The Realities of Coal Processing

Reflux Classifier (RC) technology is rapidly gaining popularity in coal processing applications in Africa because of its ability to easily handle varying feed conditions which are a reality in mining operations.
Traditional technology cannot accommodate these feed variations resulting in recovery losses whereas the RC is a lot more forgiving of solids feed rate variations. This allows a consistent separation and, as a result, a higher separation efficiency.
FLSmidth has an installed base of RC technology in coal applications in the Waterberg and in Mozambique.
Each of these units, now installed and commissioned, is capable of treating approximately 200 tph of raw fine coal.
Significantly, the success achieved by this technology in the second phase of this coal processing plant resulted in the RC being chosen as the technology of choice for retrofit to the original plant. Prior to this, test work was conducted on site by FLSmidth using its mobile test RC 300 rig to validate the expected performance of the larger RC units.
The results from the pilot plant test work proved a business case to replace the existing spiral technology, leading to the sale of four additional RC 3000 units to the mine. These will be commissioned when the extension to the existing plant is completed.
The success achieved with the RC technology is due to the fact that it offers far greater process flexibility in operation and generally has a higher efficiency which produces higher recovery at similar ash percentage.
Minimal operator input is necessary because only one operational control is required; the density set-point controlling the cut point. This equipment also offers an indirect environmental benefit, since far less steel is required for the RC equipment and therefore lower carbon emissions are associated with the installation.
The equipment incorporates a ‘laminar high shear rate’ mechanism, which represents the latest in fine particle gravity based separation technology. The lamella section enhances the efficiency/capacity of the RC, producing a more compact, higher efficient separation unit when compared with competing fine coal and mineral processing equipment such as spirals, up-current classifiers and teeter bed separators.
FLSmidth delivers the RC product as a packaged solution, which includes all auxiliary equipment, support steelwork and piping, materials handling equipment and electrical reticulation.
FLSmidth, Terence Osborn
Tel: (010) 210-4820
Email: marinda.kerr@flsmidth.com
www.flsmidth.com