Automatic Control of Drum Filters Operation

Red mud is the principal waste of Bayer process and must attempt to quality parameters, such as caustic concentration, to not damage disposal environment. In Hydro Alunorte, drum filtration is used for dewatering and washing red mud with filter cloths that retains the cake formed by red mud, recovering part of caustic soda, which returns to the process. The aim of this work was to reduce the consumption of filter cloth with improvement of operation and maintenance by drum filters. After a study of equipment performance, process parameters were adjusted and an automatic control of the drum filter operation was developed, with a complex control loop. The recovery of caustic soda increased and were observed gains on filter cloths durability which means about 40% of reduce in operation costs.