Copper Oxide Ore SX-EW Process Flow

Summary: Explore the complete Copper Oxide Ore SX-EW process flow. Learn how crushing, agitation leaching, solvent extraction & electrowinning yield 99.99% pure copper...

In the current landscape of high copper prices and depleting high-grade sulfide deposits, oxide copper resources have emerged as a critical component of global copper production. The Solvent Extraction and Electrowinning (SX-EW) process has proven to be the most efficient and cost-effective method for treating oxide copper ores, offering a low-capital alternative to traditional smelting routes. This process flow diagram describes a complete hydrometallurgical circuit that transforms raw copper-bearing oxide ore into high-purity cathode copper, achieving product quality exceeding 99.99% copper content.

The copper oxide ore SX-EW process flow is organized into four major integrated systems: the Crushing System, the Grinding-Leaching and Filtration System, the Solvent Extraction (SX) System, and the Electrowinning (EW) System. Each system is designed to operate in harmony, ensuring maximum copper recovery, minimal reagent consumption, and environmentally responsible processing.

Phase I: The Crushing System – Preparing the Feed

The efficiency of the entire plant begins with optimal size reduction.

• Primary Crushing: Run-of-mine (ROM) ore is fed into the raw ore bin, then conveyed by a heavy-duty feeder to a jaw crusher for primary reduction.
• Secondary & Tertiary Crushing: The crushed product is transported via a belt conveyor to a single-cylinder cone crusher. This is followed by a closed-circuit system where the material passes through a vibrating screen. Oversize material is returned to a tertiary single-cylinder cone crusher for fine crushing, ensuring strict size control.
• Environmental Control: The qualified undersize material is conveyed to the ground bin. Dust generated throughout this circuit is captured by a pulse-jet baghouse dust collector before being safely discharged into the atmosphere, ensuring a clean and compliant site.

Phase II: Grinding, Leaching, and Filtration System

To maximize the surface area for chemical reactions, the crushed ore must be reduced to a slurry.

• Closed-Circuit Grinding: Material from the transfer bin is fed to the primary ball mill. The mill discharge flows into a pulp sump and is pumped to a cyclone classifier. The cyclone underflow returns to the ball mill, while the fine overflow reports to a thickener.
• Agitation Leaching: The thickener underflow is pumped into a series of leaching tanks, where sulfuric acid is introduced. The aggressive agitation ensures rapid and high-yield copper dissolution.
• Solid-Liquid Separation: The leached slurry undergoes countercurrent washing and filtration using a highly efficient four-stage horizontal vacuum belt filter system. This cleanly separates the valuable Pregnant Leach Solution (PLS) from the tailings. The residue is safely conveyed off-site, while the copper-rich PLS flows into the pregnant solution pond.

Phase III: Solvent Extraction (SX) System

This phase upgrades and purifies the weak copper solution.

• Extraction Stage: PLS is pumped to the mixer-settlers. In the mixers, the aqueous PLS is thoroughly blended with an organic extractant across two stages of countercurrent extraction. The organic phase selectively binds with the copper ions.
• Raffinate Management: The leftover barren aqueous phase (raffinate) is clarified to remove any entrained organics and pumped to a holding pond for reuse as a washing solution in the leaching circuit, minimizing acid and water consumption.
• Scrubbing and Stripping: The copper-loaded organic phase undergoes a single stage of scrubbing to remove impurities, then flows to a storage tank. It is then contacted with a highly concentrated acid solution in the stripping stage. This forces the copper out of the organic fluid and into the aqueous phase, yielding a pure, high-concentration Advance Electrolyte ready for the final stage.

Phase IV: Electrowinning (EW) System

The final transformation from liquid to solid metal occurs in the tankhouse.

• Cell Preparation: The advance electrolyte passes through a plate heat exchanger for precise temperature control before entering a head tank. It then flows by gravity into individual electrowinning polymer cells.
• Electro-Chemical Deposition: Inside the cells, insoluble anodes (made of a Pb-Ca-Sn ternary alloy) and starter sheet cathodes are precisely spaced. Direct electrical current drives the copper out of the solution and onto the cathodes.
• Harvesting the Copper: After a set cycle period, overhead cranes harvest the loaded cathodes and transfer them to a washing tank. The washed plates are processed through specialized stripping and flattening machines to produce the final product: 99.99% pure cathode copper, ready to be packaged and shipped to the global market.

A Proven Path to High-Purity Copper Production

The SX-EW process described above represents a mature, reliable, and economically attractive approach to oxide copper processing. By integrating crushing, grinding, leaching, solvent extraction, and electrowinning into a cohesive flow sheet, this plant design achieves several critical objectives:

• High Metal Recovery: The closed-circuit crushing and grinding stages ensure optimal particle size for leaching, while countercurrent extraction in the SX circuit maximizes copper transfer efficiency.
• Product Quality: The combination of selective solvent extraction and controlled electrowinning produces cathode copper meeting the highest purity specifications (99.99% Cu), suitable for the most demanding applications.
• Operational Efficiency: Recycle streams—such as raffinate return to the leaching circuit and organic phase reuse—minimize reagent consumption and reduce liquid effluent discharge.
• Environmental Responsibility: Dust collection systems, lined solution ponds, and tailings management protocols ensure that the operation meets modern environmental standards.

For mine owners and project developers evaluating oxide copper resources, the SX-EW process offers a proven pathway from ore to metal. With appropriate equipment selection and process design tailored to specific ore characteristics, this flow sheet can be adapted to operations of varying scale—from small, high-grade deposits to large, low-grade bulk tonnage projects.

As copper demand continues to grow and the industry increasingly turns to oxide resources to supplement sulfide production, the SX-EW process remains the technology of choice for efficient, cost-effective, and environmentally sound copper recovery.

Are you ready to optimize your copper processing flow? Do not leave your recovery rates to chance. Contact our metallurgical engineering team today for a customized flow sheet design, equipment sizing, and a comprehensive Total Cost of Ownership (TCO) analysis.