电沉积铬中甲醛还原铬酐制备硫酸铬的工艺条件

Technological procedure for preparation of chromium sulfate using formaldehyde as a reductant of chromic anhydride

以铬酐为原料,采用化学还原法,探讨了甲醛还原铬酐获取三价铬并制备硫酸铬的化学工艺条件.实验结果表明,在硫酸存在条件下,当反应温度为90℃、甲醛过量80%时,8 m in内可使铬酐还原率达到近100%.该法操作简便、反应效率高,可为三价铬电沉积铬提供良好的原料保证,结果满意.

A new chemical reduction procedure for preparation of chromium sulfate, using formaldehyde as a reductant to deoxidize chromic anhydride, was introduced. Results show that, within eight minutes, the percent reduction of Cr （Ⅵ） achieves approximately 100% with the presence of sulfuric acid, the temperature being 90 ℃ and formaldehyde exceeding 80%. The procedure can supply ample material as electrodeposited chromium from trivalent chromium with high reaction energy.