Copper slag
It is estimated that per tonne of copper 2.2 tonnes of slag is produced from copper smelters. Currently copper slag is mainly applied as a building material (as a replacement of sand or concrete aggregate), or is being dumped. Copper concentrations in copper slag from smelters vary however between 0,5% up to 7%. This copper is currently not or barely recovered and after applying it as a building material it is considered to be lost. Besides this, leaching of heavy metals (mainly copper) from the copper slag into ground waters has a negative environmental impact.
Elemetal is able to recover >0.3% of copper from copper slag using the Elemetal Copper Recovery (ECR) process. Copper slag containing significant amounts of copper (>0.7%) will result in even higher copper recovery values. Elemetal will treat the copper slag using a washing process. The washing agent has an extremely high selectivity to extract copper. After purification and concentration eventually pure copper (grade A) can be plated by electro winning or it can be recovered as copper salt.