The present invention relates to a method for recovering vanadium and tungsten from a leach solution of a waste denitrification catalyst, and more specifically, to a method for recovering vanadium and tungsten from a leach solution of a waste denitrification catalyst comprising the steps of: recovering vanadium by adding acid and then adding a calcium compound to a leach solution of a waste denitrification catalyst to precipitate the vanadium; and recovering tungsten by adding acid and then adding a calcium compound to the remaining leach solution after recovering the vanadium to precipitate the tungsten.

The present invention provides techniques that selectively recover Re from reductive amination catalysts. In particular, the present invention allows Re to be recovered selectively relative to Ni, Co, and/or Cu, and particularly Ni, that are often present on reductive amination catalysts. The present invention uses a combination of oxidation and extraction techniques to selectively recover Re relative to Ni, Co, and/or Cu. Advantageously, the recovery is selective even when using aqueous solutions for extraction.

The present disclosure relates generally to systems and methods for recycling lead-acid batteries, and more specifically, relates to purifying and recycling the lead content from lead-acid batteries. A system includes a reactor that receives and mixes a lead-bearing material waste, a carboxylate source, and a recycled liquid component to form a leaching mixture yielding a lead carboxylate precipitate. The system also includes a phase separation device coupled to the reactor, wherein the phase separation device isolates the lead carboxylate precipitate from a liquid component of the leaching mixture. The system further includes a closed-loop liquid recycling system coupled to the phase separation device and to the reactor, wherein the closed-loop liquid recycling system receives the liquid component isolated by the phase separation device and recycles a substantial portion of the received liquid component back to the reactor as the recycled liquid component.

Method of removing cobalt deposits in a reactor for the cobalt-catalyzed high-pressure hydroformylation of olefins by treatment with aqueous nitric acid, wherein the reactor is at least partly filled with aqueous nitric acid and the temperature of the aqueous nitric acid is increased during the treatment.

A leaching agent composition, and a method of using the leaching acid composition to remove metal from catalyst material, are provided in which the leaching agent composition comprises oxidized disulfide oil (ODSO). Active phase metals and/or contaminant metals are removed, for example after typical oil removal and drying steps. Advantageously, ODSO, which is derived from a refinery waste stream, is used to replace and/or supplement commonly used leaching acid such as sulfuric or nitric acid to remove metals used in catalyst preparation or contaminant metals deposited onto the catalyst surface.

A process for recovering a metallic component from a hydrocarbon product stream is disclosed. The hydrocarbon product stream is subjected to a thermal oxidation. A process for preparing glycols from a saccharide-containing feedstock is additionally disclosed.

Disclosed herein is a method for extracting precious metals from supported catalysts. The precious metal in one embodiment is rhodium. The supported catalyst may be from equipment, such as a used catalytic converter. The method is carried out at low temperature, and does not require harsh conditions, such as the use of a strong acid. The method involves contacting the catalytic material with a polar molecule and a reactive gas.

The present disclosure relates generally to systems and methods for recycling lead-acid batteries, and more specifically, relates to purifying and recycling the lead content from lead-acid batteries. A system includes a reactor that receives and mixes a lead-bearing material waste, a carboxylate source, and a recycled liquid component to form a leaching mixture yielding a lead carboxylate precipitate. The system also includes a phase separation device coupled to the reactor, wherein the phase separation device isolates the lead carboxylate precipitate from a liquid component of the leaching mixture. The system further includes a closed-loop liquid recycling system coupled to the phase separation device and to the reactor, wherein the closed-loop liquid recycling system receives the liquid component isolated by the phase separation device and recycles a substantial portion of the received liquid component back to the reactor as the recycled liquid component.

The present invention provides a method for selective recovery of a valuable metal from a waste denitrification catalyst through alkali fusion, the method comprising the steps of: (a) adding an alkali metal to a waste denitrification catalyst, followed by mixing and alkali fusion, to generate a calcination product; (b) subjecting the calcination product to water-leaching to recover an alkali leachate and a residue; (c) adding a precipitator to the alkali leachate, followed by stirring, to recover calcium metavanadate (Ca(VO.sub.3).sub.2) or calcium tungstate (CaWO.sub.4) through precipitation; and (d) subjecting the recovered calcium tungstate to acid decomposition to prepare tungstic acid. Therefore, vanadium and tungsten can be recovered at high efficiency by a method in which a precipitator is added to a leachate, which is obtained by adding an excess amount of an alkali metal to a waste denitrification catalyst and carrying out calcination and water-leaching, and then a reaction rate is controlled.

Digestion of impure alumina with sulfuric acid dissolves all constituents except silica. The resulting sulfatesaluminum sulfate, ferric sulfate, titanyl sulfate, and magnesium sulfate for alumina contaminated with iron-, titanium-, and/or magnesium-containing speciesremain in solution at approximately 90 C. Hot filtration separates silica. Solution flow over metallic iron reduces ferric sulfate to ferrous sulfate. Controlled ammonia addition promotes hydrolysis and precipitation of hydrated titania from titanyl sulfate that is removed by filtration. Addition of ammonium sulfate forms ferrous ammonium sulfate and ammonium aluminum sulfate solutions. Alum is preferentially separated by crystallization. Addition of ammonium bicarbonate to an ammonium alum solution precipitates ammonium aluminum carbonate which may be heated to produce alumina, ammonia, and carbon dioxide. The remaining iron rich liquor also contains magnesium sulfate. The addition of oxalic acid generates insoluble ferrous oxalate which is thermally decomposed to ferrous oxide and carbon monoxide which is used to reduce the ferrous oxide to metallic iron. Further oxalic acid addition precipitates magnesium oxalate which is thermally decomposed to magnesium oxide.