关键词: 石英尾矿, 溶解, 酸浸, 反应, 二氧化硅

Abstract: High purity quartz sand is widely used in construction,glass manufacturing,casting and other industrial fields. In order to obtain the replacement products of high purity quartz sand,quartz sand tailings were treated by removing Fe and Al. In this work,the method of quartz tailings from Guangdong Heyuan as raw material refined with hydrofluoric acid associated with oxalate was proposed,and the optimum operating conditions were also provided. Oxalic acid dosage and reaction temperature were determined by oxalic acid complexation experiments. The acid leaching reaction time and material ratio were determined by refining experiments via hydrofluoric acid associated with oxalic acid. The results showed that the best operating conditions of refining the quartz sand tailings were as follows. Quartz sand tailings of 200g with the particle size≤250mm were immersed into the 100mL mixed solution of saturated oxalic acid and hydrofluoric acid in the volume ratio is 25:1 for 4 hours. Temperature was kept at 80℃。 After refining,the silica content in the refined quartz sand tailings could reach 99.97%,with the whiteness of 87.5. Experimental results demonstrated that refined solution was recycled by adding oxalic acid and hydrofluoric acid. Oxalic acid could be crystallized from the uncooled refined solution. The residual refined solution and refined quartz sand water lotion was treated as waste liquid. The impurities in the waste liquid were precipitated by the addition of a saturated lime water. The experimental results showed that the tail liquid was treated completely when the volume ratio of the tail liquid and the lime water is 1:13 and after the end solution treatment,the tail liquid can be used as recycled water discharge.

Key words: quartz tailings, dissolution, acid leaching, reaction, silica