Immobilisation and Leaching Performance of Lead-Acid Batteries Smelting Slag Using Natural and Waste Materials

The slag generated in the rotary furnaces is classified hazardous waste. In this regard, landfill disposal of lead smelting slag is not feasible since a few hundred tons are produced per year; leaching of heavy metals into ground water is of concern. The release of heavy metals into the environment has resulted in a number of environmental problems. The disposal of slag is becoming more expensive each year due to large land areas needed for its disposal. The best way to solve the disposal problem of waste materials is to decrease the quantity for disposal with utilization of waste materials in the industry. The toxicity of the waste is determined by leaching tests and depending on the characteristics of the waste the spent abrasive must be disposed of as solid or hazardous waste. The aim of this study is to investigate leaching characteristics of lead smelting slag according to leaching tests such as TCLP, and TS EN 12457-4 tests methods. In this study, mixed-level factorial design was applied to optimize process parameters for lead removal from lead smelting slag using natural (sepiolite, montmorillonite, illite and seashell) and waste material (red mud). The established model was then used as a predictor to achieve better understanding of the adsorption process and to obtain optimal settings of the experimental factors. The present study includes the safe disposal of lead smelting slag using natural and waste materials. Experimental results indicated that red mud and seashell can be used as environmentally friendly adsorbents that are capable of lead release from lead smelting slag.