SU885178A1 - Method of producing gypsum mortar - Google Patents

Description

(5) METHOD FOR PREPARATION OF THE PLASTER SOLUTION

The invention relates to the production of gypsum solutions and can be used in the building industry for the production of gypsum products. A known method of preparing gypsum solutions, which includes mixing gypsum in a binder, water and additives. The closest to the proposed technical essence and the achieved result is a method of preparing a gypsum solution by mixing gypsum in a bladder water and an additive based on a condensation product of naphthalene sulfonic acid with formaldehyde. the amount of 0.1 by weight of the current rz. Nedrstatok method - long time setting solution (up to 3 hours). The purpose of the invention is to reduce the setting time of the gypsum mortar. The goal is achieved by the fact that in the method of preparing a gypsum solution by mixing HIPSOVOGO in a binder, water and an additive based on a naphthalene sulfonic acid condensation product with formaldehyde, 0.5 to 1.0% condensation of naphthalene sulfonic acid with formaldehyde is used as an additive. from weight to grievance. The condensation product of naphthalenesulfonic acid with formaldehyde has the following indicators: the content of the active substance is not less than 5, moisture is not more than 68, ash not more than 38 |, insoluble substances not more than 0.2%, iron not more than 0.02%, calcium - no more than 0.07%. The pH of a 2.5% aqueous solution of a 7-9 method is as follows. In contrast to the known method, not naphthalene-formaldehyde sulfonic acid (SNFS, but its sodium salt (NSCNFS)) is used, and in the proposed method, the additive is introduced with water, and in the known method by displacement, with solid anhydrite and only by subsequent mixing with water. This difference in the technology of preparation of the solution introduces substantially new properties of the mixture, since when a gypsum mortar is obtained by sequential displacement of SNFS, anhydrite, and only after that the water does not preserve the high plasticity of the composition and does not accumulate It accelerates the setting of the mixture. This is explained by the fact that the additive SNFS does not have time. Dissolve in the mixing water SNFS

semi hydrate 0,

0.47

0.5 0,

one

0,

1 (sdb)

hemihydrate 0,28

0.28

0.5 0.28 1 0.28

.1 (sdb)

Phosphogypsum 0.35

0.6 0.35 0.6 0.35

VDSS;

SDB - sulfite yeast brew

It follows from the table that the addition of NSSNFS leads to an increase in plastic and is used in a known method in order to facilitate the dissolution of other additives when mixing water with a dry mixture of these additives with anhydrite. Accelerating effect, plastifying, etc. other additives, rather than SNFS, at jjtoMNFS before, are a fairly strong acid, and the introduction of acid into gypsum solutions slows down their setting.

The specific amount of the additive, and the composition and properties are shown in the table. ,

12.5

10.5

8.5 10

9 20

7

AND

19 13 10 22

11 11

9 18

ten

125

111

91

150 150

 plaster solution and at the same time to accelerate the setting.

The application of the proposed method in the national economy will allow to increase labor productivity in the production of gypsum products, improve the manufacturability of gypsum solutions.

Claims (2)

1.Ratinov V.B., Ivanov F.M. Chemistry in construction. M., stroiizdat, 1977, p. 107, 109, 127, 2.Patent UK No. 132560; cl. On 04/13/28, 08/08/1973.