Abstract: To increase the yield of the target narrow-size fraction (0.074~0.038 5 mm) and effectively suppress over grinding in the quartz grinding process,this study systematically investigated the effects of medium parameters (size,ratio,fill ing rate),material parameters (material-to-ball ratio,grinding concentration),grinding time,and grinding aids (sodium hex ametaphosphate,ammonium chloride) using a horizontal ball mill and pure quartz.The results showed that under the optimal grinding parameters (the mass ratio of ceramic balls with diameters of 10,15 and 20 mm of 3∶5∶3,filling rate of 20%,materi al-to-ball ratio of 0.1,grinding concentration of 60%,grinding time of 30 min),the yield of the target fraction increased by 25.59 percentage points,while the over-ground fraction (-0.038 5 mm) decreased by 23.94 percentage points compared with direct grinding.Grinding aids further enhanced the performance,in which sodium hexametaphosphate outperformed ammonium chloride,and at its optimal dosage (0.5%),the target fraction yield increased by an additional 6.88 percentage points,and the over-ground fraction yield decreased by a further 3.97 percentage points.Through the entire process optimization,a final prod uct with a target fraction yield of 83.96% and an over-ground fraction yield of only 5.05% was achieved,significantly impro ving resource utilization rate.This study provides a reliable technical pathway for the efficient and selective grinding of quartz.

Key words: quartz,medium size,medium gradation,medium filling rate,material-to-ball ratio,grinding aid sodium hex ametaphosphate