Full Metal Extraction from Smelter Sludges (FUMES)

Purpose and goal

The aim is to develop an economical, technically feasible and environmentally friendly hydrometallurgical method for removing impurity elements enriched due to recycling and thereby enable full recycling of copper-containing residues and at the same time contributes to high raw material flexibility. In FUMES a possible integrated pressure leaching and selective precipitation method is investigated. The aim is transfer of copper into leachate and formation of two separate fractions rich in antimony and bismuth, and arsenic, respectively to be used for further metal recovery.

Expected results and effects

The developed method enables high copper yield, increased raw material flexibility and reduces the need for primary ore concentrates, which reduces the energy need for crushing / grinding. Fractions with high contents of critical raw materials such as antimony and bismuth as well as the fraction rich in arsenic can serve as raw materials for the production of these. Via results from laboratory experiments, the proposed process concept is validated and then evaluated technically, financially and environmentally before a decision is made on an application for a full-scale project.

Planned approach and implementation

The method is developed on decopperizing sludge that is characterized, and the characterization result together with literature information and thermodynamic calculations are the basis for planning experiments under varying conditions in a pressurized leaching reactor. The reaction is followed over time by analysis of the leach solution in connection to the experiments, and the solid residue is characterized afterwards for each experiment to find inhibiting factors and counteract these. Crystallization is studied in part in a crystallization unit with a microprobe.