Precision at Every Stage: Automated Controls for a Precious Metals Refining Line
How CSI designed, built, and commissioned a complete control system for a silver refining facility — automating five independent processing sequences with intuitive operator controls and comprehensive diagnostics.
Industry
Process
Service
Full System Design & Integration
Platform
Siemens S7 PLC / PROFINET
Material
Precious metals refining
A precious metals refinery in the Greater Toronto Area was commissioning a new silver refining machine. The process — milling, sifting, blending, sampling, and lab sampling — had previously been handled manually, with operators managing each stage by hand. The customer wanted the new machine fully automated from the start, with independent control over each processing sequence, clear operator visibility into machine status, and robust diagnostics for troubleshooting. CSI was brought in not just to program the controls but to help design the machine’s sensing and instrumentation alongside the customer’s team — selecting and specifying the analog sensors and PROFINET devices needed to give the control system accurate enough feedback to automate what had been a hands-on, operator-dependent process.
CSI delivered the complete controls package — panel design, panel build, PLC and HMI programming, VFD configuration, factory acceptance testing, and on-site commissioning. The system is built on a Siemens PLC communicating with drives and I/O over PROFINET, with a touchscreen HMI providing full operator control.
The software architecture organizes the refining line into six independently controlled operations: mill, sift, blend, sample, conveyor cleaning, and lab sample. Each operation has its own start/stop controls, configurable parameters, and interlock logic — operators can run or stop any sequence without affecting the others. The Patterson Ball Mill, for example, supports multiple stopping modes including timed delays and position-based stops at load or unload positions, with variable speed control through its drive.
The HMI gives operators a clear system overview with color-coded status indicators for every motor and pneumatic device, plus dedicated screens for motor control, pneumatics, I/O status, and maintenance setup. A full diagnostics suite covers active and historical alarms, PROFINET device communication status, and interlock diagnostics at both the device and sequence level — making it straightforward for maintenance staff to identify exactly what’s preventing an operation from starting.
CSI delivered the project as a complete turnkey installation — from sensor selection and instrumentation design through panel build, PLC and HMI programming, VFD configuration, full electrical installation, and on-site commissioning. Working alongside the customer’s engineering team, CSI helped specify the analog sensors and PROFINET field devices needed to close the loop on processes that had never been automated before, ensuring the control system had the precision feedback required to run each sequence without manual intervention.
The control system gives the refinery full automated control over five independent refining sequences from a single operator interface, with diagnostics detailed enough that maintenance staff can pinpoint interlock issues without calling for outside support.
Sequences automated
Process transformation
Turnkey delivery
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