(1. 中南大学冶金与环境学院，长沙 410083；
2. 中南大学中国有色金属工业清洁冶金工程研究中心，长沙 410083)
摘 要: 采用液相还原法，以硝酸银为原料、抗坏血酸为还原剂制备银粉。系统探索加料方式、分散剂、反应温度、分散剂用量和AgNO3溶液浓度等工艺参数对银粉形貌、粒径的影响，并对分散机理进行研究。结果表明：聚乙烯吡咯烷酮(PVP)与Ag+和银粉的相互作用有利于银粉形貌和分散性的提高。采用正向快速加料法，在PVP用量为硝酸银的5%~20%(质量分数)，硝酸银溶液浓度为0.1~0.3 mol/L的条件下，可制备出分散性较好、表面光滑的球形银粉，其振实密度可达4.9 g/cm3；通过调节分散剂的用量，能够实现银粉平均粒径在1.02~2.72 μm之间的可控制备。
关键字: 微米级银粉；分散机理；聚乙烯吡咯烷酮(PVP)；可控制备
（1.School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. Cleaner Metallurgical Engineering Research Center, Nonferrous Metal Industry of China,
Central South University, Changsha 410083, China）
Abstract:The microsized silver powders were prepared by liquid reduction method using AgNO3 as feed solution and ascorbic acid as reductant. The effects of feeding mode, dispersant, reaction temperature, dispersant dosage and AgNO3 concentration on the morphology and particle size of silver powder were investigated, and the dispersing mechanism was studied. The results show that the interaction between polyvinyl pyrrolidone (PVP) and Ag+ along with silver powder is in favour of the regular spherical morphology and preferable dispersity of silver powder. The optimal dispersive spherical silver powders with smooth surface were prepared with 5%-20% PVP (mass fraction) and 0.1-0.3 mol/L AgNO3 by farward fast feeding mode, the tap density of silver powder can reach 4.9 g/cm3. The particle size of ultrafine silver powders between 1.02-2.72 μm can be prepared controllably through changing the dispersant dosage.
Key words: microsized silver powder; dispersing mechanism; polyvinyl pyrrolidone; controllable preparation
