用碳酸钠作沉淀剂制备低钠碳酸镧  

Preparation of Low Sodium Lanthanum Carbonate with Precipitant of Sodium Carbonate

作　　者：姜晓丽 陈建博 国树山 桑晓云 邢全生 张升强 

机构地区：[1]北方稀土(集团)高科技股份有限公司冶炼厂,内蒙古包头041010

出　　处：《稀土》2015年第6期118-122,共5页Chinese Rare Earths

基　　金：国家自然科学基金项目(50664004)

摘　　要：采用正加料沉淀方式,用工业级碳酸钠作沉淀剂,通过对料液浓度、碳酸钠浓度、反应温度、反应时间的控制,制备出低钠碳酸镧。在制备过程中,随着料液浓度、反应温度、反应时间的增加,钠含量呈现先降低后增加的趋势,但随着碳酸钠浓度的增高钠含量呈现降低的趋势。在最优工艺条件下制备出的碳酸盐,经XRD检测为正碳酸镧盐,晶体结构属于正交晶系,且无杂峰出现,不存在碱式盐;原子吸收光谱仪测定钠含量为20 ppm;经粒度分析仪和比表面积分析仪分析发现,其颗粒粒径分布均匀且较集中,颗粒较大,中心粒径D_(50)为52.37μm,比表面积为0.12 m^2/g,说明晶体吸附Na^+能力小,可以有效洗涤去除吸附在碳酸镧上的Na^+;经SEM测试分析发现,其粒径约在50μm,形貌呈片状,无明显团聚现象,晶体堆密度较低,说明晶体间包裹Na^+能力小,可以有效降低由于团聚而夹带的Na^+。Lanthanum carbonate with low sodium was prepared with industrial sodium carbonate as precipitant through controlling concentration of lanthanum chloride and sodium carbonate, reaction temperature and time. In the preparation process, it is found that sodium content was decreased firstly and then increased with the increase of feed concentration, reac- tion temperature and reaction time, but it was decreased with the increase of the concentration of sodium carbonate. Carbonate prepared under the optimum conditions was analyzed by means of XRD and the results show that it is lanthanum carbonate with crystal structure of orthogonal crystal system, without impurity peaks and basic salt ; the result of atomic absorption spectrometer shows that the sodium content is 20ppm;the particle size analyzer and specific surface area analyzer analysis indicates that the particle size distribution is uniform and concentrated, with medium partide diameter of 52.37μm, specific surface area of 0.12m2/g,which means the adsorption capacity of the crystals to Na ~ is small,and Na ＋ adsorbed on lanthanum carbonate can be effectively removed;SEM analysis shows that the particle size about 50μm, with flake shape without obvious agglomeration and low wrapping bulk density, which means the wrapping capacity of Na ＋ by the crystal is poor.

关 键 词：碳酸钠 大颗粒 低钠 碳酸镧 

分 类 号：TQ133.3[化学工程—无机化工]