The ore is leached with H2SO4 soln., and the solids removed, e.g. by filtration.Before the filtrate is used for winning uranium, an alkali is added to obtain pH 1.5- 3.5 in the presence of ferric ions providing a molar ratio(MR) of ferric ions/As above 1.0, so the As is pptd....
The ore is leached with H2SO4 soln., and the solids removed, e.g. by filtration.Before the filtrate is used for winning uranium, an alkali is added to obtain pH 1.5- 3.5 in the presence of ferric ions providing a molar ratio(MR) of ferric ions/As above 1.0, so the As is pptd....
To improve the sepn. of undissolved matter, gypsum (CaSO4,2H2O) is added simultaneously with the ore to an aq. leaching soln. (I( contg. sulphuric acid. The amt. of gypsum added to soln. (I) is pref. at least 10 kg/tonne of ore and leaching and sepn. are pref. carried out ...
at least 10 kg/tonne of ore; and leaching and sepn. are pref. carried out at 40-90 deg.C. The gypsum employed is pref. obtd. by adding CaO or CaCO3 to liq. effluents from which uranium has been removed. The invention increases the yield of dissolved U, and reduces the amt. of...