Mechanical evaporation is driven by heat transfer. Steam is condensed on a metallic heat transfer surface. The absorbed heat causes the water to vaporise and thus it increases in the salt concentration. The water vapour is then condensed for reuse (Kepke, n.d.). This process is mainly implemented for larger processes (Van der Merwe et al, 2009).
The advantage is that the process produces a solid salt product (individual salt product or a mixed waste) (Van der Merwe et al, 2009). The disadvantages include the energy intensity of the process, the greenhouse gas production, high maintenance and capital cost due to the use of exotic materials as well as high operating costs (Van der Merwe et al, 2009). Skilled operators are also needed on the plant (Van der Merwe et al, 2009).
