The present invention relates to a process for recovering metals from metal-bearing material, said process comprising the step of contacting the metal-bearing material with condensed phosphoric acid at a temperature of greater than 215° C. and less than 300° C. for a period of time sufficient to at least partially dissolve the metal-bearing material; to provide a leaching solution containing metal ions. The invention is applicable to a range of metals including the rare earth elements, as well as thorium and uranium. The invention is applicable to a range of metal-bearing materials, particularly phosphate minerals such as monazite and xenotime.

The present invention relates to a process for recovering metals from metal-bearing material, said process comprising the step of contacting the metal-bearing material with condensed phosphoric acid at a temperature of greater than 215° C. and less than 300° C. for a period of time sufficient to at least partially dissolve the metal-bearing material; to provide a leaching solution containing metal ions. The invention is applicable to a range of metals including the rare earth elements, as well as thorium and uranium. The invention is applicable to a range of metal-bearing materials, particularly phosphate minerals such as monazite and xenotime.

A method for recovering precious metal from an acidic aqueous solution containing dissolved precious metal and free chlorine, comprising the following successive steps: (1) combining a salt of a non-precious metal present in a low oxidation state as a solid or as an aqueous solution with the acidic aqueous solution to consume the free chlorine and form an acidic aqueous mixture, and (2) adding non-precious metal to the acidic aqueous mixture formed in step (1) to precipitate elementary precious metal.

A method for recovering precious metal from an acidic aqueous solution containing dissolved precious metal and free chlorine, comprising the following successive steps: (1) combining a salt of a non-precious metal present in a low oxidation state as a solid or as an aqueous solution with the acidic aqueous solution to consume the free chlorine and form an acidic aqueous mixture, and (2) adding non-precious metal to the acidic aqueous mixture formed in step (1) to precipitate elementary precious metal.

The present invention encompasses a method of selectively separating Ga from wastewaters with the aid of a dialysis method. This exploits the particular complexation behaviour of Ga, which forms an unstable tetrahalo complex. This forms only in the case of a sufficiently high halide concentration. Since the halide concentration becomes lower across the membrane, the Ga-tetrahalo complex breaks down in the membrane, as a result of which the Ga is retained. Other metals such as In and Fe do not show this behaviour, and therefore the tetrahalo complexes of these metals can pass through the membrane and hence can be selectively separated off.

The present invention encompasses a method of selectively separating Ga from wastewaters with the aid of a dialysis method. This exploits the particular complexation behaviour of Ga, which forms an unstable tetrahalo complex. This forms only in the case of a sufficiently high halide concentration. Since the halide concentration becomes lower across the membrane, the Ga-tetrahalo complex breaks down in the membrane, as a result of which the Ga is retained. Other metals such as In and Fe do not show this behaviour, and therefore the tetrahalo complexes of these metals can pass through the membrane and hence can be selectively separated off.

The invention relates to a composition and method for producing a solid extracting agent for extraction of scandium from sulfuric acid solutions. There is provided a solid extracting agent (Solex) for extraction of scandium from scandium-containing solutions comprising a styrene-divinylbenzene matrix with di-(2-ethylhexyl) phosphoric acid. The extracting agent further comprises tri-n-octylphosphine oxide, tributyl phosphate, isododecane, in the following ratio of components, wt. %: di-(2-ethylhexyl) phosphoric acid 32.0-37.5, tri-n-octylphosphine oxide 4.2-8.0, tributyl phosphate 0.8-1.7, isododecane 16.7-20.0, the remainder styrene-divinylbenzene, with the styrene/divinylbenzene ratio in the matrix equal to 75-80 to 20-25 wt. %. There is also provided a method of producing the Solex. The technical result is the production of a scandium-selective Solex with a high dynamic exchange capacity.

The invention relates to a composition and method for producing a solid extracting agent for extraction of scandium from sulfuric acid solutions. There is provided a solid extracting agent (Solex) for extraction of scandium from scandium-containing solutions comprising a styrene-divinylbenzene matrix with di-(2-ethylhexyl) phosphoric acid. The extracting agent further comprises tri-n-octylphosphine oxide, tributyl phosphate, isododecane, in the following ratio of components, wt. %: di-(2-ethylhexyl) phosphoric acid 32.0-37.5, tri-n-octylphosphine oxide 4.2-8.0, tributyl phosphate 0.8-1.7, isododecane 16.7-20.0, the remainder styrene-divinylbenzene, with the styrene/divinylbenzene ratio in the matrix equal to 75-80 to 20-25 wt. %. There is also provided a method of producing the Solex. The technical result is the production of a scandium-selective Solex with a high dynamic exchange capacity.

The present invention relates to a method for extracting a refractory metal selected from Nb, Ta, Mo, W and V, from a solid material comprising the refractory metal in an oxidised form, the method using a layered double hydroxide, and the use of a layered double hydroxide for extracting or purifying a refractory metal selected from Nb, Ta, Mo, W and V.

The present invention relates to a method for extracting a refractory metal selected from Nb, Ta, Mo, W and V, from a solid material comprising the refractory metal in an oxidised form, the method using a layered double hydroxide, and the use of a layered double hydroxide for extracting or purifying a refractory metal selected from Nb, Ta, Mo, W and V.