摘要
为利用碱沉淀铬鞣废液所回收的铬泥制备一定碱度的再生铬鞣剂,本研究首先通过正交实验确定了硫酸溶解铬泥的最佳工艺,然后对酸溶所得铬液进行甲酸钠蒙囿改性并采用小苏打调整碱度制备了再生铬鞣剂,最后对再生铬鞣剂的性质和鞣革性能进行了研究。实验结果表明,酸溶解的最佳条件为:用铬泥质量70%硫酸在70℃下反应40 min,铬溶出率为93.8%,所得鞣液碱度低。以甲酸钠与Cr_2O_3摩尔比为1,在70℃下反应2 h对鞣液进行蒙囿后加入小苏打调整碱度,制备了沉淀p H值6.3,碱度38.8%的再生铬鞣剂,再生铬鞣剂中配体与铬的结合方式与商品铬鞣剂无明显区别。鞣革实验表明再生鞣剂虽然鞣制所得皮革颜色灰暗,但是铬吸收率与鞣制所得皮革理化性能与商品鞣剂鞣制差异不大。本研究可为利用铬泥制备高品质铬鞣剂提供参考。
In order to use the chrome sludge recycled from chrome tanning waste-liquor by alkaline precipitation to prepare tanning agent with a certain basicity,the conditions for dissolving the chrome sludge with sulphuric acid were optimized through orthogonal experiments at first,and then sodium formate was used to modify the chrome tanning solution and sodium bicarbonate was applied to adjust the basicity.Finally,the tanning properties of the regenerated chrome tanning solution were studied.The results show that the optimal conditions for acid dissolution are as follows:sulfuric acid dosage is 70%based on chrome sludge weight,the reaction temperature and time are 70℃and 40min respectively.The chromium extraction rate is 8.4%under this condition,but the basicity of the chrome tanning solution is low.The chrome tanning solution reacts with 1mol sodium formate based on Cr2O3 at 70℃for 2 hours and then adjusts with sodium bicarbonate to obtain regenerated chrome tanning agent with precipitation pH 6.3 and 38.8%basicity.The combination between ligand and chromium of the regenerated chrome tanning agent is as same as the commercial one.In addition,although the color of the leather tanned by regenerated chrome tanning agent is murky grey,the chromium exhaustion and the mechanical properties of the leather are comparable with traditional.The study will provide a reference for the preparation of high-quality chrome tanning agents using chrome sludge.
出处
《皮革科学与工程》
CAS
北大核心
2018年第4期5-9,共5页
Leather Science and Engineering
基金
四川大学大学生创新创业训练计划(201710611403)
国家自然科学基金(21576171)
关键词
铬泥
铬鞣剂
碱度
酸溶解
蒙囿
chrome sludge
chrome tanning agent
basicity
acid dissolution
masking
