Ceramic Vacuum Disc Filter

Ceramic vacuum disc filters are used widely for dewatering iron ore slurries in mining industry. The scale of iron production processes is typically very large which means that small changes in the operation of the filter can have a significant impact on the overall effectiveness of the process. Some of the variables that determine the performance of ceramic disc filters are the rotation speed of the disc, the level of slurry in the feed basin, the vacuum level applied during the filter cake formation and dewatering stages and the solid concentration as well as the temperature of the feed slurry.

Ceramic vacuum disc filters are used to dewater a wide variety of different kinds of mineral concentrates in the mining industry. The construction and operation principle of ceramic disc filters are pretty similar to the conventional disc filters but the difference is that the filter cloths are replaced here by microporous ceramic segments. As these segments are immersed into the slurry under vacuum, the filtrate is drawn through the ceramic elements and the filter cake forms onto the external surfaces of those. When the segment rises from the slurry basin, the dewatering of the filter cake begins due to the vacuum that continues to draw the liquid from the cake into the segment. The moisture content of the cake decreases until the vacuum is broken and the cake is discharged by a scraper. The main advantage of ceramic disc filters when compared to the conventional ones is that there is no air flow through the discs at any point of the cycle due to the capillary forces acting in the pores. The vacuum losses are therefore much lower which means that also the vacuum pumps required for ceramic filters are significantly smaller than the ones required for conventional disc filters.

One of the most important applications of ceramic disc filters is the dewatering of iron ore slurries. The production capacity required in this kind of processes is normally very large and it is therefore important to optimize performance of the filter by considering all of those operation parameters that influence the overall efficiency of the separation process. The performance of ceramic disc filters is affected by variables such as the rotation speed of the disc, the level of slurry in the feed basin, the pressure difference applied during the filter cake formation and dewatering stages and the solid concentration as well as the temperature of the feed slurry. The target of this study was to determine the main effects of these variables on the dewatering of iron ore slurry.