SU779306A1 - Method of sodium chloride recovery from pickle - Google Patents

Description

(54) METHOD FOR ISOLATION OF COOKED SALT FROM A BREAST

one

The invention relates to the technology of isolation of salt from brines and can be used in the chemical industry for the integrated processing of polymineral ores.

A method of obtaining salt from brines is known, which includes pre-cleaning the brine to remove scale-forming calcium and magnesium salts, refining it and separating salt 1.

The disadvantages of the method are the necessity of pre-purification of the brine, as well as the loss of the valuable impurities of soluble calcium and magnesium salts contained in the solution of R. containing it discharged after separation of the salt.

There is also known a method for preparing common salt of crude brines, including evaporation of brine in the presence of priming gypsum to prevent scaling on the heat exchange surface, washing the resulting salt pulp from the seed In the upstream of the crude brine. Crude brine with seed content

fed to evaporation, the return of the seed eliminates the need for its constant entry into the process. Next, the washed salt pulp is divided into a filtrate and a finished product 2.

The disadvantage of the method is a large loss of sodium chloride with a discharged solution, which also contains valuable impurities of the soluble salts of potassium, magnesium and calcium sulphates.

ten

The purpose of the invention is to reduce the loss of salt.

The goal is achieved by the method of extracting table salt from brine, including its evaporation in the presence of primer - gypsum, washing the primer from the pulp in an upstream brine stream, followed by separating the salt from the filtrate, after evaporation from the pulp the solid phase is removed, which is then repulped, and the pulp is fed to

20 stage washing seed - gypsum.

The method is carried out as follows.

Claims (2)

A crude brine of salt containing impurities chlorides and sulphates of 3 77 potassium, magnesium and calcium is divided into two streams. One stream is fed to the evaporation into a four-unit compact installation, another is used to wash the salt from the seed of gypsum. The evaporation is carried out at 60-100 ° C in the Presence of 20-30 g / l of the seed of gypsum. As a result, salt pulp is obtained, containing 30–40% of the solid phase consisting of salt crystals and gypsum. The liquid phase of common salt contains impurities of soluble salts, the concentration of which in at least one of the components is close to saturation. The resulting salt pulp is fed to the separation, the result is a solution concentrated in admixture of soluble salts of chlorides and potassium sulfates, magnesium and calcium, and a mixture of crystals of sodium chloride and seed. It is supplied to the extraction of the price of chemical products - chlorides and sulphates of potassium, magnesium and calcium. The mixture of crystals repulping to a concentration of the solid phase of 50-60%, the resulting pulp is fed to the washing in a settling tank classifier. The washing is performed in the upstream of the crude brine supplied at a speed of 50-100 m / h in an amount of 2-5 m per 1 ton of salt. After washing, the pulp of salt with a concentration of the solid phase of 50-60% is thickened with shuyu shyu. After separation, a commercial product is obtained. The solution is fed to repulpable. This method, in comparison with the known, allows reducing losses of table salt by more than 2 times. Claims The method of isolation of salt from brine, including its evaporation in the presence of seed - gypsum, washing the seed from the pulp in the upstream brine with the subsequent separation of salt from the filtrate, about , in order to reduce the loss of table salt, after evaporation from the pulp, the solid-phase is separated, which is then repulped and the pulp is fed to the stripping stage of gypsum. Sources of information taken into account in the examination 1. A. Furman, S. Shreibman. Preparation and cleaning of brine. M., Himi, 1966, p. 24 2., Gonionsky V. Ts., Chernozubov V. B., et al. Obtaining table salt from concentrates of sea water. Sat Questions of atomic science and technology, series Desalination of saline waters, vol. 4, M., TsNIIatominform. 1973 (prototype).