Cleaner production and pollution control measures

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Cleaner production of waste paper and pollution control measures

1. strengthen the classification and management of waste paper recycling, improve recycling quality and efficiency and reduce pollution emissions

classifying and recycling waste paper scientifically and reasonably will not only have a direct impact on the collection and treatment of waste paper, but also achieve the purpose of graded treatment and making the best use of materials, so as to improve benefits and reduce pollution. The United States divides waste paper into three categories: pulp substitutes (white paper and its cutting edges); It can purify waste paper (refers to the pulping after removing printing ink); Ordinary waste paper (such as mixed waste paper, newspaper, corrugated base paper, etc., which accounts for more than 70% of the total waste paper). Up to now, there is no unified standard for waste paper classification in China, which needs to be studied and solved urgently

2. the waste paper regeneration system is properly closed to reduce the sewage discharge.

it is reported that the waste paper processing plant with an annual output of about 30000 tons of G & P company in Germany has taken measures to completely close the circulating water and achieved zero discharge. In order to eliminate the accumulation of organic matter caused by the closed circulation, a trickling filter has been established. Inspired by this technology, it should be feasible to properly close the waste paper processing system

3. running, emitting, dripping and leaking control system

this system is an ideal place for the recovery of overflows in the paper workshop, including the recovery of frequent and accidental emissions and their return to the pulper. It is important to have large buffer containers, which should be able to accommodate running, emitting, dripping and leaking from the paper machine

4. recovery and treatment of deinked ink sludge

the deinking method of waste paper designed in modern times. If it is counter current multi-stage washing, the ink sludge will be concentrated by flotation; In the case of flotation method, the ink sludge is directly concentrated by flotation. Under a certain load, it is completely sealed. At this time, the control of the hot melt viscosity of rubber and plastic materials is extremely important. This system will gradually accumulate dissolved organic and inorganic substances, thus bringing dissolved substances to the paper machine system. This will reduce the quality of paper and block copper and wool cloth. The blockage is the pollutant in the secondary fiber, such as adhesive and resin, so the impurities that dissolve their unique understanding of the mold structure design or suspended must be removed from the system. The removal method is to purify the reused white water with a clarifier, increase the washing capacity or add a press

the flotation deinking sludge system uses less water, that is, the reuse water increases. In order to obtain cleaner secondary fibers, the washing or pressing steps of the final pulp cannot be omitted. The ink sludge is concentrated by centrifuge or entrained press filter (flocculant is often added for filtration)

5. waste residue treatment system

all waste residues discharged from pre deslagging, screening and deslagging machines need to be concentrated to reduce the water taken away. A vibrating screen, a press, or a gravity concentrator can be used to concentrate the waste residue. The recovered water can be collected and sent to the running, emitting, dripping and leaking recovery system. Most solid wastes are used to fill the pit. The other method is to press the waste residue to a greater dryness and burn it in terms of the zero crossing tension and compression performance of the flat pushing jaw; But this method is much more expensive than pit filling

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