Control technologies for iron / Red sludge processing

Control Technologies for iron in  hydrometallurgy

Iron  is present as an associated material in nearly all initial materials. The topic of iron control is the object of continuous professional discussion, which shows how important this topic is for refining in hydrometallurgy. The hydrolytic precipitation of haematite from salt acids or sulphuric acid solutions is a technological possibility for selective separation of the iron fraction from hydrous leachates. This process is known in the literature under the name “PORI-process” and can be used  in combination with many other hydrometallurgical process steps for shaping new hydrometallurgical processes.

Red sludge processing from the  aluminium industry

Red sludge is a ferrous by-product from extraction of aluminium from its ores. The classical process is called the Bayer-process. The characteristic colour from its ores comes from iron (III)-compounds. Mostly these are Fe(OH)3 or Fe2O3. Along with iron, depending on the origin of the ore, there are considerable amounts of TiO2presenting red sludges. They can also contain traces of poisonous heavy metals such as mercury, cadmium, chromium, arsenic. The red sludges are deposited and mostly not fed into additional processing. This depositing becomes an environmental problem when poisonous substances from a deposit get into the ground water or dams break and contaminate entire swathes of land, such as happened in Hungary in 2010.

MME Engineering is in the position to make a technological contribution to the processing of red sludges and extracting iron.