Recovery of nickel from Orimulsion fly ash by iminodiacetic acid chelating resin

Macroporous resins containing imminodiacetic acid (IDA) groups (Lewatit TP-207, Purolite S-930 and Amberlite IRC-748) were studied under dynamic conditions for uptake of nickel ions from the sulphate solution at pH 4 deriving from preliminary acid leaching of Orimulsion fly ash and subsequent vanadium recovery and impurities removal stages. The effects of temperature and ionic medium on the Ni adsorption were investigated.The Lewatit TP-207 showed higher Ni uptake capacity in all operating conditions examined with an adsorption capacity of 1.32 mmol of Ni/g at 40 °C using the real process solution at pH 4.The extraction of Ni adsorbed on the resin was obtained using 10 wt.% H2SO4; the resultant concentrated solution of nickel sulphate, containing about 13 g/L of nickel, can be suitable for elettrowinning, precipitation etc.