Arsenic removal from hydrometallurgical waste sulfuric acid via scorodite formation using siderite (FeCO3)

Abstract High concentration of arsenic (As) in waste sulfuric acid (WSA) generated from hydrometallurgical mineral processing must be removed and immobilized for protecting local environments. However, the economical and efficient treatment method for WSA is still lacking. We proposed the precipitation of As in WSA as scorodite by using economical siderite (FeCO3) as an Fe source through a three-step process. Firstly, the WSA is neutralized to pH ~ 1 with Ca(OH)2 via precipitation of gypsum with low As content (~ 7.1 × 10-2