Imported liners carry a certain reputation. When a plant manager pays a premium for Japanese or European alloy steel liners, the assumption is simple: you get what you pay for. A field trial from a large cement plant in North China puts that assumption under real strain. The setup The mill was a Φ4.5 ×…
Every liner buyer eventually asks the price-per-tonne question: “Your steel costs how much more?” The honest answer is that the question is asked about the wrong tonne. The tonne that matters is the one you grind, not the one you buy. Here’s a real cost case from a steel plant’s power station: coal pulverizing ball…
SAG mills do not give liner steel an easy time. Big balls, coarse feed, constant pounding — and at one copper mine in South China, the standard ZGMn13 Hadfield liners were losing the fight badly. The mill in question: a φ28′ × 13′ (φ8.53 × 3.96 m) semi-autogenous mill, running a 140 t ball charge…
Hadfield manganese steel earned its reputation in the first chamber, where big balls deliver big impacts and the steel work-hardens as it runs. The second chamber is a different animal. Smaller balls, finer grinding, and the wear mechanism slides from impact toward abrasion. Manganese steel never gets the impact energy it needs to harden properly,…
There’s a lot of cheap high manganese steel in this market. And a lot of plants that have been burned by it — cracked plates, deformed shell liners, liners cut apart with torches on-site and then failing early for reasons nobody could explain. So here is a case about doing Hadfield steel properly. One iron…
Acidic wet grinding is where ordinary liner logic breaks down. At one copper concentrator, a Φ3.2 × 3.1 m ball mill was grinding ore with a hardness factor of 6–8 and about 2% sulfur — which put the pulp at pH 4–5, hour after hour. In that environment you are not fighting wear or corrosion…
Wet grinding in acidic pulp destroys liners through a mechanism that no hardness chart will predict: corrosion and abrasion working together. The measured weight loss in corrosive-abrasive duty can run several times, to more than ten times, the simple sum of pure corrosion plus pure wear. The two damage modes feed each other — abrasion…
Some of the best liner results come from the least glamorous projects. This one is an iron ore concentrator in Northeast China, second-stage grinding, running a MQY5064 overflow ball mill — 5.03 m diameter × 6.4 m effective length — built by a major domestic equipment maker. The plant had recently pushed annual throughput from…
Some liner grades get one paper and a pat on the back. ZG70Cr3NiMo got a decade of attention from the same engineering team — a wear test, then a heat-treatment improvement, then a failure analysis of the weak link. That sequence, rare as it is, tells you more about a steel than any single trial….
Liner metallurgy lives with a stubborn trade-off. Hard steels resist abrasion but crack under ball impact. Tough steels survive impact but wear away. Most “wear-resistant” steels on the market are general-purpose grades, and the compromise shows the first time a mill throws a big ball at them. This case is about a bainitic cast steel…