CS231045B1 - Processing method to convert vaste iron disulphate to that one with low water content esp.for pharmateutical purposes - Google Patents

Abstract

CiBtění waste sulfur ferrous after treatment ilmenitu No compounds titanium se it solves by heating bdpadu with conc. sirovou ky # selina, zředčný water and crystallization. Other kryatelien ^ e from water leads to FeSO 4. 7 HgO purity p. and. Drainage on sulfate ferrous E low content water fart farm # ceutical purposes ee done varem se mixtures ethanol and sirové acid.

Description

The invention relates to the production of pure ferrous sulphate with a water content formally corresponding to a mono- to dihydrate (hereinafter only low-iodine content), which is used for pharmaceutical purposes, from ferrous waste sulphate, not from the processing of ilmenite (FeTiO4) to titanium compounds.

The ferrous sulphate waste after treatment of the ilmenite with the titanium compound contains 30-90% FeSO4. 7 HgO, water, insoluble constituents, ferric sulphate and oxide, small amounts of organic matter, especially petroleum products, small amounts of other metals such as manganese and the rest of titanium, of the order of about 0.1%. In this form there is minimal use for him and therefore he usually deposits.

When attempting to treat the waste into pure ferrous sulfate, the main obstacle is that dissolution in water produces a strongly cloudy solution, which is very difficult to filter, even after the addition of sulfuric acid and conventional filtering agents, such as e.g. diatomaceous earth.

Crystallization of an imperfectly clarified solution results in a product which, with respect to titanium, is only slightly purer than the original.

The process according to the invention is characterized in that the waste ferrous sulphate is first mixed with conc. sulfuric acid to convert the heptahydrate to the monohydrate. The amount of sulfuric acid is selected such that a thin paste is formed which is heated to 80 to 150 ° C for 10 min to 2 hours (longer time is not a problem). Thereafter, the mixture is stirred with water at 65-70 ° C until it is largely dissolved. The solution thus obtained is easily filtered into a sparkling clear solution which is cooled to 0 to -5 ° C and the precipitated crystals are filtered off with suction.

Pure FeSO4 was obtained. 7 H ^ O, which already contains titanium only at the level of one to several thousandths, appreciate. Longer crystallization from water with a small addition of sulfuric acid (~ 0.03 mol / l) from a solution saturated at 60 to 70 ° C by cooling to 0 to -5 ° C results in a product (FeSO4.7HgO) with a titanium content of max. in tens of thousands of percent e which, in all other criteria, meets the usual requirements for ferrous sulphate heptahydrate,

P · ⁸ ·.

Both pure ferrous sulphate and the product obtained after its recrystallization can be used for dewatering non-sulfurized, low-water ferrites suitable for pharmaceutical purposes. It has been found that the efficiency of ethanol dehydration increases substantially when sulfuric acid is added to the reaction mixture. The required amount of ethanol is substantially reduced, the dehydration takes place in one operation and there is no need to use a stabilizer. It will be understood that the dehydration of the present invention may also be used for ferrous sulphate other than that listed above, provided that its purity meets the requirements of pharmaceutical purity. Dehydration alone is not a purification operation.

He did

Processing of ferrous sulphate to pure ferrous sulphate

To a 500 L boiler equipped with a stirrer and a duplicator was added 42 kg of sulfuric acid (96%) and 300 kg of ferrous sulphate waste, which was analyzed to contain 88% FeSO4, was gradually added with stirring. The mixture was heated at 90-100 ° C for 1 h.

A total of 290 L of water was then added in portions keeping the contents of the boiler at 65-70 ° C and 3 kg of diatomaceous earth, and the solution was filtered and the filtrate transferred to the same boiler. The filtrate was sparklingly clear. The contents of the boiler were gradually cooled down to -3 ° C while stirring. Excluded FeSO4. 7 HgO was separated in a centrifuge and washed with 50% ethanol,

Even pre-cooled to 0 ° C. The yield was 183 kg.

Example 2

Crystallization of pure ferrous sulphate

100 kg of the ferrous sulfate produced according to Example 1 was dissolved in 60 l of water to which 0.2 sulfuric acid was added at a temperature of 65-70 ° C. The solution was filtered β cooled with stirring at -3 ° C. Excluded FeSO4. The HgO was isolated as in Example 1. The yield was 75 kg of product, which according to the analyzes performed corresponded to the parameters declared for FeSO4. 7 HgO p.

Example 3

Production of low water ferrous sulphate for pharmaceutical purposes

100 kg of the ferrous sulfate according to Example 1 or 2 was mixed with 125 L of absolute ethanol (water content of 0.2%) and 0.5 kg of sulfuric acid was added to the mixture. The mixture was boiled under reflux for 2 h, then cooled to 18 ° C and the product was separated in a centrifuge, washed first with 80% ethanol and then with absolute ethanol. The yield was 61 kg of low water iron (II) sulphate, which at all points met the requirements for pharmaceutical chemicals.

Claims (1)

SUBJECT OF THE INVENTION A process for the treatment of ferrous sulfate sulphate into low water ferrous sulphate, in particular for pharmaceutical purposes, characterized in that the ferrous sulphate waste is heated for 10 minutes to 2 hours with sulfuric acid at a temperature of 80 to 150 ° C, the mixture is dissolved in water, It is filtered and left to crystallize and, after optional recrystallization from water, the crystals are heated with a mixture of ethanol and sulfuric acid.