Tanning production process capable of recycling waste water repeatedly from soaking to dyeing

Abstract

The invention provides a tanning production process capable of recycling waste water repeatedly from soaking to dyeing, which is characterized in that waste liquid recycling is conducted in procedures of pre-soaking, main-soaking, liming, deliming and softening, pickling and chrome tanning, retanning, neutralizing and dyeing step by step, and waste liquid in all the procedures achieves full-closed circulation recycling. The technology is tested and verified in actual production in a tanning workshop of BIOSK (sq) Chemicals Co. Limited. The process achieves recycling of waste water from the pre-soaking to the dyeing, sewage discharging is greatly reduced, a problem of tanning pollution is solved thoroughly, quality of finished leather can be guaranteed simultaneously, loose side rate of the finished leather is effectively reduced, degree of compacting and fullness of the finished leather is improved, chemical materials can be saved by 15% to 55%, for example, chromium powder is saved by 35% to 65%, partial chemical materials can be saved by more than 90%, and exceptional chemical materials such as salt can be saved by 100%.

Description

technical field [0001] The invention relates to the field of recycling waste water in the leather industry. Background technique [0002] Our previous invention: a new step-by-step recycling process of tanning waste liquid did not realize the recycling of retanning, neutralization and dyeing wastewater. At present, it has realized recycling from presoaking water to dyeing wastewater, further reducing wastewater discharge , and this technology has been verified in the actual large-scale production of the tanning workshop of Baoska (Shangqiu) Chemical Co., Ltd. [0003] In the tanning process, a large number of chemical raw materials are used, such as acid, alkali, salt, sulfide, lime, chrome tanning agent, fatliquoring agent, dyestuff, etc., and a considerable part of them enters the wastewater. Tannery wastewater mainly comes from preparation, tanning and other wet processing stages. The sewage discharge in the production process from pre-soaking to dyeing accounts for mor...

AI Technical Summary

Problems solved by technology

It is an extremely complicated and difficult problem to realize the one-time recycling of wastewater from all processes from presoaking to dyeing, and it is often accompanied by the following problems: the weight gain rate of gray leather and the yield rate of blue leather both decreased by 1.5% %-3.5%, the shrinkage temperature drops by 1.5°C-3.5°C, and the grain surface of the blue leather will be damaged, the grain surface will become thicker, the color will become darker, and even the phenomenon of "rough surface" will occur, resulting in some performance indicators of the finished leather falling short. to request

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