US 4,226,819 AGranted

Method of producing Keramzit

OwnerRafik B. Oganesianinventor

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Abstract

A method of producing Keramzit by means of treating clay to form a clayey mass, subsequently granulating it, drying the granules at a temperature of 100.degree. to 150.degree. C., heat-treating the dried granules at a temperature of 200.degree. to 500.degree. C., calcining them in two stages-at a temperature at the first stage of 800.degree. to 1,150.degree. C. for 0.5 to 10 minutes and at a temperature at the second stage of 1,150.degree. to 1,250.degree. C. for 1 to 5 minutes, and cooling the Keramzit produced. The Keramzit produced according to the proposed method finds application in manufacturing all types of light-weight concretes. The method makes it possible to produce a light-weight Keramzit having a low bulk density from 100 to 400 kg/m.sup.3 and a strength on compression in a cylinder of from 3 to 22 kgf/cm.sup.2, and a high-strength Keramzit having a bulk density of from 550 to 1,100 kg/m.sup.3 and a strength on compression in a cylinder of from 37 to 200 kgf/cm.sup.2.

Claims4

Dependent claims

A method of producing Keramzit having a bulk density of 100-830 Kg/m.sup.3 from clay granules formed and dried at temperatures in the range of 100.degree. to 150.degree. C. and then treated at a temperature in the range of 200.degree.-500.degree. C. which comprises subjecting said granules to a two-stage calcination procedure comprising:

(a) in the first stage rapidly heating said granules from said treating temperatures to a specific first calcination temperature within the range of 800.degree.-1150.degree. C.;
(b) isothermally maintaining said granules at said first stage calcination temperature for from 0.5 to 10 minutes, the time and temperature of said first stage of calcination being such as to remove gaseous products from the upper layers of said granules and to form in said granule an outer oxidized zone the thickness of which depends on the duration of said heating;
(c) rapidly heating said granules in the second calcination stage to a specific second calcination temperature which is above said first calcination temperature and within the range of 1150.degree.-1250.degree. C.;
(d) isothermally maintaining said granules at said second stage calcination temperature for from 1 to 5 minutes, wherein said oxidized zone is converted to a clinker-like high strength crust and said nucleus swells;
and then
(e) cooling the resultant product.

3 more elements

Dependencies are inferred from the claim text.