Brief introduction of non-collector flotation technology in stibnite

The stibnite and arsenopyrite used in the test were taken from tin mine and Yaogangxian respectively. After preparation, samples with a particle size of 0.053 to 0.106 mm and purity of 97.3% and 98.9% were respectively stored in a vacuum drying oven for floatation. Select the test.

Flotation adopts 40mL hanging tank flotation machine, each time using 2g of ore sample, first ultrasonic treatment for 5min, then into the flotation tank, adding medicine and slurry, flotation for 5min. The pH of the slurry was measured using a pHS-29A type acidity meter. The pulp oxidation-reduction potential Eh was determined by an electric pair consisting of a bright platinum electrode and a saturated calomel electrode. The surface tension was measured by the maximum bubble pressure method. The amount of adsorption of the foaming agent was determined by extraction colorimetry and then calculated.

Second, the test results and analysis

(1) Selection of foaming agent

Foaming agents are particularly important in the absence of collectors . The comparison test results of 15 kinds of foaming agents flotation stibnite and arsenopyrite with the dosage of 7.5 mg/L are shown in Table 1. Obviously, the different flotation agent flotation results are very different. The commonly used No. 2 oil flotation stibnite and arsenopyrites have a floating rate of 74% and 79%, respectively, while the butyl ether alcohol has a floating rate of 94%. And 96%, better than the foaming agent such as MIBC, DOW250.

Table 1 Effect of different foaming agents on the floating rate of stibnite and arsenopyrite /%

(B) the effect of pH on the floatability of two minerals

Figure 1 shows the effect of pulp pH on the floatability of stibnite and arsenopyrite when there is no collector. It can be seen that the stibnite is well floated at pH<7; the arsenopyrite floats well at pH<9. There is a big difference in the floatability of the two in an alkaline medium.

(III) Effect of Eh on the floatability of two minerals

Figure 2 shows the effect of the pulp redox potential Eh on the floatability of stibnite and arsenopyrite when there is no collector. When the pH is 5.4, the two minerals have good floatability in the range of Eh from -500 to +400 mV. When Eh>400mV, the floatability of the arsenopyrite drops sharply and does not float at 800mV. The stibnite mine is well floated at Eh 400-800 mV. Therefore, controlling the pulp redox potential Eh is expected to achieve the non-collector flotation separation of the two minerals.

(IV) Effect of KMnO4 on the floatability of two minerals

Fig. 3 is a graph showing the relationship between the floating rate and pH of two kinds of mineral-free collector flotation when KMn04 is 30 mg/L. Compared with Figure 1, KMn04 has a strong inhibitory effect on arsenopyrite. In acidic medium, the floating rate is not more than 10%, but the inhibition effect on stibnite is very weak. In acidic and weakly acidic medium, stibnite The floating rate is above 90%. Figure 4 shows that the amount of KMn04 has a significant effect on the floatability of the arsenopyrite. As the amount of KMn04 increases, the floating rate of the arsenopyrite drops sharply, but the effect on the floatability of the stibnite is extremely small.

(5) Relationship between foaming agent performance and flotation without collector

1. Relationship between foaming agent performance and mineral floatability

Table 2 lists the foam layer height, defoaming speed of several foaming agents at a solution concentration of 30 mg/L, the surface tension at 100 mg/L, and the stibnite floating rate at a dosage of 7.5 mg/L.

Table 2 Performance of the foaming agent and the floating rate of the stibnite

The results show that the smaller the surface tension, the higher the foam layer height and the slower the defoaming speed. The higher the floating rate of the stibnite, but there are exceptions. For example, the height of the foam layer of MIBC is not too high, but the mineral floating rate is higher. This may be related to its small bubble diameter and favorable flotation.

2. Effect of KMnO4 on the performance of foaming agent

Table 3 lists the effect of KMnO4 on the foaming properties of butyl ether alcohol. With the increase of the amount of KMnO4, the foaming performance of butyl ether alcohol changed accordingly, the foam layer height decreased, the defoaming speed increased, and KMnO4 was found to be No. 2 oil (starting concentration of 10.4 mg/L) in two minerals. The amount of adsorption on the surface has a certain influence (see Table 4). After KMnO4 was added, the adsorption amount of No. 2 oil on the surface of the stibnite was not significantly changed, while the adsorption amount on the surface of the arsenopyrite was decreased.

Table 3 Effect of KMnO4 on foaming performance

Table 4 Effect of KMnO4 on Adsorption of No. 2 Oil on Mineral Surface

Third, the conclusion

(1) Under certain conditions (pH=5.4, Eh=690mV), stibnite and arsenopyrite are expected to achieve flotation separation without collector.

(2) Foaming agents are extremely important when there is no collector flotation. The results of 15 kinds of foaming agent comparison test were optimized with butyl ether alcohol.

(3) When there is no collector flotation, the performance of the foaming agent has a certain correspondence with the floating rate of the stibnite. Oxidizing agents such as KMnO4 have an effect on the properties of the foaming agent and the amount of adsorption on the mineral surface.