Solvent Extraction and Electrowinning

Solvent Extraction and Electrowinning: A Practitioner’s Handbook is a practical guide to the chemistry, engineering, operation and economics of modern SX-EW plants.

Written for metallurgists, process engineers, plant chemists, operators and students, the handbook explains how a dilute and impure leach solution is transformed into a purified electrolyte and, ultimately, a saleable metal product. Copper SX-EW forms the central case study, but the principles are extended to uranium, cobalt, nickel, zinc, vanadium, rare earths and other hydrometallurgical applications.

Rather than treating solvent extraction and electrowinning as separate subjects, the book presents them as an integrated process built around three connected liquid circuits: the leach-solution loop, the organic loop and the electrolyte loop. Readers are shown how metal, acid and water move through the plant, how the circuit is designed, and how upstream decisions affect downstream cathode quality, recovery and operating cost.

A running copper heap-leach case study follows a plant treating 1,000 m³/h of pregnant leach solution at 4.5 g/L copper and producing approximately 32,000 tonnes per year of cathode copper. The same example is used throughout the extraction chemistry, McCabe–Thiele stage design, mixer-settler sizing, electrowinning calculations and integrated plant balance.

Topics covered include:

• Aqueous chemistry, acidity, pH and oxidation state
• Distribution coefficients, extraction isotherms and equilibrium
• Copper oximes, organophosphorus acids, amines and solvating reagents
• Diluents, modifiers and organic-phase management
• Extraction, scrubbing and stripping
• Mixer-settler design and alternative contactors
• McCabe–Thiele stage calculations and circuit configuration
• Entrainment, crud formation and organic losses
• SX instrumentation, interface control and operating philosophy
• Faraday’s law, current efficiency and cell voltage
• Copper electrowinning cells, anodes, cathode blanks and harvesting
• Electrolyte chemistry, additives and cathode-quality control
• Acid-mist management, electrical energy and cell-house operation
• Integrated copper, acid and water balances
• Metallurgical accounting and process reconciliation
• Uranium, cobalt–nickel, zinc, vanadium and rare-earth applications
• Commissioning, troubleshooting, safety and economics

The handbook places strong emphasis on the questions faced in real plants:

How many stages are required? How large should the equipment be? Why is the raffinate copper increasing? What causes poor phase disengagement? How does iron affect current efficiency? What determines cathode quality? Where is reagent being lost? What is driving production cost?

Clear explanations, worked calculations, operating guidance and practical illustrations bridge the gap between textbook theory and plant practice.

Whether you are designing a new circuit, commissioning a plant, diagnosing poor performance, training operators or building a stronger foundation in hydrometallurgy, Solvent Extraction and Electrowinning: A Practitioner’s Handbook provides a structured and accessible reference for understanding the complete SX-EW process.