利用废弃银铜合金触点直接制备银铜双金属粉

研究了利用废弃银铜合金触点(Ag、Cu、Sn质量分数分别约为30%、60%和2%)直接制备银铜双金属粉的工艺。原料以硝酸溶解后,采用葡萄糖预还原和水合肼二次还原,在聚乙烯吡咯烷酮(PVP)的保护下制得了粒径在1μm左右类球形超细银铜双金属粉和超细铜粉。还原前加入尿素,控制反应温度在60℃温度下,加入抗氧化剂苯并三氮唑,均可防止铜粉的表面氧化,从而获得高质量的银铜双金属粉,银、铜的回收率达到99%以上。所得产品可再用于粉末冶金法制备银铜合金触点,或者直接用于制备电子浆料。该工艺可避免银、铜的分离过程,使废弃银、铜合金触点中银、铜的回收和深加工得到有效结合,从而实现节能减排的目标。

Preparation of silver copper bimetals powder from waste Ag-Cu alloy contactor

Silver-copper bimetal powder has been prepared from waste Ag-Cu alloy contactors, which contain Ag, Cu and Sn about 30 % , 60 % and 2 % respectively. The waste alloy contactors are dissolved in nitric acid first, and then reduced with glucose and hydrazine hydrate in the protection of PVP. Finally, about 1 μm-diameter superfine approximate spherical Ag-Cu bimetal powder and Cu powders can be obtained. It showed that adding urea prior to reduction and controlling the reaction temperature under 60 ℃ , or adding benzotriazole （BTA） can prevent the oxidation of copper, and the recovery rate of Ag and Cu is higher than 99 %. The silver-copper bimetal powder product can be used as raw material in the production of Ag-Cu alloy contactor and electronic paste. The advantage of this process is that the recycling of silver and copper combines with the deep process, which can avoid the separation of silver and copper. It meets the aim of energy saving and emission reduction, as well.