Abstract: A process for the selective separation of ferric iron from an aluminum fluoride aqueous solution containing ferric iron is effected by contacting said solution with an organic extractant phase consisting essentially of a mixture of a mono (higher alkyl-substituted phenyl) phosphoric acid and a di(higher alkyl-substituted phenyl) phosphoric acid dissolved in an inert diluent to thereby transfer the ferric iron to said organic extractant phase. The efficiency of the process is further improved by adjusting the aluminum fluoride aqueous feed solution to a temperature in the range of about 140.degree. F. to about 175.degree. F. prior to contacting it with the organic extractant phase, maintaining the temperature within this range throughout the ferric iron extraction stage or stages, then heating the resulting iron-depleted aqueous raffinate to a temperature higher than 195.degree. F., and then crystallizing aluminum fluoride trihydrate out of the raffinate at this higher temperature.
Type:
Grant
Filed:
April 10, 1978
Date of Patent:
October 30, 1979
Assignee:
Freeport Minerals Company
Inventors:
David J. Miller, Tadeusz K. Wiewiorowski
Abstract: A pigment composition for high build protective coatings material comprising special combinations of pigments selected from a first group consisting of low density pigments of smooth nodular shape having a maximum particle size of 325 microns with not less than 40% by weight retained on a 325 mesh screen and a second group consisting of pigments having a median particle diameter ranging from 0.5 to 20 microns and being shaped so that not more than 20% by weight of the particles have ratios of any two dimensions exceeding 10. The total pigment volume concentration of the coating material is not less than 40% and the total volume of both groups of pigments is not less than 75% of the total volume of pigments in the coating material with a blend of both groups containing from 20 to 95% by volume of the first group of pigments and from 5 to 80% by volume of the second group of pigments.
Abstract: Chlorine dioxide is generated very efficiently and safely by reducing a chlorate in a strong acid in the presence of a catalyst containing thallium ions together with palladium ions or silver ions.
Type:
Grant
Filed:
December 2, 1977
Date of Patent:
September 25, 1979
Assignee:
The Japan Carlit Co., Ltd.
Inventors:
Isao Isa, Morioki Shibuya, Makoto Ebisawa
Abstract: A copper-containing sulfidic material is dead-roasted at a temperature of at least 750.degree. C. and the resulting calcine is leached in a sulfuric acid solution to dissolve most of the copper in preference to any iron, nickel and cobalt in the material.
Type:
Grant
Filed:
April 10, 1978
Date of Patent:
September 18, 1979
Assignee:
The International Nickel Company, Inc.
Inventors:
Ashok D. Dalvi, Ramamritham Sridhar, Malcolm C. E. Bell
Abstract: A process for recovering tungsten from tungsten bearing ores comprises producing a concentrate from the ore and leaching the concentrate at atmospheric pressure in a strong mineral acid solution, for example, a solution of sulfuric acid, hydrochloric acid or nitric acid within a temperature range of from 40.degree. to 90 Centigrade for from one to four hours in the presence of an inorganic complexing agent, and adding an ammonium salt compound for precipitating the tungsten. The precipitate is then dissolved in Ammonium Hydroxide and the tungsten recovered as Ammonium Paratungstate.
Abstract: An improved process is described for producing titanium dioxide from ilmenite-type ore. The ore is digested with aqueous hydrogen fluoride, the resulting liquid mixture treated with a water-soluble oxidizing agent, and the ferric iron impurities, in the resulting digestion solution, at a pH between about 1.0 and 6.0, are extracted out with a mono-or dialkyl, or mono- or di-(alkylphenyl) orthophosphoric acid, such as di-(2-ethylhexyl) orthophosphoric acid. The remaining solution is treated with ammonium hydroxide to precipitate hydrated titanium dioxide which is then calcined to form pigmentary titanium dioxide. Alkali metal and ammonium salts of the organophosphoric acid are also useful in the process.
Type:
Grant
Filed:
December 8, 1978
Date of Patent:
September 18, 1979
Assignee:
Allied Chemical Corporation
Inventors:
Krishnamurthy Nagasubramanian, Kang-Jen Liu
Abstract: The metal value separation efficiencies of alkyl aromatic sulfonic acid in solvent-extraction processes are enhanced by the addition to the solvent-extractant of a fused ring aromatic N-alkyl triazole and, optionally, an aliphatic .alpha.-hydroxy oxime. Especially important applications for the improved solvent-extractant are in the separation and recovery of copper from iron, cobalt from nickel, copper from cobalt, cobalt from zinc, nickel from zinc, zinc from iron, nickel from iron, copper from nickel, copper from iron and copper fron zinc.
Type:
Grant
Filed:
March 31, 1978
Date of Patent:
September 4, 1979
Assignee:
King Industries, Inc.
Inventors:
Lawrence V. Gallacher, Rachelle M. Rydzik
Abstract: A process for treating an acid waste liquid containing Fe ions which has been used for acid washing of metallic materials or articles, comprising the first stage where an organic solvent (A) is added to the acid waste liquid to extract Fe ions, the second stage where an acid is added to the resulting acid waste liquid to convert chemical species of remaining metal salts and increase the hydrogen ion concentration followed by addition of an organic solvent (B) to recover the mineral acid of concern by extraction, the third stage where an organic solvent (C) is added to the resulting acid waste liquid to extract and recover other required mineral acids, and regenerating each of the organic solvents (A), (B) and (C) in respective stages.
Abstract: Addition of zinc naphthaleneformaldehyde sulfonate to concrete mix improves compressive strength. This sulfonate is effective in concrete mixes prepared with Type I, II and III cements.
Abstract: Scrap tin plate is detinned in a continuous process by conveying it through a detinning bath containing concentrations of sodium hydroxide and of sodium nitrate or sodium nitrite which are substantially higher than standard practice. The solution is heated to a temperature higher than is used in standard practice. With this relatively high concentration and temperature the tin reacts with the sodium salts in the solution to form sodium stannate, which precipitates out of the solution and is continuously separated therefrom in a centrifuge or filter press. The detinned scrap is rinsed with water as it emerges from the detinning bath and the used rinse water drains into the detinning bath to serve as a makeup liquid.
Abstract: A method for treating nonferrous metal hydroxide sludge waste to separate and recover the nonferrous metals therein wherein the waste is first mixed with an alkali hydroxide or carbonate, dried, and then roasted and the water-insoluble residue in the roasted material is treated with sulfuric acid to produce an acid-insoluble residue and a sulfuric acid solution containing copper, aluminum and chromium and thereafter, separating the copper from this solution by liquid-liquid extraction and thereafter, separating the aluminium, chromium, zinc and nickel from the remaining solution by separate liquid-liquid extraction steps.
Abstract: A method for extracting nickel from aqueous solutions thereof which contain large amounts of alkali metal ions by contacting the aqueous solution with an extraction agent comprising an organic solution of di-2-ethylhexyl phosphoric acid and naphthenic acid.
Type:
Grant
Filed:
January 25, 1978
Date of Patent:
July 24, 1979
Assignee:
Th. Goldschmidt AG
Inventors:
Wolfgang Muller, Lothar Witzke, Werner Gottfried
Abstract: A process for treating very dilute solutions containing ecologically noxious heavy metal ions, in which the solutions are made acceptable for return to the environment, and the typically valuable heavy metal present in the solution is recovered at an economic profit. The dilute solution is flowed through an ion exchange resin, as a cross-linked polystyrene having quaternary ammonium functional groups which hold the heavy metal ions, allowing an ecologically benign effluent to return to the environment or the water to be re-used in industrial processing. Typically, an alkali metal halide is subsequently placed in contact with the resin to recover the heavy metal ion for subsequent reduction to a solid.
Abstract: This invention relates to a process for separating rutile and ilmenite from ilmenite leach tails and is effected by treating the leach tails from an acidic leach to a flotation step whereby gangue is separated from the unreacted ilmenite and rutile. The latter is then roasted at an elevated temperature in a hydrous atmosphere to convert the ilmenite to a magnetic material. Thereafter the ilmenite may then be subjected to a magnetic separation whereby non-magnetic rutile may be recovered while the magnetic portion is recycled for further separation.
Abstract: Waste gases containing 15% or less vaporized chlorides are processed to recover chlorine values as HCl by filtration of particulate material followed by the adsorption of metal chlorides on carbon beds and subsequent hydrolyzing of the metal chlorides at a temperature of 100.degree.-150.degree. C. to form metal oxides and HCl. The remaining gases such as COCl.sub.2 are further hydrolyzed to recover aqueous HCl and then the gases are scrubbed and finally incinerated to provide a discharge to the atmosphere containing CO.sub.2, N.sub.2, H.sub.2 O, O.sub.2 and about 5ppm HCl.
Type:
Grant
Filed:
December 12, 1977
Date of Patent:
June 5, 1979
Assignee:
Aluminum Company of America
Inventors:
Lee G. Carpenter, Vito Cedro, III, Donald L. Kinosz
Abstract: This invention relates to an improvement in a process for purifying nitrogen trifluoride atmospheres generally contaminated with nitrous oxide, water, and dinitrogen difluoride. The improvement for extending adsorber life resides in reducing the dinitrogen difluoride content in the atmosphere to less than 0.03% by volume prior to passing the atmosphere through the adsorber.
Abstract: There is provided an improved process for the production of chlorine dioxide wherein an alkali metal chlorate a reducing agent, and a mineral acid are reacted in a vessel, and the salt crystals are separated from the generator crystal slurry.
Abstract: A process for recovering gold from a gold bearing liquor arising from a cyanidation process including the steps of treating the liquor with ozonized air or ozonized oxygen, adsorbing the gold values from the treated liquor on activated carbon, and recovering the gold values from the loaded activated carbon.
Abstract: The efficiency of a low actual hydrogen ion concentration chlorine dioxide producing process in which a chlorate and hydrochloric acid or hydrogen chloride are fed to a reaction medium in a single vessel generator-evaporator crystallizer is increased by the use of small quantities of methanol.
Type:
Grant
Filed:
April 4, 1978
Date of Patent:
May 15, 1979
Assignee:
Erco Industries Limited
Inventors:
Richard Swindells, Maurice C. J. Fredette
Abstract: The present invention relates to removal of chromate from an aqueous solution of an alkali metal chlorate and chloride, particularly sodium chlorate and sodium chloride in a selected ratio which has been obtained by the electrolysis of an aqueous solution of alkali metal chloride containing chromate in which the essentially chromate free aqueous solution of alkali metal chlorate and chloride contains the chlorate and chloride in essentially the same selected ratio. In the process the chromate containing aqueous solution of alkali metal chlorate and chloride is acidified with hydrochloric acid to a pH value not smaller than 0.5 and passed through an anionic ion exchange resin bed which has previously been saturated with alkali metal chlorate and chloride. The bed is then regenerated by passing an aqueous solution of an alkali metal hydroxide and alkali metal chloride therethrough to remove chromate therefrom.