Smoke from kaolin wool first use e. Mineral wool insulation. Physico-chemical characteristics of fibers

Today, a huge amount is represented on the Russian market. However, not all of them are the same and are able to withstand harsh climatic conditions and reliably protect buildings and communications from heat loss. Statistical data from studies of the Russian construction complex have shown that the main type of insulation used in Russia is mineral wool products, which include mineral, kaolin, quartz, graphite wool. All of them have increased temperature resistance, their market share is a little more than 65%, the remaining 35% are various types of foam, which are significantly inferior to mineral wool.

mineral wool

Mineral wool is a heat-insulating material consisting of the finest vitreous fibers obtained by spraying a liquid melt of charge from metallurgical slags, rocks or other silicate materials. Depending on the outgoing raw materials, mineral wool is divided into: stone wool, which is made from mineral rocks (sedimentary rocks: clays, limestones, dolomites, marls and overthrown: granites, sinites, pegmatites, pumice) and slag wool made from metallurgical slags - blast-furnace, cupola and open-hearth slags, as well as non-ferrous metallurgy slags.

The thermal insulation properties of mineral wool are determined by the air pores enclosed between the fibers. Mineral wool produced by blowing and centrifugal methods. The blowing methods are based on the use of the kinetic energy of steam, compressed air or gas exiting the nozzle and encountering a jet of silicate melt on its way, as a result of which the latter is broken into drops, which first stretch into a cylinder, which then narrows and forms two pear-shaped bodies connected thread. Pear-shaped bodies decrease and turn into fibers. The centrifugal method is based on the use of the centrifugal force of a rotating disk onto which a stream of silicate melt falls.
There is also the most "fancy" method of obtaining mineral wool - centrifugal spunbond-blowing. It ensures the complete absence of non-fibrous inclusions (the so-called "kings"), as well as a small diameter of cotton wool fibers. Properties of mineral wool: with an increase in the silica content in mineral wool, its softening temperature and temperature resistance increase. Alumina increases the chemical and biological resistance of wool, iron oxide reduces temperature resistance, increases the corrosiveness of wool. The thermal conductivity coefficient depends on the average fiber thickness, bulk density and porosity. Optimum is a porosity of 90%. The fiber thickness can vary from 2 to 40 microns.

glass wool

glass wool is a thermal insulation material consisting of randomly arranged flexible glass fibers obtained by drawing from molten glass. Raw material for receiving glass wool serves as glass or glass industry waste.

Manufactured glass wool in two ways - blowing and the method of continuous stretching (spunbond-blowing). The technological process of obtaining glass fiber by the blowing method is similar to the blowing method for producing mineral wool. Glass fiber has a thickness of 4 to 30 microns, fiber length 120-200 mm. The continuous pull method looks like this. The glass charge is loaded into the bath furnace (t=1500C), under the influence of temperature it melts over the surface and flows in a thin layer into the homogenization zone, where it becomes more homogeneous.
The melt flows out through a special plate, which has holes (dies) with a diameter of 0.1 mm. A thread is drawn from the flowing stream of melt by means of a rapidly rotating drum. The continuous drawing method gives a fiber without "blobs", uniform thickness and high quality. The strength of fiberglass depends on its thickness. The thicker the fiber, the more fragile it is. The brittleness of the fiber causes it to break rapidly when vibrated. That is, the optimal fiber thickness should be 15 microns or less.

More advanced fiberglass production technologies make it possible to obtain an average thickness of 6 microns (that is, the fiber practically does not irritate the skin and mucous membranes of the respiratory tract). The technological process of obtaining ISOVER glass wool consists of the following steps. Raw materials (recycled glass, sand, soda, limestone) are melted in a furnace (t=1400C and above); after which the molten mass flows into the fiber former, which is a spinning centrifuge, where the glass is broken into fibers.

Between themselves, the fibers of glass wool are bound by a binder (it is mixed with glass fiber in the form of an aerosol during the fiber formation process). Products impregnated with resin are subjected to heat treatment (t=250C), which gives the finished insulating material the required rigidity. The coefficient of thermal conductivity of fiberglass varies (0.029-0.040 W / mK), temperature resistance + 450C, frost resistance (hundred-fold freezing and thawing) -25C. Glass wool is resistant to acid and in terms of temperature resistance and thermal conductivity, glass wool differs from mineral wool, which has a lower average density and lower temperature resistance. It is used for thermal insulation of building structures, as well as in technical insulation (pipelines, industrial equipment), as well as refrigerators and vehicles.

Kaolin wool

Kaolin wool and products based on it are refractory (high-temperature insulation, application temperature t= 1100-1250C). The raw materials for its production are technical alumina, containing 99% aluminum oxide, and pure quartz sand. The melt is produced in a five-electrode ore-thermal furnace (melting point 1750°C). The working space of the furnace consists of melting and working zones. The melting zone is equipped with three graphite electrodes, the production zone - with two. The melt jet is inflated with steam at a pressure of 0.6-0.8 MPa using an ejection nozzle.

Liquid glass, aluminous cement, refractory clays, and organosilicon binders are used as binders. The average density of kaolin wool is 80 kg/m3. It is resistant to vibration, inert to water, water vapor, oils and acids, has high electrical insulating properties, which practically do not change with an increase in temperature up to 700-800C, and is not wetted by liquid metals. Kaolin wool is produced in rolls and in the form of products of various shapes (plates, shells, segments, etc.). Kaolin wool it is made in the form of lumpy wool and various products. Scope - various industries.

Now it is difficult to find a house that does without heaters. At the same time, all mineral wool insulation in some cases resists fire well, plays the role of a good sound insulator. Our masters at warming of country houses use only high-quality materials for the insulation of walls, floors and ceilings. We use the best European mineral wool insulation ROCKWOOL, URSA, ISOVER.

Mineral wool occupies a well-deserved place among heat-insulating materials, which is widely used both in mass and private construction. One of the heaters produced using mineral materials is kaolin wool.

It is not as popular with builders as other mineral heaters. This is explained simply: in conventional housing construction, materials are simply not required that can resist temperatures above 1000 degrees. Such materials are mainly used in those industries where high-temperature processes are used.

Production and quality characteristics

For the production of insulation are used:

• technical alumina with an aluminum oxide content of 99%;
• pure quartz sand;
• binder (the following materials are used as it: refractory clay, liquid glass, organosilicon binders, aluminous cement).

To obtain a melt of sand and alumina, ore-thermal furnaces are used. The process takes place at a temperature of about 1750 degrees. With the help of an injection nozzle and steam supplied at a pressure of 0.7 - 0.8 MPa, the melt is inflated, forming the final product. The density of the insulation can be from 80 to 130 kg / cu. m.

Kaolin insulation is available in various types:

• lump cotton;
• rolls;
• plates;
• shells;
• segments.

Often, kaolin insulation is called mullite-silica fiber, which is reflected in the labeling of products made from it. Conventional fiber is referred to as MKRR, and fiber with the addition of chromium as MKRS.

The addition of chromium makes it possible to create a material with even greater temperature resistance.

Physico-chemical characteristics of fibers

Product

Characteristic
MKRR-130
MKRH-150

Maximum application temperature, deg.
1150
1300

Density, kg/cu.m.
130
150

Thermal conductivity at a temperature of 600 degrees, W / mK
0,15
0,15

Mass fraction of Al2O3, %
51
48

Mass fraction of Cr2O3, %
-
2 - 4

Weight change during ignition, %
0,6
0,6

Advantages of kaolin wool and its fields of application

Based on the above characteristics, it can be seen that kaolin insulation is a high-performance heat-insulating material, which is also used for thermal compensation purposes.

The main properties of mullite-silica fiber are as follows:

• low density, and hence low weight, allow the use of cotton wool in a variety of conditions, including at height;
• low thermal conductivity allows the use of this material wherever it is necessary to ensure reliable thermal insulation of equipment or structures;
• high temperature resistance;
• low heat capacity;
• high chemical resistance - the material is practically inert to water, acids, oils, alkalis and water vapor;

• resistance to thermal shocks;
• elasticity - guarantees the maximum tight fit of the material to the insulated surfaces;
• resistance to deformation and vibration allows the use of insulation where other materials may be subject to destruction or lose their properties;
• excellent sound insulation;
• sufficiently high electrical insulating properties, which almost do not change when the temperature rises to 800 degrees.

All these properties of kaolin insulation allow it to be used for the following purposes:

• sealing windows, doors, shutters;
• refractory lining and its repair;
• insulation of gas ducts, heat generators, chimneys;
• creation of fireproof coatings;
• filling the cavities of the refractory masonry;
• construction of buildings, courts, boiler houses;
• insulation of tanks in which liquefied gases are stored;
• as a stuffing of heat-insulating layers of kiln trolleys;
• filtration of high temperature gases in an aggressive environment;
• in catalysis and reforming furnaces;
• thermal insulation of gas turbines;
• as insulation of cable channels located in combustible walls and partitions of buildings.

As you can see, in certain areas the popularity of this heater is very wide.
Not so long ago, zirconium and yttrium oxide began to be used as raw materials for the production of cotton wool, which made it possible to obtain a material that can withstand operating temperatures up to 2700 degrees. So far, these are prototypes, but the potential for their application is very high.

Kaolin wool consists of mullite-silica fibers and belongs to the category of heat-insulating materials. It is resistant to fire and is also used to fill voids in masonry and seal slotted holes.

Description

The material is usually sold in the form of rolls. It is made in the process of melting and aluminum when exposed to high temperatures in special furnaces. Kaolin wool has been actively used for thermal insulation of buildings for many years and surpasses many other materials in its characteristics. Despite the modern variety of other products with similar properties, it is becoming increasingly popular and has found its application in the industrial field. It acts as insulation in thermal devices, combustion chambers, heat exchangers and turbines. The greatest distribution is noted in metallurgy. Also, kaolin wool is used in the manufacture of plates and other molded elements.

The material is distinguished by a high level of sound and heat insulation, resistance to vibration loads and deformation. In addition, cotton wool has other properties that are not typical for many materials with a similar purpose. The insulating agent is not affected by high temperatures in oxidizing and neutral environments, while the level of resistance can be increased through the use of Despite this, the main property of keeping warm is significantly reduced in reducing environments.

Advantages

Cotton wool MKRR-130 is optimally suited for creating brake pads, insulation of furnace arches and wall structures. Its minimal weight reduces the amount of time and effort required for installation, and reduces fuel costs. It is worth noting other positive aspects:

• carefully cleaned fibers are highly resistant to devitrification;
• minimum level of heat accumulation;
• resistance to thermal shock;
• preservation of original characteristics during repeated use;
• high degree of sound insulation;
• not affected by chemical aggressive substances, alkalis and metal melts;
• inert to mineral oils, vapours, and water;
• electrical insulation characteristics remain the same even when exposed to high temperatures.

Peculiarities

Kaolin refractory wool is made from alumina, which is based on quartz sand. In a special ore-thermal furnace, melting is carried out at a temperature within 1800 degrees. There are three electrodes in the melting zone, while there are only two in the production area. The blowing technique is used to melt the material, it is based on the impact of special steam under the condition of a pressure of about 0.7 MPa. The ejection nozzle ensures the passage of the entire blowing process. Liquid glass, clay or cement can act as binders.

Kaolin wool is sold in the form of rolls up to 10 meters long, thickness and width are 2 cm and 60 cm, respectively. It is elastic, which ensures a snug fit to any design. Today, manufacturers are trying to improve the material by adding additional components, such as yttrium oxide. This improves the stability of the fibers and expands the possibilities of use.

Fire resistant materials

They are made from a mineral base and are resistant to high temperatures, while their characteristics remain at the same level. They are indispensable in the metallurgical industry for carrying out distillation, evaporating and other processes, creating high-temperature mechanisms (motors, reactors) and parts for them. After use, refractories are sent for recycling.

Most often, products of this type have a rectangular shape and low weight, so they are optimally suited for various linings. At present, there is a decrease in the production of simple refractories, as more and more attention is paid to the production of special mortars and concretes resistant to high temperatures.

manufacturing methods

Materials have a ceramic base, are made of refractory borides, nitrides, oxides and have a high level of chemical inertness and strength. A carbon compound is also often used. Refractories retain their properties when exposed to temperatures from 1600 degrees and are used in many areas where there is a need to carry out any action under given conditions. According to the method of formation of the product are divided into several types:

• hot pressed;
• cast, melted;
• plastic formation;
• cast on the basis of liquid foam slip;
• sawn from processed blocks or rocks.

Company "Ceramics" supplies thermal insulation materials for the manufacture of new and repair of old electric furnaces.

In order to order heat-insulating materials for the manufacture of new and repair of old electric furnaces and to clarify prices, please contact our managers. You can find their phone numbers in the section Contacts.

Thermal insulation boards

Thermal insulation refractory boards- strong and technological insulating material. The plates are cut with a hacksaw, easily cut, cut out the necessary shapes, glued with inorganic glue or fixed with a metal fastener.

Refractory thermal insulation boards chemically resistant to alkalis and acids, except for strong alkalis, phosphoric and hydrofluoric acids, resistant to temperature in an oxidizing and neutral atmosphere. In a reducing environment, the thermal insulation properties of the boards are reduced.

Our company provides a service for the selection of thermal insulation materials according to individual requirements. We make thermal calculations and issue recommendations on the use of a particular material. For fixing heat-insulating plates, our company is ready to recommend various options for fasteners and glue.

Thermal blankets and mats

Exceptional thermal performance combined with high mechanical strength, flexibility, elasticity make it an indispensable material in industries associated with high temperatures, heat treatment, thermal insulation, as well as in the production of furnaces and boilers of various types. Thermal blankets are ready-to-use high-tech products.

Additional features are:

• excellent thermal stability and thermal shock resistance;
• excellent chemical stability;
• high tensile strength;
• low thermal conductivity;
• possibility of storage at low temperatures;
• high ability of thermal reflection;
• excellent corrosion resistance;
• excellent thermal stability;
• manufacturability and ease of installation.

Ceramic blankets are delivered in rolls from 10 to 50 mm thick. Width and length of rolls can be different. According to requirements Customer the optimal variant is selected according to the size and temperature of application. For fixing these materials in ovens and other facilities, our company is ready to recommend various fasteners.

Based ceramic fiber blankets are made modular blocks. Our company supplies these blocks for all the above temperatures. Modular blocks supplied with fasteners for mounting blocks on the surface of thermal units.

In order to clarify prices and place an order, you need to contact our managers. You can find their phone numbers in the section Contacts.

The table below summarizes the characteristics of ceramic fiber blankets:

OOO TD PromStroyKomplekt supplies MKRR kaolin wool to Moscow, Izhevsk, Nizhny Novgorod, Yekaterinburg and other regions of the country. To calculate the price of a batch of this material with delivery, leave an online application or contact our employees by phone numbers listed in the "Contacts" section.

Cotton wool production MKRR

Raw materials for the manufacture of kaolin wool are oxides of chromium, silicon and aluminum. Their connection is carried out in special furnaces. The mass obtained during melting and blowing is converted into a light, thin and plastic fiber, from which mats and other shapes are then made. According to its operational characteristics, the resulting product must comply with the requirements of GOST 23619-79.

Cost calculation

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Main properties and characteristics of refractory kaolin wool

Domestic manufacturers produce the following grades of material:

• MKRR-130;
• MKRV-200;
• ICRR-150.

They are characterized by the following physical and chemical parameters (according to GOST 23619-79):

• density about 130 kg per m 3;
• small specific gravity;
• thermal conductivity over 0.15 W/mK;
• application temperature not more than 1150 °C.

Mullite-silica wool grades MKRRH-150 (chromium) and MKRR-130 are inert to steam, water, non-ferrous metal melts and oils, resistant to acidic and alkaline media. It is characterized by a low level of heat capacity and high resistance to temperature changes.

Rolled mullite-silica material is easy to pack and transport by various modes of transport. Due to its low weight, it is easy to install. Cotton wool grades MKRV have high strength and tear resistance.

We will carefully deliver "Refractory mullite-silica wool"
to your city

Cost calculation

AS WELL AS:

Spheres of application of cotton wool MKRR, MKRV, MKRKh-150

The main scope of application of mullite-silica rolled material of grades MKRR-130, MKRRH-150 and MKRV-20 is the creation of insulation for various heated objects. Most often, mats are used to protect industrial equipment from the high temperatures that occur during technological processes, as well as to reduce the risk of fires and increase the efficiency of furnaces.

In addition, mats MKRR-130 use:

• to perform works on thermal insulation of furnace roofs and other technological facilities operating at high and ultra-high temperatures;
• for lining gutters and pipelines used for transporting melts;
• for thermal insulation of heat generators, gas ducts and chimneys;
• for filling joints and expansion gaps in structures operating in high-temperature conditions;
• for sealing burners, dampers, doors.

Kaolin refractory wool MKRR-130 is an excellent raw material for the manufacture of plates, blocks, shells and inserts of various shapes. It is necessary for manufacturers of catalyst carriers, automobile brake pads, high-temperature filters, and other components and parts used in the creation of machines and equipment for various industries.

Our company offers kaolin wool MKRR-130 and other refractory materials. You can get acquainted with the prices (in rubles / m 3) in the price list on the website.