Recovery of nickel from used catalysts, orimulsion fly ash and nickel cadmium batteries

摘要

The disposal of spent nickel from for example hydrosulphurisation, edible oil hydrogenation catalysts, fly ash arising from the combustion of Orimulsion fuel oil or nickel/cadmium sludges, constitutes a severe environmental hazard. This is because they contain large quantities of toxic nickel. Disposal to landfill can result in the leaching of these residues. Consequently it is desirable to ensure that sound technological and economic valorisation processes are developed to recover the potentially toxic nickel residues. The application of electrochemical techniques for recovering nickel from these potentially toxic sources is discussed. Where sdium sulphate is produced as a result pH adjustment, during the electrochemical depsoition step to recover nickel, the use of electrodialysis for recovery of acid and alkali for recycle is presented.