In the lithium ore Mineral Processing, flotation is one of the main lithium ore separation methods. All lithium ores with industrial value, especially those in the form of fine-grained impregnation, can be enriched by flotation. However, the effect of the flotation process is affected by a variety of factors, including grinding fineness, ore mud and floating impurities, water quality, slurry concentration and pH value, stirring intensity and flotation time, as well as dosing methods and dosage of reagents.
Grinding fineness affects lithium ore flotation
Grinding fineness is a key factor in the Mineral Processing. Coarse-grained spodumene is difficult to float, and the grinding fineness must be less than the upper limit of the mineral floating particle size. Too coarse grinding will result in insufficient mineral surface activity and limited bubble carrying capacity, resulting in reduced recovery rate. Too fine grinding will cause mineral mud, making it difficult for flotation reagents to play a role, and the flotation effect is poor. The appropriate grinding fineness should be determined according to the particle size of spodumene, usually less than 0.15mm, to ensure that the mineral surface is fresh and highly active, and to promote the effective interaction between the collector and the mineral surface.
Ore slime and easily floating impurities affect lithium ore flotation
Ore slime and easily floating impurities have a significant negative impact on the flotation efficiency of lithium ore. Ore slime will adsorb flotation reagents, reduce their effective concentration, and increase the viscosity of the pulp, affecting the dispersion of bubbles and the collision of ore particles, resulting in a decrease in recovery rate. Floating impurities will also consume a large amount of collectors and weaken the flotation effect. In order to improve the flotation efficiency, desludging treatment is required before flotation, and the reagent system is optimized to reduce the impact of ore slime and easily floating impurities.
Water quality affects lithium ore flotation
Water quality is crucial to the flotation process of lithium ore. The type and concentration of ions in water directly affect the pH value of the flotation pulp, which in turn affects the concentration ratio of ions such as CO3²⁻, OH⁻, and Ca²⁺ in the pulp, changes the electrical properties of the mineral surface and the interaction with the flotation reagent, thereby affecting the flotation effect. The hardness of the water quality will also affect the amount of collector used. Under soft water conditions, cyclohexane acid soap can significantly improve the recovery rate, while hard water may be unfavorable. Therefore, during the flotation process, keep the water clean and adjust the dosage and addition strategy of the reagent according to the results of the mineral processing experiment to optimize the flotation effect and ensure the stability of the process.
Slurry concentration and pH value affect lithium ore flotation
They jointly determine the flotation recovery rate and concentrate quality. When the pulp concentration is low, the flotation recovery rate decreases, but high-quality concentrate can be produced; increasing the pulp concentration can increase the recovery rate and the production capacity of the flotation machine, but may sacrifice the concentrate quality. At the same time, the pH value of the pulp plays a decisive role in the hydrophilicity of the mineral surface and the adsorption of the collector. When the pH value is high, the hydrophilicity of the surface of the ore particles is enhanced, which is not conducive to the adsorption of the collector and affects the flotation of the mineral. For lithium ore, the suitable flotation pH range is 4.0 to 9.0, in which the pH value is close to the neutral weak alkaline environment, which is conducive to the effective effect of oleic acid and its soap collectors.
Agitation intensity and flotation time affect lithium ore flotation
Agitation intensity and flotation time have an important influence on the flotation process of lithium ore. Excessive agitation will cause fatigue and fine mud on the surface of the mineral, affecting the flotation index; while too weak agitation will lead to uneven dispersion of the reagent, reduce the probability of collision of ore particles, and also affect the recovery rate. The length of the flotation time directly affects the mineral recovery rate and the quality of the concentrate. Too short a flotation time may cause the mineral to fail to float fully, while too long a flotation time will reduce the concentrate grade and increase energy consumption and cost. Therefore, it is necessary to determine the reasonable flotation time through mineral processing tests to achieve efficient extraction. In the design stage of the flotation plant, the flotation time determines the number of flotation machines of a specified model.
Dosing method and dosage affect lithium ore flotation
Reasonable use of reagents directly determines the flotation effect to ensure the effective interaction between the mineral surface and the reagents during the flotation of lithium ore. In actual production, the dosing method and dosage are key factors. The single-point dosing method adds all flotation reagents in the slurry pretreatment equipment at one time. This method has a high reagent concentration at the beginning of flotation, resulting in the priority floating of fine particles, fast flotation speed, but poor selectivity, weakened enrichment of the foam layer, and reduced selection effect. In contrast, multi-point dosing is suitable for minerals that are difficult to float, which can enhance flotation selectivity. The selectivity of flotation can be improved by adding reagents in stages, but the dosing points should not be too many to avoid inaccurate dosage of reagents.
Reasonable adjustment of the dosage of reagents is also crucial. Too little dosage of reagents will lead to a weak foam layer, reduced selectivity and recovery rate; while too much will produce a large number of large virtual bubbles, affecting the flotation effect. In addition, the dosage of the reagent needs to be adjusted according to the hardness of the water. Different water conditions will affect the effective concentration and effect of the reagent.
Conclusion
In order to improve the efficiency of lithium ore flotation and the quality of concentrate, it is necessary to conduct mineral processing tests based on the properties of the ore to determine the appropriate process parameters. By comprehensively considering factors such as grinding fineness, ore mud and floating impurities, water quality, slurry concentration and pH value, stirring intensity and flotation time, as well as dosing methods and reagent dosage, and flexibly adjusting according to the state of the foam layer and tailings, the flotation process can achieve the ideal effect.