SU1648928A1 - Process for preparing grinding ceramic bodies from corundum ceramics - Google Patents

Abstract

The invention relates to the production of ceramic grinding bodies used for fine grinding of the starting components in the preparation of ceramic products, including those based on oxides with high hardness, and can be used in mechanical engineering, electrical, electronic, chemical industries, building materials industry. and before. In order to simplify the technological process and increase the resistance of grinding media to abrasion in a method that includes wet grinding of the initial charge components, molding of grinding media, burning and cooling, the grinding of the charge components is carried out in the presence of aqueous solutions of polymers based on acrylic acid or cellulose derivatives, taken in an amount of 0.5-8% by weight of dry matter, and the grinding and grinding of grinding media is carried out simultaneously in a rotary kiln, and cooling is carried out at a speed of 400-600 ° C / hour. 2 tab. 5 o in

Description

The invention relates to the production of ceramic grinding media; raw materials used for fine grinding in the preparation of ceramic products, including those based on oxides with high hardness, and can be used in mechanical engineering, electrical engineering, electronic, chemical industries, building materials industry, etc.

The purpose of the invention is to simplify the process and increase the resistance of grinding media to abrasion.

The manufacture of ceramic grinding bodies is carried out as follows.

The starting components of the charge, for example, technical alumina, silicon, chromium and manganese oxides used for the production of high-alumina ceramics VK-94-1, taken in the required ratio, are subjected to joint wet grinding in a ball mill for (22 ± 2) h high-alumina balls. The ratio material - balls - water is 1: 1:: (1-1.2). The grinding is carried out to a specific surface of 13000-13500 cm2 / g. At%

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Mole is injected into a ball mill with a surface-active substance (surfactant), which promotes the nucleation of granules in the slurry of the material, in an amount of 0.5-8% by weight of dry matter. As such surfactants, 2-5% aqueous solutions of polyacrylamide, polyacrylonitrile, polyethylene glycol, carboxymethyl cellulose and others can be used. In addition, these surfactants contribute to the acceleration of grinding. The resulting slip is subjected to magnetic separation and then pumped into a rotary kiln, where the slip is first dried, granules are formed from it, and through the use of these surfactants in the drying, the material is granulated. Granules originate in the slip. The resulting granules move to the hot end of the rotary kiln, making translational-rotational movements, thereby increasing in size due to adhesion

Example 2. The initial components of the mixture in Example 1 were ground by a wet method with the addition of a 3% polyacrylonitrile solution, taken in an amount of 8%. The ground material in the form of a slurry was fed into a rotary kiln (temperature), the dust particles of the material were cooled to the face of them and the acquisition (of grinding media) was made with a speed of 400 ° C / h. The percentage of wear of grinding bodies 0,023%.

Example 3. The original components of the mixture in example 1 were crushed by a wet method with the addition of 5% solution of carboxymethylcellulose in the amount of 3%. The crushed material was fed into a rotary kiln (temperature), the cooling of the granules (grinding bodies) was carried out at a rate of 600 ° C / h. The percentage of 35 wear of grinding bodies is 0.025%.

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roundish spherical shape recedes. Slip injection mode and furnace mode (rotation speed) are calculated as follows. such that the granule size is between 10 and 40 mm in diameter. During the run-in process, the pellets are compacted by moving, colliding with each other and the furnace lining. The firing of pellets in a rotary kiln is carried out up to the sintering temperature of the ceramic material (for example, for VK-94-1 ceramics to a temperature of 1–70 ° C). The granules are cooled at a speed of 400-600 ° C / h, for which they enter the cooler of the rotary kiln. The sharply cooled granules are hardened during the quenching process. At the outlet of the refrigerator is placed a grid, the size of the holes of which (10 and 40 mm) provides the selection of the desired fraction of granules. The obtained granules of the required size have a spherical shape, are densely sintered and can be used as grinding bodies. The use of the polyfractional composition of the grinding bodies obtained by the proposed method contributes to the acceleration of the grinding of materials in comparison with the single-fractional size of the commonly used grinding bodies. In addition, grinding bodies have an increased resistance to abrasion compared to 55

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Characteristics of grinding media, depending on the amount of surfactant and cooling rate are given in Table. 12.

Claims (2)

Invention Formula A method of making ceramic grinding bodies from corundum ceramics, including wet grinding of the starting components of the charge, molding of grinding bodies, burning and cooling, characterized in that in order to simplify the process and increase the durability of grinding bodies to abrasion, grinding is performed in the presence of aqueous polymer solutions on the basis of acrylic acid or cellulose derivatives, taken in an amount of 0.5-8% by weight of dry matter, and the forming and burning of grinding media is carried out simultaneously in a rotary hearth, and cooling Bo is performed at a speed of 400-600 ° C / h. with grinding bodies, obtained by a known method. The invention is illustrated by the following examples. ABOUT five 0 Example 1. The initial components of the mixture — technical alumina, silica, chromium and manganese oxides, taken in the ratio required for the preparation of BK94-1 ceramics, were subjected to joint wet grinding. When grinding, a 2% aqueous solution of polyacrylamide was introduced in an amount of 0.5% by weight of dry matter. The ground material in the form of a slip was fed into a rotary kiln; in the hot zone of the kiln, the temperature reached 1670 ° C. The granules (grinding bodies) were cooled at a rate of 500 ° C / h. The percentage of wear of the grinding bodies thus obtained was 0.03%. Example 2. The initial components of the mixture in Example 1 were ground by a wet method with the addition of a 3% polyacrylonitrile solution, taken in an amount of 8%. The crushed material in the form of a slip was fed into a rotary kiln (temperature), the cooling of gravels (grinding bodies) was carried out at a rate of 400 ° C / h. The percentage of wear of grinding bodies 0,023%. 5 0 5 0 Characteristics of grinding media, depending on the amount of surfactant and cooling rate are given in Table. 12. Invention Formula A method of making ceramic grinding bodies from corundum ceramics, including wet grinding of the starting components of the charge, molding of grinding bodies, burning and cooling, characterized in that in order to simplify the process and increase the durability of grinding bodies to abrasion, grinding is performed in the presence of aqueous polymer solutions on the basis of acrylic acid or cellulose derivatives, taken in an amount of 0.5-8% by weight of dry matter, and the forming and burning of grinding media is carried out simultaneously in a rotary hearth, and cooling Bo is performed at a speed of 400-600 ° C / h. 16489286 Table 1 Apparent with density, g / cm - Resistance to abrasion (wear rate),% Apparently with density, g / cm33,5 Abrasion resistance (wear rate),% 0.022 3,553,5 0.02.0.025 3.5 0.13 3.55 3.5 0.02 0.025