Build the plant in the factory, assemble it on site

Most enquiries arrive with a tonnage target and little else. We can still reply, but the reply is a range, and ranges move. Here is what turns a range into a scoped proposal.

The ore package

A representative sample. Not your best intersection. Sample selection should follow the geological and block model, so the composite reflects what the plant will treat over its life. CIM's best practice guidelines are written to assist the Qualified Person in the planning, supervision, preparation and reporting of a mineral resource and mineral reserve estimate; the same planning discipline belongs on the metallurgical composite, settled before the sample is cut rather than argued about after. Send enough mass for bench work with material left over for a confirmatory run, because re-sampling means another shipment, another queue in the laboratory, and a schedule slip nobody put in the plan.

With it, send the assay suite: payable elements, penalty elements, and the gangue that will decide your reagent bill. Every item on that list lands somewhere in the module split. Mineralogy and liberation size set the grind, and the grind sets the mill, which is the item most likely to break the transport envelope and push the front of the plant into field erection. Hardness indices size the crushing and grinding power draw, and that draw decides whether the switchroom ships as one containerised electrical building or has to split in two. The reagent suite sets how many mixing, dosing and storage skids the reagent area needs, and whether any of them carry handling requirements that change the shipping mode. If there is clay, slimes or fine material, settling and filtration behaviour matters too: dewatering sizes the back half of the plant, a thickener at the large end of our manufacturing range cannot travel assembled at all, and the back half is where we most often watch module counts go wrong. Xinhai reports roughly 200 test work programmes a year across more than 70 ore types, according to the company's published figures. The laboratory is CNAS-accredited and operates to ISO/IEC 17025.

The site package

Modules still sit on concrete, and concrete still needs soil data. Read each item below for what it does to the module split, not only for the box it ticks.

• Topography and a geotechnical investigation at the plant pad. A module concentrates its mass onto a few bearing points instead of spreading it through a field-built structure, so bearing capacity and settlement decide the foundation type under each unit, and a weak result pushes you toward more and smaller modules, or toward piling. Topography also fixes where a crawler crane can stand and how far it has to reach, which caps lift weight before a single drawing exists.
• Water source, seasonal availability, water chemistry. Chemistry drives materials selection, and materials selection decides whether water treatment and reagent make-up can be built as repeatable skids or have to become lined and alloyed one-offs that give back most of the fabrication advantage.
• Power: grid connection distance and reliability, or the generation you will build yourself. This decides whether the substation, switchroom and control room arrive as pre-wired modules already tested in the shop, or stay field-built with cable pulled on site. Pre-wired electrical rooms are among the more dependable gains in modular scope, and the call is settled by data you either have or you don't.
• Climate extremes, seismic zone, altitude. Seismic category sets bracing and anchorage inside the module frame, and it sets the restraint that holds the module down on the deck. Cold-climate enclosure adds cladding, insulation, width and weight, and width is exactly what the transport envelope has least of.
• Access road, camp, laydown area. Laydown size decides how many modules can be staged at once, which fixes the erection sequence, which fixes the shipping sequence, which fixes the fabrication sequence in the yard. The yard schedule sits downstream of your laydown area, whether or not anyone drew it that way.

None of this is exotic. It is simply, routinely, late.

The logistics package

Nearest usable port and its heavy-lift capacity. Road classification from port to site. Bridge and culvert limits. Overhead clearances. Permit process and lead time for abnormal loads. Crane availability at site, or whether the crane is another thing you are shipping.

This is the package buyers leave out most often, in our experience, and it produces a failure mode we see repeatedly: a module size chosen for fabrication efficiency that the receiving route cannot physically accept. It surfaces after fabrication. That is the worst possible moment for it to surface.

Who signs which number

Three numbers drive a modular plant decision, and they should not all come from the same desk.

• The resource. Reported under a recognised code. Under JORC, public reporting of Exploration Results, Mineral Resources or Ore Reserves has to be based on and fairly reflect documentation prepared by a Competent Person, and the company has to obtain that person's prior written consent to the form and context in which it reports; NI 43-101 reporting runs on the equivalent Qualified Person under the CIM standards. The whole point of those codes is that an outside reader can rely on the estimate.
• The recovery and the flowsheet. From test work on your sample, signed by the metallurgist who ran it. Recovery depends on ore type and is confirmed by test work before design. A recovery figure quoted before test work is a sales number wearing an engineering font.
• The capital cost and the schedule. From the engineering contractor, estimated against the first two rather than against a catalogue. Our design institute integrates 17 disciplines and works through the normal ladder of scoping, prefeasibility and feasibility, then FEED, basic and detailed design. That progression is covered under full lifecycle mine design.

If one party signs all three, the estimate contains no independent check. Worth noticing before you fund it.