摘要:
There is described a process for the separation and purification of the platinum group metals from base metal out of acidic aqueous solutions. For this purpose there is used a substituted thiourea of the formulaR.sub.1 R.sub.2 N--CS--NH--CO--R.sub.3orR.sub.1 R.sub.2 N--CS--NH--COOR.sub.3as the precipitation agent. Preferably there are employed N,N-diaklyl-N'-benzoylthiourea wherein R.sub.1 and R.sub.2 are methyl, n-butyl, or n-hexyl.
摘要:
A method is described for precious metal recovery from acidic precious metal-cyanide solutions by means of a weakly-basic anion-exchange material comprising a polymeric felt incorporating radiation-grafted pyridinyl functional groups.
摘要:
A process for the hydroformylation of olefins which facilitates recovery of precious metal catalyst and which proceeds under mild conditions comprises using as catalyst a water-soluble complex of a platinum group metal, the reaction mixture including aqueous and organic phases and an amphiphilic reagent.
摘要:
The process comprises the steps of leaching the concentrate with hot hydrochloric acid and chlorine gas to dissolve most of the gold, platinum and palladium, treating the residue from the leaching step with an excess of an alkaline oxidizing agent to solubilize the ruthenium, slurrying the resulting solids in water, combining the precious metal values from the slurry with the liquor from the leaching step and releaching the resulting slurry with hot hydrochloric acid and chlorine. The leach liquor which is then separated from the remaining solids is a chloride solution which contains substantially all the platinum group metals and gold present in the concentrate.
摘要:
This invention relates to the separation and purification of the platinum group metals; more particularly it relates to the separation of mixtures of Pt and/or Pd from Rh and/or Ru.In more detail, the present invention relates to a process for the separation or purification of platinum group metals in which either platinum, iridium (IV) and/or palladium (II) are present in aqueous solution together with one or more other platinum group or base metals comprising the steps of:(a) adjusting the acidity, if necessary, to provide a pH less than 7;(b) contacting the said aqueous solution with an organic phase containing at least one nitrogen containing organic compound selected from the group consisting of primary, secondary and tertiary amines and quarternary ammonium compounds and at least one oxygen containing organic compound selected from the group consisting of alcohols, phenols and carboxylic acids;(c) removing from contact with the said solution the said organic phase now containing the platinum, iridium (IV) and/or palladium (II) extracted together with the nitrogen- and oxygen-containing organic compounds; and(d) contacting the organic phase obtained at stage (c) above with a strongly acidic solution and thus stripping the platinum, iridium and/or palladium from the said organic phase and obtaining an aqueous solution of the said metals.
摘要:
Residues are formed in the carbonylation of esters or ethers, particularly in the production of acetic anhydride or ethylidene diacetate. Such residues contain noble metal, typically rhodium, used as a catalyst, which must be recovered before the residues can be disposed of. The rhodium values are freed from the residues by treatment with amines, preferably primary aliphatic amines and/or hydrazine, thereby enabling the rhodium to be extracted by subsequent contact with an aqueous halogen acid.
摘要:
Metallic catalysts such as Group VIII metal complexes which are used in hydroformylation reaction for the production of alcohols from olefins will be found in the product mixture. The separation and recovery of these metal catalysts from the product mixture may be accomplished by treating said product mixture with a biphyllic ligand capable of forming a soluble complex with the metallic catalyst and thus can be removed from the desired product.
摘要:
Process for the recovery of the ruthenium present in an aqueous nitric solution, wherein the ruthenium is extracted in an organic solvent by contacting the nitric solution with an organic phase comprising an organophosphorous compound having at least one electron donor sulphur atom in the presence of a compound able to displace NO.sup.+ ions of the ruthenium complexes present in the nitric solution. Application to the recovery of ruthenium contained in a nitric solution obtained by dissolving irradiated fuel elements.
摘要:
9-Borabicyclo (3.3.1) noname (9-BBN), a relatively stable solid dialkylborane, can be used to reduce a wide variety of reducible chemical compounds, including both organic and inorganic compounds. The stability of the reagent greatly reduces the operating difficulties encountered with other dialkylboranes having similar reduction properties, which are thermally and hydrolytically unstable.
摘要:
A process for the separation and selective recovery of platinum and palladium values from an acidic aqueous medium which comprises contacting the medium with a mixed organic extraction reagent comprising a water immiscible organic solvent having dissolved therein an organically substituted secondary amine compound capable of forming complexes of platinum and palladium that are preferentially soluble in the organic solvent and whereby the contacting results in creation of an organic extract phase and an aqueous raffinate phase. After phase separation, palladium is selectively recovered by contacting the organic phase with an aqueous solution of an acidified reducing agent. Platinum is separately recovered by contacting the organic phase with an aqueous alkaline solution. The process may be employed as a method for concentrating solutions of platinum or palladium.