Copper Cathode from Oxide Ore | Hydrometallurgical Production (SX–EW) at Sormak Mines Copper ores are generally classified into two groups: sulfide and oxide. Oxide ores typically form near the surface through weathering and oxidation of primary minerals and, due to their higher solubility in acidic media, they are a highly suitable feed for hydrometallurgical copper production. With an end-to-end view from mine to product, Sormak Mines operates in the design and implementation of copper cathode production routes from oxide feeds.

Sormak’s Scope in Producing Copper Cathode from Oxide Copper

1) Feed Evaluation and Process Route Selection

No two oxide projects are the same. Differences in mineral type (e.g., cuprite, malachite, azurite, tenorite, chrysocolla), silica/carbonate content, impurities, and leaching behavior directly influence route selection. Sormak’s approach is to choose the optimal route based on the actual feed characteristics and the target market.

2) Feed Preparation (Crushing and Controlled Sizing)

Effective leaching requires proper liberation and controlled particle size distribution. After mining, the ore enters the crushing circuit and is prepared to the target process size (depending on the leaching method). The objective is not only size reduction; it is also to minimize problematic fines, control dust, and provide a stable feed for downstream operations.

3) Leaching and Pregnant Leach Solution (PLS) Generation

In this step, copper in oxide ore is dissolved using dilute sulfuric acid, producing a pregnant leach solution (PLS) that is sent to the purification stage. Depending on feed properties and project conditions, leaching can be carried out using one of two main methods:

Heap Leaching:
Sized ore is stacked on an engineered pad (with proper slope, an impermeable liner, and a collection system), and the acidic solution is applied in a controlled manner. The PLS is collected and sent to solvent extraction. This method is typically more economical and better suited to larger capacities.

Agitated Leaching:
Where faster dissolution is required, or when the feed needs finer sizing, the ore is ground to smaller sizes, the slurry is fed to agitated tanks, and dissolution is performed under tightly controlled conditions. The PLS is then separated from solids and forwarded to the next stage. Acidic residue handling and environmental requirements are a key part of this design.

Purification and Cathode Production (SX–EW)

1) Solvent Extraction (SX)

Solvent extraction is the critical step for selective copper separation from the PLS and for producing an electrolyte suitable for electrowinning. In this section:

• The copper-bearing aqueous solution contacts the organic phase in a mixer, and copper ions transfer selectively into the organic phase.

• The two phases are then separated in a settler.

• During stripping, copper is transferred from the organic phase into a higher-acidity electrolyte to provide a suitable feed for electrowinning.

Control of parameters such as pH, temperature, organic phase concentration, and prevention of impurity transfer directly affects final cathode quality and operating stability.

2) Electrowinning (EW)

In electrowinning, copper dissolved in the electrolyte is deposited onto starter cathodes (typically stainless steel) under direct current, and harvested as copper cathode sheets. In this stage:

• Anodes are typically selected from lead-based alloys.

• Temperature and electrolyte composition are controlled to prevent operational issues (such as unwanted deposits, surface quality loss, or reduced efficiency).

• Control of impurities (such as iron, chloride, and manganese) and preventing organic carryover into the EW circuit are essential to achieving consistent product quality.

Advantages of Sormak’s Approach

• Process route design based on real feed behavior (not copy-paste flowsheets)

• Capability to design and integrate leaching, SX, and EW units with a focus on stable operations

• Environmental and safety management for heap pads, ponds, and acid-bearing residues

• Focus on product quality and lower operating costs through tight control of chemical and process parameters

• Flexibility in selecting Heap vs. Agitation based on capacity, project economics, and ore type

Cooperation Inquiry / Feasibility Study / Plant Design

To receive further information on flowsheet design, technical-economic feasibility, SX–EW capacity assessment, and the best solution for your oxide feed, please submit your request via the contact form:
Company name | Project location | Feed type & grade | Capacity (t/day) | Suggested method (Heap/Agitation) | Contact number/WhatsApp