Novel leather producing process by pickling and chrome tanning by indefinitely circularly utilizing waste liquid without adding salt

Abstract

The invention provides a novel leather producing process by pickling and chrome tanning by indefinitely circularly utilizing waste liquid without adding a salt. The leather producing process is characterized in that in the picking process, edible salt is not added, and all waste chrome liquids are completely used indefinitely circularly, so that chromium powder, an edible salt, an alkali extraction agent and other chemical materials are greatly saved; the shrinkage temperature, fullness, granularity quality and other indexes of the prepared wet blue leather are in accordance with the requirement of national standard; compared with the conventional invention (application number: 201010169944.3), the novel leather producing process has the advantages that: the control range of the pH value of the waste chrome liquid in the process is greatly widened from 0.2-1.2 to 0.3-2.5, so that the process is more convenient to operate and control, and excellent wet blue leather can be produced more easily; and the temperature control range in the process is widened, and the operation is facilitated.

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 tanning process of indefinitely recycling waste liquid without adding salt is introduced for pickling and chrome tanning. 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%-40% of chromium...

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, and it is inconvenient to organize production, etc.