Leaching Test Based on Occurrence State of Fluoride in Barite
Based on the investigation of occurrence state,fluoride associated with barite was leached with HCl-AlCl3 by using Plackett-Burman design,and influences of HCl concentration,AlCl3 concentration,reaction temperature,reaction time,and liquid-to-solid ratio on fluorine leaching rate were investigated.It is found that the fluorine in barite mainly exists in the form of disseminated and banded fluorite.By using HCl at a concentration of 3 mol/L and AlCl3 at a concentration of 0.4 mol/L,after 30 min leaching reaction of ore sample with grain size of 48-75 μm,liquid-to-solid ratio of 10 mL/g,and stirring speed at 300 r/min,the leaching rate of fluorine can reach 93.20%,and the mass fraction of barite is 95.91%.Results show that all factors that influence fluorine leaching rate are arranged in descending order of importance as follows:reaction temperature>HCl concentration>reaction time>AlCl3 concentration>liquid-to-solid ratio.