A kind of tanning process for large-scale production of recycling waste liquid for pickling and chrome tanning

Abstract

The invention provides a tanning technology capable of performing salt-free pickling and chrome tanning of infinite circulating waste liquid and achieving mass production. The tanning technology is characterized in that common salt is not added during the pickling process, waste chrome liquor can be used in an infinite and circulating manner completely, and the tanning technology is suitable for the conventional bulk production technical process of tanneries; moreover, chemical materials such as chromium powders, common salt, and alkali extraction agents can be saved greatly, indexes such as shrinkage temperature, fullness, and grain quality of obtained wet blue leathers accord with national standard requirements; and compared with the prior patent (the application number is 201010592358.X), the waste liquid circulating technology can be suitable for the conventional bulk production technical process of the tanneries, the control range of the pH value of pickling and chrome tanning waste liquid for circulating utilization is widened greatly, the conventional pH value ranges from 0.3 to 2.5 and the widened pH value ranges from 0.3 to 5.0, and the tanning technology is more convenient to operate and control and is easier to produce the excellent wet blue leathers.

Description

technical field [0001] The invention belongs to the green recycling process of making full use of raw materials to reduce pollution discharge in the technical field of leather production. Herein, a large-scale production tanning process of salt-free indefinitely circulating waste liquid for pickling and chrome tanning is introduced. Background technique [0002] Today, China has become a world-recognized leather producing country, but the rapid development of the leather industry has also caused serious environmental pollution, waste of resources and ecological damage. Chrome tanning wastewater is one of the most polluted wastewater in tanneries, and it is the only heavy metal pollution in it. However, chrome tanning can endow leather with excellent performance and has always been the mainstream technology of leather tanning, which is almost unshakable. In the chrome tanning process, the effective utilization rate of chromium is generally only 60%-70%, and the remaining 30%-...

AI Technical Summary

Problems solved by technology

Such discharge of waste chrome solution with high content will not only cause great pollution to the environment, but also cause great waste of resources

[0003] At present, domestic and foreign methods of treating chromium-containing wastewater mainly include: chemical reduction method, electrolysis method, membrane separation method, adsorption method, ion exchange method, biological method, etc., but the operation process is often costly, low in efficiency, and poor in effect. Unable to achieve the real purpose of pollution control

[0004] In the past, some people used the waste chrome liquid to recycle and use it in the chrome tanning process, but often due to the existence of excessive organic matter and other impurities in it, the tanning process was slow, uneven tanning, and the color of the crust leather faded, which seriously affected the chrome tanning effect. The quality of wet blue leather is not stable, it is inconvenient to organize production, etc.