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US 3,966,569 AGranted
Method of recovering metal from metalliferous waste
AssigneeMX Processor Reinhardt & Co. AB
InventorsHans Reinhardt, Harald Daniel Ottertun
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AssigneeMX Processor Reinhardt & Co. AB
InventorsHans Reinhardt, Harald Daniel Ottertun
Estimating the term…
Metal can be recovered from metal-containing waste by means of liquid extraction processes. The waste is leached with sulphuric acid. The resulting metal sulphate solution is contacted with an organic solution of a reagent, so as to extract iron and zinc to the organic solution. The organic solution is washed with sulphuric acid in two steps, viz. with weaker acid in the first step, so as to transfer zinc to the washing solution, and with stronger acid in the second step, so as to transfer iron to the washing solution. Zinc and iron have now been separated, and are recovered from the washing solutions in known ways, for example by crystallization. If the waste contains other metals, in addition to iron and zinc, additional selective liquid extraction processes are added, before or after the iron-zinc-extraction.
A method of recovering metal from solid metalcontaining waste, such as metal hydroxide slime, comprising leaching the waste with sulphuric acid to form a metal sulphate solution having a pH value of 0-5, contacting the metal sulphate solution in a liquid extraction process with an organic solution containing an organophosphorous acid to transfer iron and zinc from the metal sulphate solution to the organic solution, contacting the organic solution in a first washing operation with an aqueous solution containing 50-200 g/1 free sulphuric acid for selectively transferring zinc from the organic solution to said aqueous sulphuric acid solution, recovering zinc from said aqueous sulphuric acid solution, contacting the organic solution in a second washing operation with an aqueous solution containing 500-1000 g/1 free sulphuric acid for selectively transferring iron from the organic solution to said aqueous sulphuric acid solution, and recovering iron from said aqueous sulphuric acid solution.
Dependencies are inferred from the claim text.