Design of combined crushing and grinding process flow for gold ore

The principle of “more crushing, less grinding” is widely accepted in gold ore processing because crushing consumes less energy than grinding. A proper design of combined crushing and grinding process flow for gold ore can reduce total comminution energy by 20-30% and increase mill throughput. OCP Machinery, with over 40 years of experience, specializes in designing three-stage crushing circuits (jaw crusher + cone crusher + VSI or HPGR) followed by a ball mill. The goal is to achieve a final crusher product P80 of 6-12mm, which allows the ball mill to operate at a lower reduction ratio. OCP’s process engineers start by analyzing the gold ore’s Bond Work Index (BWI) and abrasion index. Based on the BWI, we determine the optimal closed side setting for each crusher to maximize the reduction ratio without over-crushing (which causes gold liberation losses). A well-executed design of combined crushing and grinding process flow for gold ore includes a closed-circuit screening stage to remove fines before grinding, reducing overgrinding.

In actual operation, run-of-mine gold ore is fed to a jaw crusher for primary reduction to <150mm. A vibrating screen separates the product; oversize goes to a secondary cone crusher, and the undersize bypasses to a tertiary crusher. For fine crushing, OCP recommends either a short-head cone crusher (for BWI <18 kWh/t) or a high-pressure grinding roll (for BWI >20 kWh/t). The final crusher product is then conveyed to a fine ore bin and fed to the ball mill. OCP recently completed a design of combined crushing and grinding process flow for gold ore for a mine in Tanzania: they were using a single-stage jaw crusher feeding a ball mill, with specific energy of 22 kWh/t. After installing OCP’s two-stage crushing circuit (jaw + cone) with a 10mm screen, the ball mill energy dropped to 15 kWh/t, and throughput increased by 38%. OCP’s custom capability includes designing portable crushing modules for remote sites, and we provide full process simulation using JKSimMet software. Our direct factory pricing for the entire line (crushers, screens, conveyors, and magnetic separators) saves 20-25% compared to buying from separate suppliers. Environmentally, OCP incorporates dry dust collection and water recycling for wet scrubbers.

OCP’s 40 years of experience has enabled us to develop a proprietary “Gold Crush-Grind” model that predicts the economic optimum for any gold ore. For a Nevada gold mine with refractory ore, OCP’s combined flow including an HPGR increased gold recovery by 8% because finer crushing exposed more gold surfaces to cyanide. We also provide retrofits for existing plants. To receive a customized design of combined crushing and grinding process flow for your gold ore, send us your ore characterization data (BWI, AI, liberation size). OCP will provide a free preliminary flowsheet and energy savings estimate. Click the online chat button – our process team is available 24/7 to discuss your project. Request a complete quotation for the entire comminution circuit, including installation supervision. Start saving energy and boosting recovery with OCP’s optimized combined crushing and grinding solutions.

(The technical parameters and other information mentioned in this article may be updated or changed as the product is upgraded. Please click on the website customer service to obtain the latest equipment parameter table.)