“…When combined with sewage sludge or dredging sludge, red mud can catalyze the growth of test plants, allowing for their utilization as secondary materials . For the recovery of gold from its tailings, several technologies such as flotation and cyanidation are available. − Copper tailings have adverse environmental effects due to their acidic content; they also have a significant economic value . Nowadays, popular management choices for copper slag include recycling, metal recovery, value-added item production (e.g., abrasive tools, granules for roofing, cutting tools, abrasive tools, tiles, glass, railroad ballast, and asphalt paving), and disposal in slag dumps and stockpiles. ,− The spent refinery catalysts for metal recovery are significant potential sources for both base and critical metals such as Ni, Co, Mo, W, V, Cr, and Cu …”