PROCESS FOR THE TREATMENT OF SOLID ALKALINE RESIDUE COMPRISING CALCIUM, HEAVY METALS AND SULPHATE

摘要

The invention relates to a process for the treatment of solid alkaline residue comprising calcium, heavy metals and sulphate, the process comprising: a)reacting the solid alkaline residue with carbon dioxide by contacting the solid alkaline residue with a carbon dioxide containing gas to obtain carbonated solid material; and c)washing the carbonated solid material with an aqueous stream to obtain washed solid material and wash water comprising calcium and sulphate and precipitating at least part of the calcium in the wash water as calcium carbonate.