Nickel recovery from non-reduced ores - by lixiviation in alkaline ammoniacal soln

摘要

Lateritic nickel ores not previously reduced are lixiviated in an aq. alkaline soln. contg. 25-60% wt. NH4Cl or NH4 3SO4 at is not 250%, pref. 300 degrees C, and under pressure of 55-207 bars. Ni is recovered as a sol-complex salt of probable compsn. Ni(NH3)nCl2 (where n = 0-6) from which it is pptd. The process is of neutral character and is suitable for batch as well as continuous operations. A recovery efficiency =95% is obtd.