煅烧-无氟无硝酸浸去除石英砂杂质的工艺研究

Study on the Impurity Removal of Quartz Sand by Calcination and Leaching without Hydrofluoric Acid and Nitric Acid

采用煅烧-无氟无硝酸浸联合手段去除石英砂中的金属杂质进行石英砂提纯。首先通过ICP、XRD分析手段对石英硅矿进行矿物学分析,将石英硅矿在不同温度下煅烧水淬,烘干后分别研磨成80-120目(0.106-0.150mm)的石英砂,接着借助扫描电子显微镜(SEM)对其进行石英砂表面形貌分析,最后,在不使用氢氟酸和硝酸的条件下,采用草酸、乙酸和硫酸及其混酸对石英砂进行酸浸提纯。结果表明:石英硅矿经过900℃高温煅烧5h后研磨的石英砂酸浸除杂效果较好,且在温度80℃、搅拌速度300r/min,固液比为1:5条件下,草酸0.6mol/L、乙酸0.8mol/L、硫酸0.6mol/L,酸浸时间4 h后,Fe、Al、Ca、Na的最佳去除率分别达到85.44%、68.18%、52.62%和47.80%。

The combined method of calcination and acid leaching without hydrofluoric acid and nitric acid is used to remove metal impurities in the quartz sand to purify the quartz sand.Firstly,the mineralogical analysis of quartz silica ore is carried out through the two analytical methods of ICP and XRD.The quartz-silicon ore was calcined at different temperatures and then quenched in water,and the quartz sand is ground into 80-120 mesh(0.106-0.150mm)quartz sand after it was dried.Then the surface morphology of quartz sand was analyzed by means of scanning electron microscope(SEM).Under the condition of not using hydrofluoric acid and nitric acid,oxalic acid,acetic acid,sulfuric acid and their mixed acids were used to purify quartz sand.The results show that the quartz sand ground after calcination at 900℃for 5 hours has better impurity removal effect after acid leaching,and under the conditions of temperature 80℃,stirring speed 300r/min and solid-to-liquid ratio of 1:5,Using 0.6 mol/L oxalic acid,0.8 mol/L acetic acid and 0.6 mol/L sulfuric acid to react with quartz sand for 4 hours,the best removal rates of Fe,Al,Ca,and Na were 85.44%,68.18%,52.62%and 47.80%,respectively.