Experimental study on mineral processing of fine-grained andalusite ore in Liaoning Province

A process of mineralogy and mineral processing test study is conducted on a fine-grained refractory andalusite ore from Liaoning Province. The results of process mineralogy research on a fine-grained refractory andalusite ore from Liaoning Province demonstrate that Al₂O₃ content of 19.30%, SiO₂ content of 59.54%, Fe₂O₃ content of 8.95%, total carbon content of 4.17%, andalusite mineral content of 12.18%. The main gangue minerals are quartz （32.55%）, biotite （22.62%）, garnet （12.10%）, and carbonaceous substance （3.50%）. Under a grinding fineness where 42.00% of the andalusite ore passes −0.074 mm, the andalusite has achieved relatively good monomer liberation, with a liberation degree of 86.51%. Quartz, biotite, and carbonaceous substance exhibit close intergrowth relationships and can be preliminarily rejected through aggregates reverse flotation. In contrast, the weakly magnetic garnet can be effectively removed by magnetic separation. Based on the ore characteristics and through comparative process testing and condition optimization experiments, the final recommended mineral processing flowsheet is “grinding-reverse flotation for impurity removal （1 roughing - 1 scavenging） -positive flotation for andalusite （2 roughing- 4 selecting - middlings stepwise return）-dry magnetic separation （1 roughing - 1 selecting）”. Under the condition of grinding fineness of −0.074 mm accounted for 42.00%, use oxalic acid + sodium silicatea as combined depressants, sodium petroleum sulfonate + salicylhydroxamic acid as combined collector, high-quality andalusite concentrate with a yield of 7.11%, Al₂O₃ grade of 58.19%, Fe₂O₃ content of 0.86%, andalusite mineral content of 94.20% and recovery of 55.74% can be achieved through the aforementioned process flowsheet. Andalusite concentrate products meet the HZ-56 product quality standard specified in the industry standard for ferrous metallurgy. The research outcomes provide a technical reference for the development and utilization of fine-grained refractory andalusite resources in our country.