What should we do if the high mud content of the original ore affects the flotation effect of gold ore

By: FTM MachineryMarch 02nd,2021

Flotation is one of the commonly used beneficiation methods in gold concentrators. However, during the flotation process of gold ore, part of the gold ore ore has a large mud content and affects the flotation effect. Therefore, in the flotation of gold ore with high mud content, how to reduce the impact of ore mud on the flotation effect of gold ore has become a widespread concern.

When studying how to reduce the impact of ore mud on the flotation effect of gold ore, we must first understand the nature of the ore with high mud content. Generally, this type of gold ore often contains a large amount of easy-floating and muddy gangue (talc, serpentine, chlorite, calcite, dolomite, sericite, kaolinite, montmorillonite, feldspar, etc.). It has the characteristics of high mud content, fine particle size of metal minerals embedded, poor metal mineral floatability, small quality, large specific surface area, etc. The properties of the ore are more complex. For gold flotation, too much sludge will cause the crusher to block, the quality of the gold concentrate will decrease, it will be difficult to filter, the flotation speed of fine particles will slow down, and the selectivity will deteriorate, and the flotation selection indicators deteriorated.

In order to solve the above problems, we need to adopt corresponding solutions to reduce and prevent the harmful effects of ore sludge according to the properties of different gold ore, and strengthen the flotation of fine particles, that is, adopt suitable technological processes or use targeted flotation. The specific measures are as follows:

1. Wash the ore

Ore washing is an important way to remove sludge and affect the flotation effect. After one stage of crushing, a vibrating screen is added to wash the ore. The ore is washed to remove the muddy part. The screened sludge is processed by a spiral classifier and returned to the powder ore bin or directly ground. The grading overflow can be floated together with the grinding products or separately. For the graded overflow with very low gold grade, it can be directly discharged together with the tailings. At the same time, the ore lump on the ore washing screen can also be manually selected to remove the waste rock to improve the selected grade.

2. Use a hydrocyclone to separate part of the sludge before flotation

If the gold content in the sludge is high, the removed sludge can be floated separately. At this time, the separate flotation of fine mud should adopt a longer flotation time, maintain high concentration slurry (60%-70% slurry concentration), and low concentration flotation (generally below 20%). At the same time, dosing in sections , increase the amount of collector, reduce the amount of foaming agent, maintain large aeration, small bubbles, and weaken the rising slurry flow. For some sludge that is easy to float and has low gold content, it can also be removed by pre-flotation by adding a small amount of foaming agent before flotation.

3. Add sludge dispersant

Water glass, sodium carbonate, sodium hexametaphosphate and other sludge dispersants can be added to prevent non-selective agglomeration of fine sludge, so as to fully disperse sludge and reduce the flocculation and covering effect of sludge. In this process, the stepwise dosing method can be considered to reduce the harmful effects of a large amount of adsorbents in the sludge.

4. Increase the apparent particle size of particulate minerals

Use physical or chemical methods to increase the apparent particle size of the particulate minerals to improve the flotation rate and selectivity of the minerals to be sorted.

◆Selective flocculation flotation: use flocculant to selectively flocculate the target mineral or gangue sludge of particles, and then separate it by flotation.

◆Carrier flotation: use general flotation ore particles as a carrier, so that the fine particles cover the cover on the carrier, and then float out together with the carrier.

◆Agglomeration flotation: also known as emulsification flotation, fine-grained minerals are processed by collectors, and then under the action of neutral oil, they form mineralized oily foam.

When the flotation method is used to process the ore with high mud content in the raw ore, if the crusher is blocked, the recovery rate of gold ore decreases, and the flotation index deteriorates, it can be considered whether it is caused by the high mud content of the raw ore. Flotation is a relatively complicated method for beneficiation of gold ore. It is recommended to conduct beneficiation experiments before determining the process flow and process parameters to fully grasp the properties of the ore, and use the process flow suggested in the beneficiation test report to improve gold beneficiation indicators. Improve the rate of return on investment.

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