How does the pH of the pulp and the pharmaceutical system affect the flotation process?

How does the pH of the pulp and the pharmaceutical system affect the flotation process?

First, let's take a look at the effect of the pH of the slurry on the flotation process.

The pH of the pulp refers to the concentration of OH- and H+ in the slurry. Generally expressed in pH. The meaning of pH is the negative value of the logarithm of the hydrogen ion concentration. That is, pH=-lg[H+]

Slurry pH=7 for neutral media

Pulp pH <7 for acidic media

Pulp pH >7 for alkaline media

Most sulfide ores are flotation in alkaline or weakly alkaline slurries. The trapped acid slurry has a corrosive effect on the equipment; in particular, many flotation agents, such as xanthate, oleic acid, and pine oil (floating oil No. 2), are more effective in weak alkaline pulp.

Various minerals have a "floating" and "non-floating" pH when using various flotation agents for flotation, called critical pH. By controlling the critical pH, it is possible to control the effective sorting of various minerals. Therefore, controlling the pH of the slurry is one of the important measures to control the flotation process.

Since many minerals exist in the form of salts (such as fluorite CaF2), the hydrolysis of the salt occurs in the slurry, which will have a certain buffering effect on the pH of the slurry. In practice, this must be taken into account when adjusting the pH of the slurry.

Secondly, let's explain the impact of the relevant pharmaceutical system on the flotation process.

The type and quantity of the agent added during the flotation process, the dosing place and the dosing method are collectively referred to as the drug system, also known as the prescription. It has a major impact on flotation indicators. The type and amount of the agent is determined by the ore selectivity test. However, in the production practice, the number of drugs, the location of dosing and the mode of dosing are constantly being revised and improved.

Within a certain range, increasing the amount of collector and foaming agent can increase the flotation speed and improve the flotation index. However, too much usage can cause deterioration in the flotation process. Similarly, an appropriate amount of inhibitor and activator should be added. Excessive or insufficient will cause the flotation index to decrease.

The determination of the dosing location depends on the action, use and solubility of the agent. Medium adjustments (such as lime) are usually added to the ball mill to eliminate harmful ions that cause activation or inhibition. The inhibitor is added to the grinder before it is added to the grinder. The activator is often added to the agitation tank to prepare it for a certain period of time with the slurry. The foaming agent is added to the agitation tank or flotation machine, and the insoluble collector is often added to the mill.

Dosing method is divided into two kinds of dosing and batch dosing. The former can improve the initial speed of flotation and help to improve the flotation index. Generally, for a drug that is easily soluble in water, which is not easily taken away by the foam machine, and which is not easily reacted in the slurry and is ineffective, (yellow medicine, soda, lime, etc.) is used in one time; for water-insoluble, Some of the less selective chemicals (such as oleic acid, pine oil, sodium sulfide, etc.) should be used in batches.

Generally, 60 to 70% of the total amount of the agent is added before the flotation, and the rest are added to the appropriate places in several batches.

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