While most stackers and reclaimers used by miners across Australia are already fully automated, it is possible new levels of operational efficiencies can be reached through the Industrial Internet of things (IIoT).
It has been suggested that the sector should embrace the edge controller (EC), a technology which combines robust real time operating system deterministic controls (similar to traditional programmable controllers or remote terminal units) with general-purpose computing capabilities such as analytics, data storage and extensive communication options.
According to software designer Emerson – in a paper reproduced by the Australasian Institute of Mining and Metallurgy in 2023 – for many years it has been possible to stitch together various traditional automation technologies with satellite and radio communications, thus achieving some level of control and remote visibility. These solutions, however, are usually costly and difficult to create, operate and support.
The introduction of an EC, a new class of automation platform which combines a real-time operating system with a general-purpose operating one, will help counter this issue. In essence, ECs are a modern automation platform for enabling digital transformation and the effective application of IIoT concepts. “Because mining operations are most often remotely located, any useful technologies must be suitable for these conditions and provide extensive communication options,” Emerson said.
“ECs are built for this operating technology environment, and have the latest and most secure information computing and networking features. “[They] are especially compelling for this service because they can gather and store data locally, process and analyse it, directly inform operational logic of optimal settings, and relay the most essential information to higher level systems.
“The result is more efficient, environmentally friendly, and safer operations for all types of mining and metals operations. These benefits can be realised by applying ECs to both new designs and retrofit applications.”
When it comes to blending and stockyard optimisation, this technology can help customers track material and optimise supply chain logistics. In terms of vehicle route planning – which in turn plays an integral role in achieving stacker and reclaimer efficiencies – haulage trucks can be organised in conjunction with other mechanical equipment like excavators and the crusher.
Meanwhile, in situations where a mine excavator goes offline, an associated edge controller can communicate with haulage trucks via wireless to reroute these vehicles to operational excavators and avoid situations where the crusher remains idle and stockpiling is slowed or stalled.
“This kind of live route optimisation can deliver significant savings for mine operators,” Emerson said. “Additionally, raw data paired with analytics delivered by an edge controller can provide rich insights into the integrity of the vehicle, supporting preventative maintenance.
“The edge controller can be used to analyse hydraulic temperatures and other vehicle operating conditions during off loads into the crusher plant, and then relay this time-series data back to the centralised control centre for detailed analysis.”
As mining is a mechanically intensive process, with many pieces of rotating equipment, vibration is inevitably a problem but if it is detected and analysed it can be used to predict impending operational issues. At the machine automation level, Emerson noted, it is possible to collect a huge amount of data at a high frequency to measure vibration, temperature and noise via sensors and instrumentation.
Given the raw data itself is too excessive for transmission to the cloud due to costs and bandwidth issues, a better option is to relay this large volume of machine data to an EC, which can then use the raw data inputs to complete some preconfigured computations and send the essential time-series information to asupervisory system.
The operations team, which may be located centrally or throughout the world, can then apply analytics to this timeseries data to establish baseline equipment profiles and assess if any part of the system is becoming mechanically compromised from a processing or hardware standpoint.
With this information, staff can safely bring systems offline before an adverse breakdown occurs. This early warning system can be used in conjunction with a proactive maintenance strategy to plan shutdowns and reduce downtime.
Here, the EC, together with embedded algorithms, will give plant-wide visibility into mechanical integrity, thus ensuring greater overall equipment availability.
When selecting between a stacker, reclaimer or combined machine, miners should consider several features that affect the performance, efficiency and cost of the equipment. In this regard, capacity, flexibility and reliability must be measured. Capacity is the amount of material a machine can handle per hour and is dependent on the size, speed, and design of components like the bucket wheel, belt conveyor and scraper chain.
Meanwhile, flexibility is determined by the mobility, adjustability and versatility of components like the boom, bucket wheel and scraper chain. Essentially, it allows the machine to adapt to different materials, stockpile shapes and operating conditions.
As for reliability, it is based on the durability, robustness and safety of components such as the structure, drive system and control system, thus ensuring that the machine can operate smoothly with minimal downtime and maintenance in various environmental conditions concerning temperature, humidity, dust and corrosion.
Ultimately, each type of stacker and reclaimer has its own benefits and drawbacks. For example, a bucket wheel stacker-reclaimer can both stack and reclaim with one device, saving space and cost. It also has a high capacity and flexibility to create different stockpile shapes and reclaim material from different directions.
It is, however, complex and expensive to maintain, requiring more power consumption and lubrication – plus it is particularly susceptible to wear and tear due to the rotating bucket wheel. On the plus side, a bridge-type stacker-reclaimer can cover a large area of stockpile with a single machine (saving space and cost) and has high capacity and robust reliability due to its simple and sturdy structure and stable drive system.
It is, though, less flexible and adaptable to different materials, requires more rail tracks and foundation works and is difficult to transport and install due to its large size and weight.