The full name of the flotation is called froth flotation. It is the process of selecting minerals from the pulp by means of the buoyancy of the bubbles, depending on the difference in the surface properties of the various minerals.
The specific process of flotation is to add a certain concentration of slurry to various flotation reagents, and a large amount of diffuse bubbles are generated by stirring and aeration in the flotation machine. At this time, the suspended ore collides with the bubbles, and some of the floatable ore particles adhere to the bubbles, and float up to the surface of the ore to form a foam product, which is the concentrate; the non-floating mineral remains in the slurry and becomes the tailings. In order to achieve the purpose of sorting.
Flotation is susceptible to a number of factors during the process, including grinding fineness, slurry concentration, pulp pH, pharmaceutical system, aeration and agitation, flotation time, water quality and other process factors. The factors that affect the flotation process are detailed below.
First, grinding fineness
The requirements for fineness of grinding in the flotation include: 1. The useful mineral is substantially dissociated from the monomer. 2. The particle size of the coarse-grained monomer must be less than the upper limit of the particle size of the mineral flotation. At present, the upper limit of flotation particle size is generally 0.25-0.3 mm for sulfide minerals; 0.5-1 mm for natural sulfur ; and the upper limit of particle size for coal is 1-2 mm. 3. Avoid muddy as much as possible. When the floating capsules mineral less than 0.01 mm, flotation significantly deteriorated.
The most appropriate grinding fineness must be determined by testing and reference to production practice data. For some ores, the stage grinding and stage selection process is often used to avoid over-grinding of the ore, so that the dissociated ore particles are selected in time.
Second, the pulp concentration
The concentration of pulp is one of the main factors affecting the flotation index. The appropriate slurry concentration should be determined according to the ore properties and flotation conditions: minerals with a large flotation specific gravity or coarser grain size should use a thicker slurry, which can improve the recovery rate and reduce the consumption of flotation reagents. Selective operations use thinner pulp, which is good for obtaining high-quality concentrates, but there are gains and losses. When obtaining concentrates, the amount of chemicals, water and electricity consumption, and the flotation tank volume required to process each ore of ore must be Increase, these will affect the cost of mineral processing.
Third, the pH of the pulp
The pH of the pulp refers to the concentration of OH- and H+ in the slurry, which is generally expressed by the PH value. Various minerals have a "floating" and "non-floating" pH when using different flotation agents for flotation, called the critical pH. By controlling the critical pH, it is possible to control the effective sorting of various minerals. Therefore, controlling the pH value of the slurry is one of the important measures to control the flotation process.
Fourth, the pharmaceutical system
The type and quantity of the agent added during the flotation process, the dosing place and the dosing method are collectively referred to as the drug system, also known as the prescription. It has a major impact on flotation indicators.
In the ore dressing, it is necessary to pass the ore selectivity test in order to determine the type and quantity of the agent, and in practice, the number, location and mode of dosing should be continuously revised and improved.
Five, aeration and mixing
Inflating is to send a certain amount of air into the slurry, which is dispersed into a large number of tiny bubbles, so that the hydrophobic mineral particles adhere to the surface of the bubble.
The purpose of the agitation is to promote the uniform suspension of the ore particles in the slurry in the tank, and to make the air diffuse well, resulting in a large number of "active bubbles".
Inflation and agitation are carried out simultaneously in the flotation machine. Strengthening them is beneficial to increase the flotation index, but if it is strengthened too much, it will cause shortcomings such as bubble merger, degraded quality, increased electric energy consumption, and mechanical wear. Therefore, aeration and agitation must be appropriate.
Sixth, flotation time
The length of the flotation time directly affects the quality of the indicator. The time is too long, the grade of the concentrate is reduced; the time is too short and the grade of the tailings is increased. Therefore, the flotation time required for various minerals must be determined by experimentation.
7. Water quality and pulp temperature
Floating water should not contain a large amount of suspended particulates, nor can it contain soluble substances and various microorganisms that can interact with minerals or flotation reagents. This problem should be especially noticed when using backwater, pit water and lake water.
Flotation is generally carried out at room temperature, but sometimes it is necessary to warm the slurry in order to obtain a good sorting effect. The specific heating or not needs to be determined according to the actual situation. If it is heated, it is best to adapt to local conditions and use waste heat and exhaust gas as much as possible.
Since the content of useful components in the ore that needs flotation treatment is getting lower and lower, the particle size of the impregnation is getting finer and finer, and the composition is more and more complicated and difficult to choose. Therefore, based on the above seven factors, it must be fully practiced. To choose the right flotation process.
Car Starter,Stt Starter,Car Self Starter,Starting System In Automobile
Chengdu Huachuan Electric Parts Co., Ltd. , https://www.chcd-global.com