六方片状碱式氯化锌的制备及形貌研究

Study on preparation and morphology of hexagonal flake basic zinc chloride

碱式氯化锌的化学式为Zn_(5)(OH)_(8)Cl_(2)·H_(2)O。是一种新型的锌源添加剂,在饲料行业广泛应用。本文以ZnCl_(2)为原料,采用氨气沉淀法,直接制备直径10~60μm的微米级六方片状碱式氯化锌。采用XRD、SEM、激光粒度仪对产品进行表征和分析。研究了反应温度,通氨速率,陈化时间和反应物浓度等因素对产品形貌的影响。在ZnCl_(2)浓度为2.0 mol/L,通入NH_3的流量为300 mL/min,时间1 h,反应温度80℃,陈化时间5 h的最佳反应条件下,收率达到49.06%,形貌完好、晶型完整。利用Morphology程序对碱式氯化锌生长习性进行理论分析,计算结果与实验结果吻合,由温度引起的(003)晶面显露程度变化是导致宏观形貌非理想性的重要原因。

The chemical formula of basic zinc chloride is Zn_(5)(OH)_(8)Cl_(2)·H_(2)O.It is a new type of zinc source additive,which is widely used in the feed industry.In this paper,micron-sized hexagonal flake basic zinc chloride with a diameter of 10~60μm was directly prepared by ammonia precipitation method using ZnCl_(2)as raw material.The products were characterized and analyzed by XRD,SEM,and laser particle size analyzer.The effects of reaction temperature,ammonia flow rate,aging time,and reactant concen-tration on the product morphology were studied.Under the optimum reaction conditions of ZnCl_(2)concentration of_(2).0 mol/L,NH3 flow rate of 300 mL/min,a reaction time of 1 h,reaction temperature of 80°C,and aging time of 5 h.Lastly,the yield reached 49.06%.The growth habit of basic zinc chloride was theoretically analyzed by the Morphology program.The calculation results are in good agreement with the experimental results.The change of(003)crystal plane exposure caused by temperature is an important reason for the non-ideality of macroscopic morphology.