SU1567517A1 - Method of obtaining enriched carnallite - Google Patents

Abstract

The invention relates to the technology of processing natural carnallite into enriched and can be used in the potash industry. The purpose of the invention is to increase the product yield and reduce the content of the dust fraction. The method of obtaining enriched carnallite involves dissolving carnallite ore with a circulating mother liquor, clarifying the resulting saturated solution, and extracting enriched carnallite from it by vacuum crystallization in the presence of potash production — cyclone dust from potassium chloride drying ovens in an amount of 10-15 kg per 1 m ^{3 of} solution followed by classification and filtration of the finished product. 1 tab.

Description

This invention relates to the technology of processing natural carnallite into enriched and can be used in the potash industry.

The aim of the invention is to increase the yield of the product and reduce the content of the dust fraction.

According to the proposed method, at the stage of vacuum crystallization of enriched carnallite, cyclone dust from drying furnaces of potassium loride in an amount of 10-15 kg per 1 m solution is introduced into a saturated solution.

Cyclone dust of potassium chloride, waste of potash production, does not contain impurities of magnesium oxide and activates the process of growth of carnallite crystals. When dissolved, it binds with excess magnesium chloride, which leads to a decrease in its concentration in a saturated solution and to the intensification of the dissolution of carnallite

ore. As a result, the leaching of MgCh from the ore is improved, the yield of the product increases and the content of the dust fraction in it decreases.

Example I (according to the prototype method). The preparation of enriched carnallite was obtained by dissolving natural carnallite (average chemical soslav — 17.6% KCl; 31.2% NaCl; 22.0% MgCI2; 1.28% CaSO4; 3.0% insoluble residue) with a working stock solution (average chemical composition - 26.9% MgCI2; 3.8% KC1; 2.98% NaCl) in the ratio of 1: 2.5 at 108 ° C in auger solvent. The saturated solution was clarified from the clay and salt sludge in the sumps. In the clarified saturated solution (286 m), 6.3 tons of spent magnesium electrolyte (i.e., 22 solutions) were introduced under agitation in the form of powdered solid product with an average particle size of 1 mm. Medium Chemistry

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cue composition of spent electrolyte - 64% KC1, 12.5% MgCb; 1% (CaSO4 + - (- Cac), 2.7% insoluble residue. The resulting suspension was subjected to vacuum crystallization. The product was classified, filtered and subjected to chemical and sieve analysis. The resulting enriched carnallite (32.1% MgCl2 0.03% CaSO4, 2.9% L) conforms to the requirements of GOST 16109-70, the average crystal size is 0.18 mm. The content of the pulverized fraction in the product is 28.3%. The yield of carnallite is 574 kg / ton of ore

Example 2 Preparation of enriched carnallite was carried out analogously to example 1. However, 2.29 tons of potassium chloride drying furnaces (i.e. 8 kg / m) were added to the clarified solution (286 MJ) with stirring. The average chemical composition of dust was 98.37% KS, 1.28% NaCl The obtained suspension was subjected to vacuum crystallization. The product was classified, filtered and subjected to chemical and sieve analysis. The resulting enriched carnallite (32.2% MgCh, 0.04% CaSO4, 2.9% H2O) met the requirements of GOST 16109-70, the average size of the crystals is 0.26 mm, the content of dust prominent fractions were 6.3%, yield carnallite 62.5 kg / t of ore

Example 3 Preparation of an enriched carnalite was carried out analogously to example 2. The amount of cyclone dust of potassium chloride introduced into the crystallized solution was 2.86 tons per 286 m3 of solution (i.e. 10 kg / m). The resulting enriched carnatite (32.2% MgCh, 0, 03% CaSO4, 2.9% H2O) met the requirements of GOST 16109-70, the average crystal size was 0.28 mm, the content of the dust-like fraction was 4.9%, the yield of carnallite was 653 kg / ton of ore.

Example 4 Preparation of enriched carnallite was carried out analogously to example 2. The quantity of cyclone dust of potassium chloride introduced into the crystallized solution was 3.6 tons per 286 m of solution (i.e 12.5 kg / m). The resulting product (32.1% MgCb, 0.04 % CaSO4, 2.8% H2O) complied with the requirements of GOST 16109-70, the average size of carnallite crystals was 0.29 mm, the dust content was 4.4%, the yield of carnallite was 662 kg / t

ore

Example 5 Preparation of an enriched carnalite was carried out analogously to example 2. The amount of cyclone dust of potassium chloride introduced into the crystallized solution was 4.29 tons per 286 m of solution (i.e 15 kg / m). The resulting product (32.0% MgCb, 0.04% CaSO4, 2.9% H2O) complied with the requirements of GOST 16109-70, the average size of carnallite crystals

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amounted to 0.30 mm, dust content 4.1%, carnallite yield 680 kg / t ore

Example 6 Preparation of enriched carnallite was carried out analogously to example 2. The amount of potassium chloride cyclone dust introduced into the crystallized solution was 5.73 tons per 286 MJ solution (i.e. 20 kg / m1) The resulting product (31.7% MgCl2, 0.04 % CaSO4, 2.9% H2O) did not meet the requirements of GOST 16109-70 on the content of magnesium chloride, the average size of the crystals was 0.31 mm, the content of the pulverized fraction was 4.0%, and the yield of carnallite was 684 kg / ton of ore.

Data on the increase in the average size of carnallite crystals, the content of the dust-like fraction and the yield of the product are given in the table.

As follows from the table, the greatest effect in the direction of increasing the size of carnallite crystals, reducing the content of the dust-like fraction and increasing the yield of the product is achieved by introducing potassium chloride drying ovens in the amount of 10-15 kg per 1 m solution into the crystallized cyclone dust solution

Reducing the amount of cyclone dust reduces the average size of the crystals and makes it difficult to further use it due to the large amount of dust fraction. If the amount of cyclone dust increases above 15 kg / m1 solution, the product does not meet the requirements of GOST 16109-70

Compared to the prototype, this method has the following economic advantages: enlargement of carnallite crystals, reduction of the dust fraction, increase in the product yield, utilization of potash waste — cyclone pushes drying furnaces of potassium chloride

Claims (1)

Invention Formula The method of obtaining enriched carnalite, which includes dissolving carnallite ore with recycled mother liquor, clarifying the resulting saturated solution, extracting the enriched carnallite from it by vacuum crystallization in the presence of an additive, classifying and filtering the finished product, characterized in that reducing the content of the dust fraction, as an additive at the stage of vacuum crystallization, use the waste of potash production - cyclone dust of potassium chloride drying ovens In the amount of 10-15 kg per 1 m1 solution Electrolyte Cyclone dust KC1 Cyclone dust KC1 Cyclone dust KC1 Cyclone dust KC1 Cyclone dust KC1 22 8 ten 12,5 15 20 28.3 6.3 4.9 4.4 4.1 4.0 574 625 653 662 680 684