Abstract: According to the present invention there is provided a process for the agglomeration of titania slag particles comprising providing titania slag at a d50 particle size of below 106 ?m; mixing the slag particles with an organic binder; and agglomerating the mixture of the slag particles and organic binder into agglomerated particles with a d50 particle size in the range from 106 ?m to 1000 ?m. The agglomerated particles have a (TiO2 and FeO)/C mass ratio of more than 3.4. The invention also relates to such agglomated slag particles and a chloride process for the production of TiO2 wherein such agglomerated titania slag particles are used.

Abstract: Process for preparing TiO2 powders starting from a liquid comprising chlorinated titanium compounds, the process comprising: a) atomizing said liquid and reacting the atomized liquid with a flow of steam and air at a temperature of 100-250° C. for converting said chlorinated titanium compounds to titanium dioxide TiO2; b) the gaseous phase and the entrained TiO2 powders obtained from step a) are then fed to an oven operated at a temperature in the range 400-900° C. to remove the residual organic compounds and hydrochloridic acid from said powders.

Abstract: The present invention relates to a process for the production of intermediates useful in the processing of mineral sands and related materials characterized in that the process comprises:(a) dissolving a metal fluoride or metal chloride compound in an organic solvent; and either(b)(i) adding an ammonium fluoride to the metal fluoride or metal chloride compound dissolved in the organic solvent in step (a) to precipitate an ammonium fluorometallate from the organic solvent; and(ii) dissolving the ammonium fluorometallate from step (b)(i) in water and adding an alkali fluoride or an alkali chloride or an alkali nitrate to produce an alkali fluorometallate and an ammonium fluoride or an ammonium chloride or an ammonium nitrate; or(c) optionally adding the metal fluoride compound dissolved in the organic solvent in step (a) to an alkali fluoride dissolved in water or in aqueous hydrogen fluoride to produce an alkali fluorometallate directly.

Abstract: Titaniferous solid containing titanium (IV) oxide, for example ilmenite, is reacted with silicon tetrafluoride gas at 800.degree. C. or more and at a pressure of at least 1 atmosphere to produce titanium tetrafluoride vapor and silica. The vapor is rapidly removed from the reaction zone, preferably by rapid cooling to solid titanium tetrafluoride, at a sufficient distance from the reaction zone so as not to quench the reaction. The titanium tetrafluoride may be hydrolysed to produce titanium dioxide and hydrogen fluoride which is combined with silica to regenerate silicon tetrafluoride. It is preferred to pretreat the titaniferous solid by grinding and then roasting at 700.degree. C. to 750.degree. C. in air. Products of the reaction may be separated and purified by condensation and resublimation.

Abstract: An improved halogenator process and system is provided which significantly and economically decreases the level of impurities in the processing of various refractory metals and their halides and particularly hafnium tetrachloride which is condensed from gases produced by the chlorination of Zircon.

Abstract: Metal halides are ultrapurified by selective complexation with a complexing gent to form a charged first complex. A ligand forms an oppositely charged second complex with metallic impurities in the metal halide to be purified. A solution containing these complexes is then passed through an ion exchange column and the desired purified metal halide collected. The present method is particularly useful in the production of ultrapure metal halides, such as zirconium fluorinate, for metallic glasses.

Abstract: A process for reducing the amount of carbon monoxide emitted from a fluidized bed reactor for chlorinating titanium bearing material containing iron oxide comprising (a) feeding coke, titanium bearing material containing iron oxide, and chlorine to the reactor, the chlorine being fed to the reactor below the surface of the fluidized bed, (b) maintaining the feed rate of the materials in step (a) and the conditions of operation of the bed so that the iron oxide is substantially converted to ferrous chloride, and (c) feeding sufficient chlorine to the reactor at or near the surface of the bed to convert the desired amount of carbon monoxide to carbon dioxide.

Abstract: A process for recovering alkali titanium fluoride salts suitable for commercial use from spent pickle acid liquors containing titanium by adjusting the fluoride to titanium mole ratio to critical ranges, adding an excess of alkali metal salt, and gently agitating the resulting solution at a temperature of at least 22.degree. C. to crystallize out the alkali metal titanium fluoride salt. The resulting filtrate can be neutralized with lime to yield a much reduced quantity of environmentally safe solid wastes compared with current neutralization practices where a titanium salt is not first recovered. (Optionally, in some cases, the filtrate can be recycled back to the acid pickling operation.) The liquid waste from filtering the neutral solids is low in metals and fluorides and generally acceptable for discharge to public treatment systems.

Abstract: A process is disclosed for the regeneration of pickling solutions which contain ZrF.sub.4 by addition of a Na compound in which a charge of the pickling solution to be regenerated is analyzed and heated. The amount of Na required for the regeneration is determined in each case and is admixed with intense stirring. Then the mixture is cooled, the precipitated NaZrF compounds are separated and a regenerated pickling solution is recovered.

Abstract: The subject of the invention is a process for opening ores, particularly ores containing tantalum, niobium, zirconium and titanium, of the kind that includes the stages of leaching with mineral acids, solvent extraction, purification and separation of the products obtained, characterized by the fact that initially, instead of leaching with sulfuric acid and hydrofluoric acid being performed as a first stage, the original ore concentrate is melted together with fluorite (CaF.sub.2), followed by milling of the melting product obtained and subsequently leaching with concentrated sulfuric acid, followed by extraction of the soluble species using solvents, separation and purification of the products obtained.

Abstract: The process for purifying a contaminated chloro, bromo or iodo precursor salt of zirconium, hafnium or aluminum by means of providing a molten thermal body of one or more alkali or alkaline earth metal halides and the precursor salt containing impurities, maintaining the body at a temperature sufficient to volatilize the precursor salt away from its impurities while effecting a reducing condition in the body by means of a fluid, mobile reducing agent which is non-reducing of said precursor salt, and isolating the purified volatilized precursor salt from the body. The ultra purified isolated volatilized precursor salt can then be reacted with a fluorinating agent to produce the highly purified fluoride for use in optical fiber grade glass or the like.

Abstract: Heavy metal fluoride glasses are made by a process that requires high purity fluoride constituent compounds fluorinated oxides, or premelted glass cullet. The charge is placed in an enclosed furnace chamber having the ability of atmosphere control, heat control and position control of the charge. In particular, an inert, or nonreactive atmosphere or air is used in the furnace chamber as well as an oxygen-scavenging metal therein. The oxygen-scavenging metal at the high temperature produces a controlled oxygen partial pressure so that the air is essentially inert and non-reactive although the presence of a slightly oxidizing atmosphere is still required to produce the glass. The charge is rapidly raised to its fusion temperature and held at the temperature for a short time in proximity to an oxygen-scavenging material. The charge is immediately removed from the heating source and quickly cooled through the critical crystallization region. The total heating and cooling time being less than one hour.

Abstract: Process for the preparation of alkali metal fluotitanates by fluorination of a titanium ore, reaction with an alkali metal compound, precipitation and separation of the formed alkali metal fluotitanates, wherein the titanium ore is mixed with a hydrofluosilicate solution, the resulting suspension is evaporated at a temperature of 90.degree.-110.degree. C., the residue is subsequently taken up in water or in a mineral acid and the residue solution is neutralized with an alkali metal compound.

Abstract: The present invention relates to a method of producing a fluoride glass preform and/or fiber having a modified refractive index by heating the fluoride glass preform to a temperature that is above its glass transition temperature, but below its devitrification temperature; inserting a first electrode into the inner core of the preform and surrounding the outer perimeter of the preform with a second electrode of opposite polarity; means for generating an electromotive force; and applying an electromotive force through the first electrode and the second electrode which causes a movement of positive ions toward the electrode of opposite charge while simultaneously causing a movement of negative ions toward its electrode of opposite charge such that the movement of these ions results in a modification of the refractive index of the preform.

Abstract: Heavy metal fluoride glasses are made by a process that requires high purity fluoride constituent compounds, some of which are further refined by sublimation. Handling occurs in a protective atmosphere such as argon. The charge is placed in a sealed modified optical growth furnace having the ability of atmosphere control, heat control and position control of the charge. The charge is firstly raised to its fusion temperature, then to an admixture temperature, and finally to a higher temperature. The charge is immediately removed from the heating source and quickly cooled through the critical crystallization region. The total heating and cooling time being about one to two hours. The resulting glass ingot is partially annealed. The HMFG of (Zr or Hf)F.sub.4 -BaF.sub.2 -LaF.sub.3 -AlF.sub.2 consistently exhibits low levels of both light scattering and bulk OH contact, along with very reproducible hardness, thermal parameters, and UV and IR edge absorption behavior.

Abstract: The invention pertains to an entrained-downflow chlorination process of fine metalliferous ores particularly containing alkali and/or alkaline earth metals greater than about 0.3% by weight as the oxide. The process includes a quenching step following the chlorination step where the chlorinated products are quenched by liquid cooling fluid spray patterns adapted to prevent solidification of the alkali and/or alkaline earth materials onto the reactor walls. The chlorinator unit of this invention prevents disruption of the chlorination process due to presence of liquids or sticky particles and it contains a quenching spray means disposed below the chlorination zone in the entrained-downflow chlorinator unit, whereby the quenching sprays prevent reactor wall buildup.

Abstract: A method for preparing ultra-pure metal tetrafluorides in which 3d such as Fe impurities are separated from impure material by a combined vaporization-electrolytic separation procedure. Sublimation and distillation methods are disclosed in combination with electrolytic separation by both emf-series displacement (ESD) and direct melt electrolysis (DME).

Abstract: Process for the production of a nearly aluminum chloride-free titanium tetrachloride from titaniferous raw materials containing larger quantities of aluminum compounds in a fluid bed with the addition of a reducing agent. In the process, sodium chloride is added to or formed in the reaction mixture before the first condensation step. A sodium chloride/aluminum chloride complex is formed thereby, which is discharged together with the chloride mixture and separated from said mixture together with the metal chlorides of lower volatility. The maximum quantity of NaCl needed is 1 mole per mole Al contained in the titaniferous raw material and per mole of iron (III) chloride, calculated as FeCl.sub.3, that may form.

Abstract: A process is provided for recovering fluorine from dilute hydrofluoric acid solutions, such as waste scrubber solution obtained in the treatment of phosphates. The dilute solution is used to react with oxidic titanium material to solubilize the contained titanium and subsequently form, in the presence of potassium ions, crystals of K.sub.2 TiF.sub.6 which are commercially useful as a grain-refining agent in the manufacture of aluminum alloys.

Abstract: A process for regenerating a spent HF-HNO.sub.3 pickle which contains ZrF.sub.4, which comprises heating said spent pickle to above 40.degree. C., adding dissolved NaOH to said so-heated pickle, thereafter cooling said so-treated pickle to a temperature below 20.degree. C. whereby to precipitate Na.sub.2 ZrF.sub.6 and removing said Na.sub.2 ZrF.sub.6 from said so-cooled pickle whereby to regenerate the same.

Abstract: Using a self-supporting metal sponge ring compact in an Iodide Crystal Bar Cell, as opposed to a loose fill. The sponge ring is formed by compressing the metal into a self supporting sponge ring by any means including isostatic pressing or conventional ram pressing.

Abstract: Mercury is removed from gases containing mercury vapor by passing the gases continuously through a bed of activated carbon on which a halogen is adsorbed. The bed may have a thickness of at most 5 cm. The chlorine content of the active carbon is maintained between 5% and 12% by weight. This is preferably effected by adding chlorine to the gases in an amount such that the carbon is caused to absorb a quantity thereof which equals the quantity that is consumed during the adsorption of mercury.

Abstract: A reduction in the quantity of gelatinous solids which are formed in aqueous zirconium-fluoride nuclear reprocessing waste solutions by calcium nitrate added to suppress halide volatility during calcination of the solution while further suppressing chloride volatility is achieved by increasing the aluminum to fluoride mole ratio in the waste solution prior to adding the calcium nitrate.

Abstract: Vapor feed containing titanium tetrachloride and ferric chloride vapor is contacted with sodium chloride for complexing said ferric chloride as liquid sodium ferric chloride salt complex while leaving titanium tetrachloride as vapor residue. The salt complex is reacted with molecular oxygen for providing recovered chlorine gas product. Such gas can be recycled to said complexing operation for providing a high grade of chlorine and titanium tetrachloride-rich product. Substantially complete chlorination of ilmenite is a prime source of said vapor feed.