7 Factors Affecting Froth Flotation
Froth Flotation machine plays an indispensable role in the mineral beneficiation process, there are 7 main factors affecting froth floatation process effect.
1 Grinding Particle Size
Both large ore particles (larger than 0.1mm) and small ore particles (less than 0.006mm) affect flotation efficiency and mineral recovery.
In the case of flotation coarse particles, due to the heavy weight, it is not easy to suspend in the flotation machine, and the chance of collision with the bubbles is reduced. Further, after the coarse particles adhere to the air bubbles, they are easily detached from the air bubbles due to the large dropout force. Therefore, the coarse particles have a poor flotation effect under the general process conditions.
During the fine particles flotation separation process, the fine particles are small in volume and the possibility of collision with the bubbles is small. The fine grain quality is small, and when it collides with the bubble, it is difficult to overcome the resistance of the hydration layer between the ore particle and the bubble, and it is difficult to adhere to the bubble.
2 Excessive Ore Slurry
If the froth machine contains much ore slurry, it will bring a series of adverse effects on flotation cells mineral processing. The main influences are as follows
1 Easy to be mixed in the foam product, so that the concentrate grade is reduced.
2 Easy to cover the coarse grain surface, affecting the flotation of coarse particles.
3 Adsorption of a large number of agents, increase drug consumption.
4 The pulp is sticky and the aeration conditions are deteriorated.
In addition to oxygen, nitrogen and inert gases, there are carbon dioxide and water vapor in the air.
The gas has a selective effect on the surface of the mineral, oxygen is the most important factor affecting the surface of minerals. Oxygen is beneficial to the hydrophobicity of sulphide ores/ sulfine flotation, however, if the action time is too long, the mineral surface will return to hydrophilicity. When the gas adsorption conditions are appropriate, the mineral surface will be drained, the flotation mineral processing can be done even without a flotation agent. The Galena mine can only float up with the action of xanthate through the initial action of oxygen.
Stirring the slurry can promote the suspension of the ore particles and evenly disperse in the tank, thus promote the good dispersion of the air and make it evenly distributed in the tank, further can promote the enhanced dissolution of air in the high-pressure area of the tank, and strengthen the precipitation in the low-pressure area.
Enhanced aeration and agitation are advantageous for flotation separation, but not excessively, as excessive aeration and agitation can have the following disadvantages:
(1) Promoted the merger of bubbles
(2) Reduced concentrate quality
(3) Increased power consumption
(4) Increased wear of various parts of the flotation machine
(5) The volume of the slurry in the tank is reduced (this is because the volume of the tank is increased by the portion occupied by the bubble)
(6) Excessive agitation may also cause the ore particles attached to the bubbles to fall off.
The optimum amount of aeration and agitation in production should be determined by experimentation depending on the type and structural characteristics of the flotation machine.
5 Slurry Concentration
The slurry concentration can affect the following technical and economic indicators:
(1) Recovery rate. When the slurry concentration is small, the recovery rate is low. As the concentration of the slurry increases, the recovery rate also increases, but the recovery rate exceeds the limit. The main reason is that the concentration is too high, which destroys the aeration condition of the flotation machine.
(2) Quality of concentrates. The general rule is that the quality of the concentrate is higher in the flotation of the leaner slurry, and the quality of the concentrate is reduced in the flotation of the richer slurry.
(3) Consumption of pharmaceuticals. When the slurry is thicker, the amount of treatment per ton of ore is less, and when the concentration of the slurry is thinner, the amount of treatment per ton of ore is increased.
(4) The production capacity of the flotation equipment. As the concentration of the slurry increases, the production capacity of the froth flotation machine calculated according to the treatment amount also increases.
(5) Water and electricity consumption. The thicker the pulp, the smaller the water and electricity consumption per ton of ore processed.
In short, when the concentration of the slurry is thick, it is beneficial to the flotation process. However, if the slurry and bubbles do not flow freely, the aeration will deteriorate, thereby reducing the quality and recovery. In this case, the various ore sections of the flotation should determine the appropriate concentration of the slurry according to the nature of the ore and relevant technical requirements.
6 Interaction of pulp density, flotation conditions and ore properties
The most suitable ore pulp concentration during the flotation process is related to the ore property and the flotation processing conditions. The general rules as flow:
(1) The mineral with large flotation density uses a thicker slurry, while the mineral with a small flotation density uses a thinner slurry;
(2) Flotation of coarse-grained materials with thicker slurry, flotation of fine-grained and muddy materials with thinner ore.
7 Pulp Quality
The main effects of pulp quality score on froth flotation process in metallurgy are as follows:
(1) Recovery rate. Within a certain range, when the pulp mass fraction is low, the recovery rate is low; the pulp mass fraction is increased, and the recovery rate is correspondingly increased. However, the mass fraction of the slurry should not be too large. If it is too large, the flotation machine is difficult to inflate normally in the slurry, which in turn reduces the recovery rate.
(2) Concentrate grade. The general rule is that the concentrate grade is higher when ore flotation is carried out in a leaner slurry, while the concentrate grade is reduced when it is floated in a thicker slurry.
(3) The dosage of the agent. The flotation agent should maintain a certain mass fraction in the pulp to have a good flotation effect. When the pulp is thicker, the mass fraction of the medicament is correspondingly increased, that is, the required medicament mass fraction can be achieved with fewer chemicals, and the amount of medicament per tan ore is correspondingly reduced. Conversely, when the pulp is thinner, the amount of the agent increases.
That’s all 7 main variables affecting froth flotation. Contact us to know more info about industrial gold mining equipment, get free froth flotation PDF, flotation process flow chart, and related industry cases of gold froth flotation, zinc froth flotation, copper flotation, ore flotation.