SU999338A1 - Mix for making foundry molds and cores - Google Patents

Description

invention relates to the field of foundry

Liquid glass mixtures for the manufacture of casting molds and cores are used with carbon dioxide blowing ij, as well as self-hardening using solid (metallurgical donkeys, silicon alloys, cement) and liquid materials (ethers, for example, a mixture containing , h .:

Refractory

filler 84,0-87,5

Liquid glass 4.0-4.5

Diacetin8,0-12,0 2

However, these mixtures are poorly knocked out of the castings, which requires a high cost of embossing and cleaning the casting. The strength of the mixtures at the initial stage of solidification (after 1 h) is insufficient, moreover, the esters are very scarce and expensive materials.

Liquid-glass mixtures, including those cured by carbon dioxide blowing, and self-hardening, which contain additives of organic and inorganic origin, such as sugar, sugar derivatives, alumina-containing materials, synthetic gums, alcohols, and oxidizers are also known.

Refractory

filler100

Liquid glass 6

Synthetic

phenol-formaldehyde resin

class1.0 3j,

With such additives, knock-out is also difficult due to high-precision (5-7 parts per hour) contained in its composition of liquid glass. Reducing the amount of liquid glass does not give positive results, since the strength is significantly reduced and the crumbling during prolonged storage increases.

Closest to the invention in its technical essence and the effect achieved is a mixture for the manufacture of casting molds and cores / comprising a refractory filler, water glass and an organic amine additive 4.

The disadvantages of the mixture are low vitality and strength after purging the mixture with CO.

To eliminate this drawback, the mixture for the manufacture of casting molds and cores, including a refractory filler, liquid glass and an organic amine-type additive, contains as an organic amine-type additive in the following ratio of ingredients, wt.h.

Liquid glass 2,0-4,0

O-aminocaproate

sodium 0,2 - 0,4

Refractory

filler, the Rest

According to the invention, the amount

5 g-aminocaproate sodium in terms of dry), introduced into the mixture, should be 0.2-0.4 wt.h. by weight of the mixture. When using it less than 0.2 ma. strength does not increase

0 mixture. After purging it with carbon dioxide. Increasing the amount of α-aminocaproate sodium in the mixture over 0.4 wt.h. leads to very fast coagulation of liquid glass,

5 whereby the mixture has a very limited vitality.

The proposed mixture contains from 2.0 to 4.0 wt.h. liquid leaked. When using liquid fluid in

0 qty less than 2.0 ma.h. you are not able to get a property with the required t-strength properties, and its increase is above 4.0 mph. leads to a sharp deterioration in discharging the network.

 According to the invention, the molding mixture contains as a filler any refractory material used in a foundry, for example, quartz sand.

0 The proposed mix is prepared as follows.

Sodium b-aminocaproate is pre-dissolved in water, thus obtaining a solution of 20-40%. The resulting solution of sodium aminocaproate is stirred for 11.5 minutes with liquid glass. The liquid composition thus prepared is introduced into a refractory filler.

0 and all components of the mixture are mixed on any known equipment for 1-2 minutes.

After stirring, the eggs are dusted into a tinnet, compacted with any

5 in a known manner and screwdriver.

The invention is illustrated by the composition and properties of the mixtures, which are listed respectively in Table. 1 and 2.

Table 1

97.0 96.0 2.03.0

1.0

1 The effect of increasing survivability and preserving strength after CO2 purging is illustrated by compositions and its own, 97

94.5 95.6 3.04.0 2.0

1.0

1.0

0.4

0.2

Table 2 of the mixtures, which are listed respectively in Table. 3 and 4.

97.0 96.0 95.0 94.5

Quartz sand 2.0 3.0 4.0 3.0 Liquid glass

fl-aminocaproate 1gat (20% solution)

1.0

-aminocarine sodium (30% solution)

1.0

-Aminocaproate sodium (40% solution)

Sodium b-aminocaproate (dry

Ethylenediamine

Water

Mix prototype. Blend Time of extracts mixtures with As follows from the table. 3 and 4 mixtures 60 according to the invention have a significantly greater survivability (2 hours) than in the prototype (about 10 minutes), and after the decrease in x-strength of the mixture in the prototype, the strength of the latter after CO solidification decreases sharply. 65

Table 3

96.85

95.6 2.5 4.0

1.0

1.0

0.2

0.15 0.5

Table 4a SO purge survivability.), Min. Rods and molds made from the proposed mixture can be used in the production of castings from iron, steel and non-ferrous metals. At the same time, the knockability of the mixture from castings is significantly improved (facilitated by a factor of 5-6). Strength offered by P

79993388

mixtures at room temperature prino improve sanitary and hygienic

The reduced content of the liquid stack, the labor conditions of the moulders and the stabs, increases by 1.5-2.0 times.

The use of the inventive mixing invention is

allows to reduce the labor intensity of 250 thousand pyes. compared to the base

cleaning and obrubny works, significant-object.

The economic effect of using

Claims (1)

(54) (57) MIXTURE FOR THE PRODUCTION OF CASES AND RODS, comprising a fireproof refill, water glass and an organic additive of the amine type, characterized in that, in order to increase the survivability and strength after blowing with carbon dioxide, as an organic additive of the amine the type of mixture contains sodium S-aminocaproate in the following ratio of ingredients, parts by weight: liquid glass £ -aminocaproate sodium Refractory, filler 2.0-4.0 0.2 - 0.4 Rest § £ СО с 00 оо 00