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5 Phosphate rock flotation methods

2022-11-18 Xinhai (454)

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Froth flotation is the most widely used separation process for phosphate ores. Due to the nature of phosphate ore, such as mineral type and content, dispersed particle size, its separation difficulty and flotation type will vary. Phosphate rock is divided into siliceous phosphate rock, calcareous phosphate rock and siliceous phosphate rock according to the chemical composition of the mineral. The type of froth flotation is very different with different types of phosphate rock. The following are 5 common types of phosphate rock flotation processes.

1. Phosphate rock direct flotation process

The direct froth flotation method is to grind the phosphate ore until the minerals in the ore are dissociated after one step of grinding, then suppress the gangue minerals by adding inhibitors, and then add collectors to enrich the phosphate minerals in the froth. The process must be combined with strong inhibitors for best results. It is primarily suitable for the separation of phosphate ores with fine particle sizes of phosphate and gangue minerals, and low-grade phosphate ores including siliceous and siliceous calcium phosphate ores.

2. Phosphate rock reverse bubble flotation process

The process of reverse flotation is to adjust the pH value of the slurry to 5.0~6.0, suppress phosphate minerals by adding inhibitors, and then use selective collectors to enrich the carbonates in the froth. This process is mainly suitable for calcium-magnesium colloidal phosphate ore with high calcium and magnesium content, and is effective for separated and deposited calcium-magnesium sand phosphate ore.

3. Positive and negative foam flotation of phosphate rock

 Positive and negative froth flotation uses inorganic alkali to adjust the slurry to weak alkalinity, enriches the useful phosphorus minerals in the froth product by using a specific collector, and leaves the silicate minerals in the tank for discharge. is direct. Flotation concentrate. Mineral acids are then added to adjust the slurry to weak acidity, and the slurry of flotation concentrate is blended (reground or not) to enrich the carbonate impurities with a collector and leave the useful phosphate minerals in pool to obtain reverse flotation. concentrate. The reverse flotation operation is mainly to remove the MgO impurity in the phosphate concentrate. It is mainly suitable for calcium magnesium mixed high silicate phosphate colloidal ore.

4. Anti-foam flotation of phosphate rock

This process sequence is the opposite of direct-reverse froth flotation, which is mainly applicable to high carbonate mixed colloidal phosphate ores. Mineral particle size-200 mesh mass fraction will account for 70%~80%, and most of the carbonates have been dissociated by monomers after grinding. At this point, the carbonate gangue will be floated to the surface using a collector under acidic medium conditions to obtain a reverse flotation concentrate, followed by two-step grinding until the siliceous gangue is dissociated, while the phosphorus minerals will be in the Floating to the surface under alkaline media conditions for direct flotation. concentrate. The second stage of grinding produces a fresh surface that is more conducive to the separation of phosphorus and silicon.

5. Phosphate rock double reverse foam flotation

Two-way reverse flotation is mainly used to separate phosphorus minerals from dolomite and quartz gangue minerals. Usually, the slurry is adjusted to weak acidity with mineral acid, and then the dolomite minerals in the foam are enriched with fatty acid collectors, and quartz minerals are enriched with fatty amine collectors, and useful phosphorus minerals are kept in the tank.

The above five types have different process advantages and are suitable for different types of phosphate rocks. Only by choosing the appropriate flotation type for different phosphate mines, can we obtain a higher recovery rate of phosphate concentrate. It is recommended to entrust a qualified mineral processing production line and mineral processing equipment provider to conduct flotation tests, formulate a scientific and reasonable process flow, and determine the type of foam flotation according to the nature of the ore to avoid economic losses.