One of the major trends in the mining industry is the move towards the design and construction of modular plants tailored to specific needs. This, Annelize van der Walt, business development manager – mining and minerals at Kwatani, tells Munesu Shoko, is driven by three major factors.

Building a new processing plant can be an expensive endeavour. Mining operations are therefore turning to modular plant systems for their low capital costs reflected in higher returns on investment and improved cost to recovery ratios.

Modular plants generally offer lower capital costs and a quick return on investment compared with their conventionally larger plants, and this is a major drawcard for the junior mining sector. Additionally, modular systems offer quick lead times because they comprise quick and easily available modules that can be on site and operational within a short space of time. Several manufacturers can customise these self-contained, high recovery plants for mini- mal start-up capital, using high-quality components and in-house expertise.

One company that specialises in the custom design of vibrating equipment for modular plants is Kwatani. “We are able to customise equipment to a specific tonnage and application and then reproduce it in bulk to help reduce lead times. If a modular plant is, for example, designed to process 50 tonnes per hour (tph), we can customise every single deck beam, motor size and coil spring, among other components on that screen to fit the application at hand,” says Van de Walt.

Generally, she says, modular plant designs are influenced by transportability and to a large extent, on the exact process the plant is going to be used in. “The capacity of the plant is largely determined by the beneficiation process it is deployed in, whether it’s a DMS or sorter or leach plant. Typical sizes of modular plants we have been involved in are between 20 and 300 tph,” she says.

In terms of uptake, Kwatani has over the years seen increased requests for modular solutions in iron ore, gold, diamonds and chromite. Of late, how- ever, Van der Walt has observed increased enquiries from the lithium and tin mining sectors, mainly driven by a good run in commodity prices.

Commenting on the industry’s increased appetite for modular solutions, Van der Walt believes there are three main factors behind this trend. These are: reduced capex and fast lead times on new plants due to reduced engineered hours required; derisking of project construction with complete build factory acceptance tests (FATs) in major cities; and optimisation and increased tonnage on existing modular plant brownfield projects.

Reduced capex and fast lead times

In over 45 years of Kwatani’s experience in equipment supply, the number one driver for mining projects has most often been commodity pricing. Projects execute when the product price is high and therefore processing plants need to be supplied on highly expedited timelines.

“When a standardised module approach for plant design is implemented, original equipment manufacturers (OEMs) can procure standardised components in bulk and thus reduce the equipment cost to the client,” says Van der Walt.

The bulk engineering hours required on both structural and equipment design would typically be completed with only a limited number of checks and modifications to ensure the modules are fit-for-pur- pose. “An example of this level of expedited timeline is a recent 200 tph modular containerised sorter plant, which was ready for shipment within 12 weeks of order placement,” says Van der Walt.

Lowered risk by FAT builds

As modular plants consist of unit sections which can be transported and shipped relatively easily, Van der Walt says a recent trend is to build the complete plant in a major city (or industrial area) for FAT, then deconstruct and ship to site.

This, she says, eliminates unpleasant, costly and time-consuming integration surprises on remote sites, as engineering companies have easy access to most suppliers with a number of stock items read- ily available in distribution centres. The value add of a complete FAT build outweighs the two to three extra weeks before shipment as integrity-based peace of mind.

Brownfields optimisation

With most modular mineral processing plants having only been constructed in the past 10 years, Van der Walt says a new trend of brownfields projects is starting to emerge. As mining operations progress through the orebody, the mineralogy sometimes changes to a significant enough extent that the original design of the modular plant does not meet the process requirements any longer.

“This brings the end client to a stage where either an additional module is required, or strategic upgrades in the existing plant need to be investigated.

Based on our depth of mechanical and metallurgical expertise and on-site experience, Kwatani has assisted in debottlenecking such plants by implementing customised grizzly, screen or feeder equipment solutions aimed at increased capacity and/or efficiency on the specific section of such plants,” concludes Van der Walt.

Key takeaways

In over 45 years of Kwatani’s experience in equipment supply, the number one driver for mining projects has most often been commodity pricing
When a standardised module approach for plant design is implemented, OEMs can procure standardised components in bulk and thus reduce the equipment cost to the client
As modular plants consist of unit sections which can be transported and shipped relatively easily, a recent trend is to build the complete plant in a major city (or industrial area) for FAT, then deconstruct and ship to site
With most modular mineral processing plants having only been con- structed in the past 10 years, a new trend of brownfields projects is starting to emerge