SU7528A1 - The method of preparation of the basic compounds of calcium hypochlorite - Google Patents

Description

The invention relates to the production of basic calcium hypochlorites by the action of chlorine on milk of lime.

The inventors have found that a certain direction of the chlorinating process is able to provide stable basic calcium hypochlorite compounds on a technical scale and with a good yield.

The process is performed, for example, as follows: slaked lime and water are treated with chlorine in the usual way. After some time, precipitation of a solid of the main character begins, containing active chlorine, so that the mother liquor becomes poorer than active chlorine; with continued chlorination, the concentration of active chlorine in the mother liquor increases. Dropped solid

Consists exclusively of crystals of dibasic hypochlorite. Then stop the introduction of chlorine. The solid product is sucked off, centrifuged or pressed, separated from the mother liquor and dried at a temperature of, for example. 100 ° and above, without loss of chlorine.

When working on the proposed method, a product is obtained that corresponds to the formula: 2 Ca (OH) .2 Ca (OC1) Microscopic examination of well-formed hexahedral crystals of a precipitated body confirms the homogeneity of the product.

Further chlorination of the pasty mixture containing the dibasic body brings the concentration of active chlorine in the mother liquor to a certain extent, in relation to which a new decrease in chlorine is observed. If the chlorination process is further carried out before the secondary increase in the concentration of active chlorine in the mother liquor, then the reaction product, consisting almost exclusively of homogeneous monobasic calcium hypochlorite, is obtained as the main body. Microscopic examination of a compound precipitated in needle-shaped crystals indicates its uniformity. Further processing of the monobasic salt is performed in the same manner as the dibasic.

It is possible to use completely closed apparatus, which significantly pass through the bleach powder used so far and do not require special maintenance. The resulting products are superior in their qualities to common bleach, both in terms of the content of active chlorine, and, mainly, in terms of persistence. Compared with neutral calcium hypochlorite, they have an advantage in terms of strength and in production and technical terms, since they have a high resistance to high temperature and humidity.

The invention makes it possible, in addition to obtaining a homogeneous product of daubasic or monobasic calcium hypochlorite, to produce certain mixtures of these two bodies or a mixture of monobasic with neutral hypochlorite, i.e. with the desired content of active chlorine, because chlorination can be interrupted at the appropriate time of lowering the content of active chlorine in the mother liquor.

The content of active chlorine in the mother liquor, from which the main compound is isolated, varies with the concentration of calcium chloride in the mother liquor, i.e., the concentration of lime initially taken in the milk of lime.

The subject of the patent.

The method of preparing basic calcium hypochlorite compounds by chlorine on lime milk, characterized in that chlorination is stopped in order to produce two or one monobasic compound in the sediment when the concentration of active chlorine in the mother solution begins to increase, in order to obtain a mixture of both basic compounds in the sediment. or monobasic hypochlorite with a neutral one, chlorination is stopped when the content of active chlorine in the mother liquor begins to decrease, after which the resulting wasp ke basic compound or mixture is separated from the mother liquor in the usual manner.