| abstract |
The invention relates to hydrometallurgical ore concentrate processing, more specifically to loparite concentrate processing. The inventive method consists in grinding the concentrate in order to obtain a grain size of at least 0.075 mm, breaking down the loparite concentrate by nitric acid at atmospheric pressure and a temperature higher than 100 °C, thereby producing a hydrated cake of refractory metals and a nitrate solution of rare-earth elements, filtrating said hydrated cake and subsequent processing of the obtained products. Said invention is characterised in that the breaking down is carried out at an initial concentration of nitric acid in a pulp ranging from 300 to 500 g/l, a temperature of 105-110 °C and in the presence of catalysing additives of fluorine containing compositions in a quantity of 1.0 7.5 % in relation to the concentrate mass in terms of fluorine-ion. HF, NH4F, NH4HF2, NaF, CaF2 and mixtures thereof are used as the fluorine containing additives. |