SU835993A1 - Charge for ceramic articles and its production method - Google Patents

Abstract

Glazable non-porous ceramic articles having a mechanical strength >= to that of good quality porcelain are made by sintering at 900 degrees C opt. accompanied by simultaneous moulding an intimate mixt. of 26-60% quartz and 45-75% silica glass having a thermal expansion coefit. >8 x 10-6/degrees C and a transition temp. 550 degrees C. Spec., the quartz contains >90% SiO2, =5% Al2O3, =4% Fe2O3, =1% alkali metal oxides, =0.5% alkaline earth carbonates and =0.1% water soluble salts. The components are ground so that >50 wt.% is 10 mu dia. prior to moulding. The material can be used for tableware, sanitary ware etc.

Description

(54) CHARGE FOR CERAMIC PRODUCTS AND METHOD OF ITS MANUFACTURE and stirred for 10 min. The prepared mixture has the following grain size composition: 99.5 wt.% Below 60 µm, 98.5 wt.% Below 40 µm, 90 wt.% Below 20 µm, 75 wt.% Below 10 µm. -. X-ray inspection of the content of quartz in individual grain fractions showed that the ratio of the mixture of quartz sand and glass in separate fractions of grain deviates to less than ± 10% of the ratio in the total initial mixture; To 1 weight. finely ground mixture was added 0.15 weight.h. water and stir pestle. By subsequent wiping through a 0.5 mm sieve, further hemogenization is carried out. The mixture thus granulated is pressed by the usual for dry pressing method into cylindrical and rod-like products. Several molded. products are loaded into an electrically heated muffle furnace, heated to. and after holding for 3060 minutes, to equalize the temperature, the furnace is further heated at a rate of 2 C per minute to certain sintering temperatures. The results are given in table. 1. Table1 The molded products obtained after cooling the furnace with this kind of roasting do not show deformation. Their properties are given in table. 2. .Table2. :

95

h

Dense

Flexural strength (average of 10 tested staffs) kg.

I4,2lo44, 3-I0

Example2. Quartz sand specified in Example 1 and especially fused glass of chemical composition, in weight,%, was used as the starting material: L, O, - 6.3, V, O, 4, 6, CaO - 5.9, PHO - 3.4, ZnO - 2.7,, - 4.0, - 21.7 and SiO, .- the rest. . 45

10.1 10.2, 10.0

8.5

95

95

88

PlotPlotPs

980

1000

Special glass had a transformation temperature and a linear thermal expansion coefficient .10-o-4osLg 34.0 t

Pre-grinding of the starting materials was carried out as described in Example 1.

 41 wt.% Pre-crushed quartz sand and 59 wt.% Pre-crushed special glass are ground in a dry state together in a laboratory disk mill for 10 minutes. The mixture smoldered specified in the example, 1 granulometric composition.

To 1 weight. finely ground mixture was added 0.09 parts by weight of water, in which 0.009 parts by weight were suspended. polyvinyl alcohol and 0.02 weight.h. olein. Further preparation of the mixture and molding, as indicated in example 1, Molded products are loaded into an electrically heated muffle furnace, heated to 500 ° C, after holding for 30-60 minutes to level the temperature of the furnace and heated further with

Linear fire shrinkage, read on raw molded product,%

Density in the unbaked state, from theoretical density,

The result of the porosity test with the solution of fuchsin

Flexural strength (average value of 10 tested staffs) kg-cm

Linear thermal expansion coefficient

.four

d-5o-4oo c.

Froze The quartz sand mentioned in Example 1 and the so-called .Turingian bottle glass of chemical composition, wt.%: 6.0; CaO - 9.8; NagO - 15.1, 2, 5 And silica - the rest. This bottle glass has a temperature

heating rate per 1 min. The results of sintering are given in table. 3

Tablidaz

The molded articles that were crushed after cooling down the furnace were in impeccable condition. Their properties are given in table. four.

T a b l and. C and 4

10.3

10.0

10.2

95

95

93

Weakly Dense

Dense porous

850

.910

900

14j8.10 15.0-10 15.0-10

50 transformations. With and the linear coefficient of thermal expansion a 5o-4bos 10, degrees-.

Preparation of the starting materials follows as in example 1.

55

The properties of the sintered parts are given in table. five.

Linear fire protection, counting on raw bedding,

The density in the unbaked state, from theoretical density.

The result of the porosity test with the solution of fuchsin

Flexural strength (average value of 10 tested

-2

staff), kgsm

Linear coefficient thermal expansion

Claims (2)

Claim 1. Blend for ceramic products containing sand and glass, different from that, in order to increase the mechanical strength, density and obtain glazed porcelain-like products, it contains quartz, as raw material, enriched to oxide content. silicon 93-100% and glass composition, wt.%: aluminum oxide 1-10, oxides of alkaline earth metals .2-20, oxides of alkali metals 10-30 and silicon oxide - the rest, with the following ratio of charge components, wt.% :, : T a b l to c a 5 10.3 10.5 96 95 Dense Dense 950 960 14.3 ..10 14, Quartz raw materials25-60 Glass 40-75 2. A method of manufacturing a mixture for ceramic products including molding, waste and final calcination, cooling, and also with the fact that the final calcination is carried out at 700-900 C. Sources of information taken into account in the examination / 1. Budnikov P.P. Chemical technologists of ceramics and refractories. M., stroiizdat, 1972, p. 52-54 (prototype)