摘要:
Disclosed is a method of recovering gold from an aqueous solution having a gold concentration of 10 mg/L or lower, using a plurality of extraction apparatuses for bringing the aqueous solution into contact with an extraction agent, arranged to configure a multi-stage extraction process, the method allowing the aqueous solution to continuously flow from the first-stage extraction process to the next-stage extraction process, while recycling the extraction medium used in each stage twice or more times for the extraction process of the same stage, without back extraction and reduction.
摘要:
A compound represented by General Formula (1) below, where R denotes a C1-C10 hydrocarbon group, Z denotes any one of a sulfide group, a sulfinyl group and a sulfonyl group, and n denotes an integer of 4 to 8 is described. A method for extracting metals and a metal recovery method using a metal extractant comprising the compound represented by General Formula (1) are also described.
摘要:
The invention relates to a method for recovering gold by solvent extraction from an acidic chloride-containing aqueous solution or from slurry containing gold-bearing solids using a diester-based reagent that is poorly soluble in water as organic extraction solution. In accordance with the method, gold is extracted extremely effectively, but other precious metals and many other metals quite sparingly. Gold is stripped from the extraction phase with pure water, from which the gold can be reduced either chemically or electrochemically.
摘要:
An improved process for producing stable, high purity alkali metal or alkaline earth metal ferrate salt products is disclosed. In this process, crude ferrate salts, after being precipitated and separated from a chilled mother liquor, are purified first with a chilled anhydrous, water miscible extraction solvent to remove residual process contaminants therefrom followed by chilled oxidation resistant rinse solvent step, miscible with said extractant, followed by a drying step so as to produce a stable, purified ferrate product which can be safely stored without special provisions. Both batch and continuous modes of operation are disclosed.
摘要:
Highly pure (>99.99%) aqueous solutions of gallium chloride are obtained by (i) liquid/liquid extracting an aqueous hydrochloric acid solution of gallium values with an organic phase which comprises a quaternary ammonium chloride extractant, (ii) separating the organic phase from the aqueous phase, (iii) selectively washing said organic phase by intimately contacting same with an aqueous solution of hydrochloric acid to remove any remaining impurities, whereby purified gallium values are transferred from said organic phase into an aqueous solution thereof, and (iv) then separating said organic phase from said resulting aqueous phase, whereby said aqueous phase comprises pure gallium chloride.
摘要:
Process for the practically total precipitation of precious metals from solutions which contain them, according to which said solutions are treated with carbon monoxide in the presence of a quantity of water or a primary or secondary alcohol at least equal in weight to the total quantity of precious metal present.
摘要:
Process for separating and recovering rhodium and/or iridium from the other precious metals (Pd, Pt, Ru, Os, Au, Ag), according to which a solution containing the precious metals in any form is treated for a time between 15 minutes and 10 hours with carbon monoxide in the presence of a quantity of water or primary or secondary alcohols at least equal in weight to the total quantity of precious metals present, the crystalline precipitate which forms, and which contains all the noble metals except Rh and Ir in a state of high purity is separated and the Rh and/or Ir are recovered practically totally from the solution.
摘要:
A process for preparing a high surface area zero valent rhodium in the form of small, hollow, porous agglomerates of rhodium particles by adjusting the pH of still heels from the hydroformylation reaction of unsaturated hydrocarbons with a base until a pH of from about 3 to 8 is attained, heating the still heel in the presence of water to a temperature of about 115.degree. to 175.degree. C until the rhodium separates, the ratio of water to still heel being from about 0.1:1 to 1:1 and recovering the rhodium in the form of small, hollow, porous agglomerates of rhodium particles.
摘要:
A process for the treatment of a concentrate of by-metals comprises heatinghe concentrate at between 1100.degree. C and 1500.degree. C, preferably at about 1300.degree. C, in a gaseous stream which comprises oxygen. The heating step is effected for a period of time sufficient to ensure quantitative removal of one or more of lead, arsenic, silver, bismuth and/or tellurium and the oxidation of ruthenium, rhodium and iridium to their oxides.
摘要:
Thin flat hexagonal silver crystals are formed by rapidly mixing at a temperature of 30.degree.-80.degree. C., a water solution of inorganic silver salt containing a chelating agent for ferric iron with a water solution of ferrous sulfate containing sulfuric acid and additional chelating agent. The preferred chelating agent is phosphoric acid, and the crystals which are formed are stabilized by the addition of a protective colloid such as polyvinyl alcohol.