| 摘要 |
<p>PURPOSE:To improve the recovery rate of Ni and the content of Ni in the recovered matter by subjecting titled ore to a leaching treatment with hydrochloric acid, subjecting the leachate to a distillation treatment, holding the distillation concentrate at a specific temp. or below, subjecting the concentrate further to a roasting treatment in a specific temp. range and rinsing the resulted product of the roasting. CONSTITUTION:The magnesio-Ni silicate ore is subjected to the leaching treatment with hydrochloric acid and is separated to the leaching residue essentially consisting of SiO2 and the leachate so that the perfect leaching of the Ni in the ore is contrived. The above- mentioned leachate is then subjected to the distillation treatment and the distillation concentrate is held at <=350 deg.C to obtain the mixture composed of the chlorides of Ni, iron and Mg and to recover the unreacted hydrochloric acid. The reaction of MgCl2 to MgO is liable to arise and such is undesirable if the holding temp. exceeds 350 deg.C at this time. The distillation concentrate is then subjected to the roasting treatment at 250-450 deg.C in order to suppress the above-mentioned reaction by which only the chlorides of Ni and iron are selectively oxidized and gaseous HCl is recovered. The resulted product of the roasting is rinsed and is separated to the resulted product of the oxidation of Ni and iron and an aq. MgCl2 soln. The hydrate of MgCl2 and/or MgO is obtd. from the latter and the gaseous HCl is recovered therefrom.</p> |
