| 摘要 |
FIELD: chemistry.SUBSTANCE: claimed is a method for the extraction of tungsten from scheelite. The introduction of an acid mixture, containing sulphuric acid and orthophosphoric acid, into a decomposition reactor, heating to 70-100°C and the addition of sheelite under control of a ratio of liquid and solid phases at the level of 3:1-8:1 l/kg are realised. Then, after 1-6 h of the reaction carried out are filtration and crystallisation of the obtained filtrate, which is compensated with sulphuric acid, consumed in the reaction for obtaining a crystal of phosphotungstic acid and a residual solution. After that, dissolution of the crystal of phosphotungstic acid in water is carried out with its conversion into a solution of ammonium tungstate, containing 200-300 g/k of WO. The said solution is used for the preparation of ammonium paratungstate. The residual solution after compensation with orthophosphoric acid and water to the initial level is directed to scheelite leaching.EFFECT: reduction of expenditures and reduction of tungsten loss.4 cl, 7 dwg, 1 tbl, 9 ex |
