SU1766578A1 - Self-hardening mixture for preparation on rods and forms - Google Patents

Abstract

Usage: in the foundry industry, namely, the compositions of self-hardening mixtures used to make foundry cores and molds. The essence of the invention: a self-hardening mixture contains, mss.%: Furan-urea binder 0.8-1.5; trifolin 1.6-3.0; phosphoric acid 2.0-3.5; refractory filler else. The proposed mixture with a low content of components that are resistant to disintegration in assembled forms and high strength characteristics, which are provided by the optimal combination of furanooppe binder and trifoline, contributes to the development of cold-hardening molding sands in the working areas of workshops and increase productivity in the manufacture of cores and cleaning of oglavok.

Description

This invention relates to foundry, in particular, to self-hardening compositions, predominantly in the cold state, of mixtures intended for the manufacture of foundry cores and molds.

Known self-hardening mixture (cold-hardening furan mixture), containing, in wt.%:

Furan-carbamide binder 2.0-2.5

Orthophosphoric acid1.0-2.0

Refractory filler Else Also known are self-hardening mixtures that have low gas-creation and improve working conditions in the manufacture of cores and shapes, especially when casting them with metal.

Such properties have self-sintering mixture, containing, in wt.%:

Trifolin4,5-12,0

Orthophosphoric acid 3.5-10.0 Refractory filler Else Due to the high razmokaemost and complete loss of strength properties in a wet environment, this mixture does not receive widespread use,

The purpose of the invention is to reduce the cooling capacity of the mixture 1 and to improve the sanitary and hygienic working conditions while maintaining the strength properties. The self-hardening mixture for the manufacture of casting molds and cores contains, in wt.%: The furan-carbamide binder 0.8-1.5; trifolin 1,6VI

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3.0; phosphoric acid 2.0-3.5; refractory filler else.

The amount of trifolin 1.6–3 wt.% Provides the rods and shapes with the required strength. Orthophosphoric acid, introduced into the mixture in an amount of 2.0-3.5 wt.%, Ensures the normal conduct of the hardening process and satisfactory strength. Introduction of a furan-carbamide binder 0.8-1.5 May. % of the mixture significantly reduces the razmocaemosti rods in assembled form.

Mixtures were prepared whose composition varied within the proposed limits.

The compositions of tests of mixtures are given in table 1, the properties of mixtures in table 2. Tests of samples from mixtures were carried out according to GOST 23409.7.78. Due to the low content of the furan-urea binder in the mixture, a decrease in the emission of gases from the mixture during metal pouring is achieved.

The use of mixtures of the proposed composition contributes to the development of the use of cold-hardening molding compounds in foundries with a complex production profile and the improvement of sanitary and hygienic conditions.

Claims (1)

Invention Formula Self-hardening mixture for the manufacture of rods and molds, including fire-resistant filler orthophosphoric acid and trifolin, characterized in that, in order to prevent the mixture from soaking in a wet environment of the mold, improving sanitary and hygienic working conditions while maintaining strength properties, it additionally contains furan-carbamide binder in the following ratio of ingredients, wt.%: furan-carbamide binder 0.8-5; trifolin1,6-3,0; phosphoric acid, 2.0-3.5; refractory filler rest Table 1 table 2