RU2422388C2 - Method of producing high-silicate fibre from rock, module kubol-s apparatus for realising said method, high-silicate continuous fibre, high-silicate chopped fibre, high-silicate coarse fibre and high-silicate staple fibre made using said method - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to apparatus for producing inorganic fibre from natural minerals and rock, as well as to fibre made using the disclosed apparatus, specifically high-silicate continuous, chopped, coarse and staple fibre. The raw material used is silica-based rock. After obtaining a melt of the said rock, its temperature is brought to 1750-1850°C. After homogenisation and stabilisation of the melt, a discharge zone is created on the path of the stream of the melt to the drawing nozzle of the discharge orifice, in which the stream of the melt gives the shape of stripes with thickness 3.0-20.0 mm and the melt passes through this zone with speed V=(7-9)10^-4 m/s, and air pressure in the discharge zone over the stream of the melt is kept in the range of 0.10…0.30 Pa. The apparatus has a furnace for obtaining melt, and a feeder on the output of which there is a transfer chamber. There is a discharge orifice on the wall of the housing of the transfer chamber, in which a bushing assembly if fitted and there is a mechanism for obtaining fibre at the output of the discharge orifice. Between the furnace and the feeder there is a homogeniser made in form of two vertical and coaxial cups placed one inside the other with a gap, which form an inner receiving chamber and outer clarification chamber in which there is a vertical partition. The clarification chamber is fitted with apparatus for creating air discharge in its cavity, and there is a gap for passage of the stream of the melt between the bottom of one cup and the free end of the other cup.

EFFECT: high strength and chemical resistance of the obtained fibre owing to creation of conditions for reducing the amount of foreign, particularly gaseous inclusions in the fibre.

13 cl, 1 dwg, 16 tbl, 4 ex

Description

The group of inventions relates to means for producing continuous, chopped, coarse, staple inorganic fibers from natural minerals and rocks such as sands, quartz, crushed quartz sandstone, quartzites, as well as fibers made by the proposed means, namely, highly silicate continuous fiber, highly silicate chopped fiber, highly silicate coarse fiber, highly silicate staple fiber.

The use of inorganic fibers from natural materials - sand - as a raw material makes it possible to produce environmentally friendly, weather-resistant materials that can replace in many cases asbestos, glass, metal, wood and other materials used in industry. Therefore, the need and technical requirements for the proposed materials is increasing. Particularly noteworthy is the possibility of using sand fibers instead of glass fibers as fillers for various building materials in the manufacture, for example, of materials such as fiber-reinforced concrete.

A known method for the production of continuous fiber from rocks, including the operation of crushing the rock, melting it in a melting furnace and pulling it out of the melt through a continuous fiber spinneret / RF patent No. 2102342, IPC 6 C03B 37/00, publ. 01/20/1998 /. The rocks of the basalt group from the main to the average composition are used as rocks in the described method, and the temperature in the melting furnace is set in the range of 1500-1600 ° C.

The fibers obtained by the described method have insufficient tensile strength due to the presence of foreign inclusions in them.

Closest to the proposed method by the number of essential features is a method of producing highly silicate fibers from rocks, including the operations of loading rock into a smelting furnace, obtaining a melt, its homogenization and stabilization, obtaining fiber from a melt flowing from a nozzle of a working hole / RF patent №2118300 IPC 6 C03B 37/02, 1998 /.

The disadvantage of the described method is the lack of strength and chemical resistance obtained by the described method of fibers due to the presence in them of foreign, in particular gaseous, inclusions.

Closest to the proposed installation by the number of essential features is the installation for the production of highly silicate fibers from rocks, which contains a furnace for producing a melt, the outlet of which is connected to the input of the feeder, the outlet of which is equipped with a transition chamber, in the wall of the case of the transition chamber there is a production opening, in which a spinneret feeder is installed, and a mechanism for producing fibers is installed at the outlet of the production opening / RF patent No. 622924 U1, IPC 6 C03B 37/02, publ. 05/10/2007 /.

The disadvantage of the described installation is the lack of strength and chemical resistance of the fibers obtained in it due to the presence of foreign, in particular gaseous, inclusions.

Known high-silica continuous fiber obtained by the method described in the patent of Russian Federation No. 2233810 / IPC 6 C03B 37/06, publ. 08/10/2004 /.

The disadvantage of this fiber is its lack of strength and chemical resistance due to the presence in it of foreign, in particular gaseous, inclusions.

Known highly silicate chopped fiber obtained by the method described in the book: "Continuous glass fiber" / Ed. M.G. Chernyak. - M .: Chemistry. - 1965. - 320 p. - S. 214-215 /.

The disadvantage of this fiber is its lack of strength and chemical resistance due to the presence in it of foreign, in particular gaseous, inclusions.

Known Basalt Coarse Fiber / Composite materials based on basalt fibers. - On Sat scientific tr / Kiev: AN USSR. Institute of Materials Science named after I.N. Frantsevich; Editorial: Sergeev V.P. et al. - 1989. - 165 p. - S.9-14; UDC 666.19 /. The named fiber was obtained by stretching a jet of melt with its subsequent crushing into segments of length 70 ... 100 mm.

The disadvantage of these fibers is their lack of strength and chemical resistance due to the presence in them of foreign, in particular gaseous, inclusions.

Known highly silicate staple fiber obtained by the method described in the patent of the Russian Federation No. 223810 / IPC 6 C03B 37/06, publ. 08/10/2004 /.

The disadvantage of these fibers is their lack of strength and chemical resistance due to the presence in them of foreign, in particular gaseous, inclusions.

The basis of the proposed group of inventions is the task of creating such a method and installation for the production of highly silicate fibers from rocks, which would significantly increase the strength and chemical resistance of the resulting fibers by creating conditions to reduce the amount of foreign, in particular gaseous, inclusions in them.

The problem is solved by choosing the operating parameters and such a rock, the melt of which even before boiling has a temperature at which most of the foreign inclusions either dissolve or burn, and the gas bubbles formed in this case can be easily removed from the melt in a specially created air rarefaction zone on the path of melt flow to the die.

The proposed, as well as known, method for the production of highly silicate fibers from rocks includes the steps of loading rock into a smelting furnace, producing a melt, homogenizing and stabilizing it, producing fiber from a melt flowing from a spinneret hole, and according to the invention, rock is used as a raw material silica-based, after obtaining the melt of the said rock, its temperature is brought to 1750 ... 1850 ° C, and after homogenization and stabilization of the melt at the indicated temperature in the melt flow path the discharge orifice spinneret to create a vacuum zone in which the melt flow is shaped into a strip with a thickness of 3.0 ... 20.0 mm and it is passed through the zone with a velocity V = (7 ... 9) 10 ^-4 m / s, and the air pressure in the rarefaction zone above the melt flow support within the range of 0.10 ... 0.30 PA.

A feature of the proposed method is that sand is used as a raw material.

A feature of the proposed method is that quartz sand is used as raw material.

A feature of the proposed method is that either raw quartz sandstone or quartzite is used as raw material.

The proposed, as well as known, installation for the production of highly silicate fibers from rocks according to the method described above, comprises a furnace for producing a melt, the outlet of which is connected to the inlet of the feeder, the outlet of which has a transition chamber, in the wall of the case of the transition chamber there is a production opening, in which a spinneret feeder is installed, and a mechanism for producing fibers is installed at the outlet of the extraction opening, and according to the invention, a homogenizer is installed between the furnace and the feeder, made in the form vukh vertically and coaxially mounted with a gap in one of the glasses, forming an internal receiving chamber and an external clarification chamber, in which a vertical partition is installed, designed to receive a melt stream in the form of a strip on its upper edge, the clarification chamber is equipped with a means for creating rarefaction of air in it cavity, and between the bottom of one glass and the free end of the other glass there is a gap for the passage of the melt flow.

A feature of the proposed installation is that the vertical partition in the clarification chamber of the homogenizer is made adjustable in height.

A feature of the proposed installation is that the homogenizer is provided with a heating system made in the form of at least two rows of gas-air nozzles fixed at an angle α = 3 ... 65 ° to the vertical and radially staggered at a distance of H = (5 ... 7) D from the vertical axis of the homogenizer, where D is the diameter of the nozzle nozzles designed to direct the torch to the external receiving chamber of the homogenizer.

A feature of the proposed installation is that the homogenizer is provided with devices for carrying out bottom and side bubbling.

A feature of the proposed installation is that the entrance to the homogenizer is located below the bottom of the furnace.

We offer, as well as the well-known, highly silicate continuous fiber is made of rocks, and according to the invention it is made of silica-based rock by the method described above.

We offer, as well as the well-known, high silicate chopped fiber made from rocks, and according to the invention it is made from silica-based rocks by the method described above.

We offer, as well as the well-known, high-silicate coarse fiber is made of rocks, and according to the invention it is made of silica-based rock by the method described above.

We offer, like the well-known, highly silicate staple fiber made from rocks, and according to the invention it is made from silica-based rock by the method described above.

The authors experimentally selected the rock and set the optimal operating parameters for the implementation of the method of producing highly silicate inorganic continuous, chopped, coarse and staple fibers. Silica-based rock turned out to be such material. Silica includes, in particular, sand, quartz sandstone, quartzite / Technical Encyclopedia. - M .: JSC "Soviet Encyclopedia". - T.11, p. 581-583. - 1930 /. The proposed group of inventions provides for the use of raw materials based on silica, in which the content of silicon oxide is equal to or greater than 52%. This is due to the fact that an increase in the content of silicon oxide in the raw material makes it possible to increase the melting temperature of the rock, and this, in turn, makes it possible to remove most of the solid foreign inclusions — harmful impurities — from it during smelting.

A temperature below 1750 ° C in order to obtain a melt from silica-based rock does not ensure the removal of most solid foreign inclusions from the melt and to obtain an amorphous melt. Heating above 1850 ° С practically does not affect the quality of the product obtained, therefore, it is not economically justified. In addition, at temperatures above 1850 ° C, cases of boiling of individual fragments of the melt and, as a result, the formation of new gas microbubbles were noted. Therefore, the optimum temperature was the melt of silica 1750 ... 1850 ° C.

Obtaining a melt stream in the form of a strip is more technologically advanced than, for example, in the form of a cylindrical stream. In addition, it is the shape of the strip that makes it possible to reduce the temperature gradient across the thickness — along the cross section of the melt flow — to make it uniform. The thickness of the strip depends on the viscosity of the melt and the flow rate. The smaller the thickness and the higher the flow rate, the more high-quality fiber is obtained as a result of the process, since it allows removing more gas bubbles from the strip in the rarefaction zone. The authors experimentally revealed the optimal values of the thickness of the melt strip. The optimum value of the thickness of the melt strip is 3.0 ... 20.0 mm at a flow velocity V = (7 ... 9) 10 ^-4 m / s. So, to create a melt thickness of less than 3.0 mm and a flow velocity of more than V = 9 · 10 ^-4 m / s, additional energy costs are required to heat the melt and increase its speed, which is not economically justified. The production of a melt from silica-based rock with a thickness of more than 20.0 mm, which moves at a speed of less than 7 · 10 ^-4 m / s, does not allow to remove from it such a number of bubbles and foreign inclusions that would significantly improve the quality of the obtained fibers. The air pressure in the rarefaction zone above the melt flow is maintained within the range of 0.10 ... 0.30 Pa, since this level of rarefaction in the zone of creation of the melt strip with a thickness of 3.0 ... 20.0 mm was sufficient to remove most of the bubbles and foreign matter from the melt inclusions. An increase in the level of rarefaction is not economically justified.

The main objective of the proposed solution is the creation of a melt homogeneous in composition and, as a result, fiber homogeneous in composition. The term "homogeneous" comes from the Greek "homogenës" - uniform in composition [see Dictionary of foreign words and expressions / Avt.-sost. E.S. Zenovich. - M .: Astrel Publishing House LLC: ACT Publishing House LLC, 2004. C.158]. Therefore, the use of the term “homogenizer” as the name of the key device of the proposed installation is legal.

The homogenizer is provided with a heating system, the geometric parameters of which are found experimentally. Given the limited space, the system is made in the form of two rows of gas-air nozzles fixed at an angle α = 3 ... 65 ° to the vertical and arranged radially in a checkerboard pattern at a distance H = (5 ... 7) D from the vertical axis of the homogenizer, where D is the diameter nozzle nozzles designed to direct the torch to the external receiving chamber of the homogenizer. This design of the homogenizer heating system ensures uniform heating of the homogenizer and, as a consequence, the melt flow.

The proposed method is implemented in the installation, which is schematically shown in the attached drawing.

The installation for the production of high-silica fibers from rocks “Kibol-S Module” contains a feed loader 1, the output of which is connected to the capacity of an electric resistance furnace 2, designed to produce melt. The output of the furnace 2 is connected by a heat-resistant drain device 3 to the input of the external receiving chamber 4 of the homogenizer 5. The homogenizer 5 consists of an external receiving chamber 4 and an internal clarification chamber 6. The receiving chamber 4 is equipped with a heating system in the form of gas-air nozzles 7 arranged in two rows fixed under angle α = 45 ° to the vertical axis of the homogenizer 5 and radially and staggered at a distance of H = 6D from the axis of the homogenizer 5, where D is the diameter of the nozzle 7. The nozzles 7 are designed to create and direct the torch to the outside th receiving chamber 4 of the homogenizer 5. The installation is equipped with a bubbler system, including bubbler nozzles 8, designed to supply heated air through them to increase the intensity of melt mixing in order to increase its uniformity in chemical composition and temperature. The output of the receiving chamber 4 is connected to the input of the clarification chamber 6. The clarification chamber 6 is equipped with a device for creating rarefaction of air in the cavity above the melt layer (not shown). A device for creating rarefaction of air in the cavity of the clarification chamber 6 above the melt layer is made in the form of a rotary mechanical pump with an oil seal of the type VN-1MG, which is connected to the upper part of the cavity of the clarification chamber 6 [Lozinsky MG Thermal microscopy of materials. - M.: Metallurgy. 1976. - S.30-67]. In the clarification chamber 6, a vertical partition 9 is installed, designed to receive the required thickness on the upper edge of the melt strip. The partition 9 is made of typesetting from coaxially mounted rings with the possibility of adjusting its height depending on the viscosity of the melt. The melt level in the clarification chamber 6 is higher than in the receiving chamber 5 and in the feeder 10. The output of the clarification chamber 6 is connected to the feeder 10. The installation is equipped with four transition chambers 11, 12, 13, 14. A threshold 15 is established between the feeder 10 and the homogenizer 5. The feeder 10 has exits to each transition chamber 11, 12, 13, 14. Each transition chamber 11, 12, 13, 14 has its own outlet 16 and a heated feeder with dies 17 located below the outlet 16. Each transition chamber 11, 12 , 13, 14 is designed to create a thin layer flow asplava. Each transition chamber 11, 12, 13, 14 is equipped with a heater 18. The bottom of the transition chambers 11, 12, 13, 14 has an inclination directed towards the outlet 16. In this case, the angle of inclination for each chamber 11, 12, 13, 14 is selected experimentally from the conditions of production of one or another type of fiber and products. The transition chambers 11, 12, 13, 14 have different volumes, which makes it possible to obtain from each chamber the required amount (volume) from 1 ton to 1000 tons of fiber per year and carry out their work in an independent mode. At the entrance to each transition chamber 11, 12, 13, 14, a threshold is set at 15, 19, respectively, and an adjustable gate 20 is set above the threshold, which are designed to produce a melt flow of the required thickness and quality. Each adjustable gate 20 is made in the form of a guillotine, the working edge of which is horizontal and, if necessary, provides a complete shutoff of the melt flow into the corresponding transition chamber 11, or 12, or 13, or 14. Each adjustable gate 20 is installed with the possibility at the moment of overlapping the entrance to each transition the camera 11, 12, 13, 14 to touch its lateral plane of the side surface of the threshold 15, 19.

The bottom of the receiving chamber 4, the clarification chamber 6 and the feeder 10 are lined with refractory and electrically conductive materials made of heat-resistant alloy or silicon carbide. Each channel of the feeder 10 is heated by torches of gas-air nozzles 21.

In each transition chamber 11, 12, 13, 14 a gas-air nozzle 21 is installed.

Spinneret feeders 17 are installed below the outlet 16 for drawing fibers 22 through them. For processing fibers 22 with a sizing unit, the installation is equipped with a tank with a sizing (not shown) that is supplied to the sizing device 23.

Example 1. As a rock for obtaining continuous fiber used the following sands:

- Bezmeinsky deposit, Karakum desert, Turkmenistan,

- Mary deposit, Karakum desert, Turkmenistan,

- the granite sands of the Korfovsky quarry, Khabarovsk Territory, Russia.

To characterize the features and properties of sand, a complex of studies was conducted aimed at determining their structure, shape and nature of grains, material composition.

The structure of the sands was studied under a microscope in artificial transparent sections and in parallel with the help of mechanical (particle size) analysis, which was carried out in conjunction with the determination of the total carbonate content of the sands. For these purposes, the Sabanin method, widely used in geology, was used in combination with sieve analysis.

When determining the total carbonate content and particle size distribution, a 100 g sample of sand was placed in a 500 ml cylindrical glass vessel, poured with 10% hydrochloric acid, stirred with a glass rod, and kept for one or several days until the carbonates were visually determined completely dissolved. If necessary, acid was added. After the complete cessation of the release of gas bubbles (which indicates the complete dissolution of carbonates), the acid was drained as much as possible. Then, in order to wash off the acid and also separate clay particles, a sand sample was placed in a porcelain cup with a diameter of 20 cm, filled with distilled water and washed to a neutral medium with litmus paper, rubbed with a wooden pestle with a rubber tip to remove clay particles from the grain surface. After stirring and settling for 42 seconds, distilled water with clay suspension was carefully poured into a graduated 1 liter glass. A portion was poured with a new portion of distilled water, wiped with a pestle and after settling for 42 seconds, the suspension was drained. The operation was repeated until the water became completely transparent, thus, in a glass with drainage water, a fraction of less than 0.05 mm was obtained.

The washed sand fraction was placed on paper, dried to an air-dry state. Then, using a brush, they were collected from a sheet of paper, weighed and classified using a set of sieves into the following fractions: 1-0.5; 0.5-0.25; 0.25-0.1; 0.1-0.071 and 0.071-0.05 mm. Next, a fraction of particles less than 0.05 mm in a graduated glass with a capacity of 1 l was subjected to sieve analysis.

The mechanical analysis made it possible to determine the content of sand, silt, and clay particles, to divide them into a number of groups or fractions of different grain sizes. The sand fraction was used to determine the mineralogical composition in artificial transparent thin sections made on the basis of Canadian balsam.

To separate accessory (rarely occurring minerals and impurities) from the main ones that make up the bulk of the sands, particles of 0.25-0.1 fractions were separated by a heavy liquid; 0.1-0.071 and fractions of 0.071-0.05 mm using a medical centrifuge.

For this, a sample of sand of a certain fraction of particles together with a heavy Thule liquid, which is an aqueous solution of potassium iodide and mercury biodide with a specific gravity of 2.9 g / cm ³ ; placed in a test tube without adding 1 cm to the edge. When rotating in a centrifuge for 6-8 minutes, the heavy fraction settled to the bottom of the tube, and the light fraction floated up. After the centrifuge stopped, the light fraction and then the heavy fraction were carefully discarded from the tube.

The heavy and light fractions of particles ranging in size from 0.25 to 0.071 mm were viewed under a binocular magnifier. Some minerals have been studied in immersion preparations.

The grains of each mineral were calculated in volume percent, and then, using average density values, the latter were converted to mass.

When studying the material composition of the sand fraction, mineralogical and petrographic studies of the silt and clay fractions were used - X-ray phase analysis. Chemical analysis of sand was carried out according to the method adopted for silicate analysis / Chemical analysis of rocks and minerals, edited by N.P. Popov and I.A. Stolyarova. - M .: Nedra "- 1974 /.

As a result of separation according to the method described above, the following particle size distribution of the above sands was obtained (see table 1).

Table 1 Granulometric composition of sand and the content of carbonate part in them (wt.%) Field The size of the fractions,% Carbonate part 0.5-0.25 0.25-0.1 0.1-0.071 0,071-0,05 0.05-0.01 Bezmeinsky 1.3 39.8 31,0 10.9 2.0 14.7 Mary 0.78 37.1 37.3 7.9 1.4 15.6 Korfovskoe 0.9 37.8 38.9 8.5 1.7 14.9

Sands are mainly (65-75%) composed of sand particles 0.25-0.071 mm in size. The clay part in the studied sands is from 1 to 2% by weight. Natural carbonate ranges from 11.0 to 15.3%. The mineral composition of the sands of the investigated fractions are shown in table 2.

table 2 The mineral composition of the sands of the Karakum desert and Korfovsky quarry Fraction, minerals (rocks) Place of Birth Korfovskoe Bezmeinsky Mary Light fraction Quartz 66.16 64.85 65.72 Feldspars 6.18 3.40 7.80 Carbonates 14.9 14.7 15.6 Mica 1.75 1.82 1,61 Rock debris 2,51 2.24 1.21 Clay 8.95 12.11 9.25 Heavy fraction Ilmenite 0,034 0,041 0,065 Garnet 0,029 0.058 0,045 Epidote 0,048 0,039 0,055 Disten 0.0016 0.002 - Amphibole 0,028 0.018 0,038 Magnetite 0.018 0.0021 0.0088 Limonite - 0.0021 0.0077 Zircon 0.001 - -

As can be seen from table 2, the main rock-forming minerals of the studied sands of the Karakum desert and the Korfovsky deposit are quartz, feldspars and carbonates.

The quartz group includes grains of quartz itself in the form of single crystals, their fragments, and fine-grained aggregates. This also includes grains of crystalline modifications of silica: chalcedony and colloidal varieties of opal. In addition, this group also includes rocks: quartzite, siliceous formations and jasper. Quartz grains are concentrated in the largest fractions and often have sizes from 0.05-0.08 to 0.6 mm.

The feldspar group includes all varieties of feldspars to varying degrees, mainly poorly modified. These are both soda-lime (plagioclases) and potassium. Plagioclase is presented in the form of small, from 0.01-0.03 to 0.08-0.1 mm, isometric, sub-angular, rolled grains with more or less pronounced twinning.

Rock fragments compose individual relatively large, up to 0.5-0.6 mm, crystals with clearly expressed twinning, as well as polymorphic calcite aggregates. The shape of the fragments is rolled up, less often sub-angular, isometric. The size of the debris is relatively large - 0.04-0.05 mm. Separate fragments are covered with limonite films. In addition, among the debris there are about 5% intergrowths of quartz and feldspar containing micaceous minerals, epidote, amphibole and fragments of chalcedony (up to 1%). A microcline is also noted in the form of sub-coarse grains of 0.04-0.09 mm in size with more or less clearly defined lattice twinning.

In small amounts in the sands (heavy fraction), ilmenite, garnet, epidote, amphibole, etc. are found. In individual samples of the sands, gypsum of white and reddish-brown color, most often represented by aggregates of a fibrous-columnar structure, is noted. In the form of single grains, dark-colored minerals (augite, hornblende, tremolite, etc.) are observed in separate thin sections. In the sands of the Mary deposit, grass-green glauconite is present in the form of individual rolled grains.

Clay (0.05-0.01 mm) and fine silt (0.071-0.05 mm) fractions were subjected to X-ray phase analysis (XRD). The XRD results confirm that the main rock-forming minerals of the sands of the Karakum desert and the Korfovsky deposit are quartz, feldspars, carbonate and clay rocks (table 3).

Table 3 The results of x-ray phase analysis of the sands of the Karakum desert and Korfovsky quarry Mineral Place of Birth Korfovskoe Bezmeinsky Mary light fraction clay fraction light fraction clay fraction light fraction clay fraction Quartz + + + + + + Feldspar + + + + + + Kaolinite next + + + next + Hydromica next + + + next + Chlorites next next next next next next Amphibole next - - - next - Calcite in the carbonate part of the sand

The results of a chemical analysis of the sands of the Karakum desert and the Korfovskoye field are shown in Table 4. The analysis of tabular data shows that the chemical composition of the samples from the sands of the studied deposits differ from each other in the content of aluminum oxides (Al ₂ O ₃ ), calcium (CaO). They contain approximately the same amount of iron oxides (Fe ₂ O ₃ and FeO). Characteristic is an increased amount of CO ₂ .

Table 4 The chemical composition of the sands of the Karakum desert and the Korfovsky deposit Oxides, wt.% Place of Birth Korfovskoe Bezmeinsky Mary SiO ₂ 65.31 65.15 67.79 TiO ₂ 0.47 0.24 0.23 Al ₂ O ₃ 15.02 10.01 8.71 Fe ₂ O ₃ 1.46 1.35 1.32 FeO 2,33 1.92 1.84 Cao 3.84 7.85 7.55 MgO 1.96 1.72 2.09 Na ₂ O 3.37 2.03 1.68 K ₂ O 3.84 1.92 1.99 MnO - 0.11 0.09 SO ₃ 0.10 0.09 0.10 P ₂ O ₅ 0.11 0.09 0.10 p.p.p. - 2.20 1.71 CO ₂ 3.84 4.99 5.61 H ₂ O 1,11 0.12 0.19

Thus, according to mineralogical and chemical analyzes, it is possible to obtain fibers from sand.

Before loading into the furnace 2, the sand is completely filled with water, mixed, the sand is left in this position for 5-10 minutes until light impurities appear on the water surface, light impurities are removed, the water is drained and the purified sand is loaded into the furnace 2 in separate portions. In this case, the operations of pouring the initial sand with water, mixing, keeping it in this position for 5-10 minutes until light impurities appear on the water surface, remove light impurities and drain the water are performed 3-5 times. Light contaminants that are in the mass of sand, when they enter the water during mixing, the mass of sand is separated from it and, under the action of Archimedean force, they float to the surface of the water, where they are easily removed by draining the surface layer of water along with light contaminants. Then the sand is dried and sent to the raw material loader 1, which continuously and evenly with a thin layer distributes the sand over the entire area of the resistance electric furnace 2.

The distribution of sand over the heated surface in the cavity of the furnace 2 with a thin layer allows to intensify the melting process and the production of the melt with a higher specific removal, to reduce the time of forced downtime of the furnace 2 associated with the conclusion to the operating mode and its cooling down during stops. The extremely high thermal voltage of the melting furnace 2 allows melt rocks during bottom discharge of the melt in the form of a continuous jet with an adjustable flow rate by optimizing the diameter of the heated drain device 3. At the same time, the residence time of the melt in the furnace 2 can also be adjusted by changing the height of the heated drain device 3.

Sand continuously melts in an electric furnace 2 at a temperature of 1750 ... 1850 ° C. At the same time, for the various sands listed above, the optimum melting temperatures were established as follows:

- Bezmeinsky deposit of the Karakum desert, Turkmenistan - 1750 ... 1800 ° С,

- Marysky field of the Karakum desert, Turkmenistan - 1750 ... 1780 ° С,

- the granite sands of the Korfovsky quarry, Khabarovsk Territory, Russia - 1830 ... 1850 ° С.

The resulting melt through a heat-resistant drain device 3 was continuously poured continuously from the bottom of the furnace 2 and, under the influence of gravity, entered the receiving chamber 4 of the homogenizer 5, where its temperature was kept constant by means of a flame of gas-air nozzles 7 installed in two rows in the upper part of the receiving chamber 4 . Moreover, each nozzle 7 is fixed at an angle α = 3 ... 65 ° to the vertical and at a distance H = (5 ... 7) D from the axis of the homogenizer, where D is the diameter of the nozzle of the nozzle. The nozzles 7 in rows are arranged in relation to each other in a checkerboard pattern. In addition, the inclination of the nozzles in one row is opposite to the inclination of the nozzles in the other row, i.e. they are at an acute angle with respect to the axes of the nozzles of the first row. The value of the angle α = 3 ... 65 ° is selected from the following considerations: a decrease in the angle of less than 3 ° leads to an increase in the velocity of the melt flows, however, nozzles quickly become unusable due to an increase in their heating surface. An increase in the angle of more than 65 ° leads to a decrease in the velocity of the melt flows and, as a consequence, to a decrease in the degree of its homogenization. In addition to the directed action of high-temperature gas flows on the melt mirror, to increase the quality of homogenization, the distance H = (5 ... 7) D of the nozzle installation is important. Reducing this value to less than 5D gives a negligible effect and, in addition, reduces the life of the nozzles. An increase in the distance by more than 7D leads to a decrease in the efficiency of mixing the melt layers in depth. The values of the angle α and distance H are determined experimentally by the authors and are optimal for achieving a technical result — intensification of the melt homogenization process. In addition, the nozzles are installed in two rows and the direction of one row is opposite to the direction of adjacent nozzles of the other row. As a result, the melt is affected by two streams in opposite directions, which significantly intensifies the homogenization of the melt and ensures that the homogenizer maintains a stable operating temperature. At the same time, mixing of the upper layers of the melt occurred due to exposure to the flame of gas-air nozzles 7 installed at different angles and towards each other. To mix the melt, lateral (not shown) and bottom 8 bubbler nozzles were installed in the middle and lower parts of the receiving chamber 4, through which heated air was supplied. Moreover, due to the “short exposure” of the melt in the receiving chamber 4 of the homogenizer 5, the melt is quite gassed, turbulent, relatively unclarified (unpurified) and generally unsuitable for filamentation due to the presence of unmelted lumps of crude charge and gas bubbles, which does not allow to obtain from such a melt, a thin and strong continuous thread. To clarify the melt, it is gravity fed into the clarification chamber 6, where the air pressure in the rarefaction zone above the melt flow is maintained within 0.10 ... 0.30 Pa using a vacuum pump (not shown). A partition 9 is installed in the clarification chamber 6. The melt flow, which is under vacuum in the overflow zone through the partition 9, forms a thin layer on its upper edge, which is released from gas bubbles - gaseous inclusions that escape into the atmosphere and from solid inclusions during the overflow , for example, from non-melted lumps of a raw charge falling down in front of the partition 9 down to the bottom of the homogenizer 5, and, thus, it is clarified. From the clarification chamber 6, the melt flow flows downstream and through the threshold 15 enters the feeder 10, where due to the small thickness of the melt stream, it is possible to avoid the formation of a temperature gradient over the melt thickness, uncontrolled convection flows and the associated heat loss.

The furnace 2 has small dimensions, therefore, it is easy to carry out strict control over compliance with the thermal regime and increase the efficiency of the furnace 2 to 65% by reducing the residence time of the melt in the furnace 2 compared to a traditional glass melting bathtub by more than 50 times.

The feeder 10 is heated from above with torches of burning gas coming from gas-air nozzles 21, and electric heating elements 18, which together with a high-precision temperature controller (such as "VRT") (not shown) and temperature sensors - thermocouples like platinum-platinum-rhodium (not shown) ) - provide maintaining the temperature of the melt in the feeder 9 with an accuracy of ± 0.5 ° C. Next, the melt through the threshold 19 and the adjustable gate 20 installed at the exit of the feeder 10 enters the transition chamber 11 and is sent to the production through the extraction holes 16 to the die feeders 17. Thanks to the heating of the transition chamber 11, the previously achieved state of the homogenized melt is maintained, which allows to obtain strong thin fibers.

The heated melt enters the spinneret feeders 17, from which continuous fibers are pulled 22. The fibers 22 are processed with a sizing agent, which is supplied from the tank using a sizing device 23. After sizing, the fibers 22 are fed through a system of mechanisms to the winding machine 28, where they are wound on a bobbin, and then for processing into appropriate products.

As a result, highly silicate continuous fibers were obtained from the above sands, the main properties of which are given in Table 5. The strength of the elementary continuous fibers was determined on a weight type dynamometer with a working length of 10 mm, and for coarse fibers on a tensile testing machine PM-3 with a length of 50 mm .

Strength of Continuous Fibers Made from Sand-Based Rocks

Table 5 Place of Birth Diameter, microns Tensile Strength, MPa Bezmeinsky 9.0 2090 Mary 11.1 1990 Korfovskoe 10.1 2010 Basalt (prototype) 9.5 1800

Chopped high-silicate fibers from the above sands were obtained from the melt, which passed through the transition chamber 12. The formation of the melt jets was carried out by a slotted 2000-die feeder, from which continuous fibers were fed to the chopping machine 25.

Characteristics of high silicate chopped fibers obtained from the above sands are presented in table 6.

Table 6 Name of indicator Bezmeinsky field Mary field Korfovsky deposit Basalt (prototype) Cut length mm 6.0 6.2 6.0 6.1 Fiber diameter, microns 11.2 10.9 10.1 9.9 Not cut, no more,% 3.0 3.0 3.2 3,5

Coarse high-silicate fibers from these sands were obtained from the melt, which passed through the transition chamber 13. The formation of the melt jets was carried out by a slotted 600-die feeder made of a heat-resistant alloy. In this case, the stretching of the melt jets was carried out mechanically at a speed of 5 ... 10 m / min. Formed coarse fibers were crushed into segments using a device for chopping coarse fiber 26. The main properties of coarse silicate fibers are presented in tables 7 and 8.

Table 7 Place of Birth Diameter, microns Tensile strength, kg / mm ² Bezmeinsky 155.3 22.9 Mary 160.3 23.1 Korfovskoe 157.4 22.8 Basalt (prototype) 155.5 22.0

Chemical stability of coarse high silicate fibers

Table 8 Place of Birth Diameter, microns Resistance,%, to environments H ₂ O 0.5 n NaOH 2.0 n NaOH 2 n. Hcl Bezmeinsky 160,5 99.5 99.3 98.9 99.5 Mary 165.5 99.6 99,4 98.9 99.7 Korfovskoe 163.4 99,4 99,2 98.4 99,4 Basalt (prototype) 159.5 99.3 99.1 98.0 99.1

High-silica staple fibers from the aforementioned sands were obtained from the melt, which passed through the transition chamber 14, by blowing the primary fibers with a stream of hot gases using a known technology / cm. Kitaygorodsky N.I. Glass technology. - M.: Gosstroyizdat, 1961 .-- 624 p. /. The properties of the obtained staple silicate fiber are presented in table 9.

Table 9 Place of Birth Diameter, microns Resistance,%, to environments H ₂ O 0.5 n NaOH 2.0 n NaOH 2 n. Hcl Bezmeinsky 0.85 94.5 83.0 79.0 80.0 Mary 0.83 94.6 82.6 78.8 80.5 Korfovskoe 0.82 94.4 82.9 78.9 80.5 Basalt (prototype) 0.72 94.0 52.8 15.4 27.5

Highly silicate continuous fiber, highly silicate chopped fiber, highly silicate coarse fiber, highly silicate staple fiber obtained in the proposed installation from the above sands, as shown by studies, are superior in chemical resistance to basalts.

Example 2. Rocks - quartz sand of the Kriushinsky deposit, Chuvash Republic, Russia, and quartz sand of the Skugareevsky deposit, Ulyanovsk region, Russia. Chemical analysis of these rocks is presented in table 10. The content of silicon oxide in these rocks is equal to or greater than 96%. The named rocks were cleaned of light impurities by washing them with water, dried and fed to the raw material loader 1, then to the electric furnace 2, then acted as in example 1.

Table 10 The chemical composition of the sands of Kriushinsky and Skugareevsky deposits Oxides, mass,% Place of Birth Kriushinskoe Skugareevskoe SiO ₂ 98.05 97.9-99.2 TiO ₂ 0.019 0.02-0.09 Al ₂ O ₃ 0.35 0.25-0.6 Fe ₂ O ₃ 0.39 0.03-0.25 CaO 0.35 0.05-0.11 MgO 0.5 0.05-0.19 Na ₂ O 0.4 0.05 K ₂ O 0.04-0.08 SO ₃ 0,042 0.03-0.06 p.p.p. 0.15 0.05-0.18

As a result of the implementation of the proposed method received a highly silicate continuous fiber. The strength characteristics of the obtained highly silicate continuous fiber are presented in table 11.

Table 11 Place of Birth Diameter, microns Tensile Strength, MPa Kriushinskoe 10,2 2360 Skugareevskoe 11.1 2405

As a result of the implementation of the proposed method received high silicate chopped fiber with the characteristic fibers presented in table 12.

Table 12 Name of indicator Kriushinskoye field Skugareevskoye field Cut length mm 6.0 6.2 Fiber diameter, microns 10.9 11.3 Not cut, no more,% 3.2 3.3

As a result of the implementation of the proposed method received a highly silicate coarse fiber, the strength characteristics of which are presented in table 13.

Table 13 Place of Birth Diameter, microns Tensile strength, kg / mm ² Kriushinskoe 150.5 25.0 Skugareevskoe 160.1 28.0 Basalt (prototype) 155.5 22.0

As a result of the implementation of the proposed method received high silicate staple fiber, the chemical properties of which are presented in table 14.

Table 14 Place of Birth Diameter, microns Resistance,%, to environments H ₂ O 0.5 n NaOH 2.0 n NaOH 2 n. Hcl Kriushinskoe 0.84 95.4 88.4 84.2 85,2 Skugareevskoe 0.85 95.8 89.1 84.8 85.9

Example 3. Rock - crushed quartz sandstone of the Cheremshansky field, Buryatia, Russia, the chemical composition of which is presented in table 15.

Table 15 The chemical composition of quartz sandstone of the Cheremshansky deposit and quartzites of the Ovruch deposit Oxides, wt.% Cheremshan field Ovruch deposit SiO ₂ 99,2 97.9 TiO ₂ 0.024 0.14 Al ₂ O ₃ 0.43 1.55 Fe ₂ O ₃ 0.133 0.43 Cao 0.08 0.10 MgO 0.02 - Na ₂ O 0.02 0,07 K ₂ O 0,083 - MnO - 0.2 P ₂ O ₅ - 0.02

The named rock was cleaned of light impurities by washing it with water, dried and fed to the feed loader 1, then to the electric furnace 2, then acted as in example 1.

As a result, high silicate continuous fiber, high silicate chopped fiber, high silicate coarse fiber and high silicate staple fiber were respectively obtained from spinneret feeders 17 transition chambers 11, 12, 13 and 14. The chemical properties of staple fibers are presented in table 16.

Table 16 Field Diameter, microns Resistance,%, to environments H ₂ O 0.5 n NaOH 2.0 n NaOH 2 n. Hcl Cheremshanskoe 0.87 96.2 90.8 85.7 87.6 Ovruch 0.85 94.8 88.3 83,2 84.5

Example 4. The rock is crushed quartzite Ovruch deposit, Ukraine, the chemical composition of which is presented in table 15.

The named rock was cleaned of light impurities by washing it with water, dried and fed to the raw material loader, then to the smelter, and then acted as in example 1.

As a result, high silicate continuous fiber, high silicate chopped fiber, high silicate coarse fiber and high silicate staple fiber were respectively obtained from spinneret feeders 17 transition chambers 11, 12, 13 and 14.

The chemical properties of staple fibers are presented in table 16.

Thus, highly silicate continuous, chopped, coarse and staple fibers obtained from sand-based materials, due to the prevalence of these raw materials in the world, high physicochemical parameters that exceed basalt fibers, will be widely used in many industries, especially in the construction industry materials, as well as for the manufacture of structures and parts of machines operating in aggressive environments.

Claims (13)

1. A method for the production of highly silicate fibers from rocks, including the operations of loading rock into a smelting furnace, obtaining a melt, homogenizing and stabilizing it, producing fiber from a melt flowing from a nozzle of a working hole, characterized in that silica-based rock is used as raw material , after receiving the melt of the said rock, its temperature is brought to 1750-1850 ° С, and after homogenization and stabilization of the melt at the indicated temperature along the path of the melt flow to the extraction nozzle Holes create a rarefaction zone in which the melt flow is shaped into a strip with a thickness of 3.0-20.0 mm and passed through this zone at a speed of V = (7-9) 10 ^-4 m / s, and the air pressure in the rarefaction zone above the melt flow support in the range of 0.10-0.30 PA. 2. The method according to claim 1, characterized in that sand is used as a raw material. 3. The method according to claim 1, characterized in that the silica sand is used as raw material. 4. The method according to claim 1, characterized in that the raw materials used are either crushed quartz sandstone or quartzite. 5. Installation for the production of highly silicate fibers from rocks, by the method described in claims 1-4, which contains a furnace for producing a melt, the outlet of which is connected to the input of the feeder, at the outlet of which there is a transition chamber, in the wall of the case of the transition chamber there is a working a hole in which a die feeder is installed, and a mechanism for producing fibers is installed at the outlet of the extraction opening, characterized in that a homogenizer is installed between the furnace and the feeder, made in the form of two vertically and coax but cups installed with a gap in one another, forming an internal receiving chamber and an external clarification chamber, in which a vertical baffle is installed, designed to receive a melt stream in the form of a strip on its upper edge, the cavity of the clarification chamber is connected to a device designed to create air discharge in its cavity above the melt flow, and between the bottom of one glass and the free end of the other glass there is a gap for the passage of the melt stream. 6. Installation according to claim 5, characterized in that the vertical partition in the clarification chamber of the homogenizer is made adjustable in height. 7. Installation according to claim 5, characterized in that the homogenizer is provided with a heating system made in the form of at least two rows of gas-air nozzles fixed at an angle α = 3-65 ° to the vertical and radially staggered at a distance H = (5-7) D from the axis of the homogenizer, where D is the diameter of the nozzle of the nozzle designed to direct the torch to the external receiving chamber of the homogenizer. 8. Installation according to claims 5 and 6, characterized in that the homogenizer is provided with devices for carrying out bottom and side bubbling. 9. Installation according to claims 5 and 6, characterized in that the entrance to the homogenizer is located below the bottom of the furnace. 10. High silicate continuous fiber made of rocks, characterized in that it is made of silica-based rock by the method according to claims 1-4. 11. Highly silicate chopped fiber made from rocks, characterized in that it is made from silica-based rock by the method according to claims 1-4. 12. Highly silicate coarse fiber made from rocks, characterized in that it is made from silica-based rock by the method according to claims 1-4. 13. Highly silica staple fiber made of rocks, characterized in that it is made of silica-based rock by the method according to claims 1-4.

Images