Optimizing Ilmenite Beneficiation: A Comprehensive Guide to Modern Techniques

Ilmenite is an oxide mineral of titanium and oxygen, with a chemical formula of FeTiO3 and a theoretical TiO2 content of 52.66%. It is the main raw material for refining titanium and titanium dioxide. Crystal aggregates often appear irregular granular or scaly; the color is from gray to iron black. If it is wrapped by hematite, it will appear brown to brown-red, and has weak magnetism.

1 Gravity selection

After coarse and medium crushing of the primary ilmenite, a large amount of gangue can be discarded by gravity selection to improve the quality of subsequent products. Gravity selection is generally completed by using spiral chutes, shaking tables, centrifuges and other equipment. The general process of ilmenite gravity selection is desludging of raw ore-roughing of chute-sweeping of chute-shaking table selection. 

2 Flotation

Flotation is a method of separating minerals based on the differences in physical and chemical properties of various mineral surfaces. It is the most widely used beneficiation method in the separation of fine and ultra-fine materials. On the other hand, flotation is a beneficiation method with high precision and good separation effect, especially for fine-grained ilmenite.

3 Magnetic separation

Magnetic separation is a beneficiation method that uses the magnetic differences between minerals in an uneven magnetic field to separate different minerals. Magnetic separation is simple and convenient, and does not produce additional pollution.

4 Combined process

Due to the physical properties of ilmenite such as high density, weak magnetism and conductivity, it is sometimes difficult to achieve ideal results with a single beneficiation, so the combined process is crucial.

01 Combined process flow of magnetic separation and re-selection

The combined process flow of magnetic separation and re-selection is a one-stage grinding-weak magnetic iron separation-strong magnetic tailings discarding-strong magnetic concentrate regrinding-weak magnetic re-selection of iron-shaking table selection. Through the one-stage grinding-weak magnetic iron separation-strong magnetic tailings discarding operation, half of the tailings can be removed, and the ilmenite can be initially enriched, which can reduce the amount of re-grinding in the titanium selection operation and reduce the grinding cost; then the titanium is selected through the experiment of strong magnetic concentrate regrinding-weak magnetic scavenging-shaking table re-selection, and finally titanium dioxide is obtained.

02 Combined magnetic flotation process

The magnetic separation tailings of a vanadium-titanium magnetite contain a large amount of titanium concentrate. The first-stage magnetic separation tailings are first subjected to strong magnetic pre-selection and then flotation; the second-stage magnetic separation ore and tailings are directly flotated. The flotation section adopts a process of one roughing, one scavenging and four fines to obtain a TiO2 grade of 47.78% in the flotation concentrate.

5 Other process flows

01 Acid leaching

There are two main methods for acid leaching ilmenite, one is the sulfuric acid method and the other is the hydrochloric acid method. Compared with the disadvantages of large amount of industrial waste and substandard environmental protection, the hydrochloric acid method has the advantages of good separation and less industrial waste, and has gradually become a mainstream method for producing artificial rutile.

02 Electrostatic separation

Electrostatic separation is mainly used in the process of ilmenite concentration. This method can effectively remove some non-conductive minerals in the concentrate product, thereby improving the grade of the concentrate product.