SU910305A1 - Liquid glass containing mixture for producing casting moulds and cores - Google Patents

Description

(5 ") - LIQUID-GLASS MIXTURE FOR THE MANUFACTURE OF CASTING FORMS AND RODS

I

The invention relates to foundry, in particular, to compositions of liquid glass liquid self-hardening mixtures {} (CC) for the manufacture of molds and cores with refractory fillers having an initial temperature of up to 80 ° C.

Blend compositions based on a refractory filler, binder, hardener, foaming agent and tU water are known.

These mixtures are used for the manufacture of molds and cores with refractory fillers having an initial temperature not higher than 35 ° C.

A known liquid-glass mixture, comprising as a supplement the microbial "Ir, neutralized with caustic soda. R2. This mixture has unsatisfactory physicomechanical and technological properties when using a hot filler.

Closest to the proposed mixture for the manufacture of molds and cores, containing a refractory filler — quartz sand, bonding liquid glass, a hardener — ferrochrome slag, a foaming agent, black neutralized refined contact and water of the following composition, nass.%:

Ferrochrome slag 3.7

"O - Idko glass5,5

Contact black neutralized refined0, 1 Water, E

15 Refractory filler Else S The mixture of the above composition does not provide the required complex of physics, mechanical and technological properties in the process of making molds and rods from ZhSS with a refractory filler having the initial (during the preparation of the mixture) temperature above 35 ° C, namely: Low foam stability and associated low vitality and fluidity. A decrease in the stability of the foam in the mixture at elevated temperatures of the refractory filler occurs due to a decrease in the viscosity of the foaming agent solution and an increase in the rate of outflow of liquid from the foam films. These factors are enhanced simultaneously by evaporation of the dispersion medium and dehydration of the foam films. The survivability of the MCC is characterized by a length of time, for Jroporo, the mixture retains the property of mobility or fluidity and with it various technological operations can be carried out - transportation, pouring into core boxes or flasks, etc. The ability of the mixture to maintain these properties depends on the induction hardening period, i.e. time from the moment of preparation of the mixture to the beginning of its hardening. If the induction period is greater than the stability of the foam, the vitality will be determined by the stability of the foam, if the induction period is less than the stability of the foam, the vitality is determined by the induction period. ZhSS given composition from the mountains. As a filler, it has a low foam stability due to the above mentioned factors. In addition, the increased temperature of the refractory filler and, consequently, the mixture accelerates the processes of interaction between dicalcium silicate of ferrochromic slag and sodium silicates of water glass, reducing the induction period and, consequently, the vitality and fluidity of the mixture. The purpose of the present invention is to increase the fluidity and vitality of the mixture at the temperature of the refractory filler to. To achieve this goal, the liquid glass mixture, which includes a refractory filler, ferrochrome slag, a neutralized black contact refined, liquid glass, water, additionally contains a by-product of alkaline refining of fats and oil and soap in the following ratios of ingredients, wt.%: Liquid glass .b-b, Ferrokrom slag1 ,, 6 Neutralized black contact, refined 0.02-0.1 Soap stock P, .1-0.25 li-ZJ. Fireproof Water at Others Soapstak (TU 18 ROSOP) is a by-product of Christmas-tree refining of fats and oils and is intended for technical purposes. General Formula Soapsap RCOO a, where R - usually - C, -C. In terms of organoleptic and physicochemical indicators, soap stock must comply with: consistency at 20 ° C - from liquid to greasy, the smell is peculiar to soap flow, derived from various oils and fats; weak organic decomposition halls, total fat content, I not less than 25.0-30.0 fatty acids, not less than 15 0, total neutral oil and fatty acids bound in the form of sodium salts are allowed. A characteristic feature of sodium salts of fatty acids in the temperature range of 0-90 ° C is an increase in their solubility with increasing pressure inside the bubbles of the foam, as well as a decrease in the surface tension of the solutions. These factors determine the high stabilization of the foam at elevated temperatures of the mixture, at the same time increasing the survivability of the mixture. Neutralized black contact refined (GOST 13302-67) as a frother has a high breeding ability and gives the mixtures a high flow immediately after their preparation, however, in a short period of time the foam quickly falls off. This is due to the fact that the CRPD, which has a high surface activity, has a relatively low surface tension. In the proposed composition, the soap stock provides high foam stability in mixtures with refractory fillers at temperatures from 1 g to. The combined combination of foaming agent in certain ratios makes it possible to obtain WCC on hot refractory fillers with optimal fluidity and vitality. Soap stock is a bio-soft substance that does not adversely affect the environment. As a hardener, the mixture can be used in addition to ferrochromic slag nepheline sludge, etc. As a refractory filler in the composition of the mixture can be used molding sand according to GOST 2138-7, zircon, etc. The mixture is prepared as follows. First, in special mixers, a liquid composition is made consisting of liquid component mixtures (foaming agents, a binder and water). For this purpose, the calculated amount of frothers (KCHNR and soap stock) is poured into the mixer, then water and binder are mixed for 7-10 minutes. The preparation of LSCs is carried out in a known manner in installations of periodic or continuous action, jB installations of periodic action, refractory filler and ferrochrome slag are loaded into the mixer, which are mixed for 1-1.5 minutes, after which the calculated amount of liquid ferrochromic slag is introduced 3.21.93.2 5 , 5it.e5,5 Liquid glass Soap stock 0,050,10,17 0,10,10,05 1,852,31,85 Refractory floor89, 391,089,13 media 91

Table 1: The components of the pewey of the composition are stirred for another 2–3 minutes, after which the mixture is supplied as intended. In continuous installations, the refractory filler and the hardener are fed continuously to the mixer in a predetermined proportion, where they are measured with the liquid composition, which is also continuously fed in a predetermined proportion. The compositions and properties of the mixtures are given respectively in Table. 1 and 2. For the preparation of CSU, a refractory filler was used; heated to lower temperatures, the properties of the mixture did not deteriorate, since at these temperatures more favorable conditions are created to demonstrate the optimum physicomechanical and technological properties. As follows from the table. 2, foam stability, fluidity and durability of the proposed compositions of mixtures NW 2- at a filler temperature is much higher than the prototype. Mixture N ° 1, in which the stockpile of contents (its is less than the lower limit, has foam stability, fluidity and vitality, and mixture 5, in which the stockpund contains more than the upper limit, has increased foam resistance and vitality, but low flowability. K, 6 3 , 23.7 6.Ts 5.55.5 0.25 0.3 0.02 0.010.1 I, 1.851.9 37.33, 89.1488.8 Foam stability, 5.07.0 min 179.0139 , 0 Flowability, Pa, 06.0 Vitality, min. Compressive strength, Pa, 10 after: 2.52.3 "", 63.8 9.8.7 Gas permeability, units through:

Therefore, the optimal composition of the MCC with a filler having a temperature up to, should be considered the composition Wr 2-i.

The compositions of the mixtures according to the invention can be used in the manufacture of iron, steel castings and castings of non-ferrous alloys. Shrinkage of the mixtures is practically absent.

The quality of the surface of the casting, obtained on the proposed composition of the mixture, did not differ from the castings obtained using the known mixture. Visually, the visibility was also identical.

The use of a refractory filler having a temperature of up to 80 ° C makes it possible to eliminate the need to cool the sands after drying, to shorten and simplify the technological process of manufacturing castings.

table 2

Oormula invention

Liquid glass mixture for the manufacture of casting molds and cores, including refractory filler, ferrochromic slag, neutralized black contact, refined, water glass, water, characterized in that, in order to increase the fluidity and vitality of the mixture at refractory filler temperature up to 80 ° C, the mixture additionally contains secondary the product of alkaline refining of fats and oil-soap stock in the following ratio of components, nos.%:

Liquid glass, 6-6, k Ferrochromic slag 1.9-4.6 Neutralized black contact refined 0.02-0.1 Soapstok 0.1-0.25 910123 1 "42,0158,0189,0182.0.0 8.09,011 , 02.0 2,2,62,22,3 i + ,, 73,63,5 9,211,17,57,2

9 91030510

Water 1,, 32. Copyright witness the USSR

Refractory floor- N 530lf97, cl. B 22 C 1/10, 1975.

Media Else.

 Sources of information, 3 Instructions for use 1b

taken into account in the examination: surface-active substances -memei1. Technological properties of DS-RAS liquid in self-hardening liquid

kih self-hardening molding mixes mixes, L., bpt. 1977

.this. M., Science, 19b7. (P. 7..,

Claims (5)

SUMMARY OF THE INVENTION A liquid-glass mixture for the manufacture of foundry molds and cores, including refractory filler, ferrochrome slag, neutralized refined black contact, water glass, water, which, in order to increase the fluidity and survivability of the mixture at a temperature of refractory filler up to 80 ° C, the mixture additionally contains a by-product of alkaline refining of fats and oils-soap in the following ratio of components, wt.%: Liquid glass Ferrochrome slag Neutralized black refined contact anny Soap stock 1. Technological properties of liquid self-hardening molding sand. M., Science, 1967. 0305 10 1.9 * 4.6 0.02-0.1 0.1-0.25 9 Water 1.4-2.3 Refractory solder- ₍ Nitel. Other Sources of information taken into account during the examination 2. USSR copyright certificate Ν ’530497, cells, B 22 C 1/10, 1975. 3> Instructions for use - 4.6-6.4 5 surfactant substitutes DS-RAS in liquid self-hardening mixtures, L ,, VPTIlitprom, 1977, | p. 7 "