Fluorite Beneficiation Process Analysis

Single fluorite ore has a relatively simple composition, with fluorite as the primary mineral, and accompanying gangue minerals typically consisting of small amounts of quartz, calcite, etc. This type of ore contains a high fluorite content, and to obtain high-grade fluorite concentrate, flotation has become the mainstream and efficient beneficiation method.

At the outset of the flotation process for single fluorite ore, the crushing and grinding stages are critical. The raw ore is first crushed by a crusher to reduce particle size, then fed into a ball mill or similar equipment for fine grinding. Grinding must be precisely controlled. If the product particle size is too coarse, the separation of fluorite and gangue minerals into individual particles is insufficient, making it difficult for flotation reagents to fully act on the fluorite surface. If the particle size is too fine, it may lead to over-grinding of fluorite, increasing the difficulty of subsequent separation and potentially causing fluorite to become mixed with gangue minerals, making recovery challenging. Generally, grinding fineness should be controlled such that particles smaller than 0.074 mm account for 60–80% of the total, with specific values determined through testing based on the characteristics of the ore.

After grinding, the process proceeds to the flotation stage, where the proper selection of reagents is critical. Adjusting agents commonly use sodium carbonate, which can regulate the slurry pH to a weakly alkaline range (pH approximately 8–9), creating an optimal environment for subsequent reagent action and suppressing interference from harmful ions. Inhibitors widely use water glass, which effectively suppresses quartz and other gangue minerals. When using water glass, strict control of dosage is required. A small amount may have a certain activating effect on fluorite but insufficiently inhibit quartz; excessive amounts may inhibit fluorite flotation. To enhance water glass's inhibition of quartz while reducing dosage, it can be used in combination with polyvalent metal ions (e.g., Al³⁺, Fe³⁺) or alum, aluminium sulphate, etc. Collectors are primarily fatty acid-based agents, such as oleic acid and oxidised wax soap, which selectively adsorb onto the fluorite surface, enhancing its hydrophobicity and facilitating its attachment to bubbles for flotation. In recent years, new collectors have been developed and applied, such as certain cationic collectors that can create a stable flotation environment in the slurry, improving fluorite recovery rate and purity, and causing less environmental harm compared to traditional fatty acid collectors.

The flotation process typically employs staged grinding and flotation. First, roughing is conducted to rapidly recover the majority of fluorite, yielding a rough concentrate. Subsequently, scavenging is performed on the rough concentrate to recover fluorite missed during the roughing process, thereby improving recovery rates. Following this, multiple stages of concentrating are conducted to progressively remove gangue impurities from the rough concentrate, thereby enhancing the grade of the fluorite concentrate. Common processes such as ‘1 roughing, 6 concentrating, 2 scavenging’ can be flexibly adjusted based on ore properties and concentrate quality requirements. During the concentrating process, inhibitors such as water glass can be added as needed to enhance inhibition of gangue minerals and ensure concentrate quality.

Single fluorite ore beneficiation primarily employs flotation methods. By precisely controlling crushing and grinding, selecting appropriate reagents, and optimising the flotation process, effective separation of fluorite from gangue minerals can be achieved, yielding high-grade fluorite concentrate and laying a solid foundation for the efficient utilisation of fluorite resources.