摘要:
A process for making microporous structures that can be used as a catalyst support. The microporous structures have high porosity and high thermal stability, combined with good mechanical strength and relatively high surface area. The process is useful for making titanium dioxide for catalyst structures for use for fuel cells, sensors, electrochemical cells and the like.
摘要:
A hydrometallurgical process is provided for producing pigment grade TiO2 from titanium containing solutions. Generally, the solution is an aqueous solution. The process includes hydrolyzing the solution via complete evaporation in well-controlled conditions of temperature to form titanium oxide of well-defined characteristics. The hydrolyzing can be achieved by spray hydrolysis in a spray dryer. After hydrolyzing, the titanium oxide is calcined to transform the titanium oxide to the desired form of titanium dioxide. The titanium dioxide can be either anatase or rutile. Following calcination, the titanium dioxide is milled to provide the desired particle size distribution and then finished.
摘要:
A hydrometallurgical process is provided for producing ultrafine or nano-sized titanium dioxide from titanium containing solutions, particularly titanium chloride solutions. The process is conducted by total evaporation of the solution, above the boiling point of the solution and below the temperature where there is significant crystal growth. Chemical control additives may be added to control particle size. Nano-sized elemental particles are formed after calcination. The titanium dioxide can be either anatase or rutile. Following calcination, the titanium dioxide is milled to liberate the elemental particles and provide a high quality nano-sized TiO2 with a narrow particle size distribution.
摘要:
A hydrometallurgical process is provided for producing pigment grade TiO2 from titaniferous mineral ores, and in particular from ilmenite ore. The ore is leached with a hydrochloric acid, preferably a recycled solution at high hydrochloric acid concentration, to form a leachate containing titanium and iron chloride and a residue. The leachate may be filtered to separate the leachate from the residue. The leachate is cooled to a temperature sufficient to form crystals of FeCl2, which are separated from the leachate. The leachate may be subjected to a reduction step to reduce Fe+3 to Fe+2, before crystallizing. The leachate is subjected to a first solvent extraction to form a pregnant strip solution containing titanium and ferric ions and a raffinate containing ferrous ions. This strip solution is subjected to a second solvent extraction to form a second strip solution containing ferric ions and a raffinate containing titanium ions. The first strip solution may be subjected to an oxidization step before the second solvent extraction. The second raffinate containing titanium ions is hydrolyzed. The hydrolysis can be by water addition or spray hydrolysis. Iron chloride is converted to iron oxide and hydrochloric acid. All product streams containing chlorides are recycled, producing gaseous hydrochloric acid that is used for regenerating the leaching solution.