Introduction of Flotation Agents for Wolframite and Scheelite

01Wolframite flotation agents

The main components of wolframite are FeWO₄ and MnWO₄, and flotation is mainly aimed at wolframite fine mud, which has a high density and weak natural floatability. The beneficiation of wolframite usually requires the use of specific reagents to improve its floatability.

Wormite collectors: The main ones used are selective collectors, such as arsine acid, phosphonic acid, chelate, amphoteric collectors and a few fatty acid collectors. These collectors react with the W=O group on the surface of wolframite to improve the hydrophobicity of the mineral and enhance its adhesion to bubbles.

Activator: Sodium hydroxide, potassium hydroxide, etc. are commonly used as activators, which can increase the negative charge on the surface of the mineral, enhance the adsorption of the collector, and improve the flotation effect of wolframite.

Inhibitors: Commonly used inhibitors include starch, cellulose, etc., which mainly inhibit iron-containing minerals. By forming a stable hydrophilic film on the surface of iron-containing minerals, the adsorption of the collector is reduced, and the effective separation of wolframite and gangue minerals is achieved.

02Scheelite flotation agents

The main component of scheelite is CaWO₄, which has a high melting point and good floatability. In the flotation process, calcium-containing gangue minerals are more difficult to handle, so the selection of reagents is particularly important.

Collectors: Common ones include anionic collectors (fatty acids, sulfonic acids, phosphonic acids and chelates), cationic collectors (amines), amphoteric collectors (i.e. amino acids) and non-polar collectors. Among them, non-polar collectors are mainly used in conjunction with other collectors. Its main function is to adjust the foam structure, strengthen the hydrophobic effect, promote hydrophobic agglomeration, and thus improve the recovery rate and grade; the other collectors need to react with the calcium ions on the surface of scheelite to improve the hydrophobicity of the mineral and make it easy to attach to bubbles.

Frothing agents: Commonly used are pine oil, ether alcohol, etc., which can reduce the surface tension of water, promote the formation and stability of bubbles, and improve the flotation recovery rate of scheelite.

pH regulator: The main purpose is to adjust the pH value of the pulp through the agent, enhance the adsorption of the collector, and improve the flotation efficiency. The pH value of scheelite flotation is generally 9-10.5, and the commonly used regulators are sodium carbonate and sodium hydroxide.

Inhibitor: It is mainly used to inhibit silicon-containing minerals. It can react with the active points on the surface of silicon-containing minerals, reduce the adsorption of collectors, and achieve effective separation of scheelite and gangue minerals. Commonly used inhibitors include water glass, phosphate, white quercetin bark juice, etc. In addition, there are many effective regulators for calcium-containing gangue ores, such as tannins, polyphenylene sulfonates, EDTA, dextrin, starch, etc. For ores with more complex compositions, simply adding water glass cannot fully inhibit the gangue minerals. It is also necessary to add some metal ions (such as Al³⁺, Mg²⁺, Cu²⁺, Fe²⁺, Co²⁺, Pb²⁺ and Ca²⁺, etc.) or other agents to enhance the inhibitory effect of water glass, because these agents themselves cannot inhibit gangue minerals, but after adding them, the inhibitory effect is significantly enhanced. These agents are called auxiliary inhibitors.

The above is the introduction of flotation agents for scheelite and wolframite. In actual ore dressing plants, whether it is wolframite or scheelite, the selection of reagents must be based on actual conditions. Therefore, it is recommended to conduct ore dressing test analysis. Through different tests, the appropriate type and dosage of reagents can be finally determined to obtain ideal flotation indicators.