Wang Quanjie: Solid Waste In Leather Industry Should Be Resourceful.

Last week in Ji'nan, "the 2014 China Leather Industry Development Forum and the China Leather Association leather Specialized Committee annual meeting", Wang Quanjie, director of the national leather technology research and extension center and professor of Yantai University, pointed out: "there is no waste material in leather industry, so it is the right way to study the resource utilization of solid waste of leather."

When talking about the sources of leather solid waste, Wang Quanjie said that the proportion of chromium containing leftovers is usually small, while the proportion of chromium containing sludge and chromium free sludge is very small.

In the amount of water discharged, the CODcr and BOD5 discharged from the wastewater are relatively large. Chromium accounts for only a small proportion. The chromium content in chromium waste is 3-4% and protein >90%.

Starting from 6 different kinds of leather waste, Wang Quanjie described how to make use of them.

In the utilization of animal oils and fats, fresh skins can get high quality animal fat after they are removed from meat. They are mainly used for food and cosmetics. At this point, tanneries and slaughterhouses have different ways of handling, and tanneries produce higher quality and higher prices of oils and fats.

Soaked meat dregs can be used as high temperature oil. The oil separated can be deodorant and hydrogenated, and fatliquoring agent can be obtained. The separated oil residue can be used as fertilizer and feed. Soaked meat residue can also produce biogas and high efficient organic fertilizer.

On the use of hair, the best quality of soaked hair is used for wool spinning, felt and packing. Grey alkali hair can be directly used as fertilizer or fillers. Hydrolytic keratin can be used as cystine, leather coating and filler, and surfactant.

The use of leftover materials before tannage can be used for edible, medical and optical gelatin, and can also be hydrolyzed into collagen and polypeptides with a certain molecular weight for use in cosmetics and food additives. Ash alkali scrap is consistent with the use of leftover materials for soaking or slaughterhouses.

On the utilization of blue leather leftover materials, the non hydrolyzed chrome shavings and skin edge prototypes can be used for the preparation of regenerated leather. The traditional method can smash the skin and make a series of processes such as pulping, vulcanizing, and skin grafting. The new method can be made of leather fibers into non-woven regenerated leather. After removing the chromium from the original edge, it can be used to prepare fertilizer and feed, and become a high chromium compound fertilizer. It can be used for industrial gelatin, protein powder, protein filler and surfactant when hydrolyzed by acid, alkali and enzyme.

The use of semi leather leather can be directly used as filler, flocking, fuel and porous adsorption material. After grinding, leather and ash are decolorizing, degreasing and hydrolysis, it can be used for mechanical detergents, floor detergents, drilling auxiliaries and marine oil slick treatment agents.

The use of finishing leather leftovers can be used directly for stuffing, such as Japanese Park Lane and Hongkong racecourse. It can also be indirectly used. Desizing A series of processes of decolorizing and degreasing can be hydrolyzed into protein and polypeptide, which can be used for industrial gelatin, protein powder, protein filler and surfactant, but the cost is relatively high. It can also be used for reclaimed leather of vulcanized and nonwoven fabrics.

In addition, Wang Quanjie emphasized that leather solid waste can be used in various industries.

First of all, it can be used in agriculture and animal husbandry. Chromium containing solid waste Cr3-4% Pr>90%, because waste contains N, P, S, K, Ca, Mg, Cr, Fe, Al and other chemical elements, so the fertilizer made rice yield increased by 18%, wheat yield increased by 36%. The meat waste residue (the more oil the better) can be made into biogas and the by-product is high quality organic nitrogen fertilizer.

Secondly, in the leather industry, it can be used as chemical material and made from waste fat to make leather fatliquoring agent and degreasing agent. Proteins The finishing agent is bright, light resistant, and can be directly used as a tackifier for embossing and ironing. Bovine hair can control crosslinking and grafting of polymer materials after hydrolysis. Bovine hair can also be made into collagen modified finishing agents, such as acrylic acid, polyurethane and butadiene.

Finally, in the application of other fields, blue fiber can be made into regenerated leather and non-woven fabrics, and hydrolyzed and spun to make hygroscopic collagen fabric. Wool spinning Blankets, felt, brushes and brushes. Leather solid waste can also be made into pet toys and chewing products, and can also be made into high-grade protein and refined collagen, so as to make cosmetics with moisture and nutrition. Japanese Shiseido, French CLARINS and Estee Lauder all use this kind of collagen. Leather solid waste and synthetic polymer materials are blended and copolymerized to produce degradable plastics.