Abstract: Iron metal values and titanium metal values may be recovered from iron and titanium bearing sources such as ilmenite by subjecting the source to a reductive roast followed by leaching of the reduced source with a halogen-containing compound. Thereafter, the iron halide is crystallized and separated from the soluble titanium halides. One portion of the iron halides is subjected to a reducing step to form metallic iron while a second portion is oxidized, the iron oxides being used to precipitate the titanium as titanium dioxide. The titanium dioxide may then be separated and recovered while the liquid portion is recycled to the leaching zone.

Abstract: A method of obtaining alumina of high purity from aluminous mineral containing impurities by attacking the mineral with a sulphuric acid liquor and separating the resulting liquor from a residue which remains after the attack, the steps of(a) mixing the resulting liquor with a liquor containing HCl and H.sub.2 SO.sub.4,(b) introducing HCl gas into the mixture,(c) cooling the mixture from step (b) to precipitate hydrated aluminum chlorosulphate crystals having the formula AlSO.sub.4 Cl.6-7H.sub.2 O,(d) separating the hydrated crystals of hydrated aluminum chlorosulphate from the mother liquor,(e) heating the separated crystals to a temperature that does not exceed 600.degree. C.

Abstract: Iron metal values and titanium metal values may be recovered from iron and titanium bearing sources such as an ilmenite ore by subjecting the source to a reductive roast after crushing the source to a desired particle size. The reduced source is then leached by treatment with a halogen-containing compound to form soluble titanium halides and iron halides. Thereafter the soluble titanium halide is precipitated by treatment with iron oxides such as ferric oxide and after separation from the soluble iron halides is recovered as titanium dioxide. The soluble iron halides are then crystallized by reducing the temperature of the solution and one portion of the crystals are subjected to a reduction step to form metallic iron. The other portion of the iron halide crystals is oxidized to form ferric oxide which is used to precipitate the titanium compound.

Abstract: Titanium metal values may be recovered from titanium and iron bearing sources such as an ilmenite ore by subjecting the source to an oxidation treatment and a reductive roast after having crushed the source to a desired particle size. The reduced source is then leached by treatment with a halogen-containing compound to form soluble titanium halides and iron halides. Thereafter the soluble titanium halide is precipitated as titanium dioxide by treatment with an iron oxide such as ferric oxide and recovered. The amount of titanium dioxide which is recovered is determined by the amount of reductant utilized in the reductive roast.

Abstract: Titanium metal values are recovered from a titanium bearing source such as an ilmenite ore by subjecting the source to a reductive roast and leaching the reduced source with a halogen-containing compound. Following this the soluble metal halides are separated from gangue and the pregnant leach liquor if treated with an iron oxide such as ferric oxide to precipitate titanium dioxide. The nucleation of the titanium dioxide may be improved by using a large excess of ferric oxide in the precipitation step. The improvement will thus result in an increased yield of the desired titanium dioxide.

Abstract: Titanium metal values may be recovered from a titanium bearing source such as an ilmenite ore by subjecting the source to a reductive roast, leaching the reduced source with a halogen-containing compound followed by crystallization of the iron halide impurity which is separated from the soluble titanium halide. The soluble titanium halide is then treated with an iron oxide to form titanium dioxide. The yield of titanium dioxide may be greatly improved by effecting the nucleation of the titanium in a manner which comprises adding the iron oxide to the solution without agitation. Upon completion of the nucleation reaction, the solids are then thoroughly dispersed before removing the solid titanium dioxide.

Abstract: A process for the recovery of sulfuric acid from waste sulfuric acid containing iron sulfate and from solid iron sulfate of high water content of crystallization which consists essentially of:A. concentrating waste sulfuric acid to an acid concentration of 25-55 weight percent, based upon the suspension, by removing water therefrom;B. mixing the concentrated acid of Step A with recycled concentrated sulfuric acid obtained from Step E to form a resultant acid mixture of acid concentration of 30-65 weight percent, based upon the suspension;C. adding said solid iron sulfate of high water content of crystallization to the acid mixture of Step B thereby obtaining iron sulfate of low water content of crystallization;D. separating the iron sulfate of low water content from the resultant sulfuric acid solution of Step C;E. concentrating the separated sulfuric acid solution of Step D to an acid concentration of 45-70 weight percent, based on salt-free acid, and recycling at least a portion thereof to Step B; andF.

Abstract: Rutile which has been separated from ilmenite during a process for obtaining titanium metal values may be recovered in a more simple manner by effecting the water wash of the solid rutile at a pH above about 7.

Abstract: An improved process is described for recovering TiO.sub.2, useful as a white pigment, from ilmenite-type ores, including the steps of digesting the ore with aqueous hydrofluroic acid, separating out iron impurities from the resulting solution, precipitating hydrated titanium dioxide from the iron-free solution with ammonium hydroxide, and calcining the precipitate to obtain pigmentary TiO.sub.2, wherein the improvement comprises subjecting aqueous solutions of by-product ammonium fluoride, formed in the process, to electrodialytic water-splitting to form an aqueous solution of ammonium hydroxide and an aqueous solution of hydrogen fluoride and recycling said aqueous ammonium hydroxide to the precipitation step and said aqueous hydrogen fluoride to the digestion step.

Abstract: Titanium metal values may be recovered from a titanium bearing source by roasting said source in a reducing atmosphere, leaching the source with aqueous hydrogen chloride at an elevated temperature, cooling and saturating the leached solution with gaseous hydrogen chloride to precipitate hydrated ferrous chloride, separating the precipitated ferrous chloride from the soluble titanium chloride, raising the temperature of the solution to precipitate the titanium, separating and recovering the crystallized titanium compound.

Abstract: A catalytic ilmenite reduction procedure is described which provides a magnetic fraction consisting of the iron and titanium values of the ilmenite ores and a non-magnetic gangue. The magnetic fraction, after solubilization of the reduced iron, provides beneficiated Rutile-type titania product with purity ranges from 80 to 95% depending on the grade of ilmenite starting material. The titanias are further purified by sulfation and a metathetical reaction to convert the titanyl sulfates to chlorides by CaCl.sub.2.

Abstract: A catalyst for reduction of nitrogen oxides in the presence of ammonia, which can be advantageously prepared by treating titanium slag with sulfuric acid at an elevated temperature, optionally followed by treatment with an alkali, and decomposing the resulting product while heating at a temperature of about 400.degree. to 700.degree. C and has a high catalytic activity with a long catalytic life and a high resistance to acid substances.

Abstract: A process for the joint production of titanium dioxide and sodium tripolyphosphate from ores of titanium and phosphorus, and from sulphuric acid, in which the titanium dioxide is produced by the "sulphate process" and the impure dilute aqueous solution of sulphuric acid resulting therefrom is concentrated and used in the initial attack of phosphatic ones to provide a solution containing vanadium and chromium which can be removed without requiring any preventive conversion. The resulting sodium phosphate is then converted to sodium tripolyphosphate in a known way.

Abstract: A reduction/chlorination process is provided for the treatment of titaniferous materials such as ilmenite ores. The chlorination is selective in that the titanium constituent of the titaniferous material is chlorinated, but there is no appreciable net yield of iron chloride from the iron constituent. Where other metals such as vanadium are present they may be chlorinated with the titanium. The reduction utilizes as the reductant an amount of carbonaceous material which, based on oxygen in the titaniferous material, is at least stoichiometric to produce carbon monoxide. The selective chlorination utilizes as the chlorinating agent either ferrous chloride (FeCl.sub.2) alone or certain combinations of ferrous chloride and one or more other chlorine-containing members, notably molecular chlorine (Cl.sub.2) and hydrogen chloride (HCl). The use of ferric chloride (FeCl.sub.3) as a part or all of the chlorinating agent is the equivalent of using a FeCl.sub.2 /0.5 Cl.sub.2 mixture.

Abstract: A reduction/chlorination process is provided for the treatment of titaniferous materials such as ilmenite ores. The chlorination is selective in that the titanium constituent of the titaniferous material is chlorinated, but there is no appreciable net yield of iron chloride from the iron constituent. Where other metals such as vanadium are present they may be chlorinated with the titanium. The reduction utilizes as the reductant an amount of carbonaceous material which, based on oxygen in the titaniferous material, is at least stoichiometric to produce carbon monoxide. The selective chlorination utilizes as the chlorinating agent either ferrous chloride (FeCl.sub.2) alone or certain combinations of ferrous chloride and one or more other chlorine-containing members, notably molecular chlorine (Cl.sub.2) and hydrogen chloride (HCl). The use of ferric chloride (FeCl.sub.3) as a part or all of the chlorinating agent is the equivalent of using a FeCl.sub.2 /0.5 Cl.sub.2 mixture.