ZENITH's after-sales service team has paid a follow-up visit to a rare earth materials producer in Inner Mongolia, China, to review the operation of the MTW European trapezium grinding line installed at the plant. The visit is part of ZENITH's continuing service programme for mills already in production: engineers return to the customer's site after commissioning to see how the equipment is actually behaving under daily load, rather than only on the day it was handed over.

At this plant the MTW mill is used to grind rare earth raw material into a fine powder. That powder then moves downstream, where the rare earth elements are extracted from it. Grinding is a decisive step in the chain: the finer and more uniform the powder, the more completely the valuable elements can be released in the leaching and separation stages that follow, and the less material is carried through the circuit without being fully reacted.

What the service team checked

During the visit the engineers inspected the mill body, the grinding rollers and the grinding ring for wear, checked the classifier setting and the air flow through the system, and examined the cyclone collectors and the connecting ducting for build-up, leakage or blocked sections. The operating records kept by the customer's staff were reviewed together with the team, so that any drift in output or fineness could be traced back to a specific parameter instead of being treated as a general complaint.

Working alongside the customer's operators

The visit was not only an inspection. ZENITH engineers spent time at the mill with the plant's own operators, going through the start-up and shut-down procedure, the lubrication points and their intervals, and the signs that tell an operator the product is starting to run coarser before it becomes a quality problem. Because rare earth feed can vary in hardness and moisture from one batch to the next, the team also explained how to adjust the feed rate to keep the mill running steadily when the raw material changes.

Dust collection and housekeeping

Rare earth powder is a valuable product, so keeping it inside the system matters both for yield and for the working environment. The team checked the cyclone collectors, the connecting ducting and the sealing of the discharge points, and confirmed that the collection circuit is doing its job without visible dust around the mill. Where small leaks or worn seals were found, the fix was agreed with the plant on the spot so that it could be handled in the next scheduled stop.

Customer feedback

The customer's production staff reported that the MTW line has been running steadily since commissioning and that the powder it produces meets the requirement of the downstream extraction process. The points raised during the visit were recorded, and the wear parts that will be needed at the next maintenance interval were confirmed with the plant so that they can be ordered in good time rather than after a stoppage.

Service after the sale

ZENITH supplies grinding mills, complete powder lines and the service that keeps them running. For mills already in production, our engineers can return to site for periodic inspection, operator training and wear-part replacement, and can be reached remotely when a parameter needs to be checked quickly. Customers running an MTW mill on rare earth, limestone, gypsum or other materials are welcome to contact us to arrange a service visit.

Visit summary

Equipment: MTW European trapezium grinding mill
Material: rare earth raw material
Product: rare earth powder for downstream element extraction
Location: Inner Mongolia, China
Service scope: operation review, wear inspection, dust circuit check, operator guidance, spare parts planning