Technical Articles

Last updated: 2026-10-21 For most copper circuits, O/A ratio solvent extraction design practice places the extraction duty between 1:1 and 1.5:1 by volume. In the worked example below, 200 m³/h of PLS at 4.0 g/L Cu needs an extraction O/A of about 1.07:1 to reach 91.3% copper recovery with a 10 vol% oxime organic, while…

Last updated: 2026-10-21 Crud treatment solvent extraction programs fail for one predictable reason: crews treat the sludge and ignore the source. A copper SX plant that correctly diagnoses its crud driver typically cuts organic inventory losses from 1–2% per month to below 0.5% (illustrative, based on operator-reported figures). Crud — the stable third phase fouling…

Last updated: 2026-10-21 For cobalt–nickel separation, the D2EHPA vs Cyanex 272 decision turns on one number: Cyanex 272 separates Co from Ni roughly an order of magnitude better than D2EHPA at the same equilibrium pH, while D2EHPA carries more metal per litre at lower cost. Pick Cyanex 272 for Co/Ni and Mn rejection duty; pick…

Last updated: 2026-10-21 A sound mixer settler design typically uses 2–3 minutes of residence time per mixing compartment and a settler sized for roughly 3–8 m³/h of total phase flow per m² of settling area in copper SX duty. Getting these two numbers right fixes most of the plant’s extraction performance, entrainment behavior, and capital…

Filtered, dry stack tailings have become the default risk answer for new hydrometallurgical plants: dewatering to 85–90% solids w/w yields a soil-like cake that is compacted into a stable, unsaturated stack — no water-retaining dam — while recycling up to about 80% of process water. This guide sets out the flowsheet, water balance, design rules,…

A carefully done CCD wash ratio calculation shows that a five-stage counter current decantation circuit running a wash ratio of 2.5 recovers about 99.3% of the soluble copper when underflow density is held at 55% w/w, assuming 95% wash efficiency per stage. This article walks through the full method, a worked example for a copper…

Most excursions in filter cake moisture content trace back to two things — cloth blinding and cycle timing — not the filter itself. On one copper concentrate duty, a two-hour air-blow retrofit alone cut cake moisture from 14% to 9% w/w and eliminated third-party drying before shipment. This guide walks through measurement, diagnosis, ranked fixes,…

In the thickener vs filter press decision, duty—not preference—decides: a high-rate thickener recovers 80–90% of process water from a tailings slurry at OPEX often below US$0.5 per dry tonne, while a filter press polishes that underflow into a stackable cake below 10% moisture. Most modern hydrometallurgical plants therefore run both in series rather than choosing…

For most hydrometallurgical plants, a well-sized high rate thickener recovers 90–95% of process water from leach residues and tailings while occupying one-third of the footprint of a conventional unit of the same duty. Selecting one is a trade-off among feed characterisation, flocculant performance, rise rate and underflow density targets. This guide walks process engineers through…

The copper oxide leaching process converts oxidized copper minerals into saleable cathode by acid leaching, solvent extraction (SX), and electrowinning (EW), and a well-matched flowsheet routinely delivers 70–90 percent acid-soluble recovery (illustrative, mineralogy-dependent). This guide walks process engineers and mine owners through route selection, flowsheet design, and project risk. Key Takeaways Oxide mineralogy — malachite,…