SU1247343A1 - Method of isolating sodium,kainite and carnallite - Google Patents

Description

The invention relates to the treatment of brines containing chlorides and sulphates of potassium, magnesium and sodium, with the production of solutions of magnesium chloride and can be used in the processing of polymineral ores into chlorine-free potash fertilizers.

The aim of the invention is to increase the yield and purity of Cainite,

According to the proposed method of separating sodium chloride, kainit and carnallite from solutions, including evaporation of the solution, separating the sodium chloride that crystallized out at the same time, additional evaporation of the remaining solution at 60-80 ° C, separation of the resulting suspension of kainite, extinguishing the remaining solution with calcium chloride. of this solution, followed by the release of carnallite, the resulting kainitic suspension is heated to 90– before the separation of the kainit, at a cross-section of 1 ° C, and converted into After 10–60 minutes, Cainite is separated from the resulting suspension, and the solution is about: a step, and after the separation, potassium is supplied to potassium sulfate.

Heated to a temperature of 90-100 ° C and the conversion of Cainite suspensions obtained previously at 60-80 ° C leads to a significant increase in the yield of Cainite from the solution and an increase in its purity. This is achieved as a result of dissolution of potassium chloride at higher temperatures (90-100 ° C) and crystallization of an additional amount of kainite KCF-MgSO ЗЫ20 and leonite K SO -MgSO-4H O.

Conversion of kainitic suspensions at temperatures above is accompanied by the crystallization of poorly soluble langbeinite, which is not suitable for processing into chlorine-free potassium fertilizers, and at temperatures

By a known method 16,07

According to the proposed

85 60 20.15

below 90 ° C, the yield and purity of Cainite are reduced.

The duration of the conversion of the kainitic suspensions almost ends within 45-60 minutes.

The quality of the resulting converted kainitic suspensions is improved compared to the non-converted ones, resulting in larger crystals at higher temperatures.

Cainite solution after crushing kainit is fed to cooling to release potassium chloride.

An example is a Shenit solution after precipitating sodium chloride from it containing%: potassium 4.56; magnesium 4.74; sodium 3.05; sulphate ions 5.35; chlorine 18.72 and water 63.58, evaporated at 70 ° C with a specific removal rate of water 100 kg / (h) to contain 5.49% sulphate ions and 6.5% magnesium in solution. The kainitic suspension obtained at 70 ° C is heated to and converted at this temperature with stirring for 30 minutes. After conversion, the suspension is immediately (without cooling 1; h) separated into kainite and kainitic solution by settling and filtration. Cainite was sent to obtain chlorine-free potash fertilizers, and the kainitic solution was cooled and, after separation, potassium chloride was supplied for desulfurization.

The results of opi-s are presented in the table.

As the results of the table show, with the proposed processing technology, the yield and purity of kainite are increased due to more complete extraction from the solution of sulphate ions (magnesium sulphate and potassium sulphate), included in kainitum KC.G-MgSO and leonite KjSO MgSO 4HjO.

4.07

36.24

41.65

5.10

46.69

52.25

Note: Cainite yield is determined by recovery.

sulfate ions from solution to the solid phase. Cainite purity is the content of KCE-MgS04- in the solid phase. Evaporation is carried out at 70 C.

Compiled by L. Temirova:

Editor L.Povkhan Tehred-D.Bonkalo Proofreader M.Maksiminshynets

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VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, Projecto st., 4

Table continuation

Claims (1)

METHOD FOR ISOLATING SODIUM CHLORIDE; Cainite and carnallite, including evaporation of the solution, separation of the sodium chloride crystallized during this, additional evaporation of the remaining solution, separation of cainite from the resulting suspension, desulfurization of the remaining solution with calcium chloride and re-evaporation of this solution, followed by isolation of carnallite, characterized in that, in order to increase carnallite the degree of purity and yield of kainite, evaporation of the solution after separation of sodium chloride is carried out until the content of sulfate and magnesium ions in the solution is 3.5-9.00 and 5.5-7, 5 wt.%, Respectively, after which the resulting cainite suspension is heated to 90-100 ° C with stirring for 10-60 minutes, cainite is isolated from it, and the solution is cooled and, after separation, the potassium Florida is served for desulfation. SU. 1247343 with foam