The transformation of rubbish into Bao Qiao solution for sand control

---Nanlinda Uses Papermaking Waste Liquid to Produce Lignin-based Sand Fixing Agent to Solve the Problems of Traditional Sand Control

Nanjing Forestry University has developed a new technology that utilizes “the production of lignin from paper-making waste liquid to produce degradable sand-fixing materials”, which can effectively combine traditional chemical sand fixation with vegetation sand fixation. Experts believe that if this technology is promoted in the country, it will not only speed up the speed of sand control, but also help solve the problem of pollution in the paper industry.

China is one of the countries most seriously affected by desertification in the world. According to statistics, the area of ​​desertified land in the country amounts to 1.74 million square kilometers, which accounts for 18% of the country's total land area and exceeds the total of cultivated land in the country. The rate of desertification expansion has increased from 2,460 square kilometers per year before 1994 to 3,436 square kilometers, which directly affects the implementation of the national sustainable development strategy.

Professor Li Zhongzheng of Nanjing Forestry University said that currently chemical sand fixation is not widely used because of its high cost and difficulty in biodegradation; and the more mature “grass square” vegetation sand fixation technology has a large project investment, long cycle, and low efficiency. It usually takes 4-5 years to form an effective "sand crust." Compared with traditional sand-fixing technology, lignin sand-fixing agent can quickly form sand crust on the surface of moving sand dunes, and has good wind erosion resistance and rain erosion resistance; it is non-toxic and harmless to animals, plants and environment, and will not cause any damage. Sub-pollution; Lignin in the sand-fixing agent is a humic substance. After spraying, it can increase the content of organic matter in the sandy soil, improve the soil, and has a good function of moisture absorption and water retention. The sand-fixing agent contains a sodium lignin plant growth regulator. And nitrogen, potassium, and other trace elements conducive to plant growth can effectively promote plant growth. It is estimated that the average cost of lignin-fixing materials is 165 yuan (equivalent to 0.25 yuan per square meter) per mu, which is much lower than the fixed sand material cost of 0.8 yuan per square meter required by the national 863 tendering project. standard.

According to experiments in Ningxia and other places, the best concentration of lignin sand-fixing agent is 1%-4%. If the concentration is too high, the sand crust is too thick and too hard, and the seedling emergence rate of the sand plant is reduced accordingly; the concentration is too thin, the sand crust cannot maintain a certain late strength, the water retention performance is reduced, and the plant after emergence is likely to die. The technique of combining the use of lignin fixation with vegetation and sand fixation in large areas can be combined with aircraft spraying and aerial sowing. Only by first fixing the quicksand, and planting trees and growing grass at the right time, the combination of Qiao, irrigation and grass, and the use of shrubs can quickly and effectively curb desertification.

According to reports, this new type of degradable sand-fixing agent is prepared by using pulping liquid pulp to produce lignin. China's pulping waste liquid modified products such as evaporative concentration, spray drying and other production and processing technologies are very mature. The existing process technology and equipment conditions are properly modified to produce sand-fixing lignin products. It can not only reduce the cost of sand stabilization, but also effectively solve the problem of waste liquid pollution in small and medium-sized straw pulp and paper companies, and help western paper-making enterprises to get out of the predicament.

Prof. Li Zhongzheng calculated the efficiency account of a papermaking company implementing a pulping waste liquid modification project and producing sand-fixed lignin. He said that with an annual output of 3-4 million tons of straw pulp and papermaking enterprises as an example, the implementation of pulping waste liquid modification project to produce lignin solid sand agent needs to invest 15 million yuan, equivalent to 1/3 of other waste liquid treatment methods investment. After the project is put into production, it can annually produce 3-4 million tons of sand-fixing lignin with a new output value of about 100 million yuan and a profit of 20-30 million yuan. There are at least dozens of such straw-pulp and paper-making enterprises in northwestern China, and most of them have no pulping and waste liquid treatment measures, such as batch and batch treatment, which can effectively help enterprises solve difficulties, increase employment opportunities, increase economic efficiency, and solve pollution problems.

The production cost of lignin sand-fixing agent is about 1,500 yuan per ton, the ex-factory price is 3,000 yuan per ton, the fixed sand spray application amount is 55 kg per mu, and the cost of spraying solid sand agent is 165 yuan per mu. At present, the area of ​​land desertification in China is expanding at a rate of 3,436 square kilometers per year. If this area alone is curbed, more than 280,000 tons of sand-fixing lignin will be needed each year, which can solve the problem of 28-year-old papermaking companies that produce 10,000 tons of pollution.

Li Zhongzheng proposed to combine planting of desert plants (such as Salix, Tamarix, Caragana, etc.) at the same time as sand fixation, and provide new raw material production bases for paper-making enterprises to form papermaking as a leader with “pulp and paper-lignin”. Sand-fixing materials - sand control afforestation - pulp and paper "benign ecological cycle of sand control industry.