Conversion of an Existing Industrial Facility of Pellet Feed Filtration to Tailings Filtration

Abstract

Since 2019, a new Brazilian directive has prohibited in the country the use of dams constructed by the upstream method and limited the use of those by the downstream method. From that, some iron ore wet processing plants that used to dispose their tailings into upstream constructions had to be redesigned to filter their own tailings using their existing process and equipment. This was the situation for at least one plant in the Iron Quadrangle Region, which will be analysed in this article. First, laboratory tests were carried out to provide process parameters to support a sizing assessment of the existing equipment for the new type of material. Next, an industrial test was executed, where a deactivated auxiliary dewatering plant received the total tailings from one operational plant for a two-month period. The total tailings filtration rate obtained was 1.46 t/h.m². The average moisture content of the filtered tailings was 11.8%, while the average iron content was around 17%. The apparent bulk density of the filtered tailings was 1.80 t/m³. At the end, the operational plant was successfully redesigned to filter its total tailings. The work showed that it is feasible to adapt a plant to filter its own tailings.