We know that chalcopyrite contains copper, iron, and sulfur. Can the iron and sulfur be recovered too?
Dear Dr. Lyons,
from the point of view of an economic geologist dealing with mineral deposits and in view of what a deposit is meant, there is no rhyme or reason to recover Fe or S. We are flooded with S from the cleaning of gas and fume, excluding the sulphur deposits based on S and Fe sulphide. Iron is one of the major elements and supplied to the marked from "giant deposits" such as BIF and Kiruna-type ore deposits, to mention only the biggest ones so that even small local Fe mines are no longer competitive. High-temperature chalcopyrite is enriched in indium and as such may be attractive as a source, Au and Ag may sometimes also be included in the mineral and recovered as a by-product. Even elevated contents of Zn and Sn, locally present, are hard to extract. They occur mainly as stannite or sphalerite. Cu-Fe sulphides often go through a complex process of decomposition on temperature decrease of the mineralizing fluids which renders the extraction rather complicated because of the decomposition products and "Zwischenprodukte" (intermediate products) that come up.
Chalcopyrite is not a good target mineral excluding Cu due to its ubiquitous occurrence and rather high (but not the highest content; it is native copper) Cu content.
H.G.Dill
Dear Dr. Dill,
A splendid answer, for which I give you a thumbs up. Best wishes, Paul Lyons.
Great comment from Herald.
Talking of Kiruna type deposits, which is alkaline iron-phosphate bodies resembling alkaline-ultramafic complexes there is significant amount of P that is extracted, REE that are not extracted on their own.
Palaborwa as an alkaline-ultramafic complex extract Fe, Cu, REE.
Commodities depend on the type of deposit. Cu porphyry chalcopyrite ores have In as Herald mentioned, also Mo, Re, Au, Ag, rarely Sn, Epithermal Cu have Au, Ag, Ge, Hg. Replacement, contact scarn chalcopyrite Cu deposits as well as stratiform and VMS ones have Zn, Pb, Cd, Ge, Bi, Au, Ag, also S in pyrite for sulfuric acid can carry Mo as well.
Most of the plants do not separate concentrates of minor elements, but sell them in Cu, Zn, Pb, Mo or Au concentrates. Iron-oxide-copper-gold (IOCG) deposits extract Cu, Fe, REE, U.
Chalcopyrite concentrates are usually smelted, so the Fe goes in to silicate slag and discarded to waste. S goes volatile and is caught in water solution as dilute sulfuric acid and usually is neutralized and wasted as gypsum. I have not heard that it was used as it is not pure enough to process and contains hazardous elements as As, Sb, Hg, Bi, Tl, Po, Se, Te, which are not economical to extract. There is hydrometallurgical process to extract Cu from chalcopyrite. It produces FeOx (which precipitates within the processed tailings) and sulfuric acid, which are not utilized for economical reasons.
Very good answers from Harald and llya... Sulfer indirectly helps to extract copper from the ore in heap leaching technique (last sentence of llya's answer).
Dear Saman
Thanks for your excellent answer, which adds to Harald and Ilya's' answers. Appreciate your contribution. Paul.
You are welcome Paul, If you need more information about heap leaching please refer the following book (very good one for Chalcopyrite leaching): Bartlett, R.W., 1992. Solution mining: leaching and fluid recovery of materials, second ed. Gordan and Breach Science, Amsterdam
Thanks again, Saman, for alll your contributions. Researchgate is certanly a great way to get information.