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.

Pyro-hydrometallurgical methods are described to economically and environmentally recover a target metal from iron slag or steel slag. For instance, the method can enable subjecting an iron or steel slag feed to acid-baking with an acid to produce a dried mixture comprising at least one soluble metal salts, then subjecting the dried mixture to water leaching to an aqueous solution comprising an aqueous leachate rich in said target metal and solid residues and subsequently separating the aqueous leachate rich in said target metal from the solid residues. This acid-baking water-leaching method facilitates efficient recovery of target metal compared to conventional methods.

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 invention relates to processes for the extraction of products from titanium-bearing materials or a composition produced in a process for the production of titanium dioxide, and more particularly, although not exclusively, extracting titanium dioxide and/or one or more other products from iron making slag.

The present invention relates to metallurgical processes, and more particularly to a process for producing titaniferous feedstock and fines, a process for agglomerating titaniferous fines, and a process for producing titaniferous metals and titaniferous alloys. Recovery of rare-earth, vanadium and scandium from titanium iron bearing resources is also disclosed. Selective leaching for Scandium recovery from all magnetite type resources such as ilmenite, ferro titanic resources, nickel laterites, magnetite iron resources etc.

The present invention provides a method for selective recovery of a valuable metal from a waste denitrification catalyst through alkali fusion, the method comprising the steps of: (a) adding an alkali metal to a waste denitrification catalyst, followed by mixing and alkali fusion, to generate a calcination product; (b) subjecting the calcination product to water-leaching to recover an alkali leachate and a residue; (c) adding a precipitator to the alkali leachate, followed by stirring, to recover calcium metavanadate (Ca(VO.sub.3).sub.2) or calcium tungstate (CaWO.sub.4) through precipitation; and (d) subjecting the recovered calcium tungstate to acid decomposition to prepare tungstic acid. Therefore, vanadium and tungsten can be recovered at high efficiency by a method in which a precipitator is added to a leachate, which is obtained by adding an excess amount of an alkali metal to a waste denitrification catalyst and carrying out calcination and water-leaching, and then a reaction rate is controlled.

Methods of producing high purity powders of submicron particles of metal oxides are presented. The methods comprise providing or forming an alloy of a first metal with a second metal, optionally heating the alloy, subjecting the alloy to a leaching agent to remove the second metal from the alloy and to oxidize the first metal, thus forming submicron oxide particles of the first metal. Collections of high purity, high surface area, submicron particles are presented as well.

A process for recovering metal value-containing precipitates in consistently high concentrations from a metal-containing composition by combining selective roasting and leaching steps.

Disclosed herein, is a process for recovering valuable metals and/or their oxides from red mud bauxite residues or similar. The process comprises: calcining a red mud residue having a pH of less than about 10 to provide a calcinated red mud residue; acid leaching the calcinated red mud residue to provide a silica rich solid component and an acid leachate; separating the silica rich solid component and the acid leachate; precipitating an iron rich solid component from the acid leachate; and separating the precipitated iron rich solid component from the acid leachate to provide an aluminium rich liquor.

Methods of producing high purity powders of submicron particles of metal oxides are presented. The methods comprise providing or forming an alloy of a first metal with a second metal, optionally heating the alloy, subjecting the alloy to a leaching agent to remove the second metal from the alloy and to oxidize the first metal, thus forming submicron oxide particles of the first metal. Collections of high purity, high surface area, submicron particles are presented as well.