A metal collection solution according to an embodiment contains 48 wt % or more of HNO.sub.3, 6 wt % or less of HCl, and 5 wt % or less of HF. The metal collection solution can collect noble metals and can scan on a substrate. The metal collection solution can be used to collect the noble metals adhered to a surface of the substrate.

The present disclosure relates to hydrometallurgical methods for the isolation and recovery of platinum from rhenium-containing materials, and more particularly, from superalloys containing rhenium, platinum, and other metals. The disclosure also relates to apparatuses capable of carrying out the hydrometallurgical methods and the product streams generated from the methods and apparatuses.

Hydrometallurgical methods are described for the isolation and recovery of platinum from rhenium-containing materials, and more particularly, from superalloys containing rhenium, platinum, and other metals. In addition, apparatuses capable of carrying out the hydrometallurgical methods and the product streams generated from the methods and apparatuses are described.

Gold and silver are recovered selectively such that gold and silver are separated from non-silver and non-gold material within the scrap. Gold and silver are recovered from scrap material using mixtures of acids, in some instances. The mixture comprises nitric acid and at least one supplemental acid, such as sulfuric acid or phosphoric acid. The amount of nitric acid within the mixture are relatively small compared to the amount of sulfuric acid or phosphoric acid within the mixture. The recovery of gold and silver using the acid mixtures are enhanced by transporting an electric current between an electrode and the gold and silver of the scrap material. Acid mixtures are used to recover silver from particular types of scrap materials, such as scrap material comprising silver metal and cadmium oxide and scrap material comprising silver metal and tungsten metal.

Disclosed is a system for recovering metal from metal-containing waste liquid. The system includes a waste liquid storage unit, an extraction unit, and an electrolysis unit. The waste liquid storage unit is configured to store a metal-containing waste liquid. The extraction unit is in fluid connection with the waste liquid storage unit and includes an extraction device and a back-extraction device. The extraction device is configured to collect a target metal ion present in the metal-containing waste liquid, and the back-extraction device is configured to back-extract the target metal ion into a back-extracting liquid to form a metal compound. The electrolysis unit is in fluid connection with the waste liquid storage unit and the extraction unit, configured to reduce the target metal ion to a solid metal, or to dissociate the metal compound and deposit a solid metal.

The present invention is directed to a method for selectively recovering a mineral from an ore applying a promoter being a substituted ethylene diamine. Further, the present invention is directed to the use of said substituted polymeric alkylenediamine to separate a target mineral from an ore.

Disclosed is a process of leaching gold that can be inexpensively and efficiently carried out from a mixture containing sulfur and gold, typically from the material containing sulfur and gold that is an intermediate product recovered by the flotation method in the hydrometallurgical method. Specifically, disclosed is a process of leaching gold from the mixture containing elemental sulfur and gold, the process involving combining the mixture containing elemental sulfur and gold and an aqueous solution of hydroxide of one or more of metals of alkali metals and alkaline earth metals, the hydroxides reacting with elemental sulfur to form thiosulfate of alkali and/or alkaline earth metal, and the gold thereby being leached by reaction with the thiosulfate.

A method for separating an amount of osmium from a mixture containing the osmium and at least one other additional metal is provided. In particular, method for forming and trapping OsO.sub.4 to separate the osmium from a mixture containing the osmium and at least one other additional metal is provided.

A method for recovering precious metal from an acidic aqueous solution containing dissolved precious metal and free chlorine, comprising the following successive steps: (1) combining a salt of a non-precious metal present in a low oxidation state as a solid or as an aqueous solution with the acidic aqueous solution to consume the free chlorine and form an acidic aqueous mixture, and (2) adding non-precious metal to the acidic aqueous mixture formed in step (1) to precipitate elementary precious metal.

The present disclosure provides a three-dimensional alkynyl-containing porous aromatic framework polymer and a preparation method and use thereof. The polymer has a structure represented by Formula I: ##STR00001##
The preparation method includes: under a protective atmosphere, mixing tetrakis(p-bromophenyl)methane, 1,3,5-triethynyl benzene, a catalyst and an amine solvent, and subjecting to a Sonogashira-Hagihara coupling reaction to obtain the three-dimensional alkynyl-containing porous aromatic framework polymer having the structure represented by Formula I.