SU867908A1 - Charge for making refractory materials - Google Patents

Description

t

The invention relates to the manufacture of refractories and can be used to make refractory candles for growing single crystals using the Verneuil method.

The composition of the charge for the manufacture of refractories, containing as the main component alumina with the addition of clay or kaolin D3 and G21, is known. The use of these materials for the manufacture of refractory products for growing single crystals by the method of Verneuil is undesirable because of. a large number of additives of clay or kaolin.

The closest technical solution to the proposed is the charge for the manufacture of refractories DU comprising the following components, wt.%:

Electrocorundum

white (dimensions

grains

0.8-1 mm, content 35-37

Lives at least 99%)

Alundum powder 26-28 Technical alumina, calcined, ground, to a specific surface area of about

7000 CMVr26-28

Dextrin4.5-5.5

Water .4,5-5,5

. This mass has a high refractoriness and thermal resistance, but its use for the manufacture of fireproof candles for growing crystals by the Verneil method is difficult, due to the low ductility, which makes it impossible to design products using the drawing method. In addition, products from this mass require high firing temperatures (not less), which also significantly complicates and increases the cost of their manufacture. 3 The purpose of the invention is to provide the possibility of obtaining a refractory candle for growing single crystals by the Verneil method while simultaneously reducing the calcining temperature. The goal is achieved by the fact that the charge for the manufacture of refractory materials, including white electrocorundum with a grain size of 500-1000 µm, alumina with a specific surface area of 7000 cm / g, additionally contains microhard electrosphenous corundum, refractory clay and titanium dioxide in the following ingredient ratio, weight,% :. Electrocorundum / white with a grain size of 500-1000 µm Alumina with a specific surface of 7000 CMVr Micropowered corundum micropowder Refractory clay 2-4.5 Titanium dioxide 0.5-2 The mass is prepared and molded as follows. The mixture of ingredients is loaded into a mixer, stirred for 10 minutes, after which a 3% aqueous solution of methylcellulose in an amount of 11% on a dry basis is added. The resulting plastic mass is subjected to a double vacuum to improve the plastic properties. After that, the product (candles) is formed from the mass by the drawing method, the outer diameter of the candle is 14 mm, the inner diameter is 3 mm, and the length is about 500 mm. Stretched products are dried to a residual moisture content of not more than 0.5%, after which they are roasted in a chamber furnace with an aging at this temperature for at least 3 hours. The compositions and the properties of the resulting products are shown in Tables 1 and 2. IT Table

Electrocorundum white No. 50-80

Ground alumina to 7000 specific surface.

Electroplating corundum micropowder

Clay refractory clay

Titanium dioxide

Product properties

40

48

36 20

34

14

2 2

Claims (3)

Table 2 The proposed blend allows the manufacture of refractory candles by the drawing method, which simplifies the manufacturing technology of products. High refractoriness enables reusable use. vanilla candles for the growth of single crystals by the method of WörnEil. Claims of the Invention A mixture for the manufacture of refractory materials including white electrocorundum with a grain size of 500-1000 µm, alumina with a specific surface area of 7000 cm / ri, characterized in that, c. In order to make it possible to obtain refractory candles for growing single crystals by the WörnEil method while reducing the firing temperature, it additionally contains microplastic micropowderii. Ko Ok II 5 10 is pr, CL 20 No. N (pund, refractory clay and titanium with the following ratio of ingredients, wt.%: White electrocorundum with a grain size of 500-1000 μm40-55 Alumina with a specific surface of 7000 cm Vg30- 36 Micropowder of electroplating corundum 10–20 Clay refractory 2–4.5 Titanium dioxide 0.5–2 Sources of information that have been taken into account during the examination 1. US Patent No. 3959002, 106-65, 1976. 2. USSR author's certificate 385943, class C 04 B 35/10, 1970. 3. USSR author's certificate 165974, ipt. From 04 to 35/10, 1963 rototype).