Enrichment of high ash coal from Zonguldak Çatalağzı washery cyclone overflow by aggloflotation method

In this study, the enrichment of high-ash content bituminous coal by aggloflotation method was examined. The coal sample obtained from Zonguldak Çatalağzı washery was subjected to aggloflotation processes under various parameters using a specially designed new aggloflotation cell. In the experiments, the effects of pH, agglomeration time, amount of binder liquid (domestic waste oil), mixing speed, frother amount and dispersant amount on the aggloflotation of coal were investigated. The test results were evaluated based on the ash content, weight yield and combustible recovery of concentrated coal. The findings showed that the optimum pH value is natural pH because it provides advantages in terms of reagent consumption and cost. The optimum agglomeration time was determined as 5 minutes, and it was obvious that this time was sufficient for the coal particles to form a robust agglomerate structure. As the amount of binder liquid increased, the combustible recovery increased, but with excessive use of oil, the agglomerates became sticky. Therefore, the optimum amount of oil was determined to be 5 ml. Stirring speed was determined as an important parameter in the aggloflotation process and the optimum speed was determined as 1000 rpm. It was assigned that the frother amount did not have a significant effect on aggloflotation and 0.1 ml of frother was sufficient. The addition of dispersant reduced the ash content of the concentrate and increased the combustible recovery. The findings obtained in this study show that the newly designed aggloflotation cell is an effective in the aggloflotation of high-ash content and fine- grained bituminous coal. With the experimentally designed aggloflotation cell, the aggloflotation process, which is performed in batches and two stages in the literature, was carried out in a single stage and continuously, and time and energy savings were achieved, especially by reducing the agglomeration time from 30 minutes to 5 minutes.