Maelgwyn Mineral Services (MMS) are pleased to announce that it has been awarded another contract to supply further Imhoflot technology to Dorfner GmbH for their kaolin recovery operations. This will allow Dorfner to relocate its existing flotation process plant without a pause in production and confirms the long-standing relationship MMS has with Dorfner going back over 15 years.
Dorfner GmbH, based in Hirschau, Germany, has been mining mineral raw materials in the Upper Palatinate region since 1895 and has some of the most important German kaolin and quartz deposits. In Q2/2020 MMS supplied a further G18 Imhoflot G-Cell. This follows a logical progression in processing for the mine. The contract scope also included a 3-stage cascade with associated sumps and pumps.
Prior to 2005 the Dorfner kaolin operations’ multistage hydrocyclone plant produced a middlings stream that previously did not fulfil industrial standard kaolin grades and was either used as quarry filler or sold to the cement industry. Dorfner chose the MMS flotation technology to upgrade this stream because of its low capital cost and the fact that it could produce the required grade of kaolin without the need of a cleaner flotation step. Testwork had determined that this was not possible with conventional tank flotation. A technical paper on the testwork and development was presented at the 2007 SME Annual Conference in Denver, USA and can be accessed at the below link.
With the success of the testwork a 3 stage 1.8m diameter Imhoflot G-Cell plant was ordered by Dorfner in March 2005 and was installed and commissioned successfully in July 2005. Please see the MMS press release at the time and a video of the plant in operation (below).
The raw materials mined by Dorfner contain varying amounts of kaolin and feldspars. The company decided to split the operation to produce a saleable kaolin product, as described above, and then a feldspar rich product. Testwork indicated that this second product would require a cleaning stage. In 2011 MMS consequently supplied two more G18 Imhoflot G-Cells to act as cleaners to the already installed G-Cells, now acting as roughers. The plant was split on a weekly campaign basis to treat the two different feed types. The flexibility and the ability of the Imhoflot G-Cells to rapidly reach steady state production allowed this to happen with ease. The press release relating to this contract can be viewed here.
Fast forward to 2020 and the high-grade feldspar deposit has been depleted. The plant has been operating in its original mode with the three G-Cells alone producing a finished kaolin product. However, as you might expect after 125 years of operation, the currently mined area of the deposit is nearing depletion. The geologists identified that the best new area of raw material was located underneath the processing plant. A plan was put in place to move the process plant to a new location without a break in production. For the flotation plant this will entail the relocation of the currently unused two G18 G-Cells from the 2011 supply, together with this new 2020 G18 G-Cell supply.
This will allow Dorfner to continue its long history of production without the need for a break for many decades in the future.