1- Collectors, these are chemicals that increase the hydrophobicity of certain minerals, allowing them to adhere to air bubbles during foaming.

• Common Collectors:
  • Xanthates (e.g., potassium ethyl xanthate (PEX), potassium isobutyl xanthate (PIBX), and potassium amyl xanthate (PAX)): Commonly used in sulfide minerals, such as pyrite or arsenopyrite, often accompanying gold.
  • Dithiophosphates: Preferred for improving the buoyancy of gold and sulfide minerals. They are more selective and have less foaming ability compared to xanthate.
  • Thionocarbamates are used in specific situations for the selectivity of gold and associated sulfides.
  • Fatty acids and oleic acids: Sometimes used for flotation of oxide gold ores.
• Application: Collectors find that gold and associated minerals adhere strongly to air bubbles, making it easier to separate them from gangue (non-gold) material.
  

2- Frothing agents

Frothers stabilize air bubbles in the flotation cell, ensuring better adhesion of hydrophobic particles. They control bubble size and provide foam stability for an efficient flotation process.

• Common Foaming Agents
  • Methyl isobutyl alcohol (MIBC): One of the most commonly used frothers for a wide range of minerals, including gold.
  • Pine oil: A naturally derived foaming agent.
  • Polypropylene glycol: Used to produce fine, stable bubbles.
  • Alcohol and Polyglycol Based Frothers: Provide foam stability and are adaptable to different flotation conditions.
• Application: Frothers ensure uniform bubble formation and stability, which improves the recovery efficiency of fine gold particles.

3- Pressure Reducing Devices

Pressure-reducing agents prevent certain minerals from flotation, which allows for the selective recovery of gold and associated precious minerals.

• Common Pressure Relievers:
  • Sodium cyanide (NaCN): Used to suppress pyrite and other sulfide minerals, thereby increasing the selectivity of gold.
  • Sodium Silicate (Water Glass): Used as a dispersant to prevent the buoyancy of gangue minerals.
  • Starch and Guar Gum: Effective as organic suppressants for silicate minerals in some gold flotation circuits.
• Application: Suppressors enhance the separation of gold from gang minerals by reducing the buoyancy of unwanted impurities.

4- Activators

Activating agents are chemicals that increase the buoyancy of minerals that would otherwise be difficult to float.

• Common Activators:
  • Copper sulfate (CuSO₄) is frequently used to activate sulfide minerals, such as sphalerite or arsenopyrite, which are minerals that accompany gold.
  • Lead nitrate (Pb(NO₃)₂) is used in gold flotation to reduce cyanide consumption and improve the gold recovery process by activating minerals.
• Application: Activators alter the surface chemistry of minerals, making them more suitable for collector binding.

5. pH Regulators

pH modifiers regulate the alkalinity or acidity of the flotation sludge, which in turn affects the efficiency of other reagents and the separation process.

• Common pH Modifiers:
  • Lime (CaO): Used to increase the pH of the pulp, creating the preferred alkaline conditions for most sulfide gold ores.
  • Sulfuric acid (H₂SO₄) or hydrochloric acid (HCl): In rare cases, it is used to lower the pH for certain gold flotation processes.
  • Sodium hydroxide (NaOH): A common alkali changer.
• Application: Maintaining the correct pH environment is critical for the activation and efficiency of the collectors.

6. Sulfur Mineral Suppressants in Resistant Gold Groins

In resistant gold spoons containing sulfur minerals (e.g., pyrite or arsenopyrite), additional chemicals may be required to suppress unwanted minerals during flotation.

• Examples of reagents:
  • Potassium permanganate (oxidizing agent)
  • Sodium hydrosulfite (reducing agent)
  • Carbon suppressors for silicates
• Applications in Different Groin Areas:
  • In freely grindable gold alloys: Since gold is generally associated with sulfides, xanthates and frothers are primarily used.
  • Refractory minerals: Require specialized reagents, including pressure reducers, pH regulators, and occasional bio-oxidation pretreatments.
  • Oxide Minerals: Due to the presence of non-sulfurous minerals, fatty acids or anionic collectors are used.