(1. 中南大學(xué)冶金與環(huán)境學(xué)院，長(zhǎng)沙 410083；
2. 中南大學(xué)中國(guó)有色金屬工業(yè)清潔冶金工程研究中心，長(zhǎng)沙 410083)
摘 要: 采用液相還原法，以硝酸銀為原料、抗壞血酸為還原劑制備銀粉。系統(tǒng)探索加料方式、分散劑、反應(yīng)溫度、分散劑用量和AgNO3溶液濃度等工藝參數(shù)對(duì)銀粉形貌、粒徑的影響，并對(duì)分散機(jī)理進(jìn)行研究。結(jié)果表明：聚乙烯吡咯烷酮(PVP)與Ag+和銀粉的相互作用有利于銀粉形貌和分散性的提高。采用正向快速加料法，在PVP用量為硝酸銀的5%~20%(質(zhì)量分?jǐn)?shù))，硝酸銀溶液濃度為0.1~0.3 mol/L的條件下，可制備出分散性較好、表面光滑的球形銀粉，其振實(shí)密度可達(dá)4.9 g/cm3；通過(guò)調(diào)節(jié)分散劑的用量，能夠?qū)崿F(xiàn)銀粉平均粒徑在1.02~2.72 μm之間的可控制備。
關(guān)鍵字: 微米級(jí)銀粉；分散機(jī)理；聚乙烯吡咯烷酮(PVP)；可控制備
（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
