The Grade Engineering suite of technologies is focused on helping producers identify and implement higher-efficiency mining and processing methods for potentially valuable lower-grade materials.

Having survived a near-miss encounter with economic disaster caused by social and financial disruptions associated with the COVID-19 pandemic, mining companies are taking closer looks at two chains that keep them in business:  supply chains — the links needed for smooth and continuous inbound and outbound logistical performance; and value chains, which include the sequence of activities involved in extracting and processing metals and other mineral commodities.

As McKinsey & Co. pointed out in a recent report, The Mine-to-Market Value Chain: A Hidden Gem, October 2020, mining value chains can be complicated, involving everything from equipment fleets to port facilities, and the effectiveness of links in these chains is often restricted by siloing among departments that don’t always coordinate perfectly, share information or use a common decision-making process. Improved transparency across the entire chain, according to the report, can go a long way toward increasing earnings by optimizing throughput, product margins and operating costs. A company interested in achieving higher performance might start at one end of a chain (improve mine-to-market performance) or the other (optimize specific operations). Two recent events highlighted new tools for implementing either approach, and both offer solutions for alleviating two major conservation issues — energy and water — facing the industry.

Simulating Life-of-Mine Plant Performance

In a late 2020 announcement, Australian mining explosives and services provider Orica was named as the commercialization partner for the Integrated Extraction Simulator (IES), a cloud-based software platform designed to reduce the use of energy and water in mining through the application of simulation, optimization and machine learning. IES was developed by the Brisbane-based Cooperative Research Center for Optimizing Resource Extraction (CRC ORE).

Orica’s interest was initially driven by IES’s introduction of blast simulation into the mineral processing value chain, but the company also saw the wider application of IES as an obvious fit with its expanding digital solutions offer across the whole mining value chain. Orica said it intends to expand this capability into a global solution for mining companies, enabling them to design mineral processing using IES, and then leverage IES’s capability every day to drive continual operational improvements. By harnessing the virtually limitless scalability available through cloud computing services, mining companies can now use IES to configure multiple design options for a mineral processing plant. IES then tasks each design and simulates its performance for every day of operation over the life of a mine.

Orica will take the reins of the platform’s growth strategy from July 2021, with plans for global expansion of the technology as part of its vision of an integrated ore extraction mining services company. This includes investing in digital solutions where continuous innovation and open integration with other industry systems across the mining value chain are key to the delivery of mine optimization for customers.

Orica Vice President Digital Solutions Rajkumar Mathiravedu said, “From a technology perspective, we see enormous synergies with our existing blasting and measurement solutions, including BlastIQ, FRAGTrack and ORETrack. We are also excited to integrate our automated, data science-enabled blast design technology and solutions with IES, offering end-to-end digitized workflow solutions from orebody knowledge through to mineral processing in an open, secure and connected platform.”

CRC ORE’s general manager for the simulator, Nick Beaton, said, “We have demonstrated that the simulator can improve the value of major mine sites by some 5% to 6%, [and] this is significant for the mines using the simulator and for the whole industry. Optimization of processing operations by use of IES will also enable step-change reductions in power and water consumption, while greatly improving recoveries of marginal ores, all contributing to the future sustainability of mining operations.”

Achieving Higher ROI, Lower Capital Intensity

At roughly the same time, CRC ORE announced that Ontario, Canada-headquartered engineering consultancy Hatch had been awarded an exclusive license to commercialize Grade Engineering Consulting Services, a suite of mining technologies designed to enable more-efficient treatment of lower grade ores and wastes to extract valuable minerals — consequently, increasing the life of mines and reducing their environmental footprint.

CRC ORE said achievable outcomes for mines, when deploying Grade Engineering at production scale, include significantly improved return on investment and lower capital intensity. They predicted that, as Hatch adopts Grade Engineering and extends its reach into the mining industry, the value of such outcomes will increase for operations, clients and communities globally.

As explained by CRC ORE, industry focus on throughput as the main driver of revenue has led to a bulk average mentality with respect to in-situ cut-off grades. In many cases, average grades used to define bench or stope scale processing destination decisions such as mill, dump leach or waste include significant sub-volumes of material outside cutoff specifications. An averaging approach ignores potentially exploitable grade heterogeneity below the scale of minimum mining unit even though significant localized-grade heterogeneity is a dominant characteristic of many base and metal deposit styles and ore types.

Localized-grade heterogeneity is often overlooked in favor of maximizing extraction rates and loading efficiency. This is coupled with a desire to blend ROM and produce steady-state feed in terms of grade and physical properties to optimize and maximize recovery of saleable product particularly in crush-grind-float operations. Where blended supply of “averaged” feed struggles to achieve steady-state processing stability, this is an indication that significant heterogeneity exists within a resource that could be exploited rather than suppressed.

Grade Engineering recognized that, in many cases, out-of-specification sub-volumes assigned to destinations based on bulk averages can be removed using efficient coarse separation techniques in the “dig and deliver” interface. Coarse separation (~10-100 mm) can be used on a range of particle-size distributions ranging from ROM to SAG discharge. The earlier this occurs in the conventional dig and deliver mining cycle, the higher the potential net value of removing uneconomic material.

Opportunities for Grade Engineering are predicated on five rock-based “levers” linked to combinations of screening, sensor-based sorting and heavy media separation. These involve:

• Preferential grade deportment by size;

• Differential blasting for grade by size;

• Sensor-based bulk sorting;

• Sensor-based stream sorting; and

• Coarse gravity separation.

CRC-ORE said Grade Engineering had been developed and implemented by a consortium of more than 30 mining companies, equipment suppliers and research organizations. Emerging results from collaborative site activities demonstrate potential for generating significant value, which can reverse the trend of declining production due to declining feed grades.

Under the terms of the commercialization arrangement, Hatch will use Grade Engineering Intellectual Property for its consulting services. CRC ORE said its Grade Engineering team will relocate to Hatch’s Brisbane office, supporting Hatch with current and potential users of Grade Engineering, and Hatch will invest to further increase the reach and applicability of the technologies.