RU2805702C1 - Ceramic charge for manufacture of porcelain products - Google Patents

Abstract

FIELD: ceramic industry.

SUBSTANCE: electrical and porcelain industries. Ceramic charge for the manufacture of porcelain products contains clay, kaolin, waste and flux with the following content of charge components, wt.%: quartz-feldspar raw material “Е-2103 50-60”, clay “ДН-1 15-25”, kaolin “КЖЭ 10-20”, waste cracking catalyst 5-15. The basis of the spent cracking catalyst is aluminum and silicon oxides, with a particle size of about 1-2 microns, which makes it possible to use it as a replacement for waste materials and flux in ceramic production.

EFFECT: use of the developed ceramic mass simplifies the production process by reducing the number of crushed components while maintaining the quality of porcelain products.

1 cl, 2 tbl

Description

The invention relates to the electrical and porcelain - earthenware industry, in particular, to the technology of manufacturing ceramic materials and can find application in the production of electrical (electric porcelain), chemically resistant and household porcelain products.

A ceramic charge is known for the manufacture of porcelain products for various household purposes [Sulimenko L.M. General technology of silicates / L.M. Sulimenko. - M.: INFRA-M. – 2004.- 336 p.]. The charge includes plastic components, which are kaolins and refractory clays, fluxes, which can be feldspars, pegmatites, perlites, chalk, dolomite, talc, nepheline syenites, spodumene and other minerals, materials, as well as waste materials. The following are used as clearing agents: quartz sand, quartz waste (waste from kaolin enrichment), fireclay, waste and watered waste products. In the known technical solution, raw materials of natural origin are used, with the exception of a small amount of waste products, which makes it possible to dispose of technological defects and regulate the technological properties of the slip, reduce the shrinkage of products during drying and firing. The natural origin of raw materials and, therefore, the inevitable costs of their extraction and enrichment, fine grinding of lean and waste materials increase the cost of production.

A ceramic mass is known containing pegmatite, quartz sand, kaolin, refractory clay, porcelain scrap in the following ratio of components, wt. %: pegmatite - 26-29, quartz sand - 29-31, kaolin - 14-18, refractory clay - 6-9, porcelain scrap - 20-22 [USSR Author's Certificate No. 1063797, IPC C04B 33/24, 1982]. An excessive amount of broken porcelain may not be provided by a stable technological process, and a large total amount of stony ones (75 - 82 wt.%) increases the cost of grinding them, which is a disadvantage of this technical solution.

The closest technical solution, chosen as a prototype, is a mass for the manufacture of porcelain products containing, wt.%: pegmatite 21.2 - 24.3, quartz sand 17.5 - 20.6, clay 4.9 - 5.02, kaolin 32.1 - 35.0, skull of the 1st firing 3.2 - 3.4, skull of the 2nd firing 1.6 - 1.7, porcelain production waste 13.2 - 16.2 (cuts from the manufacture of products using the casting and molding, and the used waste from porcelain production has the following chemical composition with component content, wt.%: SiO ₂ 66.1 - 66.5, Al ₂ O ₃ 21.7 - 22.16, CaO 1.06 - 1, 16, MgO 0.88 - 0.9, K ₂ O 2.39 - 2.41, Fe ₂ O ₃ 0.28 - 0.3, N ₂ O 1.35 - 1.37, unaccounted components and PPP ( losses on ignition) - the rest [RF Patent No. 2133242, IPC S04B 33/24, 1997]. The manufacture of porcelain products includes the preparation of ceramic mass in the form of a homogenized suspension consisting of quartz sand and pegmatite (flux), kaolin, and clay (plastic raw materials ) “skulls” of the first and second firing, porcelain production waste, bringing the specified suspension to a given degree of moisture, aging the resulting cake mass until “ripening”, dissolving the cake mass to obtain a slip with a given moisture content, viscosity and density, from which by slip casting methods or Plastic molding produces porcelain semi-finished products, followed by drying and firing. The disadvantages of the composition of the mass are its multicomponent nature, multistage nature, and the need to introduce 18–21 wt.% into the mixture. % of waste and manufacturing defects, which may not be ensured by a stable technological process. The known charge is closest to the claimed solution in terms of the rational composition of the components used for the production of porcelain products.

The technical task is to simplify the technological process.

The technical result is achieved by the fact that in a ceramic charge for the manufacture of porcelain products containing clay, kaolin, waste and flux, according to the invention, quartz-feldspathic raw material E-2103 and a spent cracking catalyst are used as waste and flux, with the following content of the charge components, wt.%:

quartz-feldspar raw material E-2103 50-60

clay DN-1 15-25

kaolin KZHE 10-20

spent cracking catalyst 5-15.

Spent cracking catalyst (WCC) is formed during the operation of the catalyst at cracking plants, where in the process of oil refining, which occurs with the splitting of heavy hydrocarbons into components with lower molecular weight and the synthesis of new substances. Catalytic cracking (CC) is the most important large-scale method of oil refining. World production of cracking catalyst is more than 550 thousand tons per year, of which Russia accounts for about 50 thousand tons per year. During the operation of the catalyst, abrasion and grinding of particles occurs as a result of mechanical loads, which leads to a decrease in catalytic properties and the replacement of the used catalyst with a “fresh” one. Catalytic cracking of petroleum feedstocks represents a large source of waste catalyst that is desirable to be used. In the Russian Federation, the amount of spent catalyst reaches tens of tons per day. It is obvious that recycling of OCC contributes to the solution of environmental problems and the development of resource-saving and waste-free technologies. Studies have shown that PCC samples predominantly contain aluminum and silicon oxides (90 – 92 wt. %) with a particle size of about 1-2 microns, and the waste can be used as a replacement for waste and flux in ceramic production without grinding using existing technological circuits and equipment and without additional capital investments. There is currently no market price for OCC, and the use of spent catalyst is economically feasible, allowing the cost of production to be reduced.

A pilot batch of products containing OCC in the charge was prepared under factory conditions (Table 1). The charge was used for the production of electrical material of subgroup 110 of GOST 20419-83 (silicate porcelain, mass fraction of Al ₂ O ₃ up to 30%).

Table 1. Compositions and characteristics of the studied mixtures

No. Components of the charge, wt.% Characteristics of the charge Quartz field.
raw material E-2103 Clay DN-1 Kaolin KZhE Pegmatite Fight farf. OKC Content
clayey, % Module
potassium 1 60.0 20.0 10.0 5.0 5.0 - 43.2 7.8 2 35.0 25.0 10.0 - - 30.0 42.7 5.3 3 45.0 20.0 15.0 - - 20.0 44.9 7.3 4 50.0 15.0 20.0 - - 15.0 46.0 8.8 5 55.0 20.0 15.0 - - 10.0 47.1 9.6 6 60.0 25.0 10.0 - - 5.0 48.2 10.2

OCC do not have plasticity and therefore, in comparison with the factory control composition (no. 1), the clay content was increased by a total of 5%. The content of clay components to give the mixture the necessary plasticity must be at least 41-42%, and the potassium module must be at least 2 to maintain the sintering range (the ratio of potassium oxide to sodium oxide content). Catalyst waste was used to replace porcelain waste, pegmatite and part of the quartz-feldspathic raw material, in which the clay content is 22% (based on the kaolinite content in the mixture). The total clay content is less than 35 wt. % led to increased product defects during molding and drying.

Grinding of the charge components was carried out in a ball mill using a wet method until the residue on sieve 0056 was no more than 0.1%. Since OCC is finely dispersed, it was introduced together with DN-1 clay and KZhE kaolin after grinding the E-2103 quartz-feldspathic raw material. The moisture content of the slip was 55%. The resulting slip was dewatered to molding moisture to ensure plastic molding or dried to prepare press powder. For pressing, we used a fat ligament adopted at the enterprise and containing 3% diesel fuel and 0.8% oleic acid. The samples were air-dried and dried to zero humidity. Firing was carried out in a gas furnace according to the regime adopted for electrical porcelain of subgroup 110.

The properties of the prepared molding masses and fired ceramics are shown in Table 2. It can be seen that with an increase in the waste content in the charge, the humidity of the molding mass increases due to the nanoporous structure of zeolites, which are contained in the catalyst and are not completely destroyed. When drying, high humidity leads to cracks. As a result, when the charge contains more than 15% PCC, the amount of defects in drying increases and the strength of ceramics decreases, which is understandable, given their poor sintering. It is technically unjustified to introduce OCC into the mixture in an amount of more than 15%. It is also impractical to introduce less than 5% of PCC into the composition of the charge, since a decrease in the amount of waste leads to increased shrinkage of the semi-finished product, the appearance of defects in drying and firing.

Table 2. Characteristics of masses and ceramic materials

Batch No. Mass moisture content, % Product characteristics Extrusion Pressing Drying Water absorption,% Shrinkage
in obzh.,% Bending strength, MPa 1 18-23 13-15 good. 0.0/0.4* 13/12 65 2 33.0 23-24 crack - - 45 3 25.5 18.0 satisfaction 0.2/0.6 16/14.5 55 4 24.5 17.0 good. 0.0/0.5 15/14 63 5 23.8 16.0 good. 0.0/0.5 14/13 63 6 22.0 15.0 good. 0.0/0.4 13/12 65

Note: * -- separated by fractions - characteristics of ceramics prepared by extrusion and pressing.

Tests of the resulting ceramics showed its compliance with the requirements of the material of subgroup 110 of GOST 20419-83, namely, apparent density 2.32-2.34 g/cm ³ , open porosity 0.0%, bending strength of an unglazed sample 63-65 MPa, durability to thermal shock 180 – 190°C, electrical strength 26-28 kV/mm at a frequency of 50 Hz, average coefficient of thermal linear expansion at temperatures from 20°C to 100°C 3.4 – 5.2 K ^-1 10 ^-6 .

The use of the charge will reduce the cost of production of porcelain products by reducing the quantity and cost of the raw materials used in the ceramic charge, reduce the cost of grinding the components while maintaining the quality of the porcelain products.

The use of ceramic charge for the manufacture of porcelain products will simplify the technological process.

Claims (2)

Ceramic charge for the manufacture of porcelain products, containing clay, kaolin, waste materials and fluxes, characterized in that quartz-feldspar raw materials E-2103 and a spent cracking catalyst are used as waste materials and fluxes, with the following content of charge components, wt.%: quartz-feldspar raw material E-2103 50-60 clay DN-1 15-25 kaolin KZHE 10-20 spent cracking catalyst 5-15