TOFA (Tall Oil Fatty Acid)

  • Mining & Mineral Processing Mineral Processing Additives

    Tall Oil Fatty Acid (TOFA) is a commonly used collector in froth flotation to improve mineral separation efficiency. Froth flotation is a widely used process for separating minerals from their ores, particularly in mining copper, zinc, lead, and other non-sulfide minerals, such as phosphate, coal, and potash.

    Tall Oil Fatty Acid (TOFA) can assist and improve froth flotation efficiency by adsorbing onto mineral surfaces, improving selectivity, increasing concentrate yield, regulating pH, and being cost-effective. Tall Oil stabilizes the froth and prevents the mineral particles from falling back into the slurry. They also help improve the process’s selectivity by enhancing the attachment of the targeted minerals to the air bubbles.

    TOFA’s reagent role in froth flotation can be explained as follows:

    • Adsorption: TOFA molecules can adsorb onto the surfaces of mineral particles, particularly sulfide minerals such as chalcopyrite, sphalerite, and molybdenite. This adsorption is due to the hydrophobic nature of the TOFA molecule and the presence of carboxylic acid groups that can form hydrogen bonds with the mineral surface.
    • Selectivity: TOFA can improve the selectivity of mineral separation by preferentially adsorbing onto the surfaces of certain minerals. This can be particularly beneficial in complex ores containing multiple minerals with similar properties.
    • Higher concentrate yield: TOFA can improve concentrate yield in zinc, copper, molybdenum, and other ores by increasing the recovery of valuable minerals. This is due to the increased adsorption of the TOFA molecules onto the mineral surfaces, which can increase the probability of the froth collecting the mineral particles.
    • pH regulation: TOFA can also act as a pH regulator in froth flotation. The carboxylic acid groups on the TOFA molecule can act as weak acids or bases, depending on the pH of the flotation cell. This can help stabilize the pH and improve the mineral separation efficiency.

    Research has shown that TOFA can improve the flotation of copper sulfide ores by increasing the recovery of copper and decreasing the recovery of iron sulfides.

     References:

    • Castro, S., Henriquez, F., & Henriquez, R. (2012). Effect of tall oil fatty acid collector dosage on flotation performance. Minerals Engineering, 28, 62-65.
    • Gao, Z., Liu, H., Liu, W., & Huang, G. (2015). Flotation of mixed copper oxide and sulphide minerals with xanthate and hydroxamate collectors. Minerals Engineering, 82, 42-50.
    • Sánchez-Segado, S., & Sáez-Navarrete, C. (2019). Flotation of molybdenite in the presence of tall oil fatty acids: Effect of the degree of unsaturation. Minerals Engineering, 138, 59-64.