利用硝酸型退锡废液回收锡单质的研究

The research of recycling tin from the spent nitric etching solution

研究一种清洁、低能耗、无副产物排放的从印制电路板硝酸型退锡废液中回收锡单质的方法。通过用絮凝剂、过滤方法得到锡酸沉淀;在高温条件下锡泥与浓盐酸反应生成锡离子,用还原剂将其中的锡离子还原成单质锡。最佳的反应条件为:100 ml退锡废液的絮凝剂及用量是5%聚丙烯酰胺14 ml;10 g锡酸的最佳浓盐酸用量40 ml,油浴温度140℃;最佳还原剂硼氢化钾的浓度1.2 mol/L,反应时间30 min。通过XRD表征,证实所制备的为锡单质。

This paper focuses on a kind of clean,low energy consumption,no by-product emissions method from tin wastewater from printed circuit board.By using flocculants and filter to get the tin acid;Tin acid with concentrated hydrochloric acid to reaction of tin ions in high temperature conditions,reduced to elemental tin from tin ions with the reducing agent.The optimal reaction condition is： the best flocculants amount of 100mL is polyacrylamide amount of 14mL,the optimum of concentration of hydrochloric to dissolve 10g tin acid is 40mL,oil bath temperature is 140℃,the best reducing agent of potassium borohydride concentration is 1.2mol/L,reaction time is 30min.Characterized by XRD,confirmed the prepared is elemental tin.