METHOD FOR OBTAINING AMMONIUM SULPHATE Russian patent published in 2016 - IPC C01C1/24 

FIELD: chemistry.

SUBSTANCE: method for obtaining ammonium sulphate by neutralisation of subdump and quarry water of waste deposits of iron-copper-zinc sulphide ores, containing iron (III) sulphate, sulphuric acid and metal sulphates, with ammonia until pH of reaction mixture 4.5-5 is achieved, separation of obtained iron hydroxide Fe(OH)₃ sediment, after-neutralisation of filtrate with ammonia until medium pH 6.5-7 is reached; after-purification of ammonium sulphate solution at temperature 15-45°C for 0.5-1 hour by adsorption with modified carbon fabric, taken in weight ratio to ammonium sulphate solution, taken 1: 90-100; evaporation of ammonium sulphate solution and separation of crystals, their drying with obtaining dry product. Modification of carbon fabric is realised at temperature 80-90°C for 1-1.5 hour with 55-60% nitric acid, taken in weight ratio carbon fabric:nitric acid, equal 1:2.

EFFECT: invention makes it possible to increase product quality due to reduction of content of heavy metals.

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