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 geothermally powered aluminum production subsystem includes a geothermal system with a wellbore extending from a surface into an underground magma reservoir. A hopper receives a bauxite ore that is crushed and provided to a digestor. The digestor is heated by a heat transfer fluid heated by the geothermal system, and a product of the digestor is used to prepare aluminum.

A geothermally powered red mud processing system includes a geothermal system with a wellbore extending from a surface into an underground magma reservoir. Geothermal energy from the geothermal system is used at least in part to extract materials, such as iron, titanium, scandium, and others, from red mud that is the byproduct of an aluminum production process. The aluminum production process may also be powered by geothermal energy from the geothermal system.

Provided is a method for preparing rutile from acid-soluble titanium slag, including: grinding acid-soluble titanium slag; adding a sodium carbonate modifier, and performing microwave irradiation treatment in a microwave device; adding an ammonium bifluoride additive; and performing acid purification and calcination to obtain rutile. By means of a microwave heating mode, the equipment investment needed by the method is low, and the energy consumption is low. The purity of artificial rutile is more than 91%, byproducts are fewer, and the environmental pollution is low.

Disclosed herein is a novel approach to the chemical synthesis of titanium metal from a titanium oxide source material, such as a mineral comprising titanium. In the approach described herein, a titanium oxide source is reacted with Mg vapor to extract a pure Ti metal. The method disclosed herein is more scalable, cheaper, faster, and safer than prior art methods.

The present invention relates to a process for recovering a primary metal residue from a metal-containing composition.

Provided is a method for preparing rutile from acid-soluble titanium slag, including: grinding acid-soluble titanium slag; adding a sodium carbonate modifier, and performing microwave irradiation treatment in a microwave device; adding an ammonium bifluoride additive; and performing acid purification and calcination to obtain rutile. By means of a microwave heating mode, the equipment investment needed by the method is low, and the energy consumption is low. The purity of artificial rutile is more than 91%, byproducts are fewer, and the environmental pollution is low.

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.

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.