The recent boom in the number of mobile devices – such as laptops, tablets and smartphones – has led to a renewed look at the suppliers of the essential components that make them function. For example, LCD screen images and speaker technology are enabled by rare earth elements mined from below the earth's surface.
Many of these elements are imported from China. A recent push from the United States government has opened the door for increased domestic supply of rare earth minerals.
In response to this opportunity, a leading global manufacturer of rare earth and metal products acquired a facility in California with the goal of converting it to a state-of-the-art mining and processing operation. The massive $1 billion project spanned 14 buildings at this location and required standardizing on a common control system across each facility.
At the facility, ore is mined from one of the world's largest and richest rare earth mineral deposits. Once mined, the ore is crushed, milled and concentrated on-site. It is then put through chemical processing to remove any impurities. Heavy and light rare earth minerals are then concentrated, processed and separated either at Mountain Pass or another downstream facility.
Other on-site facilities include heat and power plants, and a chloralkali facility that takes wastewater produced and turns it back into chemical re-agents used in the separation process. In addition, a paste tailings plant removes water from non-rare earth tailings. The water is then recycled, and the tailings are converted into low-moisture material to prevent the elements from being released to the environment.
The upgraded facility mines and processes rare earth minerals that are used in smartphones, electric cars, wind turbines, and defense guidance system magnets, as well as countless other products.
The challenge was to engineer, procure and construct a homogenous sitewide process control system across 14 disparate process buildings being designed by eight separate process engineering firms.
The company wanted a homogenous platform solution with an automation master plan that each engineering firm could follow throughout implementation to ensure success. The plan needed to define the system migration process, as well as the standards for hardware, software, IT infrastructure, panels, security, instrumentation and wiring.
Thermo Systems LLC, a Solution Partner in the Rockwell Automation PartnerNetwork™ program, was selected to create the automation master plan and lead implementation in collaboration with the other engineering firms. Thermo Systems created a team of 25 on-site engineers, including Rockwell Automation engineers, as well as engineers from partner system integrators. Divided into teams of five, these engineers were available 24/7 throughout the project.
The Thermo Systems master plan was based on the implementation of a process control system from Rockwell Automation, leveraging Allen Bradley® ControlLogix® controllers.
“The new system allowed us to build the individual area process cells, commission them, and then add them to the process ring as it was built,” said David Musto, president and CEO, Thermo Systems. “We also used a combination of redundant and nonredundant systems for skid vendor applications.”
In order to increase visibility into all aspects of ore processing and refining, Thermo Systems standardized monitoring on 74 remote, human machine interface (HMI) terminals where operators receive diagnostics and updates in real time.
“We avoided development of traditional control rooms, instead putting operations at the plant floor level” said Musto. “The HMIs were the perfect solution and allowed operators to move around the facility rather than being tethered to a control room.”
The solution integrates variable frequency drives and hundreds of constant speed motors operating on standard I/O architecture and faceplates.
Speed of deployment and ease of maintenance were the driving factors in the system design. The mining company and Thermo Systems selected a single end-to-end Rockwell Automation solution, by fully integrating skid-mounted, plant-floor and electrical manufacturing systems on a common platform.
The automation master plan also issued standards for the system's remote I/O for optimal device connectivity. Multiple layers of redundancy on power supplies and communication networks were designed to prevent system downtime on the 22,500 hardwired I/O connection points.
Redundant Cisco core-level switches were also placed in strategic locations on a redundant fiber ring into the single process control system.
The control system offered multiple benefits to the mining company once implemented.
“The success of this project can be attributed to three key elements: the plan, the products and the people,” said Musto. “We created the master plan using Rockwell Automation solutions that we knew would deliver the results we needed. We also leveraged key partnerships with Rockwell Automation that ensured easy implementation and reliable support.”
The single, homogenous platform reduced implementation expenses and the amount of training needed for the company's limited staff. It is now completely maintainable by the staff, further reducing maintenance costs.
The solution allows the mining company the flexibility to expand operations in the future and select service providers that fit their needs, rather than being limited to a select number of system integrators.
The project achieved aggressive schedule milestones by leveraging the Rockwell Automation partnership, and the entire project was completed within the original time frame.
In order to optimize throughput and meet production goals, the company has developed ongoing process enhancement goals, and Thermo Systems is working with the company to execute ongoing system updates as needed.