SU1097425A1 - Mixture for making ceramic moulds and cores of heat hardening - Google Patents

Abstract

MIXTURES FOR MANUFACTURING CASTING CERAMIC FORMS AND THERMAL REVERSING RODS, including a refractory filler, crocus by-product of aniline-dye production based on iron oxides, water and a boron-containing compound, for the purpose of recycling, the waste material. knowledge of these wastes and reducing its cost, the mixture contains, as a boron-containing compound, enameling sludge in the manufacture of sanitary equipment in the form of Kta with a content of 17-21 wt.% boric anhydride with the following ratio of ingredients, wt.%: § Crocus 0.5-2.0 Water 0.5-2.0 Yulam enameling from 17-21 wt.% boric anhydride 6-18 Refractory filler - the Rest

Description

The invention relates to foundry, in particular, to compositions of the mixtures used to make ceramic rods and heat curing forms. A known mixture for obtaining sintered molds, containing powdered quartz, alumina and borax. The strength of this mixture is formed due to the high-temperature resistance of alumina and borax III. However, due to the limited interaction of alumina and the borax, this mixture does not have easy ci emaciation. In addition, during the sintering process, the mixture shrinks, which is accompanied by the deformation of the forms by the formation of cracks. J A known mixture for the manufacture of casting molds, containing a refractory filler, an aqueous solution of aluminum phosphate and hematite ore. Such mixtures make it possible to obtain forms by sintering at elevated temperatures. However, the use of hematite ore requires additional steps for its preparation (grinding and classification). The closest to the proposed technical essence and achieved the result is a mixture dp Production of casting ceramic molds and heat-curing rods, which has the following composition, wt.%: Crocus is a by-product of aniline-dye production based on iron oxides .0,5- 2.0 Sodium tetraborate 2.0-8.0 Water 0.3-2.0 Refractory filler The remaining Such mixture allows, at sintering temperatures of 200-500 ° C, to obtain forms with superior mechanical properties, gas permeability, heat resistance, reduced but crumbling. The use of such a mixture makes it possible to significantly reduce the energy consumption during the manufacture of sj forms and rods. However, the input of this mixture is an expensive and scarce product sodium tetraborate (), the content of which largely determines the cost of the mixture. The purpose of the invention is the disposal of industrial waste, the environment from contamination with said waste and the reduction of the cost of the mixture. The goal is achieved in that the mixture for the manufacture of casting ceramic molds and heat-curing rods, including a refractory filler, crocus, a by-product of aniline-dye production based on iron oxide, water and a boron-containing compound contains, as mentioned boron-containing compound, enamelling sludge during production sanitary equipment in the form of a product with a content of 17-21 wt.% boric anhydride with the following ratio of ingredients, wt.%: Crocus 0.5-2-2.0 Water 0.5-2.0 Enamel sludge Neither from 17 to 21 wt.% of boric anhydride 6.0-18.0 Refractory filler. The remaining enamelling sludge is laundry powder with a specific surface of 1500-2000 and has the following composition, in wt.%:, 0-21.0 Ti0215.0 -20.0, 0-13.0 3NaF - AlF 5.0-7.0, 4-3.5, 4-3.0, 02-0.08 Else A decrease in the enameling sludge content below 6% leads to a sharp softening of the forms, and an increase in the Bbmie sludge content of 18% leads to a decrease in the gas permeability of the forms. When enameling sludge is used, it is introduced into the mixture without prior preparation in the form of a powder. The mixture is prepared by mixing the starting components in mixers of the roller, paddle or screw type, the duration of mixing is 13 minutes. The sintering temperature, which provides the necessary technological properties, is 500-600 ° C. Lowering the sintering temperature below leads to a significant decrease in the strength properties of the molds. An increase in the sintering temperature of the top gives no significant increase in strength. PRI me R. The mixture is prepared by mixing the initial components for 3 minutes. Quartz sand 1K02A is used as a refractory base. Table 1 shows the mixtures proposed (1-4) and the prototype (Samples for determining the technological properties of the mixture are prepared in standard sleeves. Testing the technological properties is carried out according to standard methods. Temperature resistance is determined by cooling samples heated to 1000 ° C mixtures in water. The number of cycles of heating and cooling, for which the sample mass is reduced by 30%, is taken as an indicator of heat resistance. The results of measurements of the technological properties of the mixture are given in Table 2. Ingredients Contents As can be seen Table 2, the use in the proposed compositions of mixtures of a by-product in the form of enamelling sludge, allows to obtain ceramic forms whose technological properties are almost similar to the prototype. However, instead of expensive and scarce sodium tetraborate, an enamel byproduct is used that is a waste. Disposal of this waste prevents it from contaminating the environment, and at the expense of its low cost helps reduce the cost of the mixture. The proposed mixture has high strength properties, low hygroscopicity, high heat resistance, and can be used to make single and semi-permanent ceramic molds and rods manufactured by heat curing, as well as to make linings. melting and heating units. Table 1 of ingredients, May. % in mixtures

Quartz sand 1K02A

Crocus

Enameling sludge

Properties

. Compressive strength in wet condition kgf / cm

Compressive strength, kgf / cm, after sintering for 30 min at, С

86

82

78

88 2

2 2

2

14

18 10

table 2

Mixes

0.10 0.10 0.13 0.10

0.07

500

600

The precipitation after sintering, / Gas permeability, units Hygroscopicity,% Heat resistance, number of cycles

Continued table. 2

43.0

6.0

68.0

100.0

74.0

5.0.

93.0

112.0

137.0

100.0

, 03

0.01

0.01

0.00

0.00

270

230

270

190

, 01

0.01

0.01

0.01

0.01

ten

14

ten

12

Claims (1)

MIXTURE FOR THE PRODUCTION OF CASTING CERAMIC FORMS AND THERMAL CURING BARS, including refractory filler, crocus by-product of aniline-dye production based on iron oxides, water and a boron-containing compound, characterized in that, in order to ensure the disposal of production waste, it is environmentally protected from pollution by ¹ · waste and reducing its cost, the mixture contains enamel sludge as a boron-containing compound in the manufacture of sanitary equipment in the form of a product with a content of 17-21 wt.% boric anhydride in the following ratio of ingredients, May. %: Crocus 0.5-2.0 Water 0.5-2.0 Enamel sludge with 17-21 wt.% Boric anhydride Refractory filler 6-18 Else ai · ^ resistant phosphate