METHOD FOR INTEGRATED TREATMENT OF INDUSTRIAL WASTE WATER FORMED WHEN PRODUCING EXTRA-PURE QUARTZ CONCENTRATE Russian patent published in 2013 - IPC C02F9/04 C02F1/60 C01B33/143 C01B33/18 C02F103/12 

FIELD: chemistry.

SUBSTANCE: invention can be used in production of extra-pure quartz concentrate which is one of the main sources of contamination by fluorine, chlorine and salts containing fluorine and chlorine. The method is realised via reactant treatment in two steps. The first step involves neutralisation of acidic waste water with 23% NH₄OH with separation of the SiO₂ precipitate and formation of NH₄F solution. At the second step, said solution is treated with 20% lime milk. The formed CaF₂ precipitate and previously separated SiO₂ precipitate are washed, dehydrated and removed from the process as end products. The 7-8% NH₄OH solution obtained after separating the CaF₂ precipitate and flush water are returned to the first step for reactant treatment of waste water to prepare the starting NH₄OH solution. The 7-8% NH₄OH solution formed at the second step is concentrated by evaporation to 23% and returned to the first reactant treatment step. The condensate obtained during evaporation is directed for preparation of 20% lime milk, washing the SiO₂ precipitate and into recycling cycle of the main production.

EFFECT: invention enables to cut the volume of discharge of industrial wastes into the environment, prevents formation of non-recyclable sludge and also reduces consumption of fresh water during production and enables to obtain high-quality products used in different industries.

3 cl, 1 ex