Difficult-separation iron ore tailing pelletizing rotary kiln magnetic roasting treatment technology

Abstract

The invention provides a difficult-separation iron ore tailing pelletizing rotary kiln magnetic roasting treatment technology. The technology mainly comprises the following technological steps: 1, carrying out magnetic separation enrichment of iron ore tailing by a strongly-magnetic magnet separator having a field intensity of 0.6-1.2T; 2, uniformly mixing an obtained enriched tailing with coal dust and a binder according to a ratio of 100:0.5-2:1-3, drying, carrying out damp milling treatment, and pelletizing; 3, drying pellets obtained in step 2; 4, carrying out the magnetic roasting of dried pellets by adopting a rotary kiln; 5, cooling the magnetically-roasted pellets in a water quenching mode; 6, milling the cooled pellets; and 7, carrying out magnetic separation of ground ore powder to obtain iron ore concentrate. The technology allows the iron ore concentrate having a TF2 grade of about 56% can be obtained, increases the metal recovery rate to above 75% from original 65-70%, improves the resource utilization rate and reduces the environmental pollution.

Description

technical field [0001] The invention belongs to the technical field of metallurgy and relates to a magnetization roasting treatment process of a refractory iron ore tailings pelletizing rotary kiln. Background technique [0002] my country's iron ore resources are rich in lean ore and less in rich ore. Lean ore accounts for about 94.6% of the total reserves, and most of them have the characteristics of low grade of raw ore, complex mineral composition, and fine particle size. Since the founding of the People's Republic of China, the rapid development of the metallurgical industry and the immature beneficiation technology have led to a large amount of mining of such refractory ores but low utilization rates, resulting in a large amount of tailings, which not only leads to waste of resources, but also has a huge impact on the environment. [0003] For the above-mentioned refractory iron ore tailings, it is difficult to achieve good beneficiation effect by adopting conventiona...

AI Technical Summary

Problems solved by technology

Since the founding of the People's Republic of China, the rapid development of the metallurgical industry and the immature beneficiation technology have led to a large amount of mining of such refractory ores but a low utilization rate, resulting in a large amount of tailings, which not only leads to waste of resources, but also has a huge impact on the environment.

[0003] For the above-mentioned refractory iron ore tailings, it is difficult to achieve good beneficiation effect by adopting conventional beneficiation methods, such as gravity separation, magnetic separation, flotation or combined process, for example, gravity separation cannot effectively deal with fine-grained powdery low high-grade iron ore; magnetic separation cannot effectively separate hematite, limonite and iron-containing silicates; flotation cannot effectively process low-grade iron ore with complex gangue components and similar physical and chemical properties to hematite and limonite

[0004] For the above-mentioned refractory iron ore tailings, magnetization roasting reduction technology is the best sorting method at present, but the tailings have been processed through mineral processing, and the particle size is relatively fine, which cannot be solved by existing magnetization roasting equipment such as shaft furnaces and rotary kilns. Problems of industrial magnetization roasting of powdery materials

[0005] To sum up, due to the problems of poor, miscellaneous and fine iron ore, the beneficiation index has been unsatisfactory. Only strong magnetic concentrate with a TFe grade of 45-50% can be obtained, and the metal recovery rate is 65-70%. of iron lost in tailings

For example, the Jiuquan Iron and Steel Concentrator, since it was put into operation, the total amount of tailings discharged into the tailings pond has exceeded 50 million tons, and the iron grade of the tailings is about 21%. The tailings in the tailings pond contain very little strong magnetic iron minerals, and Most of them exist in the form of conjoined organisms. Conventional mineral processing methods are difficult to recycle tailings, which not only leads to waste of resources, but also pollutes the environment.

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