SU979017A1 - Mixture for casting moulds and cores - Google Patents

Description

is within 1-2 minutes, after which water glass is introduced and the mixing of the components continues for 2-3 minutes. Prepared standard samples were subjected to tests to investigate the technical properties of mixtures.

A distinctive feature of the proposed mixture is the improved knock-out of molds and cores from steel castings. This is explained by the addition of shungite-containing shale, which contains up to 3–3.5% shungate substance, 10–30% quartz, 35–45% plagioclase and 35–55% chlorite, to the composition of the mixture. The chemical composition and characteristics of the swelling of schungite shale from the Nigozerskoye field are given in Table. one.

Shungite-containing slate is introduced into the mixture in the form of finely ground powder. The effective effect of this material in the process of improving the knock-out is due to the fact that at high temperatures swelling of shungite-containing shale occurs, which contributes to the loosening of the silicate film of the bonding material. Such a process of expansion is explained by the presence of a sufficiently large amount of iron oxides in the material, which are FeO X (O, aO 50.52 1.96 16.4716.34 2.353 Contents Ingredient t1 1 23 II Liquid glass M 2.8 y 1.48 5 -, - ".--. ---- ..-... ---- .------------- ----- Ferrochrome slag444 Shungite-bearing slate 0.54 , 07.5 Quartz sand90.5 87 83.5 Shungite

to participate in redox processes, contribute to the creation of a porous structure and refractory outer shell of schungite-bearing shale granules. Inside the granule, iron oxides react with shungite carbon, which results in the formation of CO and CO2 gases, foaming granules. These processes are very intensive at higher temperatures, which have a very positive effect on the improvement of knockout. Liquid glass mixtures, both from cast iron and from steel castings.

In tab. 2 shows the composition of the mixtures.

The properties of the mixtures are given in the table below. The optimality of the mixture in terms of the content of schungite-containing shale is confirmed by compositions 1-3.

Claims (2)

From the table. 3 data shows that the mixture according to the proposed invention with the addition of shungite-containing slate provides an improvement in the knockability of liquid-glass forms and rods, especially subjected to high-temperature effects in the region above 800 ° C, compared to the prototype mixture (mixture 8), and also facilitates the working conditions at operations. Table CoetagD KjO Na2O P.P.P. expansion agent, 58 1.51 2.504.77 12.7 T a b l and c a 2, wt.% -11 4 5678 I juSB ° I ° ISDi. 4 6555 ------- - ----- - - - ---- - - 44354 4444.0 88 86 88 86 90 1.0 Claims for the Invention Mixture for the manufacture of casting molds and cores, including refractory filler, liquid glass, ferrochromic slag and technological additive, characterized in that, in order to improve the embossability of the molds and cores, mainly from synthetic castings, shungite-containing slate as the technological additive at the following ratio of ingredients, feec.% : 178 Liquid glass4.0 - 6.0 Ferrochrome slag3.0-5.0 Shungite-containing slate0.5 - 7.5 Refractory fillerOs Sources of information taken into account during the examination 1.Popilov L.Ya. Tips factory technologist. Lenizdat, 1975, p. 32, 2. USSR author's certificate for application number 2627888/02, cl. In 22 C 1/18, 1978 (prototype.