用水合肼回收电沉积铬废液中铬的工艺条件研究

Study of Process Conditions of Reclaiming Chromium from Electrodeposition Chromium Waste Liquid Using Hydrazine Hydrate

研究了用水合肼回收电沉积铬废液中铬的工艺条件。实验结果表明,在30℃下于25mL含铬废液中加入1.6mLH2SO4和0.8mL水合肼,8min即可使Cr(Ⅵ)还原为Cr(Ⅲ)。然后用浓氨水使Cr(Ⅲ)完全沉淀,再与H2SO4充分反应,得到Cr2(SO4)3,从而实现铬废液中铬的回收。

The process conditions of reclaiming chromium from electrodeposition chromium waste liquid using hydrazine hydrate as reducing agent were studied. The experimental result showed that Cr（ Ⅵ ） was deoxidized to Cr （Ⅲ） at 30 ℃in 8 min, adding 1.6 mL H2SO4 and 0.8 mL hydrazine hydrate to 25 mL chromium- containing waste liquid. Cr（Ⅲ ） was deposited using concentrated ammonia water, and then was reacted with H2SO4. Cr2 （SO4）3 was obtained and thereby chromium in the chromium waste liquid was reclaimed successfully.