As a typical refractory iron ore, Limonite has the characteristics of easy sliming and poor sorting indicators. However, due to its rich reserves, it has become a powerful backing to solve the shortage of iron ore resources.
Limonite beneficiation equipment and Limonite beneficiation production line methods and steps
The selection of Limonite beneficiation equipment, especially the equipment for high intensity magnetic separation of Limonite, must be determined according to the mineral properties of limonite. Only coarse particle beneficiation can greatly improve the grade of the concentrate, and brown iron ore with high beneficiation recovery rate is suitable.
Generally speaking, it is equipped with a complete set of Limonite beneficiation equipment, mainly including jaw crusher, ball mill, grader, high intensity magnetic separator, flotation machine, thickener, dryer, vibrating feeder, vibrating screen, belt conveyor and other Limonite beneficiation equipment.
Technological process of Limonite beneficiation equipment: raw ore crushing ball mill screening drying gravity separation flotation magnetic separation flotation.
Common methods of Limonite beneficiation production line include:
1. Single Limonite beneficiation production line process;
2. Single flotation Limonite beneficiation production line;
3. Single magnetic separation Limonite beneficiation production line flow;
4. Combined process Limonite beneficiation production line.
The Limonite beneficiation production line mainly includes single beneficiation process and combined beneficiation process. The single Limonite beneficiation production line mainly includes gravity separation, magnetic separation, flotation (positive and negative flotation), etc.
1. Limonite production line gravity concentration.
Gravity separation is the main beneficiation method of Limonite production line, that is, gravity separation is used, and in most cases, it is used for the treatment of coarse embedded ore.
In most Limonite production lines, in order to further improve the quality grade, Limonite ore dressing equipment such as ore washer, trough washer and scrubber are usually used for separation, and heavy media and jigs and other gravity Limonite ore dressing equipment are used for separation. The Limonite production line has simple equipment, low cost, small power consumption, and its disadvantages are low recovery rate, high tailings grade, which is not conducive to comprehensive recovery. It is a method of Limonite beneficiation production line.
2. Magnetic separation of Limonite production line.
Because Limonite contains iron, they are all magnetic, and the difference of iron content in Limonite also leads to its magnetic difference, so that we can carry out magnetic separation and beneficiation of Limonite production line according to the magnetic difference. Generally, strong magnetic separation is used to separate Limonite, but the difference of Limonite production line to fine grade (-20um iron mineral) also leads to the difference of its magnetic separation effect.
3. Flotation of Limonite production line.
The effect of recovering fine iron minerals by flotation alone is better, but Limonite is easy to be slimed, which seriously affects the flotation effect. Therefore, desliming or enhanced dispersion of slime should be considered before flotation. Due to the fine particle size, the slime is not easy to attach to the bubble surface, forming an independent mineralized foam layer, and easy to adhere to the coarse particle surface. The selectivity and floatability of coarse-grained Limonite are obviously decreased after gangue mud is attached to its surface; The mud ratio and surface energy (activity) are high. Firstly, it adsorbs (consumes) a large amount of flotation reagents, resulting in more oil and water in the slurry, high viscosity, and a significant decrease in the selectivity and floatability of the slurry.
The flotation of Limonite production line can adopt positive and reverse flotation methods. Research and practice show that reverse flotation is more suitable for Limonite quality improvement and impurity reduction. In addition, because Limonite particles have loose grains and large specific surface area, which are easy to absorb and consume a large amount of reagents in the flotation process, the multi-stage dosing and multi-stage separation flotation process should be adopted for the flotation of this Limonite production line. At the same time, the closed flotation process formed by the return of middlings will reduce the selection index, and the centralized return of middlings will have less impact on the beneficiation index than the sequential return of middlings.
1. Limonite production line gravity separation high intensity magnetic separation method.
Generally, Limonite beneficiation production line method can use gravity concentration and strong magnetic separation to obtain better separation effect, that is, Limonite is washed, screened, classified and deslimed after grinding with fine particles or rod mill, coarse particles use gravity concentration concentrate, medium particles use roller magnetic separator to separate concentrate, and medium particles use roller magnetic separator to separate concentrate.
To improve the iron metal recovery rate, it is possible to consider regrinding and gravity separation to significantly increase the iron grade of the concentrate. At the same time, due to the recovery of fine particle size and iron minerals in the ore slurry, a higher recovery rate can be achieved.
2. Flocculation flotation of Limonite production line
When the grinding fineness reaches a certain value, the slurry can be fully dispersed by adding sodium carbonate and sodium silicate. The flocculation process can selectively flocculate Limonite. However, sometimes a single flocculation method can not remove a large number of coarse gangue minerals, so the flotation method can be used on the basis of selective flocculation to obtain better separation indicators.
3. Flocculation high intensity magnetic separation method for Limonite beneficiation production line
For low-grade and fine-grained Limonite, only by fine grinding can a high-grade iron concentrate be obtained. At the same time, sliming will also occur, resulting in low recovery rate. At this time, flocculation strong magnetic separation method can be used as the beneficiation method for low-grade and fine-grained Limonite.
The practical application shows that under the condition of similar iron concentrate grade, the flocculation high intensity magnetic separation magnetic separation combined Limonite beneficiation production line process is 10.97% -15.73% higher than the direct magnetic separation process, and the selection effect is good. The fine-grained iron minerals that were originally lost in high intensity magnetic separation operations were recovered due to selective agglomeration, resulting in an increase in apparent size and magnetic force. Therefore, fine Limonite can adopt the process of flocculation high intensity magnetic separation combined with Limonite beneficiation production line, but the process of slurry dispersion and selective flocculation as well as the selection conditions of high intensity magnetic separator (mainly ore feeding mode, flushing water volume, etc.) should be correctly grasped.
Note: Due to different mineral properties, the Limonite beneficiation equipment and Limonite production line process used are also different, resulting in different prices of Limonite beneficiation equipment.