Floc-flotation of ultrafine coal slimes achieved by flotation column

摘要

In this investigation, the floc-flotation performance of ultrafine coal slimes in the large-scale 5500 x 7000 mm cyclonic-static micro-bubble flotation column (FCSMC) was explored. A laser particle size analyzer was used to indicate the changes in particle size distribution with or without adding a flocculant. The results show that adding a flocculant can contribute to a high content of particles with a larger size in feed, compared with raw feed without adding a flocculant. The flotation results show that the yield of concentrate is 66.69%, with the ash of 7.38% when using 5500 x 7000 mm FCSMC without a flocculant. However, the yield reaches 77.39% with an ash content of 8.70% using a combination of FCSMC and flocculant. The analyses of size distribution of flotation products show that size fractions with the highest and lowest recoveries are +0.125-0.074 mm and -0.045 mm, respectively. The recovery of -0.045 mm fraction sees a 12.29% rise from 62.14 to 74.43% with the ash increasing by only 1%, using a combination of FCSMC and flocculant. This may indicate that increasing the apparent size can be very helpful for obtaining a better flotation performance. In addition, the combination of FCSMC and flocculant to achieve floc-flotation is an effective and feasible method to improve the flotation performance of ultrafine coal slimes.