Regulators can be classified into five categories:
PH Regulators
These are used to adjust the acidity or alkalinity of the mineral pulp, thereby controlling mineral surface properties, the chemical composition of the pulp, and the operating conditions for various other reagents, ultimately improving flotation efficiency. Adjusting the pulp's pH is also a necessary step in the cyanidation process. Commonly used regulators include lime, sodium carbonate, sodium hydroxide, and sulfuric acid. In gold beneficiation, the most frequently used regulators are lime and sulfuric acid.
Activators
These enhance the interaction between minerals and collectors, thereby activating minerals that are otherwise difficult to float and enabling them to rise to the surface. For instance, sodium sulfide is used to activate gold-bearing lead-copper oxide ores, which are then subjected to flotation using collectors such as xanthates.
Depressants
These increase the hydrophilicity of minerals and inhibit their interaction with collectors, thereby suppressing their floatability. Examples include using lime to depress pyrite during selective flotation; using zinc sulfate and cyanide to depress sphalerite; and using water glass to depress silicate gangue minerals. Organic substances-such as starch and tannin-are also utilized as depressants to achieve the selective separation of polymetallic ores through flotation.
Flocculants
These induce fine mineral particles to aggregate into larger clusters, thereby accelerating their settling rate in water. Selective flocculation techniques are employed for processes such as flocculation-desliming and flocculation-flotation. Commonly used flocculants include polyacrylamide and starch.
Dispersants
These prevent fine mineral particles from aggregating, maintaining them in a dispersed, discrete state; their function is precisely the opposite of that of flocculants. Commonly used dispersants include water glass and phosphates.
