RU2491254C1 - Method of processing scrap of refractory, construction and ceramic materials for production of ceramic balls and ceramic ball - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to complex processing of industrial wastes, particularly, to processing of refractory scrap for production of balls to be used as propping agents, grinding bodies, catalyst carriers, refractory fillers and bed filters. Proposed method comprises scrap heat treatment, scrap grinding, making of balls, their drying and roasting. Note here that crushed scrap is ground together with quartz-feldspar sand with 50 and more weight percent of particles feature the sixe of 10 mcm and smaller to allow 0.044 mm-oversize in amount of not over 0.3 wt % and the content of fraction under 1 mcm not exceeding 12 wt % at the following content of mix components in wt %: scrap - 5-35, quartz-feldspar sand - 65-95.

EFFECT: higher strength, roundness making at least 0,9.

16 cl, 9 ex, 1 tbl

Description

The invention relates to a technology for the integrated processing of industrial waste, namely the processing of scrap refractory, building and ceramic materials in order to obtain spherical materials that can be used as proppants, grinding media, catalyst supports, refractory aggregates and bulk filters.

The importance of refractory, ceramic and building materials in a developing economy is constantly increasing. Their quality largely determines the level of development of a number of industries. Some materials work under conditions of high temperatures and high loads, so the main requirements for them are high density, strength, fire resistance and a certain chemical composition. Other materials are used as heat insulators, catalyst supports, therefore, they must be highly porous and have a specific phase composition. Still others are intended for service under conditions of multiple thermal cycling; therefore, they must have high thermal stability. Not a single modern material meets the entire variety of requirements. This explains the large number of types of refractory, ceramic and building materials used in industry, technology and household. This diversity determines the formation of a large amount of waste products with different chemical and phase composition and requiring an integrated approach to their disposal.

Currently, there are a large number of technical solutions aimed at processing refractory scrap, the vast majority of which allows you to get products of the same chemical composition and the same purpose as the recycled scrap.

A refractory mass is known (RF patent No. 2379255) containing a refractory magnesia aggregate, an organic binder, sodium polyphosphate and optionally boric acid and coal tar pitch, characterized in that it contains fused periclase as a refractory magnesia filler fraction or not more than 4.0 mm or a mixture of fused periclase and dust-free scrap of periclase or periclase-carbon products at a ratio of 2 ÷ 7: 7 ÷ 2, or a mixture of dust-free periclase scrap and dust-free scrap of periclase-carbon products potassium at a ratio of 4 ÷ 5: 5 ÷ 4, and as an organic binder contains formaldehyde resin in the following ratio of components, wt.%:

sodium polyphosphate no more than 2 formaldehyde resin 4-5 coal tar pitch 0-3 boric acid 0-2.

A disadvantage of the known technical solution is that by recycling scrap of periclase refractory products, a magnesia mixture suitable for use exclusively in the production of magnesium-containing refractories is obtained.

There is also known a mixture for the manufacture of refractories (RF patent No. 2332386), which is a product of complex processing of industrial waste in order to obtain refractory materials, namely the processing of refractory scrap brand "Dinas". The technical result of the invention is to increase the strength and simplify the manufacture of products. The mixture for the manufacture of refractories includes aggregate, liquid sodium glass by dry solids, silica fume metallurgical waste with a content of SiO ₂ > 80% and water, and as a filler it contains dinas scrap and aluminum oxide in the following ratio, parts by weight: dinas scrap - 100.0; aluminum oxide - 3.0-15.0; liquid sodium glass by dry solids - 2.5-7.0; silica fume metallurgical waste with a content of SiO ₂ > 80% - 2.5-7.0; water - 4.0-10.0.

The known solution is also aimed at processing exclusively dinas scrap in order to manufacture refractory products from it.

The closest in technical essence to the claimed solution is the RF patent No. 2229456 "The mixture for the manufacture of refractory high-strength spherical granules and the method of production thereof". The invention relates to the production of refractory granular materials intended for use as a proppant in oil and gas production by hydraulic fracturing. For the manufacture of refractory high-strength spherical granules with a specific gravity of 2.6-2.8 g / cm and a bulk density of 1.58-1.68 g / cm ³ pre-crushed and subsequently burnt in a rotary kiln scrap refractory mullite-siliceous products with Al content ₂ O ₃ not less than 50% and pre-calcined bauxite with an Al ₂ O ₃ content _of not less than 60% Al ₂ O ₃ in the form of a finely ground product of their joint grinding in the following ratio of components in the charge, wt.%: Calcined bauxite - 33-67, scrap refractory mullite-siliceous products - osta noe. Moreover, the ratio of Al ₂ O ₃ : SiO ₂ (by weight) should be at least 1.0. Preliminary firing of scrap refractory mullite-siliceous products is carried out at a temperature of 1250-1350 ° C. Bauxite is fired at a temperature of 1100-1700 ° C until water absorption is not more than 5-35%, depending on the content of Al ₂ O _{3 in it} . The co-grinding product is granulated, dried, dispersed and fired in a rotary kiln at a temperature of 1500-1700 ° C, after which the sieved granules are sieved.

A disadvantage of the known mixture and the method of producing spherical granules from it is that only the scrap of aluminosilicate refractories can be processed in this way, which significantly limits the raw material base of materials for the production of refractory spheres. A significant disadvantage of the known method of manufacturing spheres is the fact that in addition to the heat treatment of refractory scrap, preliminary baking of the bauxite is also necessary, and the granules themselves have a high temperature of sintering firing. Increased values of bulk density and reduced sphericity / roundness of the fired granules limit their use as proppant, since recently in the field of manufacture and use of proppants, there has been a clear tendency to decrease bulk density and increase the sphericity and roundness of the granules.

The technical problem to which the claimed invention is directed is the processing of scrap refractory, ceramic and building products in order to obtain durable ceramic spheres for various purposes with a total sphericity and roundness of at least 0.9 and variable through the use of scrap of various chemical composition with bulk density.

This result is achieved by the fact that in the method of processing scrap refractory, building and ceramic materials to obtain ceramic spheres, including heat treatment of scrap, its crushing, grinding, forming spheres, drying and firing, grinding crushed scrap is carried out together with natural quartz-feldspar sand, in which 50 or more mass percent of the particles have a size of 10 μm or less, in the following ratio of the components of the mixture, wt.%:

scrap - 5-35, silica feldspar sand - 65-95,

moreover, the joint grinding of the charge components is carried out to a residue on the grid of 0.044 mm of not more than 0.3 wt.% and the fraction content of less than 1 μm is more than 12 wt.

In this case, the formation of spheres is carried out by preparing a slurry from the ground mixture into which a water-soluble polymer binder is introduced. The slip is dispersed through the calibration holes into an aqueous solution of a fixing substance, the resulting spheres are dried and fired. Also, a slurry can be prepared from the ground charge, which is fed to a tower spray dryer for drying, then to a granulator, and the resulting spheres are dried and fired. Or the ground mixture is directly fed to the granulator, and the resulting spheres are dried and fired.

If corundum or aluminosilicate refractories are used as scrap, the mixture has the following chemical composition, wt.%:

Al ₂ O ₃ - 3-15,

SiO ₂ - 70-92,

Fe ₂ O ₃ - 1.7-5.6,

impurities - the rest.

If magnesia or magnesia-silicate refractories are used as scrap, the mixture has the following chemical composition, wt.%:

MgO - 2-28,

SiO ₂ - 52-83,

Fe ₂ O ₃ - 2-7.5,

Al ₂ O ₃ - 1-7,

impurities - the rest.

If zirconium-containing refractories are used as scrap, the mixture has the following chemical composition, wt.%:

ZrO ₂ - 2-25,

Al ₂ O ₃ - 2-10,

SiO ₂ - 50-85,

Fe ₂ O ₃ - 1.5-4.0,

impurities - the rest.

If dinas refractories are used as scrap of refractory products, the mixture has the following chemical composition, wt.%:

SiO ₂ - 80-94,

Fe ₂ O ₃ - 1-3,

CaO - 0.2-2.8,

impurities - the rest.

In addition, this scrap can be a mixture of scrap refractory materials of various chemical composition, as well as the battle of building or ceramic materials, or a mixture of both with each other and with scrap refractory materials. If necessary, sintering additives are added to the charge, the composition of which depends on the type of scrap being processed.

The water-soluble polymer binder is selected from carrageenans, pectins, gelatins, alginates, celluloses, carboxymethylated polysaccharides, agar, starch, guar gum, xanthan gum, acrylic acid derivatives, polyols, and an aqueous solution of the fixing substance forms a water-soluble polymer binder with a water-soluble polymer compound, the binder fixing the shape of the granules. Thinners, plasticizers and stabilizers are additionally added to the slip to improve the rheological characteristics of the suspension. Ceramic spheres are fired at a temperature of 1180-1260 ° C.

The result is also achieved by the fact that the ceramic sphere is obtained by the claimed method and can be used as proppant, grinding media, refractory aggregates, catalyst supports, bulk filters.

The claimed technical solution is universal and allows in the conditions of a single production cycle on the same technological equipment to process the vast majority of types of refractory scrap, as well as scrap of ceramic and building products of various chemical composition into ceramic spheres having a wide range of applications.

Before grinding, the processed scrap, if necessary for the oxidation of metal inclusions or burning of organic impurities, may be subjected to preliminary heat treatment. Crushing of scrap is necessary to improve its grinding ability. The granulometric composition of crushed scrap depends on its physical and chemical characteristics and is determined separately for each type. The need for preliminary grinding of natural quartz-feldspar sands to obtain materials in which 50 or more mass percent of particles are 10 microns or less in size is determined experimentally. In the event that more than 50 wt.% Of the sand particles have a size of more than 10 μm when it is milled together with the scrap to be utilized, no further grinding of the sand occurs. The ratio of the components in the physical mixture of scrap refractory, ceramic and building materials with natural quartz-feldspar sands was established by the authors experimentally. When the content of scrap is less than 5 wt.% And sand more than 95 wt.%, The degree of processing of scrap remains low, and the material has a narrow temperature range of sintering firing. When the content of scrap is more than 35 wt.% And sand less than 65 wt.%, The versatility of the proposed method is leveled and a separate technological cycle will be required for each type of processed material, respectively, each type of processed material will have its own sintering temperature.

Since the resulting siliceous ceramic materials are multicomponent, heterophasic and have a complex internal structure, joint grinding of the charge components must be carried out to the claimed parameters. It is this degree of grinding that makes it possible to produce commercial ceramic spheres from mixtures of natural sand and scrap of various nature. With a residue on the grid of 0.044 mm more than 0.3 wt.% And a fraction content of less than 1 μm - less than 12 wt.% Due to the uneven volumetric shrinkage of the granules during firing, their sphericity is violated. In addition, due to the reduced content of submicron particles, the total amount of the glass phase becomes insufficient to stabilize the ceramic microstructure and relax internal stresses, which significantly reduces the strength of the calcined spheres. The claimed chemical composition of the materials obtained is determined solely by the type of scrap used and the ratio of scrap / sand.

The formation of spheres can be carried out by directly feeding the ground mixture into a granulator or by preparing a slip from it, which is fed to a tower spray dryer for drying and then to a granulator. These methods can be recommended for the manufacture of spheres used as catalyst carriers and bulk filters. However, the most preferred, according to the authors, is a method in which the formation of spheres is carried out by preparing a slurry from a ground mixture into which a water-soluble polymeric binder is introduced. The slip is dispersed through at least one calibration hole in an aqueous solution of a fixing substance, and thinners, plasticizers and stabilizers can be added to the slip to improve the rheological characteristics of the suspension. The type of substances indicated and their amount are determined solely by the type of scrap processed.

, $$S{O}_4^{2-}$$

и т.д.The slip containing all the necessary additives is dispersed through the calibration holes into droplets of the required diameter, which are cured in the solution of the fixing substance, after which the resulting spheres are dried and fired at a temperature sufficient to maximize the compaction of the granules. The diameter of the calibration holes is determined by the required diameter of the spheres. The composition of the fixative solution depends on the type and quantity of the polymer binder, and the concentration of the fixative solution is selected individually for each pair - a polymeric binder / fixative. As the fixing substance, for example, salts with Me ²⁺ , Me ^{3+ cations} and anions can be used $$B{\left(OH\right)}_{\mathrm{four}}{}^{-}$$

, $$S{O}_{\mathrm{four}}^{2-}$$

etc.

The inventive method of formation allows to obtain a sphere of almost monofraction particle size distribution (fluctuations in the diameter of the granules do not exceed 10%), which cannot be achieved using other known methods of granulation. Since there is no migration of large particles to the surface of the sphere due to rapid curing, it is possible to obtain granules with practically ideal indicators of sphericity and roundness, which is especially important when using the obtained material as a proppant. A proppant with improved sphericity and roundness provides a predominantly laminar mode of movement of hydrocarbons inside the proppant pack, and a material composition close to monofraction ensures the formation of highly permeable large voids between spheres not filled with particles of smaller diameter. The presence of uniform large pores between the spheres shortens the path length of the produced hydrocarbon inside the proppant layer and maintains the laminar flow of the oil product due to the absence of a sharp change in the cross section of the channels in the proppant pack. It should also be emphasized that spheres with a defect-free surface are able to work on abrasion without chipping for a longer time than granular materials with low sphericity / roundness. This, in turn, is an indisputable advantage of the claimed areas when used as grinding media. The manufacture of spheres according to the proposed method allows to reduce the requirements for sieving quality and significantly reduce the number of sieving equipment, since in this technical solution sieving is needed only to separate the fragments of granules that can be formed during technological movements, drying and firing of raw spheres. Ceramic spheres are fired at a temperature of 1180-1260 ° C. The final temperature of the sintering firing is determined by the type of scrap to be utilized, the ratio of scrap / sand, as well as the degree of grinding of the initial charge. By collecting the chemical composition of the material, using sintering additives and optimizing the firing regime in the claimed temperature range, it is possible to obtain both densely sintered spheres with a given bulk density and the prospect of their use as proppant and grinding media, as well as porous spheres used as catalyst carriers or refractory fillers.

Examples of carrying out the invention.

Sand of the following chemical composition was used as natural quartz-feldspar sand, wt.%: SiO ₂ - 94-95, Al ₂ O ₃ - 0.7-0.8, CaO - 0.3-0.4, Na ₂ O - 0.5 -0.6, K ₂ O - 0.9-1.1, Fe ₂ O ₃ - 1.5-2, impurities - the rest.

It is possible to use any natural sand or mixtures thereof, subject to the claimed parameters of the charge.

For the obtained spheres of the 0.425-0.85 mm fraction, bulk density, sphericity / roundness indices, and the fraction of broken granules were determined in accordance with the requirements of ISO 13503-2: 2006 (E). According to the authors, this standard most adequately reflects the requirements for consumer properties of ceramic spheres. The measurement results are presented in the table.

Example 1

9 kg of quartz-feldspar sand, previously crushed so that 52 wt.% Of the particles had a size of less than 10 microns, were mixed with 1 kg of scrap of chamotte refractory products crushed to a fraction of less than 10 mm. The resulting mixture was subjected to dry grinding to a residue on a grid of 0.044 mm — 0.3 wt.%) And a fraction content of less than 1 μm — about 14 wt.%. The fractional composition was monitored on a Horiba LA-300 photosediment graph. A mixture containing 91 wt.% - SiO ₂ , 3.8 wt.% - Al ₂ O ₃ , 1.7 wt.% - Fe ₂ O ₃ , impurities - the rest, was granulated on a laboratory plate granulator and fired at a temperature of 1200 ° FROM.

Example 2

6.5 kg of quartz-feldspar sand, previously crushed so that 55 wt.% Of the particles had a size of less than 10 microns, was mixed with 3.5 kg of scrap of forsterite refractory products crushed to a fraction of less than 10 mm. The resulting mixture was subjected to dry grinding to a residue on a grid of 0.044 mm — 0.2 wt.% And a fraction content of less than 1 μm — about 15 wt.%). The fractional composition was monitored on a Horiba LA-300 photosedimentograph. A mixture containing 19.5 wt.% - MgO, 68.9 wt.% - SiO ₂ , 2.81 wt.%) - Al ₂ O ₃ , 5.65 wt. .% - Fe ₂ O ₃ , impurities - the rest, were granulated on a laboratory plate granulator and fired at a temperature of 1240 ° C.

Example 3

8 kg of quartz-feldspar sand, previously crushed so that 57 wt.% Of the particles had a size of less than 10 μm, were mixed with 2 kg of scrap dinas refractories crushed to a fraction of less than 2 mm. As a sintering additive, 0.3 wt.% Soda was introduced into the charge. The resulting mixture was dry milled to a residue on a mesh of 0.044 mm — 0.2 wt.%) And a fraction content of less than 1 μm — about 15 wt.%. The fractional composition was monitored on a Horiba LA-300 photosedimentograph. A mixture containing 93.7 wt.% - SiO ₂ , 1.95 wt.% - Fe ₂ O ₃ , 0.52 wt.% - CaO, impurities - the rest was granulated on a laboratory dish-shaped granulator and fired at a temperature of 1210 ° C.

Example 4

8 kg of quartz-feldspar sand, pre-crushed so that 53 wt.% Of the particles had a size of less than 10 microns, was mixed with 2 kg of heat-treated at 900 ° C and crushed to a fraction of less than 2 mm of scrap ceramic diaphragms spent in electrochemical activation of water and containing 80 wt.% - Al ₂ O ₃ , 20 wt.% - ZrO ₂ . The resulting mixture was subjected to dry grinding to a residue on a grid of 0.044 mm — 0.3 wt.% And a fraction content of less than 1 μm — about 15 wt.%. The fractional composition was monitored on a Horiba LA-300 photosedimentograph. A mixture containing 84.6 wt.% - SiO ₂ , 8.3 wt.% - Al ₂ O ₃ , 1.56 wt.% - Fe ₂ O ₃ , 2, 0 wt.% - ZrO ₂ , impurities - the rest, was granulated on a laboratory plate granulator and fired at a temperature of 1260 ° C.

Example 5

9 kg of quartz-feldspar sand, previously crushed in such a way that 52 wt.% Of the particles had a size of less than 10 microns, were mixed with 0.5 kg of scrap of chamotte refractory products crushed to a fraction of less than 10 mm and 0.5 kg of crushed to a fraction of less than 10 mm scrap of forsterite refractory products. The resulting mixture was subjected to dry grinding to a residue on a grid of 0.044 mm — 0.3 wt.% And a fraction content of less than 1 μm — about 14 wt.%. The fractional composition was monitored on a Horiba LA-300 photosedimentograph. A mixture containing 91.26 wt.% - SiO ₂ , 2.91 wt.%) - Al ₂ O ₃ , 2.1 wt.% - MgO, 1.17 wt. .% - Fe ₂ O ₃ , impurities - the rest, were granulated on a laboratory plate granulator and fired at a temperature of 1180 ° C.

Example 6

9 kg of quartz-feldspar sand, previously crushed in such a way that 52 wt.% Of the particles had a size of less than 10 microns, was mixed with 1 kg of scrap red building brick crushed to a fraction of less than 10 mm. The resulting mixture was subjected to dry grinding to a residue on a grid of 0.044 mm — 0.3 wt.% And a fraction content of less than 1 μm — about 14 wt.%). The fractional composition was monitored on a Horiba LA-300 photosedimentograph. A mixture containing 90.4 wt.% - SiO ₂ , 2.9 wt.% - Al ₂ O ₃ , 1.19 wt.% - MgO, 2.54 wt. % - Fe ₂ O ₃ , impurities - the rest, were granulated on a laboratory plate granulator and fired at a temperature of 1260 ° C.

Example 7

100 tons of the mixture from example 2 was subjected to dry and then wet grinding to a residue on a mesh of 0.044 mm — 0.1 wt.% And a fraction content of less than 1 μm — about 18 wt.%. During wet grinding, apatite in an amount of 1000 kg (1.0 wt.%) In terms of dry matter was added to the suspension as a sintering agent. A slurry thus prepared with a moisture content of 35% was fed into an industrial tower spray dryer, the resulting material was granulated on a plate granulator with a diameter of 3 m, dried and fired in a rotary kiln at a temperature of 1260 ° C.

Example 8

The ground mixture from Example 2 in an amount of 650 g was placed in a laboratory propeller mixer, to which 350 g of water was added, then sodium tripolyphosphate in the amount of 0.3 wt.% (3 g) was added as a diluent, and carboxymethyl cellulose was used as a polymer binder "Polycell VCMC LV" in an amount of 1.2 wt.% (12 g). The slip prepared in this way was fed into a disperser with 300 calibration holes and, using a source of horizontal acoustic vibrations with a frequency of 390 Hz, was divided into droplets, which were sent for curing into a container with a 7% AlCl ₃ solution. The cured spheres were washed from a solution of aluminum chloride under running water, dried to a moisture content of 1.5-2% and calcined in a laboratory furnace with silicon carbide electric heaters at a temperature of 1260 ° C.

Example 9

The ground mixture from Example 6 in an amount of 650 g was placed in a laboratory propeller mixer, to which 350 g of water was added, then, with constant stirring, soda in the amount of 0.5 wt.% (5 g) was added as a diluting agent, and as a polymer binder sodium alginate in an amount of 1.1 wt.% (11 g). The slip prepared in this way was fed into a disperser with 1 calibration hole and, using a source of vertical acoustic waves with a frequency of 370 Hz, was divided into droplets, which were sent for curing into a container with a 6% solution of calcium chloride. The cured spheres were washed from a solution of calcium chloride with running water, dried to a moisture content of 1.5-2% and calcined in a laboratory furnace with silicon carbide electric heaters at a temperature of 1180 ° C.

Table Properties of ceramic spheres fractions 0.425-0.85 mm Example No. Bulk weight, g / cm ³ Sphericity / roundness The share of broken granules at 69 MPa, wt.% Prototype RF patent No. 2229456 1.68 0.8 / 0.8 6.5 1.76 0.8 / 0.9 4.6 Example 1 1.5 0.85 / 0.9 6.2 Example 2 1.53 0.85 / 0.9 3.9 Example 3 1.25 0.85 / 0.9 14.1 Example 4 1.53 0.9 / 0.9 6.1 Example 5 1.09 0.9 / 0.9 fifteen Example 6 1.34 0.9 / 0.9 10.1 Example 7 1.55 0.9 / 0.9 3.6 Example 8 1.45 0.93 / 0.93 3.7 Example 9 1.3 0.93 / 0.95 8.1

Analysis of the data in the table shows that the spheres obtained by the claimed method (examples 1, 2, 4, 6, 7, 8), with a lower bulk weight, have increased strength, and the spheres obtained by dispersing the slip in a solution of fixing substance (examples 8, 9) have better sphericity / roundness compared to the prototype. Thus, these materials can be recommended for use as proppant or grinding media. Lightweight spheres (examples 3,5) also have acceptable strength with high sphericity / roundness and can be used both as proppant and as refractory aggregates or bulk filters. In addition, the porous sphere of Example 5 may be suitable for use as a catalyst support.

Claims (16)

1. A method of processing scrap refractory, building and ceramic materials to produce ceramic spheres, including heat treatment of scrap, its crushing, grinding, forming spheres, drying and firing, characterized in that the grinding of crushed scrap is carried out together with natural quartz-feldspar sand, in which 50 or more mass percent of the particles have a size of 10 μm or less, in the following ratio of the components of the mixture, wt.%:
scrap - 5-35;
quartz-feldspar sand - 65-95,
moreover, the joint grinding of the charge components is carried out to a residue on the grid of 0.044 mm of not more than 0.3 wt.% and the fraction content of less than 1 μm - more than 12 wt.%. 2. The method according to claim 1, characterized in that a slurry is prepared from the ground charge into which a water-soluble polymer binder is introduced, spheres are formed by dispersing the slip through calibration holes into an aqueous solution of the fixing substance, the resulting spheres are dried and calcined. 3. The method according to claim 1, characterized in that a slurry is prepared from the ground charge, which is fed to a tower spray dryer for drying, and then to a granulator, the resulting spheres are dried and fired. 4. The method according to claim 1, characterized in that the ground mixture is immediately fed to the granulator, the resulting spheres are dried and fired. 5. The method according to claim 1, characterized in that corundum or aluminosilicate refractories are used as scrap, while the charge has the following chemical composition, wt.%:
Al ₂ O ₃ - 3-15;
SiO ₂ 70-92;
Fe ₂ O ₃ - 1.7-5.6;
impurities - the rest. 6. The method according to claim 1, characterized in that the scrap used is magnesia or magnesia-silicate refractories, while the mixture has the following chemical composition, wt.%:
MgO - 2-28;
SiO ₂ - 52-83;
Fe ₂ O ₃ - 2-7.5;
Al ₂ O ₃ - 2-7;
impurities - the rest. 7. The method according to claim 1, characterized in that the zirconium-containing refractories are used as scrap, while the charge has the following chemical composition, wt.%:
ZrO ₂ - 2-25;
Al ₂ O ₃ - 2-10;
SiO ₂ - 50-85;
Fe ₂ O ₃ - 1.5-4.0;
impurities - the rest. 8. The method according to claim 1, characterized in that as scrap refractory products use dinas refractories, while the mixture has the following chemical composition, wt.%:
SiO ₂ - 80-94;
Fe ₂ O ₃ - 1-3;
CaO 0.2-2.8;
impurities - the rest. 9. The method according to claim 1, characterized in that said scrap may be a mixture of scrap refractory materials of various chemical composition. 10. The method according to claim 1, characterized in that said scrap is a battle of building or ceramic materials or a mixture thereof both between themselves and with scrap of refractory materials. 11. The method according to claim 1, characterized in that sintering additives are additionally introduced into the charge. 12. The method according to claim 2, characterized in that the water-soluble polymer binder is selected from carrageenans, pectins, gelatins, alginates, celluloses, carboxymethylated polysaccharides, agar, starch, guar gum, xanthan gum, acrylic acid derivatives, polyols. 13. The method according to claim 2, characterized in that the aqueous solution of the fixing substance forms a water-insoluble compound with a water-soluble polymer binder, which secures the shape of the spheres. 14. The method according to claim 2, characterized in that thinners, plasticizers and stabilizers are additionally introduced into the slip to improve the rheological characteristics of the suspension. 15. The method according to claim 1, characterized in that the firing of ceramic spheres is carried out at a temperature of 1180-1260 ° C. 16. The ceramic sphere according to claim 1, characterized in that it is obtained by the method according to claim 1.