Overview of iron tailings re-election and types of iron tailings

Re is selected from iron ore tailings selected 1t each iron ore discharge to 2.5 ~ 3t tailings, mineral processing tailings of iron having a large number of fine particle size, many types, the nature of complex features. According to the annual report of black metallurgy mining statistics in 1996, the country's iron ore concentrator selected amount of 215 million t, the discharge of tailings amounted to 130 million t, accounting for 60.46% of selected ore; key national iron ore concentrator selected amount For 110 million tons, the amount of tailings discharged is 58.026 million tons, accounting for 52.75% of the ore. At present, the amount of iron tailings piled up in China is as high as more than one billion tons, accounting for nearly one-third of the total stockpiles of tailings. Therefore, the re-election of iron tailings has attracted the attention of iron and steel enterprises, and has used magnetic separation, flotation, acid leaching, flocculation and other processes to recover iron from iron tailings, and some also supplemented non-ferrous metals such as gold and copper . The economic benefits are higher.

First, the type of iron tailings

The tailings resources of iron ore beneficiation in China can be divided into two categories: single metal iron tailings and polymetallic iron tailings according to the content of associated elements.

(1) Single metal iron tailings

According to its content of silicon, aluminum , calcium and magnesium , it can be divided into:

1. High-silicon Anshan iron tailings

This type of iron tailings is the largest type of iron tailings. The tailings are high in silicon, and some of them contain SiO ₂ up to 83%. Generally, they do not contain valence associated elements, and the average particle size is 0.04 to 0.2 mm, which belongs to this type of tailings. The concentrating plants include Benfen Nanfen, Shantoushan, Anshan Iron and Steel Donganshan, Qidashan, Gongchangling, Dagushan, Shougang Dashihe, Miyun, Shuichang, Taigang Suikou, Tangshan Shirengou and other concentrating plants.

2, high aluminum horse steel type iron tailings

The annual discharge of such tailings is not large, mainly distributed in the Ninglang area in the middle and lower reaches of the Yangtze River, such as Jiangsu Jishan Iron Mine, Maanshan Gushan Iron Mine, Nanshan Iron Mine and Huangmeishan Iron Mine. Its main feature is that the high content of Al2O3 accounts for 30% to 60%.

3. High calcium magnesium strontium type iron tailings

Such tailings are mainly concentrated in iron ore mines in the Luan area, such as jade shovel, Xi Shimen, Yuquanling, Fushan, Wangjiazi and other concentrating plants. The main elements are sulfur, cobalt and trace amounts of copper, nickel , zinc , lead , arsenic , gold, silver, etc., -0.074mm grain content accounts for 50% to 70%.

4, low calcium, magnesium, aluminum, silicon wine steel iron tailings

The main non-metallic minerals in this type of tailings are barite and jasper. The associated elements are cobalt, nickel, bismuth , gallium and copper. The tailings particle size is -0.074mm, which accounts for about 70%.

Second, polymetallic iron tailings

It is mainly distributed in the Panxi area of ​​southwest China, Baotou area of ​​Inner Mongolia and the WISCO area of ​​the middle and lower reaches of the Yangtze River. It is characterized by complex mineral composition and many associated elements. In addition to rich non-ferrous metals, it also contains a certain amount of rare metals, precious metals and rare elements. . In terms of value, the recovery of associated elements in such iron tailings has far exceeded the recovery value of the main metal-iron. For example, Daye-type iron tailings (Daye, Jinshan, Chengchao, Zhangjiatun, Jinling and other iron ore dressing plants) contain copper, cobalt, sulfur, nickel, gold, etc. Silver, selenium and other elements; Panzhihua Iron Ore Tailings contain a considerable amount of vanadium and titanium , and also contain elements such as cobalt, nickel, gallium and sulfur that are worth recovering; Baiyun Obo type iron tailings contain 22.9% iron. Minerals, 8.6% of rare earth minerals and 15.0% of fluorite .