Method for separating iron, vanadium and titanium in vanadic titanomagnetite

Abstract

The invention provides a method for separating iron, vanadium and titanium in vanadic titanomagnetite. According to the method, most of vanadium is left in slag by controlling a direct reduction temperature, iron enters a magnetically-separated substance, a by-product sodium sulphate obtained through fractional crystallization carried out through sodium-modification vanadium extraction wastewater, is added in vanadium-titanium slag after magnetic separation, and vanadium is extracted in a water-leaching manner after oxidation roasting, so as to obtain vanadium-containing solution and titanium-rich slag. According to the method, on one hand, the recovery rate of vanadium is increased, on the other hand, due to a small amount of the vanadium-titanium slag, lots of sodium salt has no need to be added, and moreover, the small amount of the added sodium salt is treated by virtue of the sodium-modification vanadium extraction wastewater to obtain the by-product, thus cost is saved, secondary resource recycling is realized, and economic benefits are improved; and in addition, the magnetically-separated substance obtained in a manner of carrying out magnetic separation at first, and then adding sodium salt in vanadium-titanium slag and carrying out oxidation roasting, is relative pure compared with the magnetically-separated substance obtained in a manner of adding sodium salt and carrying out oxidation roasting at first, and then carrying out magnetic separation, a sulphur content of the magnetically-separated substance is low, and the quality is guaranteed.

Description

technical field [0001] The invention relates to the technical field of metallurgy, in particular to a method for separating iron, vanadium and titanium in vanadium-titanium magnetite. Background technique [0002] my country's Panxi region is rich in vanadium-titanium magnetite resources. At present, the blast furnace-converter process is still the mainstream method for processing vanadium-titanium magnetite. However, with the development and progress of society, the traditional process is also facing increasing energy and Environmental pressure, especially the dependence on coking coal has become a bottleneck restricting its development. More importantly, the blast furnace-converter process can only recover the iron and vanadium in the vanadium-titanium magnetite, and the titanium element enters the blast furnace slag, due to the low grade (TiO in blast furnace slag 2 content of 22% to 25%), there is still no effective way to utilize it, resulting in a waste of valuable tit...

AI Technical Summary

Problems solved by technology

[0004] (1) High-temperature direct reduction to produce iron pearls—magnetic separation to separate iron and vanadium-titanium. This method generally controls the reduction temperature above 1300°C, so that iron oxides can be reduced, metallic iron aggregates and grows, and it is easy to separate slag and iron. The direct reduction process requires high temperature, high temperature resistance of the equipment, complicated maintenance and overhaul, and more importantly, the recovery rate of vanadium is not high, about 50% of the vanadium enters the magnetic separation material, and 50% of the vanadium Into the slag phase, the vanadium is not relatively concentrated, and the difficulty of recovery increases

[0005] (2) Low-temperature direct reduction—magnetic separation to separate iron and vanadium-titanium. Generally, the reduction temperature is controlled below 1100°C. Although most of the vanadium can be retained in the vanadium-titanium slag after magnetic separation, due to the low reaction temperature, metallic iron Insufficient agglomeration of iron and titanium elements in the magnetic separation process is not complete, so that the iron grade in the magnetic separation material is not high, the titanium grade in the vanadium-titanium slag is not high, and the product value is reduced

[0006] (3) Adding additives to reduce roasting—water leaching to extract vanadium—magnetic separation to separate iron and titanium. This process can realize the separation of iron, vanadium and titanium, but it needs to add a large amount of sodium salt additives, generally 20% of the concentrate mass Left or right or even more, so much sodium salt brings many problems to the subsequent harmless treatment of vanadium-containing liquid and tailings. At the same time, part of the sulfur element enters the magnetic separation material, pollutes the magnetic separation material, and limits the scope of use of the product.

The difference between the present invention and this patent is that the reduction temperature range of the present invention is lower, and no iron beads are produced, because experiments have proved that when producing iron beads, about 50% of the vanadium will enter the magnetic separator, and 50% of the vanadium Remains in the vanadium-titanium slag, resulting in low yield of vanadium

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