Recovery of Cobalt and Zinc from Metallurgical Wastewater Via a Selective Chelation Precipitation and Flotation Process

Harmless treatment of Zn hydrometallurgyHydrometallurgy wastewater is of great significance with the increasingly stringent environmental protection. RecoveryRecovery of strategic metalsMetals such as Co and Zn from the wastewater has dual significance for resource recoveryRecovery and environmental protection. In this work, a selective chelation precipitationSelective chelation precipitation-flotation processProcess was proposed to recover Co and Zn from Zn hydrometallurgyHydrometallurgy wastewater with low concentrations of Co, Zn, and Mn metalsMetals. Its demonstrated sodium diethyldithiocarbamate (NaDDC) can be used as a selective chelation reagent to synchronously recover Co and Zn in the precipitationPrecipitation flotation processProcess. The effects of pH value, NaDDC dosage, chelation temperatureTemperature, reaction time, and flotation reagent dosage on the recoveryRecovery efficiency of Co and Zn from wastewater were systematically studied. After optimizationOptimization, over 99% Co and Zn were firstly recycled from the wastewater by selective chelation precipitationSelective chelation precipitation-flotation processProcess, and the rest Mn solution can be further purified to qualified recycled water.