The influence of reagent system on Flotation

The so-called reagent system refers to the types of reagents added in flotation process, the dosage of reagents, the way of adding, the place of adding reagents and the order of adding reagents. In flotation plant, reagent system is the most important factor affecting the technical and economic indicators of mineral processing.

(1) Pharmaceutical species

The types of medication used in flotation plants are related to the properties of ores, technological process, mineral processing products and other factors.

Usually, it is determined by mineral washability test or process test. Some refractory ores are verified by the expanded Dalian test.

In particular, we should mention the problem of mixed drugs. Through experimental research and production practice, it is proved that the effect of mixed drugs is better than that of single agents, especially the use of mixed collectors is more obvious and the application is more common. According to statistics, 44% of 59 non-ferrous metal flotation plants in China use mixed collectors. Why is it that the mixed collector has better effect? The research shows that the surface of the mineral layer adsorbed on the mineral surface is denser by using the mixed collector, and the collector can form a hydrophobic layer on the mineral surface faster, which accelerates the adhesion rate of the ore particles to the bubbles. This is due to the inhomogeneity of mineral surface properties. Different collectors can exert different effects on mineral surface, which is conducive to the formation of hydrophobic layer on mineral surface. In addition, the synergistic effects of the agents also play a role. For example, using butyl xanthate and sodium hydroxamide as mixed collectors to separate a copper oxide ore in Tonglushan Mine is better than using single butyl xanthate, which can reduce the consumption of sodium sulfide and No. 2 oil, and the separation index is also better.

The proportion of mixed drugs should be determined by experiments. Mixed drugs are not only collectors, but also foamers, inhibitors and flocculants.

(2) dosage of medicines

The dosage of flotation agent is just right when flotation flotation. Insufficient or excessive dosage will affect the beneficiation index, and excessive dosage of reagent will increase the cost of beneficiation and reduce the beneficiation index. In addition to the higher grinding cost, flotation flotation plants may calculate the cost of reagents. Therefore, it is very important to control the dosage of reagents accurately.

(3) When designing flotation concentrator, the preparation workshop of reagent should be generally designed.

Dilute solid agents into liquids, because liquid agents are easy to add, and can be prepared into larger concentrations for water-soluble agents such as sodium sulfide, zinc sulfate, copper sulfate and so on. Generally, 10%-20% concentration can be prepared. If the dosage of the reagent is small or the water solubility is poor, the concentration of the reagent should be low, such as xanthate, oxide, dichromate, sulfur and nitrogen 9, etc. The concentration of the reagent is usually 5%-10%.

For some water-insoluble agents, organic solvents can be used to dissolve them, and then a low concentration solution can be prepared.

(4) Place and sequence of dosing

In order to give full play to the effect of flotation reagents, the general practice is as follows:

For the insoluble and poorly dispersed reagents, in order to make them have sufficient action time, the reagents are usually added to the grinder, such as black medicine and white medicine.

(2) According to the different roles of reagents in flotation, the adding sites are also different. For example, copper sulfate, xanthate and terpineol are three kinds of reagents. The general order of reagent addition is: copper sulfate is added to the center of the first stirring tank, xanthate is added to the center of the second stirring tank, and terpineol is added to the outlet of the second stirring tank.

(3) Create conditions for adding medicines to play a better role in the future. Under general conditions, flotation concentrator can better play the role of collector and depressant by adding pH adjuster and adjusting the pulp to an appropriate pH value. For example, when mixed concentrates are de-pesticided, sodium sulfide is usually added to remove the depressant ions from the mineral surface, and activated carbon is added to adsorb them, so as to achieve better results.

(4) Attention should be paid to the problem of drug failure caused by some harmful ions. For example, the reaction of copper ions with cyanide ions will invalidate cyanide. When separating copper from sulphur, if there are more copper ions in the agitated tank, cyanide should not be added to the agitated tank, but should be added directly to the separation flotation operation tank, so as to avoid the harmful ions causing the failure of the reagent.

The general order of adding drugs in flotation plants is: pH adjusting agent depressant or activator collector foaming agent for the flotation of raw ore; activator collector foaming agent for the inhibited minerals of flotation ore.

(5) Drug dosing methods

There are usually two ways to add drugs: centralized addition and sectional addition. The general principle is that all the medicines that are soluble in water, not easy to be taken away by foam and not easy to fail can be added centrally, that is, all the medicines can be added centrally at one time before roughing. On the contrary, for those medicines which are easily taken away by foam and easily invalidated by interaction with fine mud and soluble salts, it is better to add them in segments. For example, the sulfide flotation method of copper oxide ores, after the action of sodium sulfide, the sulfide film formed on the surface of minerals is not very firm and easy to fall off, so the multi-point charging method is adopted.

In order to improve the efficiency of the medicament and save the dosage of the medicament. In recent years, many experimental studies have been carried out at home and abroad on the application of physical methods to enhance the efficacy of agents. Among them, flotation, heating flotation, aerosol method, treatment of electric field and magnetic field, ultraviolet irradiation, high energy radiation to enhance the flotation process and the role of reagents are still in progress.