SU789198A1 - Sand for producing casting moulds - Google Patents

Description

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The invention relates to a foundry, in particular, to the technology of making casting molds from a sandy clay mixture with nonstick additives.

Sand-clay molding sands with anti-fuel additives, sawdust, coal 1 are known.

Sand-clay molding mixtures with carbon anti-burn additives are also known 2.

However, the surface of the castings when using this mixture is rough, the value of chemical burn is (22-24) x, 10 g / cm-,

The nonstick action of mazut additives, coal dust, is based on the ability to release shiny carbon from which a protective film is formed, preventing the surface from wetting with a liquid metal alloy, as well as through the process of converting coal to coke, blocking the pores in the mold. The addition of coal dust does not reduce the size of the burn of thin-walled castings due to the short duration of the temperature of the metal melt. Noticeable reduction in thick-walled burnout2

A wok is observed in a high content (up to 7%) of coal dust from the mixture, which hygienic conditions contain, which increases the dust-gas content of the foundry.

Most b. to the proposed mixture, according to the technical nature and effect achieved, is a mixture of G 31, including, by weight,%:

ten

Quartz sand85

Bentonite3-4

Inhibitor3-6

Diethylene glycol 3

However, diethylene glycol is deficient,

15 roads and does not give sufficient effect in terms of improving the surface cleanliness.

The purpose of the invention is to increase the purity of the surface of the castings and reduce the cost of the mixture.

The goal is achieved by the fact that the mixture for the manufacture of casting molds, including: .- duck refractory filler, clay bonded and organic additive, as an organic substitute contains a complex additive in the form of a 30-70% aqueous solution of polyglycolic juice, consisting of schuy) from diethylene glycol, triethylene glycol,

30 tetraethylene glycol, pentaztilenglikop in a ratio of, respectively, 0.01: 1: 0.25: 0.01-0.05: 1.25: 0.8: 0, 05 with the following ratio of ingredients, weight. %:

Clay binder 3-5 Complex additive 0.1-7.5 Refractory filler Remaining As an organic additive, the mixture contains the specified complex additive in combination with a universal synthetic binder (USK) in a 1: 1 ratio.

Also, as an organic additive, the mixture may contain the specified complex additive in combination with coal dust in a 1: 1 ratio.

The complex additive from polyglycols is introduced into the molding mixture in the form of an SO-VOi aqueous solution of a mixture of polyglycols (diethylene glycol, triethylene glycol, tetraethylene glycol), which is a production waste, for example, hydration of ethylene oxide or bottoms of the production of hydroxyethylcellulose and containing polyglycols in excess of the amount exceeding the amount of ethylene oxide or bottoms of the production of hydroxyethylcellulose and containing polyglycols. according to TU 38-3023-74.

The universal synthetic binder is used in accordance with Specifications 38-10541-75.

The technology of preparation of the molding mixture using the complex additive according to the invention does not change as compared with the technology used for the known composition of the molding mixture with

The invention is illustrated by the compositions and properties of the molding mixture which are listed, respectively, in Table 1, 2 and 3.

Table 1

Quartz sand grade 1KO315B4.0 4.0 4.0 4.0 4.0 Clay molding 4.0 4.04, O 4.0 4.0 Polyglycols TU 38-3023-741.0 7.0 7.5 8 , 0 0.3

Coal dust - - - - - 0.3 Binding USK-1 Waste form mixture Ost Ost Ost Ost strength in a wet state, 9-0.9-0.9% for compression, ll 0 0.95 0.95 kgf / cm 200 - 180-. 180 Gas permeability 210 185 185 4.5 4.5 -. 4.5Humidity,% 5.0 5.0 5.0

0.3 0.72.5 3.0

Table 2 0.9--0.9-0.9-0.9- 0.9- 0.9- 0.9-0.9-0.90, 950.950.950.95 0.95 0.95 0.950, 95 0.95 180-1 95-185-180- 180- 195- 190- .185- 185185200190185 185 200 195190 190 4.5-4.5-4.5-4.5- 4.5- 4.5 - 4.5-4.5- 4.55, 05.05.05.05 5.0 5.0 5.0.05 5.0 4.0 4.0 4.0 4.0 4.0 4 , 0 4.0 4.0 4.0 4.0 4.0 4.0 4.0 4.0 0.7 / 2.5 3.0 0.3 0.7 2.5 3.0 0, 7 2.5 3.0 Ost Ost Ost Ost Ost Oost 21-22

Claims (3)

3-10-7-E As follows from the tables, an increase in the amount of the complex additive in cm s above its limits according to the invention is accompanied by an insignificant decrease in the chemical slug size and the simultaneous appearance of other surface defects — gas shells, blood beads, etc. The size of the burn-in cast iron blanks, cast in sand molds from the mixtures of the invention, is low. The compositions of the table. 2 and 3 are similar to the mixtures of Table 1. The optimally prepared compositions that provide the required quality (the cast surface purity is 3.7 and 1. The mixture in accordance with the invention eliminates burns on both thin and thick iron castings. Formula 1. Mixture for the manufacture of casting molds, containing a refractory filler, clay binder and an organic additive, so that, in order to increase the purity of the surface of the castings and the ratio of the cost of the mixture, ki, the complex mixture contains as an additive Table 3 7-8 10-12 8-10 6-7 6-7 10-12 8-10 6-7 6-7. 30-70% of an aqueous solution of a mixture of polyglycols consisting of 3% diethylene glycol, triethylene glycol, tetraethylene glycol, and pentaethylene glycol in a ratio of respectively 0.01: 1: 0.25:: O, O 1-0.05: 1.25: O, 8: 0.05, in the following ratio of ingredients, wt.%: Clay binder 3-5 Complex additive 0.1-7.5 Refractory filler The remaining 2. Mixture according to claim 1, about t. L and h and s - sch the fact that, as an organic additive, the mixture contains the said complex additive in combination with a universal synthetic detergent in the ratio 1: 1, 3. The mixture according to claim 1, characterized in that then as an organic additive, the mixture contains the specified comp /; Exnuk) additive in combination-. Research institutes with coal dust in the ratio of 1: 1. Sources of information taken into account in the examination 1. Foundry production. -1976, No. 11, p. 19. 2. Authors certificate of the USSR 84745, class, B 22 C 1/00, 1949. 3. About 0itju magnezijevih Z2etiu Krav, Zivar. Vest, 1957, 4, 4, c. 97-106.