When dealing with the flotation process of copper, lead and zinc sulfide ores, it is first necessary to conduct in-depth research on the composition and structural characteristics of the ore, determine the intercalation relationship of the main metal minerals in the ore and the intercalation characteristics of the copper minerals, and on this basis design a suitable mineral processing and flotation separation process.
Detailed introduction to the four major copper, lead and zinc flotation processes
Priority flotation process
The priority flotation process is suitable for ores with simple composition, high ore grade and large differences in the floatability of useful minerals. The process includes:
- Copper ore flotation: First, add inhibitors to inhibit the floatability of lead and zinc minerals, then add collectors to promote the combination of copper minerals and bubbles, and then add frothers to stabilize the foam layer to complete the separation of copper concentrate. The amount of reagents added, pH value and temperature need to be controlled during operation.
- Lead ore flotation: After the flotation of copper ore, inhibitors are added to the slurry to inhibit the floating of zinc minerals, collectors are used to capture lead minerals, and frothers are added to stabilize the foam layer to separate the lead concentrate. The operation needs to be strictly controlled to improve the recovery rate and grade.
- Zinc ore flotation: copper sulfate is used as an activator to improve the floatability of zinc ore, then a collector is added to collect zinc ore, and then a frother is added to make it float and separate the zinc concentrate. Effective separation is achieved by adjusting the dosage of reagents and the conditions of the flotation tank.
Mixed priority flotation process
It is suitable for polymetallic ores where useful minerals are unevenly embedded or densely coexist with each other, or one useful mineral is finely embedded in another mineral, and its intergrowth, coarser embedded in the gangue. The process includes:
- Mixed flotation stage: adding collectors and frothers, copper, lead, and zinc minerals float together to form a mixed concentrate, completing the initial enrichment.
- Mixed concentrate decontamination: remove the reagent film on the mineral surface and the excess reagent in the slurry through mechanical decontamination (multiple selection, regrinding, concentration, scrubbing, filtering and washing), desorption method (using sodium sulfide and activated carbon) and heating method.
- Separation stage: adjust the pH value of the slurry and the collector (such as xanthate, butyl xanthate and black medicine) in stages to achieve the flotation and separation of copper, lead and zinc minerals in turn.
Partial mixed priority flotation process
Applicable to copper, lead and zinc polymetallic sulfide ores with similar floatability. The process includes:
- Copper and lead mixed flotation: ensure the appropriate pH value of the slurry through lime slurry adjustment. Use Ty-1 and zinc sulfate as inhibitors, ethyl xanthate and J-21 as collectors to achieve effective separation of zinc minerals from copper and lead minerals, ensure moderate foam viscosity, and create conditions for the next step of copper and lead separation.
- Copper and lead separation: adopt the method of suppressing lead and flotating copper, use ethyl oil and 2# oil as collectors and frothers to obtain high-grade copper concentrate. Subsequently, the grade of lead concentrate is improved by gravity separation shaker, and inhibitors such as cyanide and oxygen sulfur method are selected according to the type of mineral to adjust the flotation reagent.
- Zinc selection from tailings: Rough selection of tailings from copper-lead mixed flotation, lime, copper sulfate, butyl xanthate and 2# oil are used to adjust the flotation pH value to obtain high-grade zinc concentrate. Then two concentrations and one scavenging are carried out to ensure the improvement of the grade of zinc concentrate.
Equal flotation process
Following the principle of “easy first and difficult later” sorting, the minerals to be recovered are divided into two parts, easy to float and difficult to float, according to the difference in natural floatability, and mixed flotation is carried out to obtain mixed concentrate, and then copper, lead and zinc concentrates are separated in turn. The process includes:
- Mixed flotation stage of easy-floating minerals: The floatability of easy-floating minerals is improved by the natural floatability of minerals or collectors, and preferential flotation is carried out to form a preliminary mixed concentrate.
- Mixed flotation stage of difficult-floating minerals: The floatability of difficult-floating minerals is improved by adding sulfiding agents and adjusting the pH value to obtain a mixed concentrate of difficult-floating minerals.
- Separation stage: copper concentrate is obtained by activating copper minerals with copper sulfate, collecting xanthate and frothing with frother; lead concentrate is obtained by adding inhibitors, collecting black medicine and frothing with frother; and zinc concentrate is obtained by activating zinc minerals with copper sulfate, collecting sulfur and nitrogen collectors and frothing with frother, so as to achieve effective separation of copper, lead and zinc minerals in turn.
Conclusion
Through a comprehensive understanding of the four major copper, lead and zinc flotation processes, we can see that when processing copper, lead and zinc sulfide ores, choosing the right Mineral processing and flotation process is crucial to improving the recovery rate and grade of the ore.
Whether it is priority flotation, mixed priority flotation, partially mixed priority flotation or equal flotation process, each process has its applicable ore characteristics and operating points.
In actual production, it is necessary to flexibly select and adjust the flotation process according to the composition, structural characteristics and changes in process conditions of the ore to achieve the purpose of economy, efficiency and environmental protection.