A vanadium recovery process (10), the process comprising: (i) passing an ore or concentrate (12) containing vanadium, titanium and iron to a reduction step (18) forming a reduced ore or concentrate; (ii) passing the reduced ore or concentrate to a ferric leach step (22) to produce a ferric leachate (26) containing iron and a ferric leach residue (30) containing vanadium; (iii) passing the ferric leachate (26) to a ferric oxidation step (28) producing an iron product (68); (iv) passing the ferric leach residue (30) to an acid leach step (32) producing an acid leachate (44) containing vanadium and an acid leach residue (36) containing titanium; (v) Passing the acid leachate (44) to a vanadium recovery step (46, 48) from which a vanadium product is produced; and (vi) Passing the acid leach residue (36) to a titanium pigment production process (42) whereby a titanium dioxide pigment is produced.

A vanadium recovery process (10), the process comprising: (i) passing an ore or concentrate (12) containing vanadium, titanium and iron to a reduction step (18) forming a reduced ore or concentrate; (ii) passing the reduced ore or concentrate to a ferric leach step (22) to produce a ferric leachate (26) containing iron and a ferric leach residue (30) containing vanadium; (iii) passing the ferric leachate (26) to a ferric oxidation step (28) producing an iron product (68); (iv) passing the ferric leach residue (30) to an acid leach step (32) producing an acid leachate (44) containing vanadium and an acid leach residue (36) containing titanium; (v) Passing the acid leachate (44) to a vanadium recovery step (46, 48) from which a vanadium product is produced; and (vi) Passing the acid leach residue (36) to a titanium pigment production process (42) whereby a titanium dioxide pigment is produced.

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.

A production method includes: an alkali extraction step of adding an alkali and water, or an alkali solution, to raw material ash containing an ammonium sulfate component, sulfuric acid, vanadium, and at least one other metal selected from nickel, iron, and magnesium, wherein a pH of 13 or higher is achieved, to obtain an alkali leachate; a solid-liquid separation step on the alkali leachate to obtain a leach filtrate containing vanadium; an evaporation concentration step of evaporating and concentrating the leach filtrate to obtain a concentrated liquid; and a crystallization/solid-liquid separation step of cooling and crystalizing the concentrated liquid and recovering a precipitate containing a vanadium compound. Another production method includes an alkali extraction step, a solid-liquid separation step, an evaporation concentration step, an alkali concentration adjustment step of further adding an alkali or alkali solution to a concentrated liquid to obtain a concentration-adjusted liquid, and a crystallization/solid-liquid separation step.

A production method includes: an alkali extraction step of adding an alkali and water, or an alkali solution, to raw material ash containing an ammonium sulfate component, sulfuric acid, vanadium, and at least one other metal selected from nickel, iron, and magnesium, wherein a pH of 13 or higher is achieved, to obtain an alkali leachate; a solid-liquid separation step on the alkali leachate to obtain a leach filtrate containing vanadium; an evaporation concentration step of evaporating and concentrating the leach filtrate to obtain a concentrated liquid; and a crystallization/solid-liquid separation step of cooling and crystalizing the concentrated liquid and recovering a precipitate containing a vanadium compound. Another production method includes an alkali extraction step, a solid-liquid separation step, an evaporation concentration step, an alkali concentration adjustment step of further adding an alkali or alkali solution to a concentrated liquid to obtain a concentration-adjusted liquid, and a crystallization/solid-liquid separation step.

The present disclosure provides a method for co-extraction of vanadium, titanium and chromium from vanadium slag. The method selectively reduces pyroxene and fayalite wrapped on spinel through low-temperature hydrogen reduction, iron removal by ferric chloride, and low-temperature leaching of the vanadium slag by oxalic acid, thereby destroying a structure of the spinel, dissociating a spinel phase and a silicate phase, and fully exposing the spinel phase. The method also directly leaches the vanadium slag at a low temperature by acidity and strong complexation of the oxalic acid, and destroys the structure of the spinel, such that vanadium, titanium, chromium and oxalate are complexed into a solution to co-extract vanadium, titanium and chromium. The present disclosure extracts vanadium, titanium and chromium from the vanadium slag, with a leaching rate each being greater than 99%.

The present disclosure provides a method for co-extraction of vanadium, titanium and chromium from vanadium slag. The method selectively reduces pyroxene and fayalite wrapped on spinel through low-temperature hydrogen reduction, iron removal by ferric chloride, and low-temperature leaching of the vanadium slag by oxalic acid, thereby destroying a structure of the spinel, dissociating a spinel phase and a silicate phase, and fully exposing the spinel phase. The method also directly leaches the vanadium slag at a low temperature by acidity and strong complexation of the oxalic acid, and destroys the structure of the spinel, such that vanadium, titanium, chromium and oxalate are complexed into a solution to co-extract vanadium, titanium and chromium. The present disclosure extracts vanadium, titanium and chromium from the vanadium slag, with a leaching rate each being greater than 99%.

An improved method for recovering metals from spent catalysts, particularly from spent slurry catalysts, is disclosed. The method and associated processes comprising the method are useful to recover spent catalyst metals used in the petroleum and chemical processing industries. The method generally involves a combination of a pyrometallurgical and a hydrometallurgical method and includes forming a potassium carbonate calcine of a KOH leach residue of the spent catalyst containing an insoluble Group VIIIB/Group VIB/Group VB metal compound combined with potassium carbonate, and extracting and recovering soluble Group VIB metal and soluble Group VB metal compounds from the potassium carbonate calcine.

Embodiments relate to systems and methods for regenerating and recirculating a CO, H.sub.2 or combinations thereof utilized for metal oxide reduction in a reduction furnace. The reduction furnace receives the reducing agent, reduces the metal oxide, and generates an exhaust of the oxidized product. The oxidized product is transferred to a mixing vessel, where the oxidized product, a calcium oxide, and a vanadium oxide interact to regenerate the reducing agent from the oxidized product. The regenerated reducing agent is transferred back to the reduction furnace for continued metal oxide reductions.