1. General methods and indicators reported zinc ore flotation of lead oxide There are several methods, but in practice usually is after addition of vulcanizing agent, with the thiol collectors flotation agent. As for other flotation methods (fatty acid method, carboxyquinoline, etc.), there is no application in practice. Vulcanization-xanthate flotation is very effective for ore mainly composed of white lead ore and lead bismuth. The general selection criteria are as follows (the table below).
Lead Oxide Flotation Index of Major Lead-Zinc Mines in Yunnan | |||||||
Types of | Mineral area | Process introduction | Main pharmacy (g / ton) | Flotation indicator | |||
Sodium sulfide | Yellow medicine | Original ore grade % | Concentrate grade % | Recovery rate% | |||
Carbonate | Huize | Flotation after deliming | 1700 | 490 | 3.9 | 43.56 | 71.9 |
Gangue stone | Yan Liang | Direct flotation | 5500 | 350 | 8.56 | 55.43 | 87.1 |
Silicate | Lanping sandstone | Direct flotation | 1900 | 520 | 2.44 | 55.9 | 75.4 |
Gangue stone | Lanping West Slope | Sulfur-oxygen mixed | 1700 | 330 | 6.6 | 51.28 | 86.5 |
　 | Zhaoxing | 　 | 5100 | 450 | 11.83 | 60.81 | 83 |
Limonite veins stone | 澜沧 | Direct flotation | 4800 | 520 | 8.54 | 41.86 | 58.1 |
2. The impact of slime
Sludge is harmful to the flotation of oxidized ore, but in the flotation of lead oxide, deliming is not desirable. Generally, adjustment or improvement of the process should be used to reduce the impact of slime.
Practice has proved that the white lead ore in the fine mud still has good floatability, and the de-sludge before the lead flotation is mostly to reduce the total recovery rate (see the table below). Therefore, before the flotation of lead oxide ore, it is generally not pre-selected to remove mud to ensure a high recovery rate. This is also the case in the production practice of some selected factories abroad.
Comparison of dephosphorization and non-desilting before lead oxide ore flotation | ||||||||||
　 | Sludge (%) | Concentrate (%) | Middle mine (%) | Total concentrate (%) | Tailings grade % | |||||
Yield | grade | Recovery rate | grade | Recovery rate | grade | Recovery rate | grade | Recovery rate | ||
澜沧Old factory sand lead ore to remove raw mud (-9 microns) | 7.9 | 4.26 | 4.5 | 33.5 | 53. 3 | 8.04 | 5 | 26.34 | 58.3 | 4.25 |
No mud | - | - | - | 33.17 | 56 | 8.05 | 5.3 | 26.11 | 61.2 | 4.04 |
Desmutation after grinding in Xinzekeng Mine, Huize (-10 microns) | 10.4 | 2.54 | 7.1 | 20.81 | 74 | 1.58 | 4.4 | 　 | 78.4 | 0.82 |
No mud | - | - | - | 18.45 | 72.9 | 3.9 | 9.8 | 82.7 | 0.85 | |
Although fine mud can be recycled, it is economically reasonable to not remove mud; but the presence of slime still has an adverse effect on flotation. Therefore, when the lead oxide ore is flotation, it is often necessary to add a regulator to reduce the influence of the slime. The most commonly used modifier is water glass, which improves concentrate grade and recovery. When the pulp are more soluble calcium and magnesium ions, Floatation, it is more effective than the soda water glass.
The adverse effects of slime are often manifested in the so-called "malignant cycle", that is, the fine mud is easy to float into the foam during rough selection, and when it is selected, it falls off from the foam and enters the selected tailings. At the time of selection, it is floated by the action of a higher concentration of the collector and the foaming agent, so that the cycle is endless, causing the flotation process to deteriorate. This is sometimes not controlled by a single agent. Take the method of returning the selected tailings to the rough selection tail (rough selection II) to ensure that the main part of the rough selection is open, which can prevent the adverse effects of the slime; or the flotation of the middle ore separately, allowing a large amount of slime to be and then moved into the far discarded (this time, the re-election of tailings grade is slightly higher than the final tailings, but very little metal loss), only allow re-election bubble return process, but also to prevent the vicious circle of influence slime . [next]
3. Vulcanization process
The key factor in the flotation of lead oxide ore is the vulcanization process. The commonly used vulcanizing agent is sodium sulfide, and its amount is related to the amount of lead mineral to be vulcanized. To a large extent, it is related to the material composition of the ore, the amount of slime, and the amount of soluble ions. In fact, sodium sulfide is not only a vulcanizing agent, but also a good adjusting agent. In many cases, it can replace other adjusting agents (such as soda, water glass, etc.). Therefore, for different ores, the amount of sodium sulfide is changed. Very large, it is between 500 and 5000 g / ton. The appropriate amount of any ore and sodium sulfide generally has a range in which the change in sodium sulfide does not cause large fluctuations in the lead flotation index.
The location of the sodium sulfide addition and the agitation conditions have a great influence on the vulcanization process. This is discussed differently in different literatures. In fact, this is different from ore. Kunming has continuous flotation of lead oxide ore in different regions (scale 30~60 kg/h), and the requirements are different. When flotation of the lead oxide in the Xinping pit vein mine of Huize, the sodium sulfide is added to the pulp before the xanthate, and the slurry is adjusted in a general mixing tank (the air will be inhaled from the slurry surface when stirring); At the time of the mine, it is required that the stirring time should not be too short or too long after adding sodium sulfide (see table below). In the flotation of the veins in the Liangkeng vein, sodium sulfide needs to be added after the other chemicals are adjusted, and the air cannot be absorbed while stirring.
Effect of Stirring Conditions of Flotation of Sodium Sulfide in Runziquan Lead-Site on Flotation Index | |||||||
Sodium sulfide stirring condition | Raw ore grade Pb (%) | Selected concentrate grade (%) | Lead concentrate (%) | Tailings grade Pb (%) | |||
Time, minute | Inflated | Yield | grade | Recovery rate | |||
1.5 | Not inflated | 6.35 | 17.87 | 5.1 | 53.06 | 42.62 | 3.84 |
3 | Not inflated | 6.4 | 17.88 | 5.82 | 52.35 | 47.61 | 3.56 |
4 | Not inflated | 6.4 | 18.41 | 5.72 | 50.8 | 45.56 | 3.7 |
7 | Not inflated | 6.1 | 16.08 | 4.33 | 50.35 | 35.74 | 4.1 |
Therefore, when the lead oxide is floated, the location and stirring conditions of the sodium sulfide should be carefully studied and determined.
4. The main collector of collector flotation lead oxide ore is high-grade xanthate (China is a diced yellow medicinal herb, and foreign is a medicinal medicinal herb). However, in addition to the addition of the main collector, the addition of an appropriate amount of collector is advantageous for improving the recovery of lead and precious metals, such as ammonium black medicine, hydrogen thiophene thiazole and the like. In the Zairem mine in the Soviet Union, lead oxide ore is added in a turbid aqueous solution using transformer oil to further capture coarse-grained lead oxide minerals, which has a certain effect. In addition, hydrocarbon oil and xanthate are added together to the flotation operation. Improve lead recovery by 5 to 6%.
When flotation of lead oxide minerals in the old tailings of the Chaihe lead-zinc mine (flotation with sulfides and oxides), mixed use of butyl xanthate and butylammonium black, the highest recovery of lead is beneficial. Recovery of silver and sulfur (see table below).
Effect of Collector Monomer and Mixture on Recovery Rate of Sulfur and Silver in Crude Concentrate | |||||||||||
Collector dosage g / ton | Collector name | product name | Yield(%) | grade(%) | Recovery rate(%) | ||||||
Pb | Zn | S | Ag g / ton | Pb | Zn | S | Ag  | ||||
75 | Butyl xanthate | Lead concentrate | 5.54 | 5 | 4.4 | 11.4 | 196.26 | 63.97 | 10.95 | 52.71 | 38.69 |
75 | Mixture of butyl xanthate and butylammonium black drug (2:1) | Lead concentrate | 11.53 | 2.75 | 3.7 | 7.6 | 121.46 | 68.32 | 18.26 | 71.22 | 48.83 |
The mixed metallurgical research institute used Zhongxinji yellow medicine, which also achieved good results. Sec-octyl xanthate collectors than xanthate ability for Galena based white lead oxide ores, the recovery can often be increased by 1 to 2%; if galena ore containing arsenic, pyromorphite, alumina, lead There are more mines, and the effect of Dinghuang is often not good. The use of Zhongxin-based xanthate can greatly improve the recovery rate. Flotation of vanadium, lead and zinc mines requires no pre-activation and a significant savings in collectors.
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