Filter presses in metal refinery plants has a wide range of applications. In fact in the metallurgical plant the filter press can be used

• in the main production line or
• in the filtration of waste residue resulting from the metal refining process.

Usually the metal refinery plants receive from the mine a mineral concentrate like zinc concentrate, copper concentrate, bauxite etc. To extract and purify the metal contents from the mineral concentrate the metallurgical plants applies pyrometallurgical process or chemical process or combination of both and also electrowinning process. All of this processes produce slurry that has to be filtered by the filter press in order to purify the metal. A typical case is the leaching process where some acid, like sulfuric acid is used in order to extract and transform the valuable metal from the solid phase to the liquid phase. In this case the acid solution has to be filtered by the filter press to eliminate all the impurities from the acid solution. After the leaching and filter press filtration process could be used a cementation or precipitation process where other chemicals are added to the acid solution to transform again the metals that are in the liquid phase to the solid phase. And again filter press are used for the filtration of this solution. These are only few filtration cases where the filter press are used in the main metal production line.

The filter press are used also in the filtration of the residue resulting from the extraction process like the residue of alumina refinery from Bayer Process called as red mud or the slurry produced from the smelter like in the copper smelter or even the tailings slurry from Nickel refinery.

Other applications are in the purification of sulfuric acid used for the leaching process or in the purification of electrowinning solutions and in the filtration of the slurry produced after the electrowinning process. Usually the filter press for metallurgical application are special. As these filter press should able to work in acid conditions and also in high temperature conditions. For this reasons Dewater Filter Press designs and produce customised anti acid filter press with filter press parts coated with stainless steel, or polypropylene. And special filter press frame design painted with epoxide painting. In addition the filter press plates can be customised to resist to the high temperature conditions and to be also able to make cake washing and cake drying in order to increase the filtration performance.