Abstract: Titanium metal values may be recovered from a metal bearing source by subjecting the source to an oxidation step. The oxidized source is then divided, one portion being set to a reductive roast followed by leaching with hydrochloric acid. Thereafter, the remaining portion of the oxidized source is brought into contact with the leached solution whereby titanium dioxide is precipitated. The precipitated titanium dioxide is separated and recovered while the soluble metal values are treated for recovery thereof with a concurrent formation of hydrogen chloride, the latter being recycled back to the leaching zone.

Abstract: The red mud by-product of the Bayer process by which aluminum oxide is reed from bauxite as an aluminate, is digested with concentrated sulfuric acid or with sulfur trioxide gas to produce sulfates that can be leached out to the resulting mass with water. The solution is then heated at a pH of 1 to precipitate titanium oxide hydrate by hydrolysis. The remaining sulfates of the solution are then obtained in solid form by evaporation, or by precipitation with acetone, and the solid is then roasted to convert the aluminum and iron to the oxide. After leaching out the sodium sulfate with water, the aluminum and iron oxide are separated by the Bayer process, which works in this case even though x-ray diffusion patterns show that the aluminum oxide is mainly .alpha.Al.sub.2 O.sub.3.

Abstract: Titanium metal values may be recovered from a titanium bearing source by subjecting the titanium bearing source to a reductive roast followed by leaching the reduced source with a hydrogen chloride source. Thereafter the leached titanium bearing source is precipitated by contact with a metal oxide such as ferric oxide in which the metal is present in a highly oxidized state. The precipitated titanium dioxide is separated and recovered while the spent liquor is treated to form hydrogen chloride which may be recycled to the leaching zone with a simultaneous formation of the metal oxide for recycle to the precipitation zone.

Abstract: The present invention provides a method for recovering vanadium, niobium, tantalum and zirconium from vanadiferous residues arising from the chlorination of titaniferous ores. Such residues contain chlorides of these metals and/or titanium, aluminum, iron, chromium and manganese together with carbon and unreacted titaniferous ore. The method comprises first moistening these residues with water and then treating them with hot water for a sufficient period of time to extract substantially all the vanadium into solution which is separated from insoluble material comprising carbon and unreacted titaniferous ore together with substantially all the niobium, tantalum and zirconium.

Abstract: A process is disclosed which removes iron from ilmenite ore thereby rendering it suitable for use in the chlorination process for forming TiO.sub.2 from titanium ores. One advantage of the disclosed process is that the iron is removed from the ilmenite by a method which performs a reduction step in the sulfuric acid process for producing TiO.sub.2 from titanium ore.

Abstract: Production of titanium dioxide which is characterized by recovery of reusable H.sub.2 SO.sub.4, highly pure Fe oxide and hydroxide and fractional recovery of Mn, V and Cr, etc., from FeSO.sub.4. nH.sub.2 O and waste acid of 20 - 40% H.sub.2 SO.sub.4 containing abundant heavy metallic ions, which are by-produced in the production of TiO.sub.2 by dissolution of Ti raw materials such as ilmenite, steel production slag, such as electric furnace slag, convertor slag with H.sub.2 SO.sub.4.

Abstract: Minerals, for example, zirconium minerals, are subjected to a chemical process of comminution, in particular with the aid of strong acids. These acids dissolve the carbonatic and silicious cements which hold together the crystalline forms of different mineral species from one another, e.g., magnetic and non-magnetic species to render them amenable to further separation in a subsequent ore dressing stage, e.g., by high intensity magnetic separation. This process is operative as these cements dissolve in acid more readily than most of the other compounds of the ores. This separation was found to take place more effectively than by the usual methods of mechanical grinding and without the disadvantage of an unfavorable particle size distribution which results from grinding. It was found that the same process conditions also resulted in a particularly favorable removal of naturally occurring radioactive contaminants from the minerals, in particuar thorium and uranium.

Abstract: In the production of synthetic rutile from a titanium and iron-containing ore by reducing most of the iron(III) in said ore into iron(II) with a steam-containing gaseous reducing agent at a temperature of about 850.degree. to 1100.degree. C, followed by leaching to remove the iron(II) and iron(III) and drying of the residue, the improvement which comprises using as said reducing agent a gas containing hydrogen and steam and optionally at least one of CO and CO.sub.2 wherein the H.sub.2 + CO : H.sub.2 O + CO.sub.2 molar ratio of the reducing agent is between 0.36 and 1.8. The reducing agent may comprise a mixture of hydrogen and steam or it may be the partial combustion product of a hydrocarbon. Advantageously, the ore is oxidized at 550.degree. to 1200.degree. C prior to reduction. The reduction permits ready dissolution of the iron during leaching without risk of hydrogen evolution.

Abstract: Upgrading of titanium values in a slag such as Sorelslag by working up the lag such as by alkali salt roasting to render the slag leachable in a plurality of leaching stages to recover titania (and other) values of 94 to 97 percent purity useful in a sulphate or a chloride process for producing titanium dioxide.

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 small amount of sulfate ion is added to the hydrochloric acid leach liquor used to beneficiate ilmenite ore whereby fines or slime formation in the mother liquor is minimized or reduced and the color of the solid beneficiated ilmenite product is lighter.

Abstract: In the production of a solid-free solution of titanyl sulfate by digesting ilmenite or titanium slag with sulfuric acid, and filtering the resulting solid-containing solution of titanyl sulfate to separate the solids, the improvement which comprises filtering the solution under a pressure of about 1 to 16 bars to form a filter cake of a thickness of about 10 to 35 mm. The filter cake is washed with about 0.1 to 0.5 m.sup.3 of water per m.sup.3 of filtrate, the wash water is passed through the filter cake at a flow rate of about 0.1 to 1.2 m/h under a pressure of about 1 to 16 bars, and the filter cake is then squeezed to a solid content of about 50 to 70% by weight.

Abstract: The present invention provides a method for recovering niobium from a hydrochloric acid solution which contains niobium and vanadium and which may also contain other metals such as, for example, zirconium, titanium, iron, chromium and aluminum. Broadly, the method comprises heating such a solution at a low pH for a period of time sufficient to form a niobium-containing precipitate substantially free of vanadium. Preferably, the solution is heated in the presence of a small amount of sulfuric acid. The precipitate then is recovered from the solution.

Abstract: A continuous process for extraction of niobium, rare earths and thorium from niobium ore concentrates which includes digesting the ore with a hot solution containing 13 to 16 moles of sulphuric acid per liter, diluting the solution to a concentration of 10 to 13 moles of sulphuric acid per liter, separating the insolubles from the solution which includes alkaline earth sulphates and the sulphates of thorium and rare earths that are present, reducing titanium in solution to the trivalent state and diluting the solution to a concentration of 5 to 7 moles of sulphuric acid per liter, separating the precipitated niobium oxide and sulphates of thorium and rare earths, and then concentrating the resulting solution to the level desired for recycle to the digestion stage.