纳米比亚某低品位铀矿石拌酸制粒柱浸试验研究OA

This study investigated parameter optimization for heap leaching of a low-grade uranium ore from Namibia deposit through systematic column leaching experiments.Mineralogical composition analysis shows that the uranium ore contains a high proportion of high acid consuming gangue miner-als,with tetravalent uranium accounting for 68％.The main uranium minerals are easily leached uraninite and coffinite.The uranium is enriched of in the fine-grainedportion.After crushing to-8 mm,the mass fraction of fine-grained uranium at-0.425 mm reaches 15.09％,and its uranium grade is as high as 0.032％,which leads to the deterioration of direct heap leaching permeability and requires acid-agglomeration pretreatment.Column leaching experiments established the optimal pa-rameter combination:irrigation rate of 20 L/(h·m2),heap height of 9 m,aciddosage for pre-agglom-eration of 20 kg/t,binder dosage of 125 g/t,and initial leachate acidity of 100 g/L H2SO4.Under op-timized conditions,the irrigation duration is shortened to 55 d,and the uranium extraction rate is in-creased to 80％.This study has demonstrative significance for the development of similar low-grade,high acid consumption,high fine-grained,and high tetravalent uranium resources.