Awesome Earthmovers visited KGHM’s Carlota copper mine 

Awesome Earthmovers visited KGHM’s Carlota copper mine in March to see their 2-year-old Cat 6015B Hydraulic Mining Shovel. Located around 80 miles east of central Phoenix, Arizona, the mine sits in the mountains at an elevation of 4,200 feet above sea level. 

Open-cast copper mining is a complex and capital-intensive process that requires careful planning, engineering, and environmental management to minimise its impact on the surrounding environment and communities. Environmental monitoring, reclamation, and closure plans are important components of responsible mining practices to mitigate the potential negative effects of open-cast copper mining on ecosystems, water quality, and local communities.

The Carlota Mine, located in the picturesque Miami-Globe mining region of Arizona, has a rich history of copper production. Discovered in the mid-1990s, the mine’s resources were confirmed after years of collecting baseline environmental, social, and geological data to assess its feasibility and potential impact on the environment. Production began in 2008, with the first copper cathode being produced in the fourth quarter of the same year. The mine was later acquired by KGHM Polska Miedź SA as part of the Quadra FNX acquisition in 2012.

Extraction of copper ore from the Carlota mine follows conventional methods used in open pit mining, including blasting and hauling the ore with haul trucks. The extracted ore is then deposited on heaps for leaching with a sulfuric acid solution. The copper-enriched solution obtained after leaching is processed at the SX-EW (solvent extraction-electrowinning) to produce high-quality copper cathodes, which are the final product of the process. In 2015, the site introduced the SSL (subsurface leaching) system, allowing for the injection of sulfuric acid under low pressure directly into the heap, which has improved the extraction of metal from the ore that was not fully leached in the past.

The geology of the Miami-Globe mining district is known for its economically large-scale porphyry copper, gold, and molybdenum deposits, such as the Miami-Inspiration and Cu Resolution. The area is made up of igneous, metamorphic, and sedimentary rocks of various ages ranging from the early Proterozoic to the Tertiary. The Carlota deposit is formed by the surface mineralisation of copper oxides in the Proterozoic Pinal Schist, with chrysocolla being the dominant ore mineral occurring as coatings, crusts, and filling in fractures and heavily disintegrated rock masses.

The Cat 6015B mining shovel is a heavyweight machine purpose-built for mining applications. With an operating weight of over 140 tonnes and a maximum digging depth of 28 feet, it is capable of handling large-scale excavation tasks in challenging mining environments. Equipped with real-time machine health monitoring, the 6015B offers enhanced productivity and efficiency. Its spacious operator cabin is designed for comfort and features excellent visibility, ensuring operators can work efficiently and safely during long hours of operation. Built to withstand the harsh conditions of mining operations, the 6015B is constructed with durability and reliability in mind, with easy access to service points for efficient maintenance. With its powerful performance, cutting-edge technology, and operator comfort features, the Cat 6015B is a trusted choice for mining companies seeking a high-performance machine to optimize productivity and reliability in their operations.

Having previously rented, the Carlota mine embarked on a process to purchase their own mining shovel. They initially considered various brands and went so far as to actually visit sites to see machines in live production work.  Senior Mine Supervisor, Richard Powers noted that the aesthetics of the Cat 6015B played a significant role in their decision to purchase the machine. Richard further emphasised that the ease of maintenance, particularly with regards to the cooling system, was a key deciding factor in their purchase.

When we arrived, the mining shovel was perched on its ideal bench height for efficient operation of 10 to 12 feet, although it can occasionally handle 15 feet. The 6015B can move 11,000 to 15,000 tonnes of material per shift, when paired with the Cat 785 trucks. The 11-yard3 bucket allows for loading in 8 to 11 passes. In case of any backup requirements, a Cat 993K wheel loader is available as support. 

Although conventionally paired with Cat 775 or 777 haul trucks, Carlota have chosen to pair their 6015B with heavier 785s having found that it works well with the right operator. Andrew Peru is one of the first operators Carlota hired in 2007 and has 18 years’ experience with 2 years on the 6015B. Richard Powers is full of praise for Andrew: “As a Senior Mine Supervisor, I’ve had the opportunity to work with various professionals in the mining industry, and I can confidently say that Andrew Peru is a notch above the rest.” 

According to Andrew, this machine is not only sturdy and comfortable, but it’s also quick and powerful in loading applications. Having previously operated a Komatsu PC1200 and Hitachi face shovel, Andrew finds the 6015B to be a standout choice. One of the perks Andrew enjoys while operating the 6015B is listening to 80s music on the built-in radio. Moreover, Andrew appreciates that the 6015B is easier on his back compared to the machines he has operated in the past. 

Jessica Goodwin, Operations and Safety Coordinator, shares her experience with the Cat VisionLink®telematics system used in the Cat 6015B. According to Jessica, this advanced system provides her with valuable information to effectively manage maintenance and operations. The system sends her alerts when planned maintenance is due, allowing her to proactively schedule maintenance and order service kits in advance. Jessica also mentions that the system provides fuel burn reports and tracks machine activity, notifying her when the machine is working or idle. Additionally, Jessica and the maintenance supervisor receive daily email updates from the VisionLink system, giving them real-time insights into the machine’s performance. For Jessica, the most important feature of the VisionLink system is the planned maintenance alerts that provide her with a 50-hour advance notice, enabling her to efficiently manage maintenance tasks and ensure smooth operations. Overall, Jessica’s comments highlight the value of the Cat VisionLink telematics system in enhancing machine performance and maintenance management.

Carlota has developed a strong relationship with the dealer, Empire Cat, who supplied the Cat 6015B. Empire Cat has been incredibly supportive in terms of maintenance and training. Jessica, who serves as Carlota’s main contact with Empire Cat, mentions they have always been responsive and helpful, especially when it comes to services. In fact, George McKeon, who Carlota considers their go-to person at Empire Cat, is the first call they make when they encounter any issues they can’t solve on their own. Jessica also states that Carlota has faced few problems with their Cat equipment, with only some O-rings having to be replaced. In addition to maintenance, Empire Cat has also been a dependable source for parts and ground engaging tools (G.E.T.), ensuring that Carlota’s operations run smoothly and efficiently. Overall, the relationship between Carlota and Empire Cat is built on trust, reliability, and excellent customer service.

The initial expectation for the mine was a 7-year lifespan – that has now stretched to 16 years. Jessica notes that the people at the mine are versatile and willing to step into various roles as needed, often wearing multiple hats to get the job done. She describes the workforce as a close-knit family, where everyone is willing to help and support each other. Safety is also a top priority, with a positive safety culture that is ingrained in the mine’s operations. Richard shares Jessica’s sentiment and believes that the mine’s success is largely due to the genuine care and dedication shown by the majority of the employees. For them, it’s not just a job, but a sense of responsibility towards the operation and their fellow colleagues.