翁泉沟硼镁铁矿的硫酸法加工(Ⅰ)──磁铁矿的阻溶及其机理

PROCESSING OF ASCHARITE-MAGNETITE SYNGENETIC MINERAL BY SULFURIC ACID(Ⅰ)──DIGESTION RETARDATION OF MAGNETITE AND IT'S MECHANISM

在用硫酸分解翁泉沟硼镁铁矿时，可以加一种氧化剂作为磁铁矿的阻溶剂和晶质铀矿的助溶剂．加入氧化剂后，在磁铁矿表面生成一层Fe_2O_3膜，使化学溶解速度减慢，并使Fe_3O_4-Fe_xS“腐蚀电池”停止作用，从而减缓其电化学溶解速度．本文用穆斯鲍尔谱和阳极极化曲线证实了Fe_3O_4颗粒有Fe_2O_3薄膜存在是磁铁矿溶解速度减慢的原因.

In the digestion of ascharite-magnetite syngenetic mineral,sodium chlorate acts as the digestion retardant of magnetite and as digestion promotor of uraninite.Sodium chlorate oxidizes Fe3O4 to Fe2O3,the smaller reaction ability of Fc2O3 depress the digestion rate of magnetite.Furthermore,the formation of apassivation film on the surface of magnetite reduces the effect of“Corrosion cell of Fe3O4-FexS”,which also decelerate the digestion rate of magnetite,This mechanism has been confirmed by Mossbauer spectroscopy and anodic polarization measurement.