Technical Study on Leaching Low-grade Pyrolusite Using Scrap Iron as Reductant

Studies on reduction leaching technology of low-grade pyrolusite were carried out.Scrap iron was used as reductant to leach low-grade pyrolusite in sulphuric acid.The optimum technical conditions of leaching pyrolusite by single-factor test were confirmed as follows: the mass ratio of scrap iron to pyrolusite was 0.25∶1,the mass ratio of sulphuric acid to pyrolusite was 1∶1,the liquid-solid ratio was 5∶1,reaction time was 1 h and initial reaction temperature was 10 ℃.The leaching rate of manganese in pyrolusite reached above 98% under the optimum leaching conditions.