Beneficiation of titanium ore

Is generally believed that the content of these ores and sands reached, it has industrial exploitation value: titanium iron ore rock TiO ₂ content of between 10% to 40%, or rutile TiO ₂ content of more than 3%; placer The ilmenite-containing iron ore is above 15kg/m3, or the rutile is above 2kg/3; some symbiotic ore with many valuable components, even if the TiO ₂ grade is lower, can be comprehensively considered for mining.

Ilmenite is generally mixed with a lot of waste sandstone and other minerals, and its TiO ₂ grade is low. Beneficiation is based on the different composition and different physicochemical properties of these minerals, using different mineral processing methods to separate ilmenite from them to improve the TiO ₂ grade. Since ilmenite is often associated with many minerals, it is difficult to select a ilmenite concentrate with high TiO ₂ grade and low impurity with only a single beneficiation method. In order to improve the grade of TiO ₂ , it is necessary to select different combinations of beneficiation methods according to different minerals in a segmented manner to achieve the desired effect.

I. Mineral processing

The rock ore is mainly composed of titanium-containing composite iron ore, which has a dense structure and is difficult to select. The general beneficiation process can be divided into the following stages.

Pre-selection

The mined rock will be selected to discard part of the tailings to improve the beneficiation capacity, increase the selected grade and reduce the cost. Pre-select the common magnetic pulley magnetic separation, heavy medium cyclone and coarse-grain jump.

2. Iron selection

By selecting iron containing titanium composite iron ore, iron ore or vanadium iron concentrate for iron making can be obtained, and most of the iron can be separated from titanium. The magnetic separation method is commonly used for iron selection.

3. Selection Titanium

The tailings after iron selection are subjected to multi-stage crushing and sieving, and various methods such as re-election, magnetic separation, electric selection, and less flotation are selected according to various mineral source components to improve the TiO ₂ grade of the titanium ore.

Second, the ore dressing

Due to the stable physical and chemical properties of ilmenite and its relatively high density, it can be deposited in the process of scouring, handling and hydraulic sorting in rainy areas, enriched in the surface and riverbed, or flooded to the river exit. It is deposited offshore. Therefore, ilmenite is widely used in coastal sand mines, riverbed sand mines, alluvial sand deposits, residual slope sand mines and low valley sand mines.

On riverbeds, sand ore is often sent to a mining vessel for reprocessing using a chain bucket or a suction or bucket wheel conveyor.

On the beach, bulldozers, scrapers, loaders, bucket wheel excavators are often used to transport roughing plants through belt conveyors or sand pump pipes.

The collected sand is first subjected to slag removal, sieving, classification, de-sludge and concentration, followed by rough selection. Yunnan mines are also wet.

The rough selection is based on the density of minerals, and the gangue tailings with small density are discarded. The heavy minerals with high density are about 90%. The common cone concentrators and spiral concentrators are used. The roughing plants are all mobile, often with mining. combine together.

The selection is carried out by wet re-election, wet magnetic separation and flotation, followed by dry magnetic separation, electro-selection and gravity separation. [next]

Third, commonly used mineral processing methods

1. The principle of hand beneficiation is to separate the mixed impurities by visual hand picking according to the different shape characteristics of different minerals such as color, gloss, grain size and crystal form, and initially remove the gangue such as quartz . This is a kind of The original and simple method of mineral processing. Suitable for rough selection of ilmenite.

2. Gravity selection

Gravity selection is also a rough selection for coarse screening. Due to the different relative densities of ilmenite and other impurity minerals, in a moving medium, the sedimentation velocity is different, and the ore particles and impurities are separated. The relative density of titanium-containing minerals is greater than 4, and most of the gangue minerals such as feldspar and quartz with a relative density of less than 3 can be removed by gravity selection. The density of ilmenite is larger than that of less soil, and it is washed with running water. The sand with relatively low density flows away with water, and finally the ilmenite sand with higher density is selected. Ilmenite but after the gravity still contains selected from ilmenite similar to the relative density of zircon, monazite, rutile, leucoxene, cassiterite, magnetite and chrome iron ore and other minerals, and some of the gangue. For large-scale gravity selection, chutes, knockout machines, spiral concentrators and shakers can be used. If washing, sieving and deliming are used, gravity can be selected, then a screw machine can be used. The screening medium is usually water and air.

3. Float selection

Flotation is the use of different mineral or chemical properties of various mineral surfaces, adding some foaming flotation agents to produce a large amount of foam, due to the different immersion humidity of different minerals at the interface between air and water, resulting in The selected adsorption, a certain component floats out as the foam floats, and the other components precipitate and separate. When the ilmenite ore floats, the commonly used flotation agents are sulfated soap, Taikoo oil, sodium dodecanoate, water glass, sodium fluoride, sodium fluorosilicate and sodium alkyl sulfonate. Flotation equipment has a complete set of standard equipment. The effect of this law is good. However, the cost is high, the selection and deployment of flotation agents are complicated, and wastewater discharge is difficult to handle.

4. Magnetic separation

Magnetic separation is a selection of ilmenite. It uses the different magnetic permeability of various minerals to make them pass through a magnetic field. Because of the different reaction to the magnetic field, the magnetic permeability is high, and it is sucked up by the magnetic disk. When it loses magnetism, it falls, and the collecting funnel collects it. The magnetic permeability is low. It is not sucked up, left in the original or with the rotating belt, and is separated as a tailings belt. Ilmenite is a paramagnetic mineral that can be attracted by a magnet and cannot absorb iron by itself. It can be magnetized and demagnetized. Its magnetic properties are neutral and weak magnetic. The order of change in the magnetic properties of minerals from strong to weak is: magnetite > ilmenite > hematite > garnet > biotite > monazite. Zircon and rutile are non-magnetic minerals. The coarse ore is passed through a single-disc or three-disc dry magnetic separator, and weakly magnetic garnet, monazite, and non-magnetic zircon, rutile, and gangue are separated by a belt. From the example of ilmenite ore dressing, it is known that the mineral composition of ilmenite ore after several times of magnetic separation is still very complicated, and still contains more non-titanium minerals. The strength of the magnetic field, the magnitude of the current and the temperature have a great influence on the effect of magnetic separation. This method uses a lot of ore dressing for ilmenite. In order to ensure the purity of the mine, non-titanium minerals are removed as much as possible to facilitate the smooth production. Often the purchased ore will be pulverized by a magnetic separation before the Raymond grinding.

5.Electrical selection

Electrification is also a selection of ilmenite, which is used when other methods are used to achieve the separation requirements. With this electrostatic selection, generally better results can be obtained. Electro-election is a method of sorting different minerals according to the difference in electrical properties of minerals in a high-voltage electric field. When the rectification of the two minerals is different, or when the difference between the sorting potentials exceeds 3800 V, the electrostatic concentrator is used to select the points. Commonly used are electrostatic feeders and corona concentrators. The selection process of Beihai Concentrator is shown in the figure below.