Flotation agents can be classified into collectors, foaming agents and adjusting agents according to their functions.
In nature, most minerals are hydrophilic except coal, graphite, sulfur, talc, molybdenite and other mineral particles, which are hydrophobic on the surface and have natural floatability, so are gold minerals. Adding a reagent that changes the hydrophilicity of mineral particles to make them floatable is often called a collector. Collectors are usually polar collectors and nonpolar collectors. The polar collector consists of polar group which can interact with the surface of mineral particles and non-polar group which plays a hydrophobic role. When such collectors are adsorbed on the surface of ore particles, their molecules or ions are aligned directionally, polar groups toward the surface of mineral particles, and non-polar groups toward the outside form hydrophobic film, which makes the ore position floatable and associated with sulfide minerals such as copper, lead, zinc and iron. Organic sulfide compounds are often used as collectors in flotation. For example, alkyl (ethyl, propyl, butyl, amyl, etc.) disulfide sodium carbonate (potassium), also known as xanthate, commonly known as xanthate. For example, NaS2C, OCH2, CH3, ethyl gold and butyl xanthate are used in the flotation of gold bearing polymetallic ores. Alkyl two thiosulphate or its salts, such as (RO) 2PSSH, R in the formula is alkyl, commonly known as black medicine.
Alkyl dithiocarbamate and xanthate ester derivatives are also commonly used collectors for sulfide minerals. It is also a common collector for flotation of gold bearing polymetallic sulphide ores, often used in conjunction with xanthate.
Non-ionic polar collector molecules do not dissociate, such as sulfur esters, non-polar collector for hydrocarbon oil (neutral oil), such as kerosene, diesel oil and so on.
(2) foaming agent
Surface active molecules with hydrophilic and hydrophobic groups are directionally adsorbed on the water-air interface, which reduces the surface tension of aqueous solution and makes the air filled with water easy to disperse into bubbles and stabilize bubbles. Foaming agents and collectors are adsorbed together on the surface of mineral particles to make the ore particles float upward. Commonly used foaming agents are: pine oil, commonly known as No. 2 oil, phenolic acid mixed fatty alcohol, isohexanol or octanol, ether alcohols and various esters.
(3) adjustment agent
Adjustment agents can be divided into five categories: (1) pH adjustment agents. It is used to adjust the acidity and basicity of the pulp, to control the surface characteristics of minerals, the chemical composition of the pulp and the action conditions of other reagents, so as to improve the flotation effect. In the cyanidation process, it is also necessary to adjust the pH value of the pulp. Commonly used lime, sodium carbonate, sodium hydroxide and sulfuric acid. When selecting gold, the most commonly used regulators are lime and sulfuric acid. (2) activator. It can enhance the function of minerals and collectors, so that the difficult floating minerals are activated and float up. Sodium sulfide is used to activate gold bearing copper oxide ore and then flotation with collectors such as xanthate. (3) Inhibitors. Improve the hydrophilicity of minerals and prevent minerals from acting with collectors, so that their floatability is inhibited. For example, lime is used to restrain pyrite, zinc sulfate and cyanide are used to restrain sphalerite, silicate gangue minerals are restrained by water glass, and organic substances such as starch and glue (tannin) are used as inhibitors to achieve the purpose of polymetallic separation and flotation. (4) flocculant. The fine mineral particles are aggregated into large particles to accelerate their settling velocity in water, and the selective flocculation is used for Flocculation-desliming and flocculation-flotation. Commonly used flocculants are polyacrylamide and starch. (5) dispersant. Prevent the aggregation of fine ore particles, in a monomer state, its role and flocculant is exactly the opposite, commonly used are sodium silicate, phosphate and so on.
The types and dosage of flotation agents vary with the ore properties, flotation conditions and process characteristics. The prescription (or reagent system) can be provided by the testing unit, and can be changed according to the above conditions in the production practice.