The order: three crushers take the headline, eighteen feeders ride inside
On 8 January 2024, Metso announced contracts to deliver three Superior MKIII primary gyratory crushers to copper processing plants in Kazakhstan and Mongolia. The same contracts also carry a total of 18 apron feeders, together with systems engineering, electrical and control solutions and other auxiliary equipment, at a combined order value of over EUR 30 million booked into the Minerals segment's fourth-quarter 2023 orders received. Metso's bulk materials handling director described the projects as examples of the company's ability to supply feeders for all applications, most notably to complement its crusher portfolio. What the release does not publish is just as important for buyers: it gives no model, width, chain size or capacity for any of the 18 feeders, and no split of the units between the two mines. The feeders were specified somewhere - inside the package engineering - but not in public. That is the normal shape of a comminution package order, and it is why the feeding scope deserves a buyer's attention before signature, not after: once the package is signed, the feeder decisions have already been made by whoever wrote the package.
Start with the load: lump size, drop height and bed depth set the pan
An apron feeder under a primary crusher or a coarse-ore bin does the harshest feeding job in the plant: it extracts material under load and absorbs the impact of whatever falls onto it. Metso's feeding brochure describes its apron feeders as suited to large, lumpy, abrasive and heavy materials, including wet, sticky or frozen operations, with a rugged welded frame for intense loading and deep-profile cast manganese pans that withstand both impact loads and abrasive material. For a buyer, the specification therefore starts with the duty statement, not the catalogue: maximum lump size, the drop height from bin or truck onto the pans, the bed depth the feeder must pull, and whether loading arrives as a steady draw or in surges. Those four inputs decide pan profile and thickness, the impact rails under the loaded run, and frame duty. Two feeders with the same nominal width and capacity can be very different machines once the impact case is priced in - and in a crusher package, this is precisely the layer most likely to be settled by a standard design assumption unless the buyer writes the loading case into the order documents.
The chain class is the skeleton: eight models on a crawler-chain ladder
Metso's published apron feeder range runs to eight models - AF4, AF5, AF8 and AF10 as pre-configured units, then AF13, AF14, AF16 and AF18 - matched to chain sizes that climb the crawler-tractor ladder from FL4 and D4 up to D11. Across the range, minimum widths run from 762 mm to 2,743 mm, minimum lengths from 2,500 mm to 12,000 mm, and the line is rated up to 17,000 tonnes per hour. The running gear is built from heavy-duty tractor components - chain, rollers and tail wheels - sealed for life and requiring no lubrication, a design Metso credits with long wear life and ready parts availability. For procurement, the chain class is the decision with the longest shadow. It fixes the sprockets, rollers and links the site will stock for decades, and it is the strongest commonality lever in a multi-unit order: 18 feeders across two copper mines are far cheaper to support if they climb the same one or two rungs of that ladder. A buyer inside a package deal should therefore ask for the chain class of every unit by position - crusher feed, bin discharge and reclaim duties rarely need the same class, but every extra class is a separate spares shelf.
Drive and control: the feeder is a metering device, not just a mover
A feeder under a gyratory crusher earns its keep by metering: holding the crusher's cavity level steady means varying the feed rate, so the drive arrangement and its speed control are process equipment, not accessories. It is notable that the 2024 contracts explicitly include electrical and control solutions alongside the feeders - the metering interface was part of the package scope. Metso's current apron feeder design uses a direct drive, and its upgrade literature describes a single compact multistage planetary reducer mounted on the head shaft through a spline or shrink-disc connection, replacing the older multi-reducer, chain-and-sprocket countershaft layouts that multiplied spare parts; the same literature specifies reversible, segmented sprockets for quick change-out and a shaftless tail wheel with hydraulic take-up that needs no lubrication. What a buyer should pin down is the control side: the speed range offered, how feeder speed is signalled from crusher level or power draw, and what happens on a feeder trip. Those answers live in the controls package, and once the package is signed they are expensive to renegotiate.
Wear parts are the real lifecycle bill: pans, rails and rollers
Across a feeder's life, the purchase price is the small number; pans, impact rails and carrying rollers are the recurring one. Metso's apron feeder upgrade brochure sets out the wear architecture a buyer can specify or retrofit: cast manganese pans, cast from austenitic manganese steel with a stiffened underside, work-harden in service to a hardness of up to 600 BHN for high-impact, highly abrasive duty; an overlapping pan design with wings that almost eliminates spillage; optional wear indicators to monitor pan condition; and the instruction to adjust or replace the impact rails whenever pans are changed, so the working clearance is preserved. Carrying rollers in the same programme are heat-treated forged alloy steel, sealed for life and modular, designed to be changed without removing material from the feeder or lifting the chain. In an 18-unit order this layer is where negotiation has leverage: pan material and profile, a first set of wear parts in the base scope, wear indicators fitted from new rather than retrofitted, and roller commonality across the fleet all cost little at order stage and much more as later variations.
What an 18-feeder package order tells other buyers
For buyers outside this deal, the reference value of the Central Asia order is structural rather than technical. A single supplier took the crushers, the feeding scope, the systems engineering and the controls for two greenfield copper concentrators, which puts interface responsibility - feeder to crusher, controls to both - in one pair of hands; the price of that convenience is specification freedom, because the feeder layer gets engineered as part of someone else's package. The checks in this article are the editorial counterweight, and they are questions, not findings about these 18 units, whose configuration Metso has not published: ask for a per-unit datasheet (model, chain class, width, length, drive) rather than a package-level line item; write the loading case - lump, drop, bed depth, surge - into the order basis; specify pan material and the first wear set explicitly; and confirm how feeder speed is controlled and interlocked with the crusher. This site already covers screw feeders under hoppers and hopper design; the apron feeder, the machine that feeds the primary crusher itself, is the missing first step of that chain - and as this order shows, it is usually bought inside a package, which is exactly when it needs its own specification.
Manufacturer announcements and our analysis are distinguished. Product claims require verification for the specific application.
Sources
Metso to deliver primary gyratory crushers and apron feeders to two copper mines in Central Asia - Metso ↗Metso Corporation press release (8 January 2024), opened in full. Primary source for the contracts: three Superior MKIII primary gyratory crushers for copper processing plants in Kazakhstan and Mongolia, a total of 18 apron feeders, systems engineering and electrical and control solutions, at a combined order value of over EUR 30 million booked in fourth-quarter 2023 orders received. The release publishes no model, size or capacity for the individual feeders.
Metso to deliver primary gyratories & apron feeders to two copper mines in Central Asia - International Mining ↗International Mining (8 January 2024), opened in full. Independent trade-press report of the same contracts, carrying the same equipment scope and order value; used here as corroboration of the Metso announcement.
Feeding solutions - Metso (brochure) ↗Metso Feeding solutions brochure (2025 edition), opened in full. Source for the apron feeder range used here: models AF4 to AF18, chain sizes FL4 and D4 to D11, minimum widths of 762 to 2,743 mm, minimum lengths of 2,500 to 12,000 mm, capacity up to 17,000 t/h, deep-profile cast manganese pans, sealed-for-life tractor components and direct drive. This is product-line data for the range as published - not the configuration of the 18 units in the 2024 order, which Metso has not disclosed.
Apron feeder upgrades - Metso (brochure) ↗Metso Apron feeder upgrades brochure, opened in full. Source for the wear and drive details used here: cast manganese pans work-hardening in service to up to 600 BHN, overlapping pan design with wings, optional wear indicators, impact rails to be adjusted or replaced with the pans, a single multistage planetary reducer mounted on the head shaft, reversible segmented sprockets, a shaftless tail wheel and sealed-for-life forged alloy-steel carrying rollers.
