Gold Ore HPGR: A large gold mine had long been using a conventional crushing + ball milling circuit to process high‑hardness quartz vein gold ore. Because the gold particles were finely disseminated and tightly locked with the gangue, the ball mill had to over‑grind to achieve liberation. This generated more than 25% of –200 mesh slime. A large portion of fine gold could not be recovered by gravity concentration or flotation, resulting in gold recovery below 75% and high gold grade in the tailings. A Gold Ore HPGR overcomes these limitations. Meanwhile, steel ball consumption reached 1.2 kg/t, liners had to be changed frequently, and grinding electricity accounted for more than 60% of the plant’s total power consumption.
Gold Ore HPGR Production Site
Gold Ore HPGR: Engineered Solution for Fine Crushing & Partial Grinding
Our engineering team deployed an HPGR‑1200×1000 High Pressure Grinding Roll to replace the existing fine cone crusher and undertake pre‑grinding duties. After primary jaw and secondary cone crushing (–45 mm), the material enters the HPGR and is subjected to 6 MPa pressure in a packed bed. Particles fracture along grain boundaries, generating micro‑cracks instead of being shattered by impact. The discharge shows a higher degree of mineral liberation, and the micro‑cracks lower the Bond work index for the downstream ball mill.
KEY PERFORMANCE RESULTS
-
Gold recovery increased by 8% – Selective breakage in the HPGR creates clean liberation boundaries between gold and gangue. –200 mesh slime decreased from 25% to 15%, flotation recovery rose from 75% to 83%, and tailings gold grade dropped by 0.3 g/t.
-
Grinding energy reduced by 30% – HPGR consumes only 2.5 kWh/t. With micro‑cracked feed, the ball mill’s specific energy fell from 22 kWh/t to 15 kWh/t, achieving an overall saving of 30%.
-
Steel ball consumption cut by 40% – The micro‑cracked ore is easier to grind; steel ball consumption dropped from 1.2 kg/t to 0.7 kg/t, saving more than RMB 2 million per year in media costs.
-
Throughput increased by 25% – The HPGR runs stably at 220 t/h, a 25% increase compared to the original fine cone crusher, with no over‑crushing issues.
Gold Ore HPGR Workshop Live Shot
CONCLUSION
This project demonstrates that introducing an HPGR into a gold ore comminution circuit, through selective breakage and micro‑cracking, significantly improves gold liberation while drastically cutting energy and media consumption. For high‑hardness gold ores with fine dissemination, the HPGR is the core equipment to achieve “more crushing, less grinding – early recovery, more recovery”.
