— Large amounts of copper slag are produced every year and major fractions of it are currently disposed, not withstanding the multiple ways the material can be used. Application of the slag is often limited by the presence of hazardous elements and their leaching behavior so they can potentially pollute soil, surface water and underground water.

These molten copper slags are dumped near the smelter site and is either allowed to cool slowly under air forming a dense, hard crystalline product or granulated with water resulting in a glassy, amorphous material.

 — Recycled smelter slags can be used in both in situ and ex situ treatment. However, their application has some limitations. One of the challenges is how to handle spent slag adsorbents, as they contain the accumulation of solid waste loaded with high concentrations of toxic contaminants.

 — Copper slag has been found to possess excellent physical and mechanical properties (Gorai et al., 2003) and its utilisation as a construction material has the potential to reduce waste disposal and reduce the risks to the environment (Mobasher et al., 1996, Alp et al., 2008, Al-Jabri et al., 2011).

 — As copper slag has been identified as a hazardous waste, it requires the adoption of adequate precautionary measures for safe disposal [94]. Therefore, recovering copper and other metal values from the slag would be a prudent approach to promote environmental protection and a circular economy [2].

 — Although the disposal of copper slag is considered the least favorable option, this trend will continue even at a higher rate [6, 7]. Since 1902, 652 Mt of ore has been extracted from the Bor region, yielding 4.93 Mt of copper and 280 metric tons of gold.

 — Copper slag, a waste solid produced in the copper smelting process, is a high-quality secondary resource with huge output. The recycling and utilization of copper slag is of great interest because it avoids the loss of valuable metals and the threat of harmful metals, and saves a lot of natural resources and energy.

 — The typical pyrometallurgical techniques are used to treat copper with processes involving calcining or smelting reduction followed by wet magnetic separation, which can recover metals such as Fe, Cu, and Co …

 — Copper slag, generated mainly during copper smelting, and classified as a potentially harmful waste, is an important secondary resource containing not only valuable metals, such as Cu, Fe, Zn, Co and Ni, in abundant quantities, but also hazardous elements, such as Pb and As.

Former slag disposal methods did not consider environmental safety carefully enough, which led to contamination of soils located in the vicinity of slag heaps and smelters (see [3] for a review). Some studies have also pointed out that improper slag disposal may cause serious ecological problems.