Pyrite is depressed in flotation process to improve the concentrate grades of pb, zn and cu or bulk , in order to reduce onward smelting process cost. Don't think making iron/steel/ out of pyrite concentrate has become viable commercially. Heard that some research institutes or a plant have produced pyrite concentrate out of pb-zn tailings on pilot scale for economic study for a shorter duration. Further need to enquire or confirm with concentrators of developed nations.

There are a number of copper-lead-zinc mines that spring to my mind. I'm pretty sure most of these had pyrite and there is a lot of literature on them, though only a few still operate. This in by no means an exhaustive list. Unfortunately I can't recall any having a sulphide scavenging circuit on the end, it's likely most of these were built at a time went there likely wasn't a limit on sulphides in tails.

• Thalanga (Queensland, Australia)
• Rosebery (Tasmania, Australia)
• Hellyer (Tasmania, Australia)
• Woodlawn (NSW, Australia)
• Black Mountain (Northern Cape, South Africa)
• Myra Falls (BC, Canada)

The Iberian Pyrtite Belt that runs across Southern Spain to Portugal has many Cu-Pb-Zn operations - including the original Rio Tinto operation. The largest still operating is Somincor (Neves-Corvo) which is operated by Lundin Mining.

Also, FQM Pyhäsalmi in Finland has a setup you are looking for. Also in Peru there are several processes like this, but cannot recall their names.

Sorry but I could not understand the ARD environmental impact point of view on my mind . Not sure of Environmental impact consideration of ARD by government statutory bodies here. But have not seen scavenging cell batteries recovering pyrite and other non viable sulphide minerals from pb-zn or cu tailings. It's good initiative to protect aquatic life and vegetation in near tailing pond area. 

The mines located in Sudbury Ontario have been floating Pyrite to send it to a more protected area in their tailings dam to minimize acid drainage. They first float Chalcopyrite, then Pentalndite and then Pyrite.

The polymetalic ores are usually floated in a sequential manner. Cu and Pb go together and Zn is depressed. Then the Zn is floated . The Pb is separated from Cu but this separation is difficult.
The Pyrite flotation needs to be executed only after its kinetics is the fastest in the circuit.
Open cycle tests and mineralogical analysis plus benchmarking from other plants may shed light into this problem EM2PO can help to develop met testing to tailor a flowsheet for this ore if needed.

Thanks to you all for the helpful comments!
I would say that social and environmental risks are the ones that have increased the most in importance in the past decade. We've done a lot of studies where we use the sulfide rich con for paste back-fill, however none of them have been commissioned yet with the 4 products and perhaps I shouldn't call a pyrite con to no imply commercial value.

I am pretty sure Brunswick mine was floating at least Cu, Pb, Zn, and a PbZn concentrate which also contained lots of pyrite. Similar ore is now being processed by Trevali.
For such a suite of minerals you may need to look at separation methods other than flotation alone. It is too easy to seek a straight line path to your goal. Consider a copper, lead, zinc, pyrite sequence. Yes it would seem that could be done by flotation, however you are looking at three or four essential identical sized flotation plants. Depending on the tonnage processed and exact mineralogy it would be worth looking at a sequence of float/gravity/ float or some variation there of. By early on discard of a non sulfide tail you have reduced the tonnage processed. Reichart cones can process a large tonnage with a small footprint and relative low cost, thus you have achieved your low sulfide tails.

Helen,

Approach the mitigations of ARD from an ease/simplicity of implementation.

Note that irrespective of the method, some form of effluent water treatment will be needed.

With sulphide bearing tailings, the simplest approach is to keep the tailings submerged (under a water cover). This minimize the oxygen intake by the tailings mass and reduce acid generation.

As far as removing the pyrite from the tailings, one needs to know how low a sulphur content in the resulting rock tailings for them to be non-acid generating. The practicality of removing the amount of pyrite necessary to get to that sulphur content needs to be examined.

You mentioned paste-fill. Sulphur-bearing paste-fill may be advantageous. In a related train of thoughts, if the project is located in a dry climate, it might be worth examining a dry-stacked tailings approach. I believe there is a couple of operations which have taken this approach - to minimize the area of the tailings management facility as well as minimize the environmental risk. Can't remember the names of these operations at the moment.

With a complex Cu-Pb-Zn-Pyrite, managing the flotation response of pyrite is somehow tricky - if a bulk flotation approach is taken to maximize metal recoveries prior to concentrate regrinding for liberation, then subsequently depressing the pyrite can be problematic. On the other hand, the use of cyanide or thio-species to depress pyrite for a sequential selective flotation process makes it difficult to scavenge the pyrite by flotation.

If I may jump in, I worked at a very complicated ore, at the Novoshirokinskiy mine in Russia. Thay had been floating concentrates of Pb with Au and Ag, and Zn, and Py since start and have now started to extract Cu-Au a couple of months ago in order to be more competitive.

Hello, I don't think this is not very difficult. We have do many flotation projects all over the word like this. This is normal that copper and pyrite together with lead and zinc. But I think the best way is to do a metallurgical test first, then you'll know which is the best way to separate the four elements.

I think it will also help to read up on pyrite depression if its a concern to you. Like suggested, you might want to run some lab tests, and try lime, to see if can help depress the pyrite.

Good Luck!

At Morococha Centromin-Peru now Pan American Silver operation unit ,we run five production lines copper,lead-silver,zinc,pyrite and tungsten with all sale able well earned concentrates to La Oroya Smelter.

Yes it is possible. As down line operation should be Pyrometallurgy. Different minerals have different melting and boiling points for separation. Pyrite gives you S which is extracted as H2SO4. Balance waste is used for leaching and electrolysis of metal sulphides solution.

If feasible float four types of concentrates. First a concentrated bulk of Lead and Copper and Zinc floats pyrite depresses a Ph of 7.5 to 8.0; Copper Lead separation. Then fleet zinc and pyrite even depressed pH of 10.5 to 11.8. The next step is to activate the previous Pyrite to conditioning lowering the pH by the addition of sulfuric acid with pH of 5 to 6. For much more able to help you tell the heads of each element ore Pyrite Gold if you have that percentage. This work was conducted in Tamboraque San Juan Peru.

If copper is in oxidised form then it is easy to leach. 1st float lead copper --separate lead from copper. Then 2nd stage float Zinc. Pyrite can be depressed using cyanide in all concentrates.