SU1380830A1 - Sand for making moulds and cores - Google Patents

Abstract

The invention relates to foundry and can be used to make casting molds and cores from liquid-glass mixtures. The purpose of the invention is to increase the strength of the mixture, reduce its fallability and improve embossability. The goal is achieved by introducing into the mixture a liquid-bauxite slurry modified with a refined alkylaryl sulfonate. The mixture contains, in wt.%: Refractory filler based on silica 91.5-92.5; liquid glass-bauxite suspension, modified with refined alkylaryl sulfonate (in the amount of 0.3-0.5 wt.%) 6.5-8.0; water 0.5-1.0. The liquid-glass bauxite suspension, modified with refined alkylaryl sulfonate, contains, in wt%: liquid glass 58.0-62.0; bauxite 28.0-32.0; refined alkylarylsulfonate (RASH paste) 0.3-0.5; water - the rest. The introduction of a modified liquid-bauxite suspension into the mixture contributes to a more uniform distribution of the binder over the grains of the filler and the production of thin and homogeneous films, which makes it possible to obtain mixtures with higher physicomechanical effects. In addition, the consumption of the pet decreases, which contributes to an improvement in the vybivaemosti mixture. 1 hp f-ly, 2 tab. i W

Description

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The invention relates to foundry and can be used to make casting molds and cores from liquid-glass mixtures.

The purpose of the invention is to increase the strength of the mixture, reducing its shedding capacity and improving the knockability.

The mixture contains a refractory filler, in which quartz sand K0315A (B) is used, a fiberglass bauxite suspension, which is modified with refined alkyl aryl sulfonate and water. The PACS paste is used as the refined alkylaryl sulfonate.

Modifying the bauxite suspension with a foam-PAC reduces its surface tension and reduces the wetting angle, which contributes to a more uniform distribution of the binder over the grains of quartz sand and obtaining thin and uniform binder films on its surface. This makes it possible to obtain core mixtures with higher physicomechanical properties.

The preparation of the liquid-bauxite slurry is carried out as follows.

Liquid glass with a modulus of 2.67 and a density of 1440 kg / m, bauxite and water are loaded into a ball mill, where the binder components are mixed for four hours.

The liquid-glass-no-bauxite suspension thus obtained is modified with a foam-PAC by mixing the components in a ball mill for 30-35 minutes. The optimal composition of the binder, wt.%: Liquid glass 58-62; bauxite 28-32; foaming agent PAC 0.3-0.5; water the rest.

Binders prepared in this manner examine and determine the surface tension of the binder and the wetting angle of the quartz plate.

The compositions of the liquid-bauxite slurry and its properties are given in table. one.

As can be seen from the table. 1, the addition of DS-PAC to the composition of the foaming slurry reduces the surface tension and the wetting angle of the binder, which has a positive effect on the distribution of the binder over the grains of quartz sand during the preparation of mixtures and thereby improves the physical and mechanical properties of the core mixtures.

The compositions of mixtures with a modified liquid-bauxite slurry and their properties are given in Table 2.

The mixtures are prepared in runners by mixing quartz.

sand, water and modified slurry for 5 minutes.

From tab. 2 that the mixtures prepared using modified bauxite suspension have a higher level of physical and mechanical properties (first of all, less work of knockout. In addition, the necessary level of physical and mechanical properties of the seismic mixture can be obtained with a lower content of binder mixtures. Mixtures have higher rates of formability, which is especially important for obtaining high-quality rods in the sand blasting method of their manufacture.

In addition, the labor intensity is reduced.

knocking the cores out of the castings reduces the consumption of the binder while maintaining and even obtaining higher physicomechanical and working properties from the prepared mixtures as compared to the mixtures prepared on the unmodified bauxite suspension.

The implementation of the invention increases the strength of the mixtures, reduces their crushability and improves aybivaemosti.

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Claims (2)

1. A mixture for the manufacture of casting molds and cores, containing a refractory filler based on silicon dioxide, a liquid-glass-bauxite suspension and water, characterized in that, in order to increase the strength of the mixture, reduce its crushability and improve embossability, liquid-glass-glass The bauxite suspension is modified with refined alkylaryl sulfonate in an amount of 0.3-0.5 wt.% with the following ratio of ingredients, wt.%: Refractory silica-based filler 91.5-92.5 Liquid-glass-boxy 40 Anna refined alkylarylsulfonate in the amount of 0.3-0.5 wt.% 6.5-8.0 Water 0.5-1.0 45 2. A mixture according to claim 1, characterized in that the liquid-bauxite slurry contains ingredients in the following ratio, wt.%: Liquid glass58.0-62.0 50 Boksit28,0-32,0 Refined alkyl-aryl sulfonate (RASH paste) 0.3-0.5 Water Rest. Table 1 Spreadsheets