Importance of tailings disposal

Tailings are the products with the lowest content of useful components discharged from mining production. They are stored in tailings ponds for a long time, which not only occupies a large amount of agricultural and forest land, but also makes the local land resources unbalanced.

Because the tailings contain a large number of toxic substances, which mainly come from the large amount of flotation reagents added during the flotation process and the metal elements in the ore, such as common cyanide, black medicine, yellow medicine, pine oil, copper ions, lead ions, etc., which penetrate into the soil, air and water, and will also cause harm to humans, livestock, fish and farmland. For example, 14 rivers near 9 key ore dressing plants in metallurgical mines are polluted, Anshan Iron Ore Dam covers an area of ​​15 km2, Bayan Obo Mine tailings cover an area of ​​11 km2, Jinchuan Nickel Mine tailings dust 10 km2, and dust causes the surrounding land to become desertified, causing a large area of ​​farmland to reduce or even completely stop production.

Some small mines even discharge tailings directly into nature. A mine in Shanxi Province owns dozens of small iron mines, but only 1/10 of its tailings are discharged into tailings ponds, while the rest are directly discharged into surrounding rivers and woodlands. Since most mine tailings have been ground to 0.074mm and stored in tailings dams or rivers, valleys, lowlands, etc., they often seep and overflow. The dust on the surface of unreclaimed tailings ponds can be blown to the surrounding areas by the wind, sometimes even forming mine dust storms, which seriously deteriorate the living and production conditions in the surrounding areas.

Statistics at home and abroad show that the construction investment of tailings ponds is huge, accounting for 5% to 40% of the total cost of the entire mining industry. The maintenance and repair of tailings ponds requires a lot of money. According to statistics from relevant departments, my country's metallurgical mines need 1-3 yuan for tailings pond infrastructure construction and 3-5 yuan for operation and management fees per ton of tailings. With the continuous increase in the number of tailings, the height of the tailings dam has also increased, and the hidden dangers of unsafe conditions have also increased. For example, in September 1962, the Huogudu tailings pond in Yunnan Province collapsed, 3.3 million m3 of tailings and 380,000 m3 of water gushed out, 5.4*106m2 of cultivated land, 11 villages and a farm were destroyed, 171 people died, 92 people were injured, 13,970 people were affected, and the direct economic loss was 20 million yuan. In April 1988, the flood discharge tunnel of the Lixi tailings pond in Shaanxi Province collapsed, and 1.36 million cubic meters of tailings sand and water leaked, causing serious water pollution in 16 counties and cities in Shaanxi and Henan provinces, with direct economic losses of 32 million yuan.

The harm of tailings is so serious that it can be seen how important tailings treatment is. At present, my country has a tailings treatment process - tailings dry discharge process, which can effectively reduce the damage to the ecological environment, humans and livestock caused by large-scale accumulation of tailings and leakage of tailings water by multiple dehydration of tailings and then pile them in the tailings pond, and also avoid the harm of tailings dam breach.