The difference between hydrophobic flocculation and conventional flotation is that a large agitation energy input is required. In most cases, a neutral oil is added, and the separation method of the floc and the dispersed ore is various. Its advantages: a can learn from the long-term experience of conventional flotation reagents; b easy to remove the mechanical inclusions of flocs; c floc structure is dense, strong, not subject to mechanical damage; d suitable for higher pulp concentration operation. Therefore, this method is easy to realize industrialization and is a dynamic sorting method for fine-grain mineral sorting.

Manganese ore processing, metal manganese slime in a serious loss, recovery from sludge metal manganese is part of micro-fine mineral processing problems, in this regard, at home and abroad have done a lot of research work proposed high intensity magnetic separation, high Gradient magnetic separation, selective flocculation flotation, magnetic sorting, dihydrosulfuric acid, sulfuric acid method, sulfur dioxide and sulfuric acid combination method, bacterial leaching method, controlled dispersion-shear flocculation flotation, hydrophobic flocculation flotation, etc. .

The useful minerals in China's manganese carbonate ore are mainly rhodochrosite. The gangue minerals vary from mine to mine, and are mainly quartz , with chlorite. Therefore, according to the process characteristics of manganese ore mud, the author chooses the artificial mixed ore of single mineral rhodochrosite, iron chlorite and quartz, and uses the fine particle sorting process developed in recent years-hydrophobic flocculation flotation method to carry out the above three mineral separations. The possibility and the best separation conditions for research, seeking a solution for efficient recovery of manganese minerals from manganese ore. At the same time, the mechanism of the separation process was also studied, trying to provide an effective method and theoretical basis for the treatment of manganese ore mud in China.

1. Single mineral hydrophobic flocculation flotation test

The test was carried out in an XFG-80 inflatable gutter flotation machine. Condition tests such as the speed of the flotation machine, the stirring time, the flotation temperature, the type and amount of the collector, and the like were carried out. Through a lot of experiments, the following conclusions are drawn:

(1) Sodium oleate has the strongest ability to capture rhodochrosite. The optimum pH value is in the range of 5-10.

(2) The ability of the oxide wax to absorb the rhodochrosite is second only to sodium oleate, and it has a good ability to capture rhodochrosite in the range of pH=7-9.

(3) The petroleum sulfonate has a weak ability to capture rhodochrosite, which may be related to its poor foaming ability. It has better collection ability in the range of pH=7～9, and the insertion peak shifts to low pH as the dosage increases.

(4) Under the conditions of the above three collectors, the chlorite decreases with the increase of pH value. Quartz has a low floating rate under the three collector conditions and does not change much with pH.

Second, mixed mine test

On the basis of the single mineral test, the hydrophobic flocculation flotation test of single mixed ore was carried out, ie rhodochrosite and chlorite, and rhodochrosite and quartz were mixed separately for hydrophobic flocculation flotation.

Figure 1 and Figure 2 show the results of hydrophobic flocculation flotation test of 1:1 distribution of rhodochrosite and chlorite.

Fig. 1 Results of sorting test of 1:1 distribution of rhodochrosite and chlorite.

Figure 2: Sodium oleate dosage test of rhodochrosite and chlorite 1:1 mixed ore at pH=10

It can be seen from Fig. 1 that at pH=10, the grade and recovery rate of the rhodochrosite peak.

Figure 2 shows that when the amount of sodium oleate is increased from 40 mg/L to 80 mg/L at pH=10, the recovery rate is increasing (from 72% to 89%), and the dosage is increased, and the recovery rate is basically stable. As the amount of sodium oleate increased, the grade of manganese concentrate increased slightly.

Figure 3 and Figure 4 show the results of hydrophobic flocculation flotation test of rhodochrosite and quartz mixed ore. It can be seen from Fig. 3 that the concentrate grade and recovery rate of rhodochrosite are high in the range of pH 7-9. It can be seen from Figure 4 that with the increase in the amount of sodium oleate, the manganese grade and recovery rate increase slightly.

Figure 3: Manganese ore, quartz 1:1 mixed ore, floating rate - pH test results

Fig. 4 The test results of the floating rate-NaOC dosage at the pH=10 of rhodochrosite and quartz 1:1 mixed ore

Simulate the mineral composition of the slime in a mining area, and divide the rhodochrosite, chlorite and quartz into mixed ore (including Mn12%) for separation test. According to the above conditions, when the pH is 10, the amount of sodium oleate is 120mg/ L, the separation result is shown in Fig. 5. Under this condition, a manganese concentrate grade of 21% and a manganese recovery of 66% were obtained from a mixed ore containing 12% manganese.

Figure 5 simulation mixed sample sorting test results

It can be seen from the above test that when sodium oleate is used as the collector, the optimum pH for the flocculation and flotation separation of the fine-grained magnesite and chlorite single mixed ore is about 10, and the amount of sodium oleate is 120 mg/L. The manganese content is 30% and the manganese recovery rate is 88%. The optimum pH value of fine-grained rhodochrosite and quartz single-mixed ore is 7-9. When the amount of sodium oleate is 100mg/L, the manganese grade is 30% and the manganese recovery rate is 93%. A hydrophobic flocculation flotation test simulating a mixed ore of a mine in a mining area. When the pH is 10 and the amount of sodium oleate is 120 mg/L, a manganese-containing grade of 21% can be obtained from a mixed ore containing 12% of manganese. , a manganese concentrate with a recovery rate of 66%.

Third, the results and discussion

Through a lot of experimental research work, the following conclusions can be drawn.

(1) The single mineral test shows that the collector, pH value and rotation speed have a great influence on the floating rate of minerals. With sodium oleate as the collector dosage of 120mg/L, pH=10, temperature of 24°C, and rotation speed of 3000r/min, the floating rate of rhodochrosite can reach 90% and the volcanic mineral floating rate is below 10%. The wax has a good selectivity at pH=8, and the sodium petroleum sulfonate has a good selectivity at pH=9.

(2) The results of mixed ore sorting indicate that the separation of rhodochrosite and chlorite mixed ore at pH=8 is the best. When the dosage of sodium oleate is 140mg/L, the concentrate index: β=31%, ε=89%, and the separation effect of rhodochrosite and quartz mixed ore in the range of pH=7～9 is better. When the amount of sodium oleate is 100 mg/L, the manganese concentrate index is: β = 30%, ε = 93%. Simulate the mixed ore sample of a mine in a mining area (containing manganese grade α=12%). Under the optimal conditions, the manganese concentrate index can be obtained as β=21% and ε=66% after one sorting.

(III) Studies on the interaction between the infrared spectrum and the x-ray photoelectron spectroscopy on the surface of the agent and the mineral show that the sodium oleate and the surface active material Mn ^{2+ of the} rhodochrosite form Mn(ol) ₂ ; the sodium oleate has a surface on the chlorite surface. A small amount of chemisorption, when the pH is high, the coordination of hydroxyl groups on the surface active sites inhibits the chemical interaction between oleate and Fe ²⁺ and Mg ²⁺ particles. Sodium oleate has no chemical adsorption on the quartz surface.

(4) The mechanism of hydrophobic flocculation is: when the two hydrophobic ore particles are close to a certain extent (60-80 nm), the first is electrostatic interaction, van der Waals interaction, long-range hydrophobic interaction, so that the hydrophobic ore particles are rapidly approaching, when the adsorption layer hydrocarbons When the chain begins to contact, the hydrophobic association of the hydrocarbon chain begins to take effect, bringing the hydrophobic ore particles together. The long-range hydrophobic interaction results from the structuring of the interfacial molecular arrangement, and the hydrophobic association is similar to the phenomenon of micelle formation. The long-range hydrophobic interaction range is 60nm, which is the same as the range of the van derrick force, but is 1~2 orders of magnitude larger than the Fan's force. The variation law is attenuated with the distance index and is different from the power law of the Fan's force. Long-range hydrophobic interaction is not sensitive to changes in electrolyte concentration, pH and other conditions.

In summary, the treatment of manganese carbonate ore by selective hydrophobic flocculation flotation is a more effective method, and it is worthwhile to further study the treatment of manganese ore.

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