What are the types of fluorite beneficiation processes?

Fluorite, with a chemical composition of CaF₂, is an important strategic non-metallic mineral resource in the world and plays an irreplaceable role in many fields such as metallurgy, chemical industry, and optics. With the rapid development of global industry, the strategic position of fluorite has become increasingly prominent. However, natural fluorite often coexists with gangue minerals such as calcite, barite, and quartz, and has a low grade. Therefore, how to obtain high-quality fluorite products is the key. This article will focus on the significance, process and application of fluorite beneficiation.

01The significance and necessity of fluorite beneficiation

Natural fluorite ore is usually of low grade and contains a large amount of impurities, which cannot directly meet the requirements of industrial production. The main purpose of beneficiation is to improve the grade of fluorite, remove impurities, and make fluorite products meet the quality standards of different application fields. Through mineral processing, low-grade fluorite ore can be enriched into high-grade fluorite concentrate, improving the utilization efficiency of resources; at the same time, effective removal of impurities can avoid the interference of impurities on subsequent processing, reduce production costs and improve product quality. Mineral processing is an indispensable key link in the development and utilization of fluorite resources.

02What are the mineral processing processes for fluorite ore?

1. Fluorite hand selection process

The hand selection method is suitable for fluorite ores with high grade, blocky shape and obvious differences in color and appearance from the gangue minerals. In this type of ore, fluorite minerals have large crystals and are easy to distinguish with the naked eye. Sorting mainly relies on manual labor. Mineral processing workers separate fluorite ore from gangue ore by observing the physical characteristics of the ore, such as color, luster, and shape. Generally speaking, fluorite ores are mostly bright colors such as green, purple, and yellow, with a glassy luster, while the gangue ore is relatively dull in color.

The hand selection method is simple to operate, does not require complex equipment and reagents, and has low investment costs; in some small mines or remote areas, the hand selection method can quickly obtain a certain amount of high-grade fluorite ore. However, this method is inefficient, labor-intensive, and the sorting accuracy is greatly affected by human factors, making it difficult to achieve large-scale production.

2. Fluorite flotation process

Conventional flotation: suitable for various types of fluorite ores, especially those with fine-grained interpenetration, low grade, and complex symbiotic relationship with gangue minerals. By using the difference in the physical and chemical properties of the surfaces of fluorite and gangue minerals, by adding appropriate flotation agents, the surface of fluorite minerals is made hydrophobic, while the surface of gangue minerals is made hydrophilic. Usually, the flotation process includes three main stages: roughing, concentrating, and scavenging. During the entire flotation process, it is necessary to reasonably adjust the type and dosage of reagents, as well as flotation time, pulp concentration and other parameters according to the properties of the ore and flotation indicators.

Reverse flotation: mostly used to remove impurities such as carbonates in fluorite, such as calcite, dolomite, etc. When the content of carbonate impurities in fluorite ore is high and affects the quality of fluorite concentrate, reverse flotation can effectively separate fluorite from carbonates. Commonly used reagents are sulfuric acid adjusters to adjust the pH value of the pulp to acidic, activating the surface of carbonate minerals; fatty acid collectors adsorb it on the surface of carbonate minerals to form hydrophobicity.

3. Fluorite ore gravity separation process

Gravity separation is based on the density difference between fluorite and gangue minerals. Under the action of gravity, centrifugal force or other external forces, mineral particles of different densities produce different movement trajectories, thereby achieving separation. Generally speaking, the density of fluorite is 3.18-3.28g/cm³, while the density of common gangue minerals such as quartz (density 2.65g/cm³) and calcite (density 2.71g/cm³) is relatively low. Therefore, fluorite concentrate can be effectively obtained by gravity separation.

Gravity separation is mostly suitable for processing coarse-grained ores with large density differences between fluorite and gangue. It has low cost, does not require the use of a large amount of chemical agents, and is environmentally friendly; the equipment operation is relatively simple and the maintenance cost is low. However, the recovery rate is limited, and it is difficult to obtain high-grade fluorite concentrate, which usually needs to be used in combination with other beneficiation methods.

4. Fluorite Magnetic Separation Process

When fluorite contains magnetic impurities, such as iron minerals (magnetite, hematite, etc.), magnetic separation can be used to remove these magnetic impurities and improve the quality of fluorite concentrate. Especially in some fluorite ores that coexist with iron ores, magnetic separation is an important means of iron removal. Commonly used strong magnetic separators are used for separation, which can generate higher magnetic field strength, effectively adsorb magnetic impurities, and separate magnetic minerals from fluorite. According to the different ways of generating magnetic fields, they can be divided into electromagnetic strong magnetic separators and permanent magnetic strong magnetic separators.

5. Fluorite Combined Process

Flotation-gravity separation process: For some complex fluorite ores, a single flotation or gravity separation method is difficult to achieve ideal beneficiation indicators. The use of a combined flotation and gravity separation process can give full play to the advantages of both and improve the recovery rate and concentrate grade. Generally, the raw ore is pre-enriched by gravity separation, a large amount of waste rock is discarded, the grade of the selected ore is improved, and the flotation cost is reduced; then the flotation method is used to further enrich the fluorite minerals to obtain high-grade fluorite concentrate. This combined process is suitable for fluorite ores with coarse-grained and fine-grained distribution.

Flotation-magnetic separation process: When the fluorite ore contains magnetic impurities and there are high requirements for the quality of the fluorite concentrate, the combined process of flotation and magnetic separation is an effective choice. Usually, fluorite minerals are first enriched by flotation, and then the magnetic impurities remaining in the flotation are removed by magnetic separation to obtain high-quality fluorite concentrate. This process is widely used in the treatment of fluorite ores that coexist with iron ore.

03Application fields of fluorite

Metallurgical industry: In steel smelting, fluorite is added to blast furnaces or converters as a flux, which can reduce the melting point and viscosity of slag, promote the separation of slag and molten iron, and improve the quality of molten iron and smelting efficiency. At the same time, fluorite can also be used in non-ferrous metal smelting, such as aluminum, copper, etc., which helps to remove impurities and improve metal properties.

Chemical industry: Fluorite is the only raw material for the production of hydrofluoric acid, which is generated by reacting with sulfuric acid. Hydrofluoric acid is further used to produce fluorine refrigerants, fluorine-containing polymers, fluorine-containing pesticides, fluorine-containing medicines, etc. Among them, fluorine-containing polymers such as polytetrafluoroethylene (PTFE) have excellent high temperature resistance, corrosion resistance and low friction properties, and are widely used in high-end fields such as aerospace, electronics, and machinery; fluorine refrigerants occupy an important position in the refrigeration industry.

Optical industry: High-purity, optical-grade fluorite crystals have unique optical properties, with low refractive index and small dispersion. They are ideal materials for manufacturing high-performance optical lenses, prisms, filters and other optical components. In precision optical instruments such as astronomical telescopes, microscopes, and camera lenses, fluorite lenses can effectively reduce chromatic aberration and improve imaging quality.

Ceramic and glass industry: In ceramic production, fluorite can be used as a flux to reduce the firing temperature of the green body, promote the densification of the green body, and improve the strength and gloss of the ceramic; in glass manufacturing, fluorite can reduce the melting point of glass, improve the fluidity and transparency of glass, and can also be used as an opacifier to produce milky white glass.

Xinhai Mining can provide fluorite mining engineering, fluorite beneficiation engineering, tailings pond design, construction and overall operation management services after completion in a variety of cooperation modes according to customer needs. Including production operation management, equipment operation management, safety operation management, environmental operation management, human resources management and financial management. At the same time, Xinhai can also provide complete sets of fluorite beneficiation equipment and after-sales and project development services.