|
Match
|
Document |
Document Title |
|
|
4311679 |
Treatment of sodium tungstate leach liquor containing dissolved silica, phosphorus, and fluorine impurities
Basic sodium tungstate leach liquor is treated to reduce the concentration dissolved therein of silica, phosphorus and fluorine impurities in a process which comprises providing a small but...
|
|
|
4305754 |
Chromium recovery from scrap alloys
Disclosed is a process for recovering chromium, vanadium, molybdenum, and tungsten from secondary resources such as alloy scrap comprising a refractory metal and base metals such as cobalt nickel,...
|
|
|
4303623 |
Separation of trace molybdenum from tungstate solutions
Dissolved molybdenum is removed from sodium tungstate solutions by adding sulfuric acid to lower the pH value of the solution to between about 8 and about 5, adding to the sodium tungstate solution...
|
|
|
4303622 |
Chemical treatment of low-grade wolframite concentrate having high Mo/WO.sub.3 ratio
A process is disclosed for recovering tungsten and molybdenum values from tungsten concentrates containing molybdenum in an amount at least about one-twentieth of the amount of contained WO 3 . The...
|
|
|
4298581 |
Process for recovering chromium, vanadium, molybdenum and tungsten values from a feed material
Disclosed is a process for recovering chromium, vanadium, molybdenum, and tungsten from secondary resources such as alloy scrap comprising a refractory metal and base metals such as cobalt, nickel,...
|
|
|
4298582 |
Vanadium recovery from scrap alloys
Disclosed is a process for recovering chromium, vanadium, molybdenum, and tungsten from secondary resources such as alloy scrap comprising a refractory metal and base metals such as cobalt, nickel,...
|
|
|
4278644 |
Process for partitioning Mo and W from a mixed CaMoO.sub.4 -CaWO.sub.4 precipitate
Disclosed is a process for recovering chromium, vanadium, molybdenum, and tungsten from secondary resources such as alloy scrap comprising a refractory metal and base metals such as cobalt, nickel,...
|
|
|
4273745 |
Production of molybdenum oxide from ammonium molybdate solutions
Molybdenum is recovered from an ammonium molybdate solution containing phosphate anions by digesting in an ammonium molybdate solution at least one water-soluble compound of at least one metal...
|
|
|
4268486 |
Selective chromate removal from a chlorate solution
A method has been devised for removing hexavalent chromium from concentrated aqueous alkali metal chlorate solutions by reacting the solution with a hydrazine compound and separating trivalent...
|
|
|
4259297 |
Chromate removal from concentrated chlorate solution by chemical precipitation
A method has been devised for removing hexavalent chromium from concentrated aqueous alkali metal chlorate solution by reacting the solution with an inorganic sulfur containing compound and...
|
|
|
4255397 |
Process for removing tungsten from cemented tungsten carbide
In a process for recovering tungsten from cemented tungsten carbide, the tungsten carbide is oxidized to form an oxidized product and the oxidized product is digested in an aqueous solution of...
|
|
|
4211753 |
Recovery of molybdenum values from dilute solutions
Molybdenum is recovered from dilute, ammoniacal, molybdenum containing solutions by adding ferrous ions to the solution to precipitate an iron hydroxide-ammonium molybdate complex. The precipitate...
|
|
|
4207295 |
Processing of chromium ore
Method for the recovery of chrome hydrate or high purity Cr 2 O 3 from chromium ores by roasting the ore with Na 2 CO 3 and CaO, water leaching the roasted mass, precipitating aluminum...
|
|
|
4199551 |
Recovery of molybdenum and uranium from activated charcoal containing molybdenum and residual uranium
Molybdenum is separated from molybdenum-containing activated charcoal or char also containing small amounts of uranium obtained as a by-product in uranium leaching processes by stripping with an...
|
|
|
4168240 |
Process for the preparation of a chrome tanning agent and Glauber's salt
A process for the preparation of a chrome-tanning agent and Glauber's salt from sodium bisulphate contaminated with chromium compounds obtained as by-product from the manufacture of chromic acid...
|
|
|
4165362 |
Hydrometallurgical processing of molybdenite ore concentrates
An improved process is described for the hydrometallurgical liquid phase oxidation of molybdenum disulfide ore concentrates, in which the reactants include in the range of from about 0.12 to about...
|
|
|
4162294 |
Process for working up nonferrous metal hydroxide sludge waste
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,...
|
|
|
4157942 |
Method for recovery of metals from metal plating baths and neutralizing toxic effluents therefrom
Method for recovering metals from cyanide and hexavalent chromium plating baths comprising immersing plated articles in a reclaiming bath containing an aldehyde or an aldehyde percursor, and...
|
|
|
4140597 |
Method of recovering the component metals from sintered metal carbides
The disclosure is of a simple and economical method for recovering the component metals from a sintered metal carbide. The sintered metal carbide is employed as an anode and treated by electrolysis...
|
|
|
4139460 |
Method for decontaminating waste material from chromium mineral processing by wet treatment with sulphur
A method for decontaminating waste materials, wherein the residue of water leaching of the roasted chromium mineral containing water soluble hexavalent chromium compounds is wet ground and...
|
|
|
4115513 |
Processing of ammonium paratungstate from tungsten ores
To obtain highly purified, lamp grade ammonium paratungstate crystals from any of several different tungsten ores, the ore is reduced to finely divided status and slurried in heated HCl solution to...
|
|
|
4108596 |
Recovery of chromium values from waste streams by the use of alkaline magnesium compounds
A process and a product formed thereby for the recovery of chromium values from aqueous solutions (e.g., waste liquors) comprises contacting an acidic solution containing sulfate ion and trivalent...
|
|
|
4086150 |
Chromate removal by precipitation
Chromates are removed from aqueous alkali metal chlorate solutions by either of two processes. In the first process, a water-soluble sulfide is added to react with the chromate, and then a ferrous...
|
|
|
4083921 |
Purifying molybdenum flotation concentrates
Copper, iron, and lead impurities are removed from molybdenum flotation concentrates by mixing the feed concentrates with a nonvolatile chloride salt, heating the mixture to a temperature of from...
|
|
|
4080420 |
Leaching of tungsten values from tri (alkaline earth metal) tungstate
A process is provided for treating tri (alkaline earth metals) tungstates with an aqueous solution containing cations selected from ammonium, sodium and potassium ions and mixtures thereof, and...
|
|
|
4075278 |
Process for recovering molybdenum values from spent catalysts
A process of recovering molybdenum from waste products and particularly from spent catalyst based on active alumina and containing molybdenum compounds comprising mixing the spent catalyst with...
|
|
|
4075277 |
Process for recovering molybdenum values from spent catalysts
A process of recovering molybdenum in the form of molybdic acid from waste products and particularly from spent catalysts containing a support based on gamma-alumina wherein the molybdenum is in...
|
|
|
4072501 |
Method of producing homogeneous mixed metal oxides and metal-metal oxide mixtures
Metal powders, metal oxide powders, and mixtures thereof of controlled particle size are provided by reacting an aqueous solution containing dissolved metal values with excess urea. Upon heating,...
|
|
|
4054442 |
Method for recovering scheelite from tungsten ores by flotation
A flotation process for recovering scheelite from low-grade tungsten ores containing calcium-bearing minerals other than scheelite. Calcium oxide (lime) is added to an ore pulp together with a...
|
|
|
4045340 |
Method for recovering and exploiting waste of the chromic anhydride production
A process of recovering and exploiting wastes from chromic anhydride production, wherein the slurry comprising a water suspension of solid waste residue from chromic anhydride processing is...
|
|
|
4033867 |
Chromate reduction in aqueous medium
A method for reducing the residual chromate level in effluent waters comprising catalytic reduction of the chromate ion by hydrogen to the trivalent chromium state and removal of the chromium by...
|
|
|
4029733 |
Extraction of metals from sea nodules
The method comprises the steps of crushing of the ore, neutralization by a mixture of water and sulphuric acid, introduction of a controlled quantity of sulphur dioxide gas at a pH value between...
|
|
|
4018866 |
Metal carbonate recycle to reduction circuit in the cuprion process
A process in which copper, nickel, cobalt and molybdenum are recovered by direct leaching of comminuted raw manganese nodules after the nodules are reduced in a reduction circuit with an aqueous...
|
|
|
3991156 |
Process for treating molybdenite concentrates to produce a lubricant grade product
A simple, efficient and economical process for purifying molybdenum disulfide concentrates by contacting and digesting the molybdenum disulfide feed material with an aqueous acid solution...
|
|
|
3988418 |
Hydrometallurgical production of technical grade molybdic oxide from molybdenite concentrates
An improved hydrometallurgical method is provided for producing technical grade molybdic oxide from molybdenite concentrates. According to this method, the molybdenite concentrates are leached in...
|
|
|
3975495 |
Metals recovery from hydrochloric acid solutions
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,...
|
|
|
3969484 |
Process for recovering tungsten from alkaline leaching solution of tungsten ores
This invention relates to a process for recovering tungsten from an alkaline leaching solution of tungsten ores. This invention comprises adjusting the pH of an alkaline leaching solution which is...
|
|
|
3966569 |
Method of recovering metal from metalliferous waste
Metal can be recovered from metal-containing waste by means of liquid extraction processes. The waste is leached with sulphuric acid. The resulting metal sulphate solution is contacted with an...
|
|
|
3964901 |
Production of copper and sulfur from copper-iron sulfides
A hydrometallurgical process for treating iron containing metal sulfides for rendering iron and non-ferrous metal values active and amenable for selective extraction and separate recovery. Sulfur...
|
|
|
3965238 |
Method of recovering uranium
Uranium values are obtained from phosphate rock by acidifying phosphate rock containing uranium values and at least one other heavy metal with a mineral acid so as to obtain a crude acid, solvent...
|
|
|
3961029 |
Process for recovering chromic acid solution from a waste liquor containing chromic ions
From a chromate ion-containing aqueous waste liquor the chromate ion can be advantageously recovered in the form of chromic acid by the process comprising the steps of adding a reducing agent to...
|
|
|
3950131 |
Continuous method for reclaiming chromium hydroxide from spent chrome tanning liquors and re-use thereof in subsequent tanning
A continuous method is provided for reclaiming chromium compounds which heretofore were discharged as industrial waste from chrome liquor tanneries. The method includes continuous agitation of...
|
|
|
3939245 |
Process for the separation of tungsten and molybdenum
The known process of separating molybdenum from a tungsten-molybdenum containing alkaline solution has been improved by carrying out the chemical reaction between the solution treated with...
|
|
|
3937785 |
Treatment of chromium ore residues to suppress pollution
Method for treating solid ore residue obtained by production of chromium chemicals from chromite ore, to reduce leaching of chromium compounds therefrom after disposal, which involves reducing the...
|
|
|
3899568 |
Alumina removal from chromate leach liquors
This invention relates to an improvement in the method for removing dissolved aluminate from alkaline chromate leach liquor by acidification of the leach liquor to precipitate alumina hydrate which...
|
|
|
3896210 |
Method for recovering molybdenum from particulate silicate slags
Particulate ferrosilicate slags which contain oxides of metals such as calcium, magnesium and aluminum are treated to extract molybdenum values therefrom. The treatment includes oxidation of the...
|
|
|
3896209 |
Reduction of hexavalent chromium
Under acidic conditions the hexavalent chromium present in aqueous solutions is chemically reduced to trivalent chromium with hydrogen peroxide. This process is improved if the pH of the aqueous...
|
|
|
3887680 |
Process for recovering tungsten from tungsten carbides containing an iron group of metals
The process wherein tungsten carbide containing an iron group metal such as cobalt is oxidized to form a friable oxidation product, the oxidation product is ground and thereafter treated to recover...
|
|
|
3862908 |
Microspheres of urania and other materials
As compositions of matter non-agglomerating microspheres of oxides in the 5 to 500 micron size range. The particles have a uniform crystallite structure with a grain size of 1 micron or less, and a...
|
|
|
3857699 |
PROCESS FOR RECOVERING NON-FERROUS METAL VALUES FROM REVERBERATORY FURNACE SLAGS
The process includes selectively extracting metal values such as molybdenum and copper from ferrosilicate slags containing less than 5 percent by weight magnetite (Fe 3 O 4 ) into a molten...
|