Methods and systems for the extraction of metals from an aqueous feed solution containing the metal ions. The aqueous feed solution is contacted with one side of a hydrophilic membrane support while an organic liquid is contacted with an opposite side of the hydrophilic membrane support. Metal ions migrate from the aqueous feed solution through the membrane support and into the organic liquid. The metal ions may be re-extracted from the organic liquid using a strip solution. The steps of extraction and reextraction may be carried out in a system including two hollow fiber membrane modules that each include a plurality of hydrophilic polymer hollow fibers.

A method of purifying a high specific activity Sn-117m composition is provided that includes extracting an iodide complex of Sn-117m with an organic solvent from an acidic aqueous cadmium solution comprising a dissolved irradiated cadmium target, an acid, and a source of iodide. The organic solvent layer comprising the iodide complex of Sn-117m is substantially reduced in cadmium content. The Sn-117m may be back extracted into an aqueous solution.

The invention relates to a method for concentrating metals, in particular silver and/or tin and/or lead from scrap containing metal, by treating the material/scrap containing silver and/or tin and/or lead with a sulfonic acid of the formula RSO.sub.2OH in the presence of an oxidizing agent, wherein R can be an organic group or ammonia.

The invention related to the recycling field of waste printed circuit boards (WPCB), and especially involved a complete non-cyanogens wet process for green recycling of WPCB, which belonged to the field of recycle economy. In the invention, the process included that WPCB were broken by the jaw crusher, and then mixed copper powders and nonmetallic powders were separated by the method of air classification, the mixed copper powders were smelted and casted to get copper anode plates, the copper was purified by electrolytion, the valuable metals (such as copper, gold, silver, platinum and palladium, lead and tin) were recycled from the copper anode slime, and the waste water was recycled. The recovery ratio of all-metal was above 98%. The purity of the cathode copper was up to 4N level. The ratio of de-coppering was above 96%. The recovery ratio of gold was above 98.