Flotation is a complex beneficiation process. During the operation of the flotation plant, the operation of the flotation machine has an important impact on the flotation effect, which will directly affect the indicators of flotation products. It is very important to operate and adjust the flotation machine scientifically. The operating factors of the flotation machine mainly include the amount of aeration, the size of the circulating hole area, the gap of the mixing mechanism, the amount of foam scraping and the level of the liquid level, etc. In this paper, Fodamon engineer will discuss the influence of the above flotation machine operation factors on the flotation effect.
A. Adjustment of flotation machine inflation
Due to the particularity of flotation, the air charge of flotation machine is very important in the flotation process, and the appropriate air charge is the premise of good flotation index. Too much aeration will reduce the selectivity to useful minerals. When the aeration exceeds the limit, flotation bubbles will even merge to form air flow, resulting in liquid surface overturning, unable to form a stable foam layer, so that useful minerals will be lost in the tailings.
Generally, when the pulp concentration fed into the flotation machine is high and the floatability of useful minerals is good, the air charging capacity can be appropriately increased to ensure that the flotation machine has a high processing capacity. When the concentrate index is strictly required, the mineral floatability is poor or the flotation pulp concentration is low, the air charge can be appropriately reduced. According to the sequence of different flotation chambers, the air charging capacity of each flotation chamber is also different, so it should be ensured that each flotation chamber can form a stable foam layer.
B. Circulating hole area of flotation machine
In actual production, the area of circulating holes should be adjusted according to the quality of flotation products, the processing capacity and type of flotation machine to form an appropriate circulating capacity. At the same time, the sundries on the circulating holes should be treated regularly to avoid the blockage of the circulating holes.
C. Flotation machine mixing mechanism clearance
The radial and axial clearances between the impeller and stator of the mechanically agitated flotation machine have a significant impact on the performance of the flotation machine. The increase of the radial and axial clearances between the impeller and stator will lead to the decrease of the air charging capacity, pulp suction capacity and air charging uniformity coefficient of the flotation machine, and increase the power consumption of the flotation machine.
Generally, the radial clearance of the mixer mechanism of the flotation machine is not more than 8mm, and the axial clearance is not more than 10mm. When the flotation machine is discharged for maintenance, the clearance can be detected with a metal or plastic feeler gauge. During the detection, multiple points shall be measured along the circumference of the impeller and the average value shall be taken.
D. Froth scraping and liquid level adjustment of flotation machine
Foaming is an important process of the flotation machine, which is related to the flotation liquid level and has an important impact on the product quality and recovery rate of flotation concentrate. If the foam layer cannot be scraped out of the flotation machine in time, it will lead to the backlog of foam layer and the loss of useful minerals in the tailings, which will not only affect the recovery rate of concentrate, but also affect the processing capacity of the flotation machine. On the contrary, if the foam is scraped out with a part of pulp, the concentrate quality will be reduced. Therefore, it is very important to adjust the flotation liquid level. It should be noted that when the flotation liquid level is raised, the amount of foam scraping will increase, and the foam layer will become thinner. It should be judged according to the flotation machine structure and process links, and adjusted in time.
The above is the influence of flotation machine operation on flotation effect. In the actual production, the operation requirements of the flotation machine are different according to the different process stages. It should be comprehensively considered according to the actual situation and the process production conditions, and operate the flotation machine scientifically and reasonably to ensure the long-term stability of the process indicators and economic benefits.