SU593804A1 - Liquid-glass self-setting sand for making moulds and cores - Google Patents

Description

See h: b provides pshuchenie high pokayatpey final strength of the forms and core when the content of liquid glass in an average of 6 weight%. In view of this, the blendability of the mixture is difficult, and the addition of starch only slightly improves it, which is associated with a low temperature, the destruction of starch and its derivatives (150-200 ° C). The aim of the invention is to reduce the consumption of liquid for the binder while maintaining high the final strength of the mixture and the improvement of its knock-out; For this, the liquid-crystal self-hardening of the mixture for the manufacture of foundry molds and cores, including a refractory foam, a binder-liquid glass, a hardened body-silicon oil, sodium addition, tel. contains .furyl alcohol in the following ratio of ingredients, weight,% g Liquid glass3, Sodium silicofluoride 0.45-1.00 Furyl alcohol 0.09-0sis Refractory filler Else When combining furyl alcohol with liquid glass, a popimer silicate composition is formed, in which furyl alcohol plays the role of a dispersant of structural elements and some diluent of the system. Up to KOif centrifugal, 3% of fur alcohol by weight (liquid glass has a transforming effect. It disperses the structure of alemic minerals and transforms the system into a monodisperse with a larger amount — furyl alcohol mainly teasbav system. Achieving high strength properties of mixtures while reducing the consumption of the binder : is due to the fact that when introduced into the water glass of furyl alcohol, the viscosity of the composition decreases by 3 times. The increase in the viscosity of the polymer silicate binder contributes to a more uniform distribution after his grain fillers .and vn

The table is an increase in the frequency range. With TVJM, the amount of liquid glass is greatly improved, which is associated with a decrease in the amount of liquid glass and burnout of the smoothing that softens the mixture. When the content of furyl alcohol is less than Oe09 of cVa%, there is no increase in the strength and improvement of the knockability of the mixture, and at a content of more than 6.15% by weight, it is sufficient; level of strength indicators tie improves. It is preferable to use liquid glass with a modulus of 2.6-3.1 and a density of 1.48-1.52 g / cm. To prepare the mixture, a polymer-silicate composition is first prepared by adding furyl alcohol to the liquid glass with constant stirring for 2 minutes. Then, a refractory filler (quartz sand) is loaded into the runners, after which sodium silicofluoride is introduced and the mixture is mixed with the sand for 2-3 minutes. The latter is introduced into the prepared polymer-silicate composition and mixed with the dry ingredients again. 2.6-3 minutes after which the mixture is ready. For use in the scoreboard i, the example is examples of the composition of the mixtures, using the prepared method in the above / above way. Properties of mixtures are given in Table. 2. It is known that the mixture with a liquid glass content of 6 weight up to a compressive strength after 24 hours of hardening 21, 4 kgf / cm at the same time, the work of knocking out this mixture rises 1OO j. Thus, the proposed mixture reduces the possibility of reducing the content of liquid glass (from up to 4% by weight,%) while maintaining a high level of bed strength indicators, and its knockability is substantial: better (work of embossing is lower), it is:.: y. known mixture

Quartz sand (Kichiginsky KO315) W Yzkoye brand B glass Silicon fluoride sodium Furyl alcohol.

93.85 5.0 1.0 0.15

.but. “.

(kgf / cm-) through time, h

Formula Liquid Stages for the manufacture of drinking forms and rods, including, refractory filler, CBSS hardener-silicon, liquid fluoride sodium fluoride, characterized by the fact that CT08 in order to reduce the consumption of bond-ZZ shego while maintaining a high final strength of the HOCTR mixture and improving it knockout, it additionally contains furyl alcohol in the following ratio of ingredients, wt.% g40

Liquid glass3, O-5, O

Silicon fluoride sodium, 45-1, pO.

T a 6 p and c p 2

35

thirty

thirty

Sources of information taken into account in the examination:

1.L ss A, M, Quick-hardening forms {eral mixtures. M., Mechanical Engineering, i965, p. 224-249.

2. Chernogorov P.V., Nikiffov A, P. Plastic self-hardening mixtures in the foundry industry, Chel Binsk, I97O, p. eight.

3. Japanese patent N947-26931, cl. 11A2 01.06.68 ..