Pre-selection method of low-ore grade magnetic iron ore

Abstract

The invention discloses a preselecting method of low-grade magnetic iron ore, comprising the steps of crushing the raw ore of the magnetic iron ore by coarse crushing, intermediate crushing and fine crushing operations, conveying to subject to ultra-fine crushing operation, and then crushing by a high-pressure roller mill, scattering the crushed product by a wet cylindrical sieve, conveying the ore on the cylindrical sieve to the vibrating sieve by a belt to perform wet gradation, conveying the ore on the vibrating sieve to a dry magnetic separator by the belt to discard the waste, returning the ore concentrate of the dry magnetic separator to the high-pressure roller mill to crush the ore concentrate again, perform magnetic separation and discarding tailings of the ore concentrate below the vibrating sieve and the ore concentrate below the cylindrical sieve in a wet coarse grain intermediate-field intensity magnetic separator, and selecting the coarse ore concentrate of the intermediate-field intensity magnetic separator by a grinding separation technology. The invention has the advantages that the invention selects quantities of qualified mine tailings by wet magnetic separation before grinding ore, reduces ore grinding work, reduces ore grinding energy consumption and has high system processing capacity; the invention can be widely used in magnetic ore dressing plant, and in particular suitable for treatment of preselecting low-grade magnetic iron ore with the iron grade lower than or equal to 22%.

Description

technical field [0001] The present invention relates to a mineral processing method for magnetite ore, in particular to a method for preselecting low-grade magnetite ore that adopts ultra-fine crushing-coarse wet magnetic separation and throwing off tailings, which can be widely used in magnetite processing plants, and is especially suitable for processing Pre-selection of low-grade magnetite ore with iron grade ≤22%. Background technique [0002] According to the data, the industrially developed countries in foreign countries have hardly developed and utilized low-grade magnetite with iron grade ≤ 22%, and only a few countries have developed and utilized it. A more typical example is the dressing plant of the Kachikanal Mining and Dressing Company in the former Soviet Union. The ore processed is titanium magnetite ore with an iron grade of 15.8%. The annual processing capacity is 40 million tons, the concentrate grade is about 61.5%, and the ore dressing ratio is close to ...

AI Technical Summary

Problems solved by technology

But for the extremely poor magnetite ore with a grade below 22%, because the grade is extremely low, its cut-off grade is generally delineated artificially. When the grade difference between the ore and the surrounding rock is small, the separation effect of the dry magnetic separator is not good. Ideal; for example, the Gaocun Iron Mine of Masteel is an open-pit stope, and the waste rock mixing rate is low (about 3%). The results of multiple dry separation tests show that the yield of tailings is 10-15%, and the grade increase is less than 2%. The loss of magnetic iron is greater than 1.5%; the grade of extremely lean magnetite ore in the dressing plant of Katchikanal Mining and Dressing Company in the former Soviet Union is 15.8%, and the crushed products with a particle size of 10-25 mm are subjected to dry magnetic separation, and the tailing yield is only 4%. around, the grade increased to around 17.5%

In terms of flotation reagents, although the reverse flotation reagents suitable for Anshan-type quartz-type iron ore have made significant progress, there are still few or no high-efficiency reverse flotation reagents suitable for other types of iron ores.

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