Assessment of the Tri-Flo Separator in Tabas Coal Preparation Plant on the Basis of the Laboratory Studies

About 40 percent of total raw coal feeding to Tabas coal preparation plant, consists of particles in the size range of -50+6 mm. These particles are washed in a 700 mm (diameter) two-stage Tri-Flo dense medium separator. In order to understand the mechanism of separation, a laboratory setup including a transparent 70 mm Tri-Flo separator, tanks, pumps and the required instrumnets was designed and manufactured. In laboratory studies, some polymeric colorful tracers were added to the separator with different air core sizes, and were captured and counted in products’ tanks. The results indicate that probable error of separation (Ep) decreases while air core gets bigger. Relying the findings of laboratory studies, the industrial Tri-Flo was optimizaed using density tracers in the specific gravity range of 1.20 – 2.20 g/cm3, when the separator was treating raw coal. In this phase, we tried to change dense medium flow rate and internal tube diameter in the meaningful levels to evaluate the separator performance, rapidly. An increase of 9% in the production yield and 0.5% increase in clean coal ash were the results of increasing the internal tube diameter in industrial separator from 205 mm to 235 mm. 3% increase in the production yield and 1% decrease in the clean coal ash was also observed with increasing the medium flow rate. Similar to the results observed in laboratory separator, increasing the flow rate and pipe diameter leads to clearer separation in industrial separator. This research presents a successful use of the laboratory results for optimization of an industrial separator.