Factors affecting the flotation process

There are many factors affecting the flotation process. Among them, grinding fineness, slurry concentration, flotation time, pharmaceutical system, slurry temperature, flotation process, water quality, flotation equipment type, etc.

1. Grinding fineness

Flotation requires not only the dissociation of mineral monomers, but also the appropriate inclusion size. The ore particles are too coarse, and the useful minerals have not been dissociated from the monomers. Even if the minerals have been dissociated from the monomers, the particles are large in size and heavy in weight, making it difficult for the bubbles to be brought up or even if they are brought up, they are easily detached from the bubbles during agitation.

The ore is too fine, which not only increases the grinding cost, but also produces slime. Because of its large specific surface area and strong surface activity, the slime adsorbs a large amount of flotation reagents or other ore particles, which easily deteriorates the flotation process, reduces the concentrate grade and recovery rate, and increases the consumption of chemicals.

(1) Float requirements for fineness:

1 useful minerals basically achieve monomer separation;

2 The particle size of the coarse-grained monomer mineral must be less than the upper limit of the particle size of the mineral float;

3 Avoid muddy as much as possible. When the diameter of the flotation ore is less than 0.01mm, the flotation index drops significantly. When the particle size is less than 2-5 microns, the useful mineral and the gangue are almost impossible to separate.

(2) Measures to improve coarse flotation:

1 increase the amount of aeration, resulting in more large bubbles or a large amount of microbubbles in the slurry;

2 Properly strengthen the stirring strength to suspend the ore particles and increase the probability of collision. Or use shallow grooves to reduce the probability of falling off the ore;

3 increase the concentration of pulp properly;

4 Improve the pharmaceutical system. Causes strong hydrophobicity.

(3) Measures to improve fine flotation:

1 Improve the classification efficiency and reduce the formation of slime. Generally, a multi-stage crushing and multi-stage closed-circuit grinding method is adopted;

2 Add a slime dispersant. Such as soda, water glass, etc. to eliminate the mud cover. The gangue slime can also be agglomerated with an electrolyte (NaCl, (NH)2SO4, etc.);

3 batches of drugs in batches to maintain the effective concentration of the slurry;

4 using a leaner pulp concentration;

5 de-sludge.

2, pulp concentration

The slurry concentration affects the following process indicators:

(1) Recovery rate. Dilute, low recovery rate; high, high recovery rate, and reached the maximum value, after the maximum value, and then decreased. Mainly due to the deterioration of the aeration conditions.

(2) Concentrate quality. Rare, high; thick, low.

(3) dosage of the agent. In inverse proportion.

(4) Production capacity of flotation. In direct proportion.

(5) Flotation time. Thick, long time, is conducive to improve recovery and production capacity.

(6) Hydropower consumption. Thick, low consumption.

The most suitable general rule for slurry concentration is:

(1) When the flotation has a larger proportion of minerals, a more concentrated pulp is used; for minerals with a smaller specific gravity, a thinner slurry is used;

(2) Flotation coarse-grained materials use thicker pulp; while flotation fine-grained or mixed-form materials use thinner pulp.

(3) The coarser and finer slurry is used for rough selection and sweeping, while the separation operation of the selected operation and the difficult-to-separate mixed concentrate is applied to the rarer slurry to ensure the quality of the qualified concentrate.

Common pulp density metallic minerals are: roughing 25-40%, selected by 10-20% 20-40% scavenging, roughing up to 50-55%, the lowest selection of 6-8%.

3. Pharmacy system

The pharmaceutical system (also known as the prescription) includes the type, dosage, formulation, location, and method of addition.

(1) dosage of the agent. Flotation agents are a major factor in regulating the floatability of minerals. Insufficient dosage can not be adjusted, and minerals are difficult to sort. Excessive dosage can also cause adverse effects, which not only reduces concentrate quality, loses selectivity, but also causes waste. Special emphasis is placed on “appropriate amount” and “selectivity”.

Hazards caused by excess collector :

a. will destroy the selectivity of the flotation process, resulting in a decline in the quality of the concentrate;

b. making it possible to further select foam concentrates and separate flotation of mixed concentrates;

c. The amount of other drugs can be increased accordingly;

d. The buoyancy of sulfide minerals will deteriorate.

Excessive foaming agent causes a large number of sticky and fine bubbles, which tend to cause the gangue mineral to adhere to the bubbles and affect the quality of the concentrate.

(2) Adding places and methods

The dosing location should be added to the corresponding operating point according to the use and solubility of the drug. There are two ways to add: one join and one join. The segmentation can prevent over-dosing and failure, and can improve the efficacy and save the dosage, so it is widely used in various factories.

The following principles should be considered when deciding where and when to add a drug:

a. To be able to better play the role of the latter agent;

b. The insoluble agent has time to fully function, such as black medicine added to the mill;

c. How fast the agent works;

d. The time at which certain harmful ions in the slurry cause the agent to fail.

Dosing order: Flotation of ore is: regulator - inhibitor - collector - foaming agent; flotation suppressed minerals are: activator - collector - foaming agent.

(3) Measures to improve efficacy

Mixed medication; dispersed dosing. Such as fog; thick paste dosing, slurry flotation.

4, flotation time

Flotation time refers to the time required to achieve a certain recovery rate and concentrate grade, sorting minerals. Generally, as the flotation time increases, the recovery rate of useful minerals increases, but the concentrate grade decreases.

The law is as follows: the ore is good in floatability, the ore grade is low, the monomer dissociation degree is high, and the flotation time can be shorter under the condition of fast acting of the medicament; on the contrary, the flotation time is longer. Flotation of ore with a high amount of mud requires a longer flotation time than ore containing less mud.

5, the quality of water

Floating water should not contain large amounts of suspended particulates, nor should it contain a large amount of soluble matter that can react with ore or flotation reagents.

6, the temperature of the pulp

As the temperature increases, the chemical reaction rate will also increase, and the effect is good.

7, aeration and mixing

The amount of floatation, foaming agent and other factors determine the amount of foam in the flotation. The amount of inflation depends on the type of flotation machine and the requirements of the flotation process. The smaller the bubble, the better the dispersion, and the larger the total surface area of ​​the bubble, which is advantageous for flotation. However, the bubble is too small and the rising speed is too slow, which is not good for flotation. Adding an excessive amount of foaming agent reduces the amount of air inhalation of the flotation machine.

The amount of foaming agent should be adjusted based on the adjustment of the amount of inflation. The agitation of the slurry is to ensure the suspension and uniform dispersion of the ore particles, to promote the dispersion and even distribution of the air, to promote the dissolution of air in the high pressure zone of the flotation machine and to precipitate microbubbles in the low pressure zone. Increasing slurry agitation can increase the probability of collision between the ore particles and bubbles.

However, excessive aeration and agitation are unfavorable. It not only destroys the stability of the foam layer, but also causes the merger of bubbles. A large amount of slime is brought into the foam, which causes the quality of the concentrate to decrease, and the volume of the slurry of the flotation machine is reduced. Small, increased power consumption accelerates the wear of moving parts.

Modernize with CEP modular packages –great improvements easy and efficiently!

With CEP Modular Escalator Modernization solutions you can renew individual components or complete systems. For example, you can choose upgrades that improve the safety and appearance of your equipment while leaving the mechanical components intact. With modular modernization you benefit from the latest technology and keep your equipment in line with the latest regulations, all with minimal inconvenience to tenants and visitors.


Modular Escalator Modernization

Modular Escalator Modernization,Energy Saving Escalator Modernization,Escalator Vvvf Modernization,Escalator Controller Modernization

CEP Elevator Products ( China ) Co., Ltd. , https://www.elevatorcomponent.nl

Posted on