In nature, most minerals have poor floatability, which must be improved by flotation reagents, and this improvement must be selective, meaning it can only improve the floatability of one mineral or a group of minerals, but can often weaken the floatability of other minerals.
It is important for flotation to be widely used in mineral processing because it can control flotation processes with ease and effectiveness through the use of flotation reagents, successfully separate minerals according to customers’ needs, and make comprehensive use of resources. Flotation reagents are the most flexible, effective, and convenient way to control mineral flotation behavior.
There are many kinds of flotation reagents, including both organic and inorganic compounds, acids and bases, as well as different salts. Flotation reagents are classified in many ways. The most basic method is to classify reagents according to their uses, which fall into three categories:
1.A collector is an organic substance that can selectively act on a mineral surface and make it hydrophobic. The collector increases the hydrophobicity of the minerals, causing the ore particles to firmly adhere to the bubbles and float upward.
Typical representatives are:
Non-ionic: kerosene, diesel, xanthate, hydrocarbyl thiocarbamate;
Anionic type: xanthate, black medicine, oleic acid, sodium hydrocarbyl sulfate;
Cationic type: mixed amine, lauric acid.
2. As a result of surface active substances, air disperses into small bubbles at the water-air interface, preventing bubbles from merging and enhancing bubble stability during the mineralization and flotation processes.
Typical representatives are:
Surfactants: butyl ether oil, terpineol oil, mixed alcohol, ether alcohol oil;
Non-surfactant: diacetone alcohol oil.
3. The purpose of this agent is to adjust the interaction between other agents (mainly collectors) and mineral surfaces, to adjust the properties of the pulp and to improve the selectivity of flotation processes.
Agents (mostly inorganic salts) that can promote the interaction between collectors and minerals, so as to improve the floatability of minerals. This effect is called activation.
The use of inorganic salts (mostly) to promote the interaction between collectors and minerals.
Typical representatives are: copper sulfate, sodium sulfide, etc.
Contrary to activators, agents that can weaken the effect of collectors and minerals, thereby reducing the floatability of minerals (various inorganic salts and some organic compounds). This effect is called inhibition.
Typical representatives are: sodium sulfide, water glass, tannin, starch, etc.
③Medium pH adjuster
This is to form media properties that are beneficial to a flotation of some minerals, and unfavorable to a flotation of other minerals by adjusting the properties of the ore pulp. You could, for example, adjust the ore slurry’s ion composition, the pH value, or the concentration of soluble salts using it.
Typical representatives are: dilute sulfuric acid, sodium hydroxide, sodium bicarbonate, etc.
④Dispersant and Flocculant
Adjust the dispersion, agglomeration and flocculation of the fine mud in the slurry. Typical representatives of flocculants are: lime, alum, starch, bone glue, polyacrylamide, polyoxyethylene and so on.
Typical representatives of dispersants are: water glass, soda, various polyphosphates, etc.
Flotation reagents have a variety of functions and classifications. Reagents may fall under this category under certain conditions and fall into another category under other conditions.