Flotation process of lead-zinc sulfide ore

Lead-zinc ore is a polymetallic mineral rich in elemental lead and elemental zinc, mainly in the form of lead-zinc sulfide and oxide lead-zinc ore. Among them, lead-zinc sulfide ore is also called lead-zinc raw ore, which accounts for a relatively large proportion and has high industrial value.

In the beneficiation process, sulfide lead-zinc ore is mainly based on flotation. Among them, the proportion of zinc ore in most lead-zinc ores is higher than the content of lead ore. The main principles to deal with lead-zinc sulfide ore. The common flotation processes of lead-zinc sulfide ore mainly include several methods: priority flotation, mixed flotation, equal flotation, split-speed branch flotation and separation potential control flotation.
1. Priority flotation of lead and zinc sulfide
The process of priority flotation of lead-zinc ore mostly adopts the method of first suppressing zinc and floating lead, and then reactivating zinc to obtain lead and zinc concentrates. In order to effectively improve the recovery rate of lead concentrate and the index of zinc concentrate, the ore can be finely ground to -74μm to account for more than 80% in the grinding link, and then the lead flotation process with strong collector and high alkalinity is adopted, and excess lime and Xanthate, under the condition that the pH value of the ore slurry is >12, the newly dissociated pyrite is inhibited, and the surface of the newly dissociated galena is protected by xanthate, and then the lead is recovered by preferential flotation; copper sulfate is used to The flotation tailings are activated, the zinc sulfide rough concentrate is recovered with butyl xanthate, and the rough concentrate is selected under high alkali conditions to obtain zinc concentrate; the floating zinc tailings are thickened and activated with sulfuric acid, and the sulfur concentrate Then use xanthate to recover.

The flotation process can effectively obtain high-grade lead concentrate and high-recovery zinc concentrate, and the dosage of chemicals is small. The production process is simple and easy to control, but the recovery rate of lead concentrate is low. It is mainly suitable for the separation of lead-zinc ores with simple mineral composition, high grades of lead and zinc minerals in the raw ore, and large differences in floatability of lead-zinc minerals.
2. Lead-zinc sulfide mixed flotation
Mixed flotation of lead-zinc sulfide ore generally adopts mixed flotation to extract lead and zinc first, and then separates lead and zinc.

Grind the raw ore to a fineness of -74μm, accounting for 0% to 75%, and regrind the medium ore. Under the condition of not adjusting the pH value of the ore pulp, use xanthate or black powder as the collector, and the lead sulfide ore and part of the zinc sulfide The ore is flotation at the same time to obtain a concentrate mixed with lead and zinc. For the tailings in the flotation process, it is first activated with copper sulfate, then mixed with xanthate as a collector to flotation to obtain a mixed concentrate of zinc and sulfur, and then separated by lime and cyanide flotation to obtain Zinc and sulfur concentrates.

This process can discard a large amount of gangue minerals after coarse grinding, reduce follow-up operations, and can effectively save the amount of chemicals used in separation operations, but the cyanide used in the process has caused great pollution to the environment. It is mainly suitable for the treatment of lead-zinc ores with small difference in floatability, low grade, and useful minerals in aggregates or close symbiosis.
3. Lead and zinc sulfide can be flotation
Etc. Flotation flotation lead-zinc sulfide ore is to separate lead-zinc sulfide with similar floatability, and then separate lead and zinc. This process does not need to add inhibitors in the roughing stage, so that lead ore, lead-zinc conjoined organisms and some easy-floating zinc ores can be floated up, and the floated products can be separated from lead and zinc after regrinding.

This process has the characteristics of both mixed flotation and preferential flotation, with less reagent consumption, good flotation index, and effectively eliminates the adverse effects of reagent flotation flotation separation technology, but the flotation process is complicated and flotation It takes a long time and requires a lot of equipment. It is mostly used for lead-zinc minerals that contain two parts that are easy to float and difficult to float.
4. Sub-speed branch flotation of lead and zinc sulfide
Sub-speed branch flotation of lead-zinc sulfide ore refers to the rapid flotation of lead-zinc ore that is about to float, while the slow-speed and difficult-to-float lead-zinc ore is left in the subsequent flotation process for separation.

This kind of technological process can obtain better flotation index, and at the same time, it can also reduce the configuration volume of flotation machine, reduce the amount of metal circulation and loss, etc., and effectively save energy consumption. It is mostly used for lead-zinc sulfide minerals whose flotation behavior changes due to different embedding components.
5. Lead-zinc sulfide separation potential control flotation
Separation potential control flotation sulfide lead-zinc ore is to control the process and even direction of the oxidation-reduction reaction on the surface of sulfide ore in the slurry system by changing the electrochemical conditions of the flotation system during the flotation process, affecting the surface of lead-zinc sulfide ore. The state and the form and stability of the collector on the surface of the sulfide ore are used to increase the hydrophilic-hydrophobic properties of the surface of the lead-zinc ore to realize the process of selective flotation separation of the lead-zinc ore. The whole dose of lime and combined inhibitor zinc sulfate + sodium sulfite can be added to the ball mill to complete the selective flotation and separation of galena, sphalerite and pyrite in a highly alkaline pulp environment and low oxidation potential.
The process formula is simple, the dosage of chemicals is small, the environmental pollution is small, and the selectivity is high, and it is mostly suitable for the separation of low-grade lead-zinc sulfide or sulfide ore.

The above is an introduction to the flotation process of lead-zinc sulfide ore. In actual operation, if you want to choose a suitable, correct and scientific lead-zinc ore beneficiation process, it is recommended to choose a beneficiation factory with beneficiation qualifications to conduct a beneficiation test first. Carry out comprehensive ore analysis fundamentally, and then formulate a beneficiation process that meets the actual situation.