Floc-flotation of ultrafine coal slimes achieved by flotation column

ABSTRACT

In this investigation, the floc-flotation performance of ultrafine coal slimes in the large-scale 5500 × 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 × 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.

KEYWORDS:

• FCSMC
• flocculant
• floc-flotation
• recovery
• ultrafine coal slimes

Funding

This work was supported by the National Nature Science Foundation of China (No. 51504254, 51274198) and the Fundamental Research Funds for the Central Universities of China (No. 2015XKMS039).

Additional information

Funding

This work was supported by the National Nature Science Foundation of China (No. 51504254, 51274198) and the Fundamental Research Funds for the Central Universities of China (No. 2015XKMS039).