Technical Articles

Last updated: 2026-10-27 A decanter centrifuge mineral slurry duty earns its place when solids are too fine for screens and a cake drier than thickener underflow has value: expect 2,500–3,500 g, cake at 15–25% w/w moisture on crystalline solids, and operating cost of US$1.5–4 per dry tonne. This guide maps where the machine fits, how…

Last updated: 2026-10-27 Slurry yield stress is the stress a slurry must exceed before it will flow at all, and it decides more equipment choices than viscosity ever will. Gravity flow through launders and chutes typically stops between about 50 and 200 Pa, while pipeline restart pressure is set by the aged yield stress of…

Last updated: 2026-10-27 Most thickener flocculant dosage problems come down to three failure modes — under-dose, over-dose and polymer destroyed by shear before it reaches the slurry — and plants that diagnose all three typically cut polymer spend by 20–40% while holding overflow turbidity below 200 NTU and underflow density within 2% w/w of target….

Last updated: 2026-10-27 In the pressure filter vs filter press decision, cake moisture usually casts the first vote: membrane filter presses typically reach 8–12% w/w on fine hydrometallurgical solids, where pressure leaf filters level out at 14–18%. Cost per dry tonne casts the second vote, and above roughly 20 t/h of dry solids the continuous…

Last updated: 2026-10-27 Paste thickener design is settled on bed depth and underflow yield stress, not on settling area alone: a deep cone vessel carrying 6–10 m of compression bed routinely holds underflow at 62–70 wt% solids where a high-rate thickener of the same diameter plateaus near 56–58%. This guide explains why, and how to…

Last updated: 2026-10-26 Laterite nickel HPAL (high pressure acid leach) turns low-grade limonite ore into battery-grade nickel and cobalt at overall recoveries of 92–96% Ni and 90–94% Co — beyond any smelting route on these ores. This guide walks through the pressure acid leach flowsheet, from autoclaves at 250 °C to mixed hydroxide precipitate, with…

Last updated: 2026-10-26 The shrinking core model turns leaching kinetics into one diagnostic question: which resistance — liquid film, ash layer, or surface reaction — sets the pace? In the worked example below, the same 10 mm copper oxide particle reaches 80% conversion in 4.0 h, 10.0 h or 15.0 h depending on the answer,…

Last updated: 2026-10-26 Nine recurring failure points account for most unplanned stops in a gold carbon-in-leach (CIL) circuit, and every one of them sits inside the cyanide leaching equipment train — agitators and gearboxes, interstage screens, airlift pumps, carbon transfer systems, and safety instrumentation. Plants that systematically address these nine items commonly lift CIL plant…

Last updated: 2026-10-26 In the carbon in pulp vs carbon in leach decision, carbon in leach (CIL) wins for most modern gold plants: running leaching and adsorption in the same tanks removes 20–30% of vessel count and neutralizes preg-robbing ores that can strip 5–15% of recovery from a CIP circuit. Carbon in pulp (CIP) stays…

Last updated: 2026-10-26 A gold leaching tank is normally sized for a total residence time of 24–48 hours — the single number that fixes tank farm volume, agitator power and capital cost for a carbon in leach (CIL) circuit. Derive the residence time from test work, split it across 6–8 tanks, then select agitators, materials…