SU703963A1 - Self-solidifying mixture for manufacturing casting moulds and cores - Google Patents

Description

(ii4) CUSTOM MIXTES FOR THE MANUFACTURE OF CASTING FORMS AND RODS

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Bavki material of the specified type pyrophyllite or schungite in the following ratio of ingredients (in weight)

Liquid glass

Ferrochrome slag

Pyrophyllite or

shungit 0.8-1.3

Refractory fillerOther

Pyrophyllite A1,2.SU a, J / OH / 2. (PCT USSR) has the following physical and mechanical properties: specific gravity 2.66-2.90 g / cm, fire resistance 15 0-16tO C.

Shungite is a fossil material of shale origin and contains a significant amount of carbon in its composition.

The chemical composition of pyrophyllite and schungite is given in table. one.

Pyrophyllite and shungite are used in finely powdered state. -.

The optimum content of pyrophyllite is. 0.8-1, O wt., Schungite - e, 8-1.3 wt.

When contained and additives based on aluminum-containing mineral material below the lower limit, the required improvement in the knock-out of the molds and cores of castings is not achieved;

As liquid glass, it is preferable to use aqueous solutions of sodium silicate with a density of 1.42-1.7 g / cm with a modulus of 2.6-3.1.

The mixture is prepared as follows.

Sand, ferrochromic slag, bentonite and pyrophilic litt or shungite, i.e., are loaded into runners. all loose

materials, and mixing them carried out for 1-2 minutes, then water glass is introduced and mixing is carried out for another 2-3 minutes, after which the mixture is ready for use.

The invention is illustrated by the following example.

Self-hardening mixtures were prepared containing 5.5 wt. liquid glass weight. ferrochrome slag, various amounts of pyrophyllite and shungite (the rest is quartz sand). For comparison, a known mixture (2) was prepared with the same content of liquid glass,

ferrochrome slag and 2.5 weight. bentonite. The test results are shown in 13 tables. 2

From the data in Table 2, it follows that the mixture according to the present invention with the addition of pyrophyllite or shungite provides an increase in the strength of the forms and cores and the improvement of their knockability.

18.0 63.0-NDPYROFILLIT 28.0 70.0 0.7, 16 per, 52.39 Shungit

Table 1

0.2 0.5 0.8

Claims (2)

0.3 0.750.330.2 0.2 5-5077039 Claims of the Invention Self-hardening mixture for the manufacture of casting molds and cores, including a refractory filler, water glass, ferrochromic slag and up to 5 tons based on aluminum-containing mineral material of heavy metal and that, in order to increase the strength of the molds and cores and improve their knock-out from the castings, it contains, as an additive based on aluminum-containing mineral material, pyrophyllite or shungite in the following ratio of ingredients (wt.%): 5 Liquid glass 5.0-6, 0 Ferrochrome 3,0-i, 0 P 0.8-1.3 rofillit or shungite Other refractory filler Information Sources, n Tide into account in the examination 1.1. Foundry, 6, No. 2, p. 29-30. 2. Slevarenstvi%, 1967, 1 5, I 8, 309-303.