Abstract: A hydrometallurgical process for the removal of arsenic and antimony from a so-called “dirty” copper concentrate (101) is described. The process comprises the following steps: Step 1: repulping (100) the “dirty” copper concentrate with an alkaline lixiviant (102, 103), and subjecting the “dirty” copper concentrate to an alkaline leaching process (“the Leach”) in a Leach reactor (110). The arsenic and antimony are dissolved in the Leach to produce a “clean” copper concentrate (138) and leach discharge liquor (132). Step 2: subjecting the Leach discharge liquor (132) to a lime treatment step (151) in order to regenerate (150) the alkaline lixiviant as well as precipitate an impurity rich precipitate (161) containing arsenic and antimony. Then the impurity rich precipitate (161) is separated (160) from the regenerated alkaline lixiviant (162). The impurity rich precipitate is washed and disposed of in an environmentally safe condition.

Abstract: A hydrometallurgical process for the removal of arsenic and antimony from a so-called “dirty” copper concentrate (101) is described. The process comprises the following steps: Step 1: repulping (100) the “dirty” copper concentrate with an alkaline lixiviant (102, 103), and subjecting the “dirty” copper concentrate to an alkaline leaching process (“the Leach”) in a Leach reactor (110). The arsenic and antimony are dissolved in the Leach to produce a “clean” copper concentrate (138) and leach discharge liquor (132). Step 2: subjecting the Leach discharge liquor (132) to a lime treatment step (151) in order to regenerate (150) the alkaline lixiviant as well as precipitate an impurity rich precipitate (161) containing arsenic and antimony. Then the impurity rich precipitate (161) is separated (160) from the regenerated alkaline lixiviant (162). The impurity rich precipitate is washed and disposed of in an environmentally safe condition.

Abstract: A hydro-metallurgical method 80 for the removal of uranium, thorium, radium, lead, bismuth and polonium and/or other radionuclides from a radioactive copper concentrate to produce an upgraded copper concentrate having lowered emission levels. The method comprises the step of: subjecting the copper concentrate to an acidic leaching process (NONOX leach) 120 using a sulfate and chloride containing lixiviant under electrochemically controlled conditions, to allow at least partial removal of one or more of the radionuclides to produce the lowered emission upgraded copper concentrate, wherein the leaching process is conducted at elevated temperature and under pressure to suppress boiling in the leaching process.

Abstract: A hydro-metallurgical method 80 for the removal of uranium, thorium, radium, lead, bismuth and polonium and/or other radionuclides from a radioactive copper concentrate to produce an upgraded copper concentrate having lowered emission levels. The method comprises the step of: subjecting the copper concentrate to an acidic leaching process (NONOX leach) 120 using a sulfate and chloride containing lixiviant under electrochemically controlled conditions, to allow at least partial removal of one or more of the radionuclides to produce the lowered emission upgraded copper concentrate, wherein the leaching process is conducted at elevated temperature and under pressure to suppress boiling in the leaching process.

Abstract: The present invention relates to the recovery of base metals, in particular but not exclusively copper, via integrated hydrometallurgical and pyrometallurgical processing of base-metal sulphides, in particular but not exclusively iron-containing base-metal sulphides.