The ore is crushed and ground to liberate the mineral particles....

The ore is crushed and ground to liberate the mineral particles. It is then leached with sulfuric acid:

UO3 + 2H+ ====> UO22+ + H2O
UO22+ + 3SO42- ====> UO2(SO4)34-

The UO2 is oxidised to UO3.

With some ores, carbonate leaching is used to form a soluble uranyl tricarbonate ion: UO2(CO3)34-. This can then be precipitated with an alkali, eg as sodium or magnesium diuranate. Alkaline leaching is not undertaken in Australia at present.

Two methods have been used for concentration and purification of uranium: ion exchange and solvent extraction. Early operations in Australia used ammonium type resins in polystyrene beads for ion exchange, but solvent extraction is now in general use.

In solvent extraction, tertiary amines are used in a kerosene diluent, and the phases move countercurrently.

2R3N + H2SO4 ====> (R3NH)2SO4
2 (R3NH)2SO4 + UO2(SO4)34- ====> (R3NH)4UO2(SO4)3 + 2SO42-

"R" is an alkyl (hydrocarbon) grouping, with single covalent bond.

The loaded solvents may then be treated to remove impurities. First, cations are removed at pH 1.5 using sulfuric acid and then anions are dealt with using gaseous ammonia.

The solvents are then stripped in a countercurrent process using ammonium sulfate solution.

(R3NH)4UO2(SO4)3 + 2(NH4)2SO4 ====> 4R3N + (NH4)4UO2(SO4)3 + 2H2SO4

Precipitation of ammonium diuranate is achieved by adding gaseous ammonia to neutralise the solution (though in earlier operations caustic soda and magnesia were used).

2NH3 + 2UO2(SO4)34- ====> (NH4)2U2O7 + 4SO42-

The diuranate is then dewatered and roasted to yield U3O8 product, which is the form in which uranium is marketed and exported.

In situ leaching of sandy unconsolidated orebodies is being trialled in Australia (see UIC briefing paper # 40). At Beverley and Honeymoon, the uranium is recovered with weak acid leaching, oxygen being injected into each well. In the Beverley plant, the pregnant liquor then loads up a plastic ion exchange resin. The loaded resin is washed with sulfuric acid, hydrogen peroxide is added, and uranyl peroxide precipitated. With low temperature drying this becomes U3O8.

If you want to extract the Cu, then you do a subsequent Cu SX/EW. The Ni and Co you would use a Ion exchange resin as well. the lead and zinc and silver are not practically extractable given the relative solubility of their sulphate salts.