SU1346581A1 - Method of producing magnesium sulfate solution - Google Patents

Abstract

This invention relates to methods for producing a magnesium sulphate solution, which is an intermediate in the manufacture of magnesium compounds. The purpose of the invention is to intensify npoiu; ecca and increase the purity of magnesium sulfate. The method consists in the fact that magnesite is dissolved in sulfuric acid at pH 8.6-9, the feed rate of sulfuric acid is 1.5-2 kgf / kg MgO and a temperature of 80-85 ° C. Further into the reaction mixture in order to remove impurities from metals An aqueous suspension of bleach and two-water gypsum is injected at T: W 1: 3-4, followed by blending for 5-7 minutes. Moreover, two-water gypsum is introduced in an amount that provides its content in a solution of 0.07–0.25 equivalents per CaO of the initial content, and bleach in an amount of 1–1.1% of the stoichiometry of the active chlorine required for the oxidation of ferrous iron and manganese. . A solution of magnesium sulphate is obtained; craving, wt.%: MgO 6.93, CaO 0.189; traces, Oi traces, Mn traces. The processing time is 10-30 minutes. 2 hp f-ly, 1 tab. (L oo 4 cr 00 00

Description

production of magnesium sulphate, an intermediate in the production of magnesium compounds.

The aim of the invention is to intensify the process and increase the purity of the product.

The method is carried out by dissolving caustic magnesite in sulfuric acid with an excess of magnesite and a rate of introduction of sulfuric acid 1.5-2 kgf / kg MgO into an aqueous suspension of magnesite, providing a pH of the reaction medium of 8.6-9 and a temperature of 80-85 ° C. heat of reaction without external heating. Into the reaction mass, then an aqueous suspension of bleach and two-water gypsum is introduced in a T: W ratio of 1: 3-4. The amount of bleach is taken to ensure that the concentration of active chlorine is 1-1.1 of the stoichiometric value.

Example 1. Into a 10 m reactor, an aqueous suspension of caustic, magnesite composition is injected, wt%: MgO 83; CaO 2.5; FejOj 1.3; 1.1; SiOj 2.5; SOj-1,6; ppt the rest, with a ratio of 8 m. Sulfuric acid of 92 wt.% In the amount of 1250 kg at a rate of 1.5 kgf / kg MgO is fed into the reactor. Five minutes after the addition of the acid in the reactor, the pH is set at 8.6 and the temperature is 80 ° C. 0.005 m of an aqueous suspension containing 7 kg of CaS04 21120 and 10 kg of bleach is added to the reaction mixture. After 5.6 minutes

required for the oxidation of ferrous iron and manganese. The amount of the magnesium sulfate solution is separated from the two-water gypsum, which is a solid phase, and sent to the seed to crystallize the walnut. 8.4 m of CaS04 solution is obtained from the solution and collector for magnesium sulphate, improved filtration of precipitations, valuable hydro- parameters of the proposed method

iron (III) and manganese (IV) oxides are listed in the table.

zi

1 1 2 3

four

five

6

7

eight

9

ten

eleven

12

13

CaO content in feedstock. The solution is held for 5-7 minutes, the magnesium sulfate is separated from the precipitates of gypsum, manganese, iron, aluminum, and others, and sent for further processing. I

Example 1. Into a 10 m reactor, an aqueous suspension of caustic, magnesite composition is injected, wt%: MgO 83; CaO 2.5; FejOj 1.3; 1.1; SiOj 2.5; SOj-1,6; ppt the rest, with a ratio of 8 m. Sulfuric acid of 92 wt.% In the amount of 1250 kg at a rate of 1.5 kgf / kg MgO is fed into the reactor. Five minutes after the addition of the acid in the reactor, the pH is set at 8.6 and the temperature is 80 ° C. 0.005 m of an aqueous suspension containing 7 kg of CaS04 21120 and 10 kg of bleach is added to the reaction mixture. After 5.6 minutes

The magnesium sulfate solution is separated from the solid phase and sent for recycling. Get 8.4 m of magnesium sulfate solution, the parameters of the proposed method

13465814

Table continuation

The proposed method makes it possible to reduce the duration of the process up to 10-30 minutes versus 60-90 minutes according to the known, in addition, to reduce the content of Ca in the magnesium sulfate solution to 0.16-0.199 versus 1.5% according to the known other metals - to traces.

Claims (3)

1. A method for producing a magnesium sulphate solution, which includes dissolving magnesite in sulfuric acid and then purifying the resulting solution from metal impurities by precipitating it. by treating with a reagent, which is the case, in order to intensify the process and increase the purity of the target product, Magnesite rhenium is carried out at a pH of 8.6-9 and a feed rate of sulfuric acid of 1.5-2 kgf / kg MgO, and the resulting solution is purified by introducing an aqueous suspension of bleach and two-water gypsum, followed by holding the mixture for 5-7 minutes , with the two-water gypsum being introduced in an amount to ensure its content in the solution is 0.07-0.25 equivalent, CaO of the raw material. 2i The method of claim 1, wherein sulfuric acid is injected with a disadvantage of 20-25% by weight of stoichiometry. 3. A method according to claim 1, characterized in that the aqueous suspension of bleach and two-water gypsum is used at T: W 1-3: 4.