Flotation machine function and evaluation

1. Flotation machine basic functions

A flotation machine is an industrial equipment to achieve flotation. Its key component – the inflatable stirring mechanism, which determines the type, characteristics and effectiveness of the flotation machine. From the point of view of the flotation process, the flotation machine should have the following functions.

1. Flotation machine makes the slurry in turbulent flow to ensure the suspension of the ore particles and the dispersion of the chemicals, and to achieve the adhesion of the ore particles and chemicals with certain kinetic energy movement and collision.

2. Flotation machine introduce air to produce air bubbles of suitable size, sufficient quantity and stability, so that they can be dispersed in the pulp, move with certain kinetic energy, and collide with pharmaceuticals and ore particles to produce selective adhesion and realize mineralization.

3. The mineralization bubbles can rise to the liquid surface, forming a three-phase froth layer and producing secondary enrichment; the froth concentrate and tailings can be discharged in time.
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Particle size effect on flotation process

There are many factors affecting the flotation process, among which the more important ones are:
particle size (grinding fineness), pulp density, chemical addition and adjustment, bubble and foam adjustment, pulp temperature, flotation procedure, water quality, etc.

Experience has proven that flotation process factors must be determined and selected according to the characteristics of the ore properties and through experimental studies in order to obtain the optimal technical and economic indicators.

1. Particle size effect on flotation

In order to ensure a high process index for flotation, it is important to study the effect of particle size on flotation and to determine the most suitable feed size (fineness) and other process conditions according to the nature of the ore. Flotation requires not only adequate monomeric dissociation of the minerals, but also a suitable feed size. Ore particles are too coarse, even if the minerals have been monomeric dissociation, because more than the bubble flotation capacity, often can not float. The upper limit of flotation size for each type of minerals is different, such as sulfide minerals are generally 0.2-0.25 mm, non-sulfide minerals for 0.25-0.3 mm, for some less dense non-metallic minerals such as coal, the upper limit of particle size can also be improved. However, the grinding size is too fine (such as less than 0.01 mm) is also detrimental to flotation. Practice has shown that there are differences in flotation behavior for various particle sizes(Refer Table 1)

The data in the table illustrate that different minerals have their own optimal particle size range for flotation. Both too coarse (>0.1 mm) and too fine (>0.006 mm) particle sizes are not conducive to flotation and recovery is reduced. Read more

Froth Flotation Introduction

Flotation is undoubtedly the most important and versatile mineral processing technique, and both its use and application are continually being expanded to treat greater tonnages and to cover new areas. Originally patented in 1906, flotation has permitted the mining of low-grade and complex ore bodies which would have otherwise been regarded as uneconomic. In earlier practice the tailings of many gravity plants were of a higher grade than the ore treated in many modern flotation plants.
Flotation is a selective process and can be used to achieve specific separations from complex ores such as lead-zinc, copper-zinc, etc. Initially developed to treat the sulphides of copper, lead, and zinc, the field of flotation has now expanded to include platinum, nickel, and gold-hosting sulphides, and oxides, such as hematite and cassiterite, oxidised minerals, such as malachite and cerussite, and nonmetallic ores, such as fluorite, phosphates, and fine coal.