Chalcopyrite (12015-76-8) Physical and Chemical Properties
Chalcopyrite
Primary copper–iron sulfide mineral (CuFeS2) commonly handled as a copper ore in metallurgical and mineral processing supply chains.
| CAS Number | 12015-76-8 |
| Family | Copper iron sulfides |
| Typical Form | Crystalline solid (ore) |
| Common Grades | EP |
Chalcopyrite is an inorganic sulfide mineral of the chalcopyrite structural class, stoichiometrically represented by the formula \(\ce{CuFeS2}\). It crystallizes in a tetragonal (quadratic) lattice and typically occurs as brass‑yellow, metallic luster grains; the structure is a compact, extended sulfide framework in which copper and iron occupy crystallographic cation sites coordinated by sulfide anions. Electronically, chalcopyrite is best described as a mixed metal sulfide rather than a discrete molecular species; formal oxidation-state assignments vary in the literature and across computational representations, so the material is most usefully treated as an extended inorganic solid with localized metal–sulfur bonding rather than a neutral covalent molecule.
As a sulfide mineral, chalcopyrite is essentially insoluble in neutral water and shows low polarity and negligible lipophilicity in the molecular‑solvent sense; its chemical behavior is dominated by surface reactions, oxidative weathering and acid/leach chemistry rather than solution equilibria typical of molecular solutes. Under oxidizing conditions (atmospheric exposure, acidic waters, or oxidative leaching), surface sulfide is converted to sulfate and oxide phases with concomitant mobilization of copper and iron; these processes control environmental behaviour (acid generation, metal release) and metallurgical extractability. Mechanistically, metal release from chalcopyrite requires oxidative breakdown of the sulfide lattice and subsequent stabilization of dissolved metal species by complexation and protonation in the aqueous phase.
Chalcopyrite is the principal copper ore in many mining operations and is central to sulfide‑ore metallurgy and hydrometallurgical extractive processes. Common commercial grades reported for this substance include: EP.
Basic Physical Properties
Density
No experimentally established value for this property is available in the current data context.
Melting or Decomposition Point
No experimentally established value for this property is available in the current data context.
Solubility in Water
No experimentally established value for this property is available in the current data context.
Solution pH (Qualitative Behavior)
Chalcopyrite is effectively insoluble as a bulk solid in neutral aqueous media; it does not establish an aqueous equilibrium pH in the way a soluble salt or acid/base would. Surface oxidation and microbial or chemical weathering of sulfide minerals produce sulfate and protons, causing local acidification (acid mine drainage) and promoting metal mobilization. In controlled hydrometallurgical leaching (e.g., oxidative bioleaching, ferric‑sulfate leaching), solution pH is a process variable that governs copper/iron speciation and extraction efficiency.
Chemical Properties
Acid–Base Behavior
No experimentally established value for this property is available in the current data context.
As a crystalline sulfide, chalcopyrite does not exhibit discrete acid–base equilibria (no measurable \(\mathrm{p}K_a\) in the sense of molecular acids/bases). Acidic solutions (sulfuric acid, acidic ferric sulfate) accelerate lattice dissolution and metal leaching; basic solutions have limited direct reactivity toward the intact sulfide lattice but may influence downstream speciation of dissolved metal ions and secondary precipitates.
Reactivity and Stability
Chalcopyrite is chemically stable under reducing, anoxic conditions but is prone to oxidative alteration in air/moisture and in the presence of oxidants. Weathering typically produces secondary copper and iron oxide/hydroxide and sulfate phases; this oxidative breakdown is the central pathway for copper liberation in both environmental and extractive contexts. Thermal decomposition of sulfide minerals can generate sulfur‑containing gases (e.g., SO2); therefore thermal processing is conducted under controlled conditions in industrial metallurgy. Finely divided material increases surface area and reactivity; dusts are physically irritant and present larger reactive surface per unit mass.
Molecular and Ionic Parameters
Formula and Molecular Weight
- Molecular formula: \(\ce{CuFeS2}\)
- Molecular weight: 183.5
- Exact mass: 182.808675
- Monoisotopic mass: 182.808675
- Topological polar surface area (TPSA): 2
- Heavy atom count: 4
- Formal charge: 0
- Complexity: 0
These parameters are computed descriptors appropriate for the stoichiometric unit; chalcopyrite should be treated as an extended inorganic solid in materials and process contexts rather than an isolated molecular species.
Constituent Ions
Chalcopyrite contains copper, iron and sulfide in its lattice. Different formal electronic descriptions are used to represent the local oxidation environment; representative notations found in compositional descriptions include \(\ce{Cu^{+}Fe^{3+}S2^{2-}}\) and ionic fragment representations such as \(\ce{Cu^{2+}}\), \(\ce{Fe^{2+}}\) with sulfide anions in simplified computational SMILES. Practically, the mineral behaves as a copper–iron sulfide where metal–sulfur bonding and solid‑state electronic structure determine chemical reactivity and leachability rather than simple discrete cation/anion equilibria.
Molecular/structure identifiers (stoichiometric unit and computational descriptors):
- SMILES: [S-2].[S-2].[Fe+2].[Cu+2]
- InChI: InChI=1S/Cu.Fe.2S/q2*+2;2*-2
- InChIKey: DVRDHUBQLOKMHZ-UHFFFAOYSA-N
Identifiers and Synonyms
Registry Numbers and Codes
- CAS number: 12015-76-8
- ChEBI ID: CHEBI:86202
- DSSTox Substance ID: DTXSID00923245
- InChIKey: DVRDHUBQLOKMHZ-UHFFFAOYSA-N
Synonyms and Common Names
Reported synonyms and common names include: - chalcopyrite - cupric ferrous sulfide - Cupric ferrous sulfide (from MeSH) - Cuivre jaune - Cuivre pyriteux - Kupferkies - Copper iron sulfide (CuFeS2) - Copper(2+) iron(2+) sulfide (1/1/2) - Copper iron sulfide - Chalcopyrite, naturally occurring mineral, grains, approximately 0.06-0.19in
(These synonyms reflect historical and depositor-supplied naming variations for the same stoichiometric mineral.)
Industrial and Commercial Applications
Functional Roles and Use Sectors
Chalcopyrite is the most important copper ore and the dominant feedstock in copper mining and sulfide‑ore metallurgy. It is a primary source material for pyrometallurgical concentration (froth flotation concentrates, smelting) and for hydrometallurgical extraction routes (oxidative leaching, bioleaching) where oxidative dissolution yields soluble copper species for downstream recovery. The mineral is also of interest in geology and mineralogy as an indicator of sulfide mineralization and is used in academic and industrial research on sulfide oxidation and ore processing.
The commercial grade designation reported for this substance includes: EP.
Typical Application Examples
- Bulk mining and milling: chalcopyrite-bearing ore is crushed, ground and concentrated (flotation) to produce copper concentrates for smelting and refining.
- Metallurgical feedstock: concentrates are processed thermally (smelting, converting) or leached oxidatively to recover copper metal or copper salts.
- Geochemical and mineralogical studies: used as a reference sulfide phase in studies of weathering, acid generation, and metal mobility.
If specific product configurations, concentrate assays, or process chemistries are required for procurement or process design, specification and testing of the actual material source are necessary.
Safety and Handling Overview
Health and Environmental Hazards
Powdered chalcopyrite is an irritant to skin, eyes and the respiratory tract; dust control and appropriate personal protective equipment (PPE) are required when handling bulk or processed material. As a copper and iron containing sulfide, environmental concerns relate to oxidative weathering which can generate acid rock drainage and mobilize copper and other associated metals; appropriate containment and water management are required in mining and processing operations. Avoid generating airborne dust and limit worker inhalation exposures.
Storage and Handling Considerations
Store bulk chalcopyrite in a dry, well‑ventilated area away from strong oxidizing agents to limit unintended oxidative reactions. Prevent dust formation by using sealed transfer systems, local exhaust ventilation and dust suppression where applicable. Use standard industrial PPE (gloves, eye protection, dust respirator where dusts are present) and practice good industrial hygiene. For detailed hazard, transport and regulatory information, users should refer to the product‑specific Safety Data Sheet (SDS) and local legislation.
