SU577185A1 - Method of preparing water-resistant magnesium oxychloride cement - Google Patents

Description

(54) METHOD FOR PRODUCING WATERPROOF MAGNESIUM CEMENT Caustic dolomite95-97 Heat-treated superphosphate 5-3 Solid magnesium sulfate salt 8-12 (over 100% in terms of anhydrous magnesium sulphate). The composition of cement with the addition of electrothermophosphoric slag is as follows, weight. Caustic Dolomite 60-80 Electrothermophosphorus Slag 40–20 Solid magnesium sulphate salt (over 100% in the re-8-12 couple on the anhydrous magnesium sulphate salt). Cements, the indicated compositions obtained by the proposed method, produced samples by the method of semi-dry pressing with the following parameters: 5-8% Plot weight 800 - 850 kg / s Pressing pressure The test results of the pressed samples are given in the table. In addition to providing a mold, it also improves the decorative qualities of magnesian cement based on caustic dolomite and silica or phosphate additives. This is due to two reasons: salt electrolyte, introduced in the solid state, when the initial components are milled together, acts as a grinding intensifier (such as surfactants) and thus sharply reduces grinding oil, and, consequently, increases the whiteness of the cement. So, when grinding magnesia cement without a solid electrolyte salt, iron is up to 2%, and using solid salt-electrolyte, it is 0.2-0.25%, i.e. reduced by almost 10 times. The whiteness coefficient of the proposed method in this regard is 76-78%, which corresponds to grade 1 in whiteness, and in a known manner, 72%, which corresponds to grade 3 in whiteness. When introducing a dye into cement with a whiteness ratio of 76-78%, the chromaticity (i.e., decorative qualities) will be better than with a lower initial whiteness by a known method. When a salt electrolyte is introduced in the form of a solution, a special unit for control and preparation is required, as a result of which the solution becomes soiled and, therefore, when cement is mixed with this solution, its brightness decreases. With the introduction of salt in the solid state according to the proposed method, this disadvantage is completely eliminated, since the limit on the preparation of the solution is eliminated. The application of the proposed method in comparison with the existing ones provides the following advantages: it eliminates a special technological redistribution of the preparation and control of the salt electrolyte solution, which naturally reduces costs; provides the possibility of manufacturing products not only by the method of casting, but also by the method of pressing and improves their decorative properties, which significantly expands the area of use of such cements. The estimated economic effect in the production of cement by the proposed method on a specially created pilot plant is up to 100 thousand rubles per year.

Compressive strength of air storage samples after 3, 7 and 28 days of dolomite-superphosphate molded pressed

Dolomite - slag samples:

cast pressed

Coefficient of water resistance and softening after 1 and 6 months of storage for dolomite-superphosphate samples

cast

650, 780, 860

635, 762, 850 805, 815, 865

not manufactured

240, 460, 470

380, 400, 450 450, 560, 570

not manufactured

1.18; 0.91; 1.27, 1.15; 0.91

0.90 not manufactured

, Dolomite-slag specimens: cast

pressed white ratio,%

Claims (1)

1. USSR author's certificate 268964, class, From 04 to 9/04, 1970.