SU767030A1 - Method of preparing potassium sulfate - Google Patents

Description

The indicated ratio of liquor in the mixture was selected according to research as optimal for high content of basic potassium sulfate (respectively, K2SO4) {respectively 85-98%), which provides the best conditions for recrystallization of technical potassium sulfate and obtaining high percentage purified.

Keeping the dissolution of technical potassium sulphate in a mixture of uterine sulphate solution and water, significantly unsaturated with potassium and magnesium chlorides, magnesium sulphates and calcium, makes it possible to reduce to the required standards the content of these salts in the newly crystallized potassium sulphate.

Fine filtration of the saturated sulphate solution before cooling and crystallizing the purified potassium sulphate from it provides a tolerable content of iron, heavy metals and water-insoluble substances.

Example. Take 10 kg of Cainite ore of the following composition,%: K 10.14; MD 5.7; Na 14.77; C1 29.29; SO4 30.55; HjO 8.93; insoluble residue 6.57, and by mechanical stirring at room temperature, displace within 3 hours from 18.5 kg of uterine sulphate solution containing,%: K 5.97; Md 2.71; Na 1.01; C1 5.57; SO 12.60; HjO 72.14. Then, for another 2 hours, the obtained shenitic suspension is allowed to stand.

The resulting chenite by filtration under a vacuum of separation: is eaten from the chenite liquor. In this case, 9.1 kg of chenite and 19.4 kg of puterine solution are obtained. Their compositions,%: filtered schenite - K 16.33; MD 4.82; Na 3.35; C1 8.91; S04 34.03; HjO 32.56; Puterine uterine solution - K 3.97; Md 3.33; Na 4.07; C1 15.72; S04 5.14; 67.70.

. The filtered schenite containing a lot of sodium chloride AND unbound KgS04 is washed with 1.8 kg of cold water and filtered again. At the same time receive 3.2 kg promvody and 7.7 kg of washed puffing.

The composition of this wire,%: K | 7.47; Md 5.35; Na C1 3.90; 33.53. The main part of the washed whelp in the amount of 6.3 kg is dissolved within 5 minutes at a temperature of 100 ° C. 14.8 kg of prepared 9.1% KCl solution. When complete dissolution of chenite is achieved, the resulting solution is cooled to 25 ° C.

The resulting sulphate suspension is maintained at room temperature. for 2 h, and then filtered under vacuum on a Buchner funnel.

As a result of phase separation, 2.6 kg of high-grade potassium sulphate and 18.5 kg of uterine sulphate solution are obtained.

The composition of the obtained wet potassium sulfate,%: K 35,78; MD 1.02; Na 0.07; C1 0.26; Voll 47.79; Fe 0.04; insoluble matter 0.09 and HjO 14.95; KjOcyx 50.65; in terms of dry substance: K2SO4 93.33; impurities of other salts of 6.67%.

Further, the obtained high-grade potassium sulfate in the amount of 2.6 kg is subjected to recrystallization, i.e. lead further the process according to the proposed method.

This amount of potassium sulfate is dissolved in a mixture of 16.5 kg of uterine sulfate solution from the recrystallization cycle and 2.6 kg of water (solution to water ratio 6.3) at a temperature of 95 ° C.

Salt composition of the uterine sulphate plant of this cycle,%: K2S04 13.28; Md Zots. 3.66; NaCl 0.04; N82504 0.08; 82.94.

As a result of dissolution, 21.7 kg of a saturated sulphate solution is obtained, which is thoroughly filtered on a fine filter on a model sand filter until a clear solution is obtained. Its salt composition is as follows,%: K2S04 18.63; WgS04 3.35; NaCt 0.04; H20 77.98.

The filtered solution is cooled to 20 ° C. As a result of crystallization, 1.5 kg of high-grade purified potassium sulfate and 19.8 kg of uterine sulfate solution are obtained. Of this amount, 16.5 kg of solution is used to prepare a mixture: water ": 6; 3: 1, used to dissolve technical high-grade potassium sulfate, and an excess amount of 3.3 kg in the main ore processing cycle is used to dissolve puppy.

The resulting potassium sulfate fully meets the requirements of the specification for purified potassium sulfate. Its composition,% (in terms of dry substance): K2S04 99.73; Md and Sa 0.18; C1 0.045; Fe 0.002; insoluble substances 0,043; Gylagi content 4.6% ..

Claims (2)

Invention Formula The method of producing potassium sulfate, which includes the interaction of chenite with potassium chloride and the separation of potassium sulfate from the mother liquor, characterized in that, in order to increase the purity of the target product, potassium sulfate is recrystallized by dissolving in the ratio of 5-7: 1, is subjected to fine filtration semi57670306 valuable solution followed by its crystalline-1. Patent-FRG N 2142114, cl. C O D 5/08, 1970. Sources of information 2. Patent of Germany N 1071066, cl. C 01 D 5/00, taken into account in the examination of Sh.05.57 (prototype).