浸酸铬鞣方法对铬鞣废液直接循环利用性能的影响

Effects of Pickling-chrome Tanning Methods on Direct Recycling Effectiveness of Chrome Tanning Wastewater

对比了常规浸酸、甲基磺酸浸酸、芳香族磺酸无盐浸酸三种浸酸方法对铬鞣效果的影响,研究了三种铬鞣废液直接循环利用过程中废液中铬含量、氯离子等的变化及其对铬鞣效果的影响。结果表明,与常规浸酸-铬鞣工艺相比,甲基磺酸和芳香族磺酸浸酸铬鞣均能使铬鞣废液铬质量浓度从1142 mg/L降低到153.5 mg/L以下;铬鞣废液被直接循环利用10次过程中,常规浸酸铬鞣废液中的铬和氯含量波动较大,导致蓝湿革内的铬含量和收缩温度波动较大;甲基磺酸和芳香族磺酸无盐浸酸铬鞣废液中的铬质量浓度均保持在400 mg/L以下,并减少了废液的化学组分和浓度,改善了铬鞣废液直接循环利用技术的工艺稳定性。

The effects of pickling-Chrome tanning methods including conventional pickling,methanesulfonic acid pickling and salt-free aromatic sulfonic acid pickling were compared with each other,and the changes of chromium(Cr)and chloride concentrations in the spent tanning liquors with recycling times and the influences of them on chrome tanning effectiveness were investigated.The results indicated that,compared with conventional technology,the Cr concentrations in the spent chrome tanning liquors were reduced to 153.5 mg/L below from 1142 mg/L by both methanesulfonic acid and aromatic sulfonic acid pickling-chrome tanning methods.Recycling the spent chrome tanning liquors to the operations of pickling and tanning by 10 times,the contents of chromium and chloride in the spent liquors of conventional technology fluctuated greatly,resulting the Cr contents and shrinkage temperatures of chrome tanned leather changed randomly.The concentrations of chromium in the liquors from methanesulfonic acid and aromatic sulfonic acid pickling-chrome tanning methods kept below 400 mg/L,which helps to improve the technological stability of direct recycling of chrome tanning liquors.