Mine tailings are indispensable emissions in the process of mineral processing and are harmful substances in people's eyes. It covers a large area and is put into production. According to statistics, China's tailings discharge totals more than 5 billion tons, with a total area of ​​65,000 square kilometers, and it is growing at a rate of 500 million tons per year. How large is the area. According to the compensation standard for land acquisition of farmers, the one-time compensation for occupied farmland is about 16,000-28,000 yuan per mu, plus the construction investment of the tailings pond. The overall production is similar to the production of the ore dressing production line.
Tailings contain a lot of toxic heavy metal ions and residual flotation reagent, will mine and its surrounding environment pollution and destruction. If the tailings are re-corroded, or some of the migratory elements entering the tailings chemically migrate, it will cause serious pollution to the atmosphere and water and soil, leading to land degradation, and its impact will be long-lasting. Through the investigation of 9 national key mineral processing units, 15 rivers near the plant were polluted, and the dust caused the surrounding land to be sanded, resulting in 235.5km2 farmland production and 268.7km2 farmland production reduction.
When the tailings storage capacity exceeds 1000m3, it is easy to cause dam failure. Once the damage of the dam is not to be underestimated, the pollution assessment team of the Clark University of the United States indicates that the tailings dam damage is only in the hidden dangers of 93 accidents and pollutions in the world. In the nuclear explosion, nerve gas and other hazards. As of 2007, the total number of statistical tailings dams in China was 43. In 2008, several dam failures occurred successively. The most serious one was Shanxi 襄汾, and the 980 stern tailings dam broke. The accident discharge capacity was 26.8m3, and the death occurred. The number of people was 277, 4 people were missing, 3 were injured, and the direct economic loss reached 96.192 million yuan.
From the above facts, it is not difficult to see that tailings bring very serious harm to humans, the environment and the land. However, tailings also contain useful ingredients of other ingredients, or can be recycled, or can be used twice, which can bring good economic benefits.
China Yantai Xinhai Tailings Comprehensive Utilization Research Institute conducted a study on a gold mine tailings in Tibet. The results show that gold is mainly used in tailings, accompanied by tin , copper and silver . The gold recovery is 30% and the tin recovery rate is 20%. Silver recovery is 16%. The cost of tailings is 5 yuan / t, the output value is 16.8 yuan, and the profit is 11.7 yuan. Another example of a magnetic iron tailings saddle, which still contains 20% iron, Ma On Shan Institute of grinding and re-re-election for this mine, finally obtaining grades of up to 65.76% of high-quality iron ore concentrate, concentrate an annual output of 39 200 t, in Can obtain economic benefits of 12 million yuan.
Tailings also contain other useful substances, such as: silicate, aluminosilicate, carbonate minerals, and trace metals and other minerals, which are used as building materials, ceramics, and other roads. In an iron ore mine in Shanghai, the tailings with an annual output of 500,000 tons are used for the production of paving roads and building stones. The annual economic benefits can be recovered about 2.8 million yuan; some substances in the tailings can also be used as raw materials for fertilizers, such as Zn. Trace elements such as Mn, Cu, Mo, V, B, Fe, and P are all elements required for plant growth and development. For example, the Maanshan Mine Research Institute uses a magnetizer to magnetize the iron tailings of the magnetic separation plant to produce a magnetized tailings that is applied to the soil. It has been proved by experiments that after the tailings are applied to the soil, the yield increase effect of crops is remarkable. The average yield of early rice is 12.63%, the yield of medium rice is 11.06%, and the yield of soybean is 15.5%. The tailings can also reclaim vegetation. A mining company in Anshan invested more than 40 million yuan in its own mines, and completed a total of 15.59 million square meters of mine vegetation restoration. The mine area recovered 70%. After 3-5 years, the tailings pond was on the tailings. Planted a large economic forest with an economic value of several hundred million, and the environmental benefits are incalculable.
It can be seen that if the tailings can be used correctly, it will no longer be a harmful substance. On the contrary, it can promote the economic development of our country and make the mine green and tailless. I believe that the tailings will be used in the near future. stand up.
Choosing the right lug nuts and wheel studs for your wheel application is important for safety reasons as well as appearance.
Carries Right hand and Left hand lug nuts in all sizes as well as lug bolt kits. Sizes include 9/16, 7/16, 1/2, 12x1.25mm, 12x1.5mm, 14x1.5mm, 12x1.75mm, 14x2mm, and more.
produced by automatic cold extrusion machine, and surface treatment: zinc plated, chrome plated, balck, and neo-chrome plated.
Wheel Nuts, Wheel Lug Nut, Truck Wheel Nut, Aluminum Wheel Nut, Spline Drive Lug Nut
Ningbo Xiangsheng Auto Parts Co., Ltd. , http://www.partsaa.com