Copper Ore Types & Processing Routes
Copper ores are broadly classified into sulphide ores (chalcopyrite, chalcocite, bornite, covellite), oxide ores (malachite, azurite, chrysocolla, cuprite) and mixed / transition ores. Sulphide copper ores are predominantly processed by flotation. Oxide and mixed ores are processed by flotation (after sulphidization for some oxide minerals) and/or hydrometallurgical routes (leaching + solvent extraction + electrowinning, i.e. SX-EW).
WSHT designs copper beneficiation flowsheets based on the specific ore type and mineralogy of each deposit.
Crushing & Grinding Circuits for Copper Ores
Typical copper ore crushing circuits combine primary jaw crushing, secondary cone crushing and tertiary cone crushing, often followed by SAG milling and ball milling in larger operations. The grinding circuit reduces the ore to a size suitable for flotation, with hydrocyclone classification controlling the target grind.
WSHT designs custom crushing and grinding circuits matched to the ore hardness, abrasiveness, head grade and target production rate.
Copper Flotation — Rougher / Scavenger / Cleaner
Flotation is the dominant concentration process for sulphide copper ores. A typical copper flotation circuit includes rougher flotation (to maximize overall copper recovery), scavenger flotation (to recover remaining copper from rougher tailings), and 1-3 stages of cleaner flotation (to upgrade concentrate grade). Re-cleaner and re-grinding stages are often included for complex ores.
WSHT supplies complete flotation circuits including mechanically-agitated and column flotation cells, reagent preparation and dosing systems, and automatic level / airflow control.
Copper-Sulphur (Pyrite) Separation
Many copper ores contain significant pyrite (iron sulphide) that reports to flotation concentrate if not suppressed. Copper-sulphur separation — typically using lime-based high-pH pyrite depression or selective re-flotation — is used to upgrade copper concentrate grade and reduce the mass of concentrate for downstream smelting or leaching.
WSHT designs copper-sulphur separation circuits optimized for each ore's specific mineralogy.
Concentrate Dewatering & Hydrometallurgical Options
Copper flotation concentrate is dewatered using thickeners and pressure / vacuum filters prior to shipment to smelters or further on-site processing. For deposits with favorable economics, hydrometallurgical processing of flotation concentrate (pressure leaching, atmospheric leaching) plus solvent extraction and electrowinning (SX-EW) is an option.
WSHT designs complete concentrate handling and SX-EW flowsheets as required for each project.
Heap Leaching for Low-Grade Copper Ore
Low-grade copper oxide and secondary sulphide ores are often most economically processed by heap leaching using dilute sulphuric acid (for oxide ores) or acidified ferric iron / bio-leaching (for secondary sulphides). Pregnant leach solution (PLS) is processed by solvent extraction (SX) followed by electrowinning (EW) to produce high-purity cathode copper.
WSHT provides heap leach process design support including solution chemistry, irrigation system design and SX-EW circuit sizing.