本文提出了一种锆英砂两步碱熔制备氧氯化锆的新工艺,主要研究了氢氧化钠碱熔和水洗过程.考察了操作条件对锆英砂分解过程的影响,最优的工艺条件为:碱矿比为0.7+0.6,碱熔温度为700℃,反应时间为30分钟,在此条件下,锆英砂的分解率可达97.25%.在锆英砂碱熔过程中,在第一步加碱时,主要的反应产物为Na2ZrO3和未反应的ZrSiO4,在第二步加碱时,ZrSiO4和NaOH进一步反应,生成Na2ZrO3和Na2SiO3,对产物进行XRD分析,未见Na2ZrSiO5衍射峰.对反应产物的水洗过程进行了研究,最优的工艺条件为:液固比为5:1,水洗时间30分钟,水洗温度50℃,水洗三次.在最优的水洗工艺条件下,水洗料中SiO2和Na2O含量分别为3.51%(40%ZrO2)和4.46%(40%ZrO2),对水洗机理废研究表明,在水洗过程中,Na2ZrO3和Na2SiO3的形态发生变化,大部分Na2ZrO3发生水解,转化为ZrO(OH)2,Na2SiO3主要为溶解过程,少量的Na2SiO3发生水解,生成H2SiO3. In this work,a two-step zircon method to produce zirconium oxychloride was introduced,the alkali fusion technique with NaOH and water leaching process were investigated.The effects of the operating conditions on the decomposition of zircon were determined,the optimal conditions are as follows:alkali/zircon mass ratio of 0.7+0.6,fusion temperature of 700℃and fused time of 0.5h+0.5h.Under these conditions,the decomposition of zircon sand can reach to 97.25%,In the fusion process of zircon sand,the products of first-step are mainly Na2ZrO3 and ZrSiO4,the products of second-products are Na2ZrO3 and Na2SiO3,diffraction peak of Na2ZrSiO5 were not observed.As well as the conditions of water leaching process are investigated,the optimal conditions are as follows:liquid-solid ratio of 5:1,leaching time of 30min,leaching temperature of 50℃and leaching three times.Under these conditions,the contents of SiO2 and Na2O of leaching product were 3.51%(40%ZrO2)and 4.46%(40%ZrO2).The crystal phase structures of Na2ZrO3 and Na2SiO3are transformed in water leaching process.