Malachite is a carbonate mineral, well known as basic copper carbonate, and often coexists with other copper minerals. Because the embedded particle size of malachite is relatively complex, the separation process is difficult. At present, flotation is the main method for malachite separation. At the same time, malachite, as a kind of mineral, is essentially a mineral body formed by sulfide ore through long-term oxidation in nature and erosion of groundwater. In this process, a large amount of clay materials will be produced, forming a large amount of slime, which will adversely affect the flotation process. This article will take you to understand the impact of slime on malachite flotation and the solution.
The slime has the physical and chemical characteristics of small mass and large specific surface area, which causes a series of problems for malachite flotation. The particle size of malachite ore slime is generally 20 μ Below m, the fine particles have small mass and low momentum, so the probability of collision with bubbles is small, the flotation rate is low, and the recovery rate is low. At the same time, the fine particles are mixed and the concentrate grade is reduced.
The influence of slime on malachite flotation is mainly manifested in two aspects: competitive adsorption with and mutual coagulation of slime cover.
The slime has a large specific surface area and high surface energy, which aggravates the non selective agglomeration between gangue and useful mineral particles, increases the adsorption capacity of reagents on the surface of mineral particles, increases the dosage of reagents, and reduces the selectivity of reagents.
The essence of slime cover is that fine and coarse ore particles coagulate each other under the action of static electricity. When the surface potential of the two particles is opposite or the potential is the same, but the value difference is large, the slime cover phenomenon will be caused. The non selective cover of slime is extremely harmful to the dispersion of ore particles. It reduces the adsorption capacity of traditional Chinese medicine on the mineral surface during flotation, hinders the attachment of bubbles to useful minerals, and significantly reduces the surface difference of separated particles. The gangue covering reduces the concentrate grade on the useful minerals, and the useful minerals covering on the gangue reduces the recovery rate.
Generally, in malachite flotation, in order to reduce the adverse effect of slime on malachite flotation, the following four schemes are often adopted:
There are many methods of desliming in industrial production, such as desliming bucket, spiral classifier, spiral chute, cone classifier, shaking table, etc., or a combination of two or more. The desliming process can obviously improve the ore frame environment and improve the separation effect. However, the existing equipment cannot effectively separate the slime from the useful minerals for the ore with very complex inlay.
Sectional dosing is a common method for malachite ore flotation, which can improve the utilization efficiency of reagents and keep the concentration of reagents in pulp at an ideal level in each stage of flotation. Fundamentally, the staged dosing avoids the one-time adsorption of all reagents by the slime. By increasing the number of dosing segments, the selectivity of reagents can be amplified to compensate for the adverse effects caused by too fine gangue minerals.
In malachite flotation, ultra-fine argillated minerals have a large specific surface area. Fine minerals seriously affect the dispersion of pulp. Essentially, fine mud increases the viscosity of pulp suspension, increases the friction between particles, and worsens the flotation process. Flotation with relatively dilute pulp concentration can improve the fluid characteristics of pulp, enhance the dispersion of ore particles, reduce the cover of slime on useful minerals, and improve the efficiency of reagents.
Common dispersants are sodium hexametaphosphate (SHMP), Na2CO3 and sodium silicate. Dispersants can solve the problem of covering the useful minerals with slime, prevent the agglomeration of fine slime and reduce the viscosity of the slurry. However, the effect of excessive sodium hexametaphosphate was not obvious. It will seriously reduce the flotation recovery rate, which is mainly because sodium hexametaphosphate can significantly reduce the adsorption capacity of the collector on the mineral surface. Therefore, the use of sodium hexametaphosphate should be reduced as much as possible when the mineral dispersion is ideal.
The influence of slime on malachite flotation and the solution are introduced above. Malachite in different regions has different properties and particle sizes, so appropriate slime removal methods should be selected according to the actual situation. You can also consult with professional manufacturers to try to improve flotation indexes as much as possible.
