ProProcess Engineering starts commissioning Modular Fines Flotation Plant for Anglo American Platinum

Posted by Paul Moore on 24th August 2021

South Africa’s ProProcess Engineering, based in Germiston, Johannesburg, recently switched on the power to Anglo American Platinum’s new Modular Fines Flotation Pilot Plant and has commenced C1-C3 commissioning. In August 2020 ProProcess was awarded the Engineering, Procurement and Construction contract for the plant for Anglo American which it describes as a “world class test facility for platinum concentrate flowsheet optimisation.”

Stefan Van Dyk, ProProcess Project Manager states: “The aim of this project was to produce a modular, transportable, cost effective and built for purpose pilot plant. Pilot plants have much less stringent  equipment requirements than production plants and this needs to be kept in consideration to avoid over designing the plant, thus unnecessarily escalating the capital outlay. This required a lot of out of the box thinking and many new ideas and concepts were explored to ensure a built for purpose plant. Anglo American has very high safety, maintainability and operation requirements and standards for their production plants. As the pilot plant would be placed into a production environment it was crucial to determine which standards to adhere to and where concessions could be obtained.”

The plant had to be designed with maximum road transportability in mind, as the pilot plant is earmarked to be moved around various concentrator sites owned by Anglo. To this end the entire plant consisting of 40+ flotation cells (including a high intensity flotation cell), a mill,  ~30 tanks (some agitated), ~50 pumps (including centrifugal slurry, peristaltic, vertical spindle), blowers, compressors, etc were fitted onto 16 road transportable ISO frame skids conforming to 40 ft marine container dimensions.

Tanja Marcus, the Process Lead said: “For the process to operate effectively adequate buffer capacity between the individual unit operations needed to be catered for in the design. A slurry with a high density (SG >3) is fed into the plant. To avoid settling of this material in the tanks a very steep angle of 45-60 degrees on the tank cones had to be used. The tanks also had to fit the height of the skid, thus limiting the tank height to ~1.8m. This lead to oddly shaped vessels that consist mainly of cone, with very little tan-to-tan height. Some of the reagents required on the plant are hazardous. To avoid additional equipment in the form of a scrubber and associated neutralisation reagents, the potential hazard was designed out to cause minimal risk.”

Kean Southern, Mechanical Lead said: “ProProcess applied our specialised modular approach to the design of this plant for simplified site installation and ease of transport. This meant each skid frame was custom designed and built to 40ft shipping container dimensions, eliminating any restrictions on road transport, or the need for special permits. All equipment is pre-mounted, piped up and tested at our workshop before shipment to site. Once testing is complete, all that is required is for flexible, interconnecting piping between the frames to be disconnected (which is made easy with the use of flanges and claw couplings). Given the numerous pipe sections run between frames, each connection of flexible hose needed to be tagged to ensure the correct hoses were reconnected during assembly. Since the plant arrives on site already partially assembled, site installation is a breeze.”
Emile Strydom-Bouwer, Electrical Lead commented: “All skids are prewired to Male Power Sockets on local junction boxes. The MCCs are similarly prewired to Male Power Sockets on the MCC wall. The interlinking cables have a Female Power Socket at either end thus no on site glanding and terminations will take place. A potential problem is that the cable can be energised and cause an electrical shock. We, as a design team, mitigated this risk by specifically manufacturing a late-make/early-break pin set and connected it to the safety circuit. Thus the cable can only be energised once fully inserted at both ends.”