gravity tailings are sent to the scheelite flotation cycle, and the resulting flotation concentrate is processed hydrochloric acid. At the Ixsjöberg factory (Sweden), replacing the gravity-flotation scheme with a purely flotation scheme made it possible to obtain scheelite concentrate containing 68-70% WO3 with a recovery of 90% (according to the gravity-flotation scheme, the recovery was 50%). Much attention has recently been paid to improving the technology for extracting tungsten minerals from sludge in two main areas: gravitational enrichment of sludge in modern multi-deck concentrators (similar to the enrichment of tin-containing sludge) with subsequent finishing of the concentrate by flotation and enrichment in wet magnetic separators with high magnetic field strength (for wolframite sludge).

An example of the use of combined technology is factories in China. The technology includes sludge thickening to 25-30% solids, sulfide flotation, tailings enrichment in centrifugal separators. The resulting rough concentrate (WO3 content 24.3% with recovery 55.8%) is sent to wolframite flotation using organophosphorus acid as a collector. Flotation concentrate containing 45% WO3 is subjected to wet magnetic separation to obtain wolframite and tin concentrates. Using this technology, wolframite concentrate containing 61.3% WO3 with a recovery of 61.6% is obtained from sludge containing 0.3-0.4% WO3. Thus, technological schemes for the enrichment of tungsten ores are aimed at increasing the complexity of the use of raw materials and separating all associated valuable components into independent types of products. Thus, at the Kuda factory (Japan), when enriching complex ores, 6 commercial products are obtained. In order to determine the possibility of additional extraction of useful components from stale enrichment tailings in the mid-90s. TsNIGRI studied a technological sample containing 0.1% tungsten trioxide. It has been established that the main valuable component in the tailings is tungsten. The content of non-ferrous metals is quite low: copper 0.01-0.03; lead - 0.09-0.2; zinc -0.06-0.15%, gold and silver were not found in the sample. Studies have shown that successful extraction of tungsten trioxide will require significant costs for regrinding the tailings and at this stage their involvement in processing is not promising.

The technological scheme of mineral processing, including two or more devices, embodies everything character traits complex object, and optimization of the technological scheme can apparently be the main task system analysis. Almost all previously discussed modeling and optimization methods can be used to solve this problem. However, the structure of concentrator circuits is so complex that additional optimization methods need to be considered. Indeed, for a circuit consisting of at least 10-12 devices, it is difficult to implement a conventional factorial experiment or carry out multiple nonlinear statistical processing. Currently, several ways to optimize circuits are being outlined - an evolutionary path to generalize the accumulated experience and take a step in the successful direction of changing the circuit.

Pilot testing of the developed technological scheme for the enrichment of general waste and an industrial plant

The tests were carried out in October-November 2003. During the tests, 15 tons of initial mineral raw materials were processed in 24 hours. The results of testing the developed technological scheme are presented in Fig. 3.4 and 3.5 and in table. 3.6. It can be seen that the yield of the standard concentrate is 0.14%, the content is 62.7% with a WO3 recovery of 49.875%. The results of spectral analysis of a representative sample of the obtained concentrate are given in table. 3.7, confirm that W-concentrate III of magnetic separation is standard and corresponds to the KVG (T) grade of GOST 213-73 " Technical requirements(composition,%) to tungsten concentrates obtained from tungsten-containing ores." Consequently, the developed technological scheme for the extraction of W from the stale tailings of the ore processing of the Dzhidinsky VMC can be recommended for industrial use and the stale tailings are converted into additional industrial mineral raw materials of the Dzhidinsky VMC.

For the industrial processing of stale tailings using the developed technology at Q = 400 t/h, a list of equipment has been developed, given in To carry out an enrichment operation with a particle size of +0.1 mm, it is recommended to install a KNELSON centrifugal separator with continuous unloading of the concentrate, while for centrifugal enrichment class -0.1 mm must be carried out on a KNELSON centrifugal separator with periodic unloading of the concentrate. Thus, it has been established that the most effective way extraction of WO3 from general waste with a particle size of -3+0.5 mm is carried out by screw separation; from size classes -0.5+0.1 and -0.1+0 mm and primary enrichment tailings crushed to -0.1 mm - centrifugal separation. The essential features of the technology for processing the stale tailings of the Dzhida VMC are as follows: 1. A narrow classification of the feed directed to primary enrichment and finishing is necessary; 2. An individual approach is required when choosing a method for primary enrichment of classes of different sizes; 3. Obtaining waste tailings is possible with the primary enrichment of the finest feed (-0.1+0.02mm); 4. Use of hydrocyclone operations to combine dewatering and size separation operations. The drain contains particles with a particle size of -0.02 mm; 5. Compact arrangement of equipment. 6. Profitability of the technological scheme (APPENDIX 4), the final product is a standard concentrate that meets the requirements of GOST 213-73.

Kiselev, Mikhail Yurievich

Vladivostok

annotation

This paper discusses technologies for the enrichment of scheelite and wolframite.

The technology for enriching tungsten ores includes: preliminary concentration, enrichment of crushed products of preliminary concentration to obtain collective (rough) concentrates and their finishing.

Keywords

Scheelite ore, wolframite ore, heavy-medium separation, jigging, gravity method, electromagnetic separation, flotation.

1. Introduction 4

2. Pre-concentration 5

3. Technology of enrichment of wolframite ores 6

4. Technology of enrichment of Scheelite ores 9

5. Conclusion 12

References 13

Introduction

Tungsten is a silver-white metal with high hardness and a boiling point of about 5500°C.

The Russian Federation has large proven reserves. Its tungsten ore potential is estimated at 2.6 million tons of tungsten trioxide, of which proven reserves amount to 1.7 million tons, or 35% of those in the world.

Developed deposits in the Primorsky Territory: Vostok-2, OJSC Primorsky GOK (1.503%); Lermontovskoye, OJSC Lermontovskaya GRK (2.462%).

The main tungsten minerals are scheelite, hübnerite and wolframite. Depending on the type of minerals, ores can be divided into two types; scheelite and wolframite (huebnerite).

When processing tungsten-containing ores, gravitational, flotation, magnetic, as well as electrostatic, hydrometallurgical and other methods are used.

Pre-concentration.

The cheapest and at the same time highly productive methods of preconcentration are gravitational ones, such as heavy-medium separation and jigging.

Heavy medium separation allows you to stabilize the quality of food entering the main processing cycles, to isolate not only the waste product, but also to separate the ore into rich coarsely disseminated and poor finely disseminated ore, which often require fundamentally different processing schemes, since they differ markedly in material composition. The process is characterized by the highest density separation accuracy compared to other gravity methods, which allows for high recovery of the valuable component with minimal concentrate yield. When enriching ore in heavy suspensions, a difference in the densities of the separated pieces of 0.1 g/m3 is sufficient. This method can be successfully used for coarsely disseminated wolframite and scheelite-quartz ores. The results of studies on the enrichment of tungsten ores from the Pun-les-Vignes (France) and Borralha (Portugal) deposits under industrial conditions showed that the results obtained using enrichment in heavy suspensions are significantly better than when enriching only on jig machines - into the heavy fraction recovery was more than 93% of the ore.

Jigging Compared to heavy-medium enrichment, it requires lower capital costs and allows you to enrich material in a wide range of densities and sizes. Coarse jigging has become widespread in the beneficiation of coarse and medium disseminated ores that do not require fine grinding. The use of jigging is preferable when enriching carbonate and silicate ores of skarn and vein deposits, while the value of the ore contrast index is gravitational composition must exceed one.

Technology of enrichment of wolframite ores

The high specific gravity of tungsten minerals and the coarse-grained structure of wolframite ores make it possible to widely use gravitational processes in their enrichment. To obtain high technological indicators, it is necessary to combine devices with different separation characteristics in a gravitational scheme, in which each previous operation in relation to the subsequent one is, as it were, a preparatory operation, improving the enrichment of the material. Schematic diagram enrichment of wolframite ores is shown in Fig. 1.

Jigging is used starting from the size at which tailings can be recovered. This operation is also used to isolate coarse tungsten concentrates with subsequent regrinding and enrichment of jigging tails. The basis for choosing the jigging scheme and the size of the enriched material is the data obtained by separating the material by density with a particle size of 25 mm. If the ores are finely disseminated and preliminary studies have shown that large-piece enrichment and jigging are unacceptable for them, then the ore is enriched in thin suspension-carrying flows, which include enrichment on screw separators, jet chutes, cone separators, sluices, and concentration tables. With stage-by-stage grinding and stage-by-stage enrichment of ore, the extraction of wolframite into rough concentrates is more complete. Rough wolframite gravity concentrates are brought to condition according to developed schemes using wet and dry enrichment methods.

Rich wolframite concentrates are enriched by electromagnetic separation, and the electromagnetic fraction can be contaminated with ferrous zinc blende, bismuth minerals and partially arsenic (arsenopyrite, scorodite). To remove them, magnetizing roasting is used, which enhances the magnetic susceptibility of iron sulfides, and at the same time, sulfur and arsenic, which are harmful to tungsten concentrates, are removed in the form of gaseous oxides. Wolframite (Hübnerite) is further extracted from sludge by flotation using fatty acid collectors and the addition of neutral oils. Rough gravity concentrates are relatively easily brought to standard using electrical methods enrichment. Flotation and flotation gravity are carried out with the supply of xanthate and a foaming agent in a slightly alkaline or slightly acidic environment. If the concentrates are contaminated with quartz and light minerals, then after flotation they are cleaned on concentration tables.

Related information.

Main enrichment

For some beneficiation factories, in pre-beneficiation, first Xinhai will use moving screen jigger, and then enter into finishing operations.

Gravity enrichment

For wolframite gravity technology, Xinhai usually uses a gravity process that includes multi-stage jigging, multi-stage table and middling product regrinding. That is, after fine crushing, worthy ores, which, through the classification of a vibrating screen, carry out multi-stage jigging and produce coarse sand from jigging and gravity. Then the ballast products of the large class jigging will enter the mill for further grinding. And the ballast products of the small class jigging, through the classifications, will enter into sorting multi-stage table, then coarse sand is produced from gravity and from the table, then the tailings from the table will enter the tailings hopper, the middlings from the table are then returned to the regrinding cycle stage, and the gravity coarse sand from the jig and the table enters the finishing operation.

Cleaning

In the wolframite finishing operation, a combined flotation and gravity enrichment technology or a combined flotation technology - gravity and magnetic enrichment is usually used. At the same time, returns the accompanying item.

The finishing operation usually uses a combined method of flotation and enrichment table and washing of sulfur pyrites through flotation. At the same time, we can enter into the flotation separation of sulfur pyrites. After this, wolframite concentrates are produced, if wolframite concentrates contain scheelite and cassiterite, then wolframite concentrates, scheelite concentrates and cassiterite concentrates are produced through a combined flotation and gravity enrichment technology or a combined gravitational and magnetic flotation technology enrichment.

Fine sludge treatment

The processing method for fine sludge in Xinhai is usually as follows: firstly, desulfurization is carried out, then, according to the properties of the fine sludge and material, gravity, flotation, magnetic and electrical enrichment technology is used, or a combined beneficiation technology of several technologies is used to return the tungsten ore, and at the same time time will carry out the utilization of associated ore minerals.

Practical examples

The Xinhai wolframite object was taken as an example; the size distribution of the ore of this mine was inhomogeneous, and the ore was very heavily sludged. The initial technological scheme used by the enrichment plant, which includes pre-enrichment crushing, gravity and re-cleaning, resulted in a number of technological defects huge losses small class tungsten ores, high price enrichment, such as the poor state of comprehensive enrichment indicators. In order to improve the wolframite sorting status, this beneficiation plant authorized Xinhai to carry out technical reconstruction tasks. After careful research on the ore properties and beneficiation technologies of this factory, Xinhai optimized the technology for beneficiation of wolframite of this factory and added fine sludge processing technology. and ultimately obtain ideal enrichment rates. The enrichment indicator of the factory before and after the transformation is as follows:

After the transformation, the extraction of tungsten ore increased significantly. And mitigated the effects of fine sludge on the wolframite sorting process, achieved good recovery rate, effectively improved the economic efficiency of the factory.