In the practice of flotation, in order to overcome the flotation process of fine mud deterioration flotation machine and eliminate the harmful effects of fine mud, Fodamon engineers share the following common measures for you:
1. When there is not too much fine mud, add dispersant to reduce its impact.
Generally, water glass and sodium hexametaphosphate can be added. The dispersant is a pure electrolyte, whose function is to increase the electric potential on the surface of the slime. When the slimes are close to each other, they repel each other because of the same electricity, which makes the slimes play a role of dispersion and prevents the non selective agglomeration of the slimes.
The method of adding dispersing agent is simple and suitable for the case with less mud. However, this method can not solve the shortcomings of poor selectivity and large dosage of chemicals caused by fine mud, so it is often necessary to strengthen the selection operation in production practice.
2. Pre-removal of slime before flotation
There are two methods for pre-sliming: flotation and mechanical de-sludge. Flotation demudging is to use a small amount of foaming agent and collector to float out a part of ore mud, and then perform coarse flotation. Mechanical desilting uses a classifier (such as a hydrocyclone) to remove a portion of fine mud before flotation. The desilting grade is mainly determined by the performance of the classification equipment. After desilting, it can also improve the effect of coarse flotation. The main problem is that the fine mud is difficult to handle. If the useful mineral content in the fine mud is very small, it can be discarded. However, the grade of the useful mineral in the fine mud is often similar to that of the original ore. If it is discarded, the metal in the fine mud will be lost in vain.
3. Mud and sand separation
Process requirements for separate flotation of fine mud:
a. It is better to use a longer flotation time. It is reported that the flotation time of particle size less than 10 μ m is as long as 40-60 minutes;
b. High concentration pulp mixing (up to 60% – 70% pulp concentration), low concentration flotation (generally below 20%);
c. The dosage of collector was increased and the dosage of foaming agent was reduced by the step-by-step administration;
d. Large air charge, small bubble, weakening rising pulp flow
In the actual production, it is difficult to meet the technical requirements of fine mud flotation, so the indexes of fine mud flotation are not high. Although the above-mentioned method of treating slime is adopted in production, it does not solve the special process of slime flotation. According to the current research trend, there are two ways to improve the flotation speed of fine particles: one is to increase the flotation particle size of fine mud; the other is to reduce the particle size of Flotation Bubble.