Experimental study on magnetic separation process of Hongxing iron ore

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Experimental study on magnetic separation process of hematite

this paper Manufacturer of Red Star magnetic separator The research on magnetic separation technology with complex red iron ore as raw material makes progress research for the shortage of iron ore resources in China, so as to provide certain guidance for the rational development and utilization of the iron ore resources, so as to ease the current situation of iron ore resources shortage in China.

 Magnetic separation process

1. Ore properties

Hematite is mainly composed of hematite and magnetite, and is mainly composed of red iron ore and iron ore powder. Among them, limonite is mainly distributed in the clay minerals such as gibbsite and kaolin in the form of disseminated or reticular. It is inlaid with quartz and clay minerals, and the disseminated particle size is generally 2-20m. It belongs to refractory iron ore. Hematite mainly exists in the form of schistose Specularite, leaf like, mica flake aggregate, oolitic granular and compound oolitic granular. Hematite is distributed in limonite in the form of network and vein. Hematite is inlaid with quartz and clay minerals. Limonite is distributed in clay minerals such as kaolin in disseminated form, and limonite and kaolin exist in rhythmic zoning, The embedding relation is very complex, and the particle size is 20-100m.

 Hematite

2. Research methods of magnetic separation

Magnetic roasting magnetic separation process test: crushing the raw ore to 0-3 mm, taking a certain amount of ore sample, mixing it with pulverized coal in proportion, putting it in 10-13 box type resistance furnace, roasting to the time at the temperature, rapidly quenching with water, grinding the roasted sample in the rod mill to Time, pour out the pulp, conduct magnetic separation test under a certain magnetic field strength, recover concentrate and tailings, filter, dry and weigh, calculate the yield, sample and analyze the main chemical composition of concentrate tailings. The recovery rate of iron concentrate and the grade of iron concentrate were measured.

3. Influencing factors of magnetic separation test

(1) Roasting temperature

The effect of roasting temperature on iron grade and recovery of iron concentrate was studied under the conditions of 10% pulverized coal (0-1 mm) dosage, 15 min roasting time, 0.16 T magnetic field strength and 1.5 min grinding time.

The results show that with the increase of roasting temperature, the grade and recovery of iron concentrate increase gradually. When the roasting temperature increases from 850 ℃ to 950 ℃, the concentrate grade increases from 60.72% to 62.14%, and the recovery rate increases from 45.73% to 87.36%; when the roasting temperature reaches 1050 ℃, although the concentrate grade still keeps rising trend, the recovery rate drops sharply.

(2) Pulverized coal consumption

Under the conditions of roasting temperature 950 ℃, roasting time 15min, magnetic field strength 0.16t and grinding time 1.5min, the experiment of pulverized coal dosage was carried out. With the increase of the amount of carbon powder, the grade and recovery rate of iron concentrate gradually increased. When the amount of pulverized coal increased from 5% to 15%, the concentrate grade increased from 61.17% to 61.82%, and the iron recovery increased from 54.64% to 85.90%. When the amount of pulverized coal exceeds 15%, although the grade of concentrate is improved, the recovery rate of concentrate is decreased. Therefore, it can be considered that when the amount of pulverized coal is 15%, the sample is basically reduced fully. Considering the cost of concentrate and roasting, the amount of pulverized coal is 15%.

(3) Roasting time

The effects of roasting time on iron concentrate grade and recovery were studied under the conditions of roasting temperature 950 ℃, pulverized coal (0-1 mm) dosage 15%, magnetic field intensity 0.16 T and grinding time 1.5 min.

When the roasting time is extended from 10 rain to 15 min, the concentrate grade increases from 61.33% to 62.28%. Although the recovery rate decreases, it is still at a high level. When the roasting time was prolonged to 60 min, the concentrate grade decreased to 60.21%. This shows that the reduction of ore sample is basically sufficient when the roasting time is 15 min. When the roasting time reaches 60min, the reduction of concentrate grade is likely to be due to the reduction of ore sample, which leads to the reduction of magnetic products. Considering the cost and product grade, the roasting time is 15 min.

(4) Grinding particle size

Under the conditions of roasting temperature 950 ℃, roasting time 15min, carbon powder (0-1mm) dosage 15%, magnetic field intensity 0.16t, the effect of grinding particle size on iron concentrate grade and recovery was studied. After the raw ore is roasted, the ore becomes more brittle. From the point of view of saving grinding cost, this is very advantageous. It can be seen that with the increase of mineral recovery, the recovery of the concentrate increases. However, it is found that when the particle size of less than 0.074mm accounts for 98%, the particle size exceeds the lower limit of particle size that can be processed by the magnetic separation equipment due to grinding too fine, so that the yield of concentrate is very small. According to the above results, the grinding time of 2 min is ideal. At this time, 87% of the grinding particle size is less than 0.074mm.

(5) Magnetic field strength

The effect of magnetic field intensity on iron concentrate grade and recovery was studied under the conditions of roasting temperature 950 ℃, pulverized coal (0-1 mm) dosage 15%, roasting time 15 min and grinding time 2 min.

During the test, it was found that when the magnetic field intensity was 0.08t, the yield of concentrate was very small. When the magnetic field strength increases from 0.12T to 0.16t, the recovery rate of concentrate is greatly improved, but the concentrate grade changes little.

The above is my company's 266771 magnetic separation process, and I hope that through the reasonable configuration of magnetic separation process, I can select the reasonable equipment.

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