Experimental study on enhanced flotation of low rank coal by high efficiency collector

Flotation of low-rank coal presents challenges due to its low surface hydrophobicity. The poor flotation behavior of low-rank coal is mainly caused by the high content of functional oxygen groups present on the coal surface. A high-efficiency flotation collector (XZ-1) was developed to address the problem that low-rank coal is difficult to be recovered by flotation with conventional non-polar oil collector. Results showed that when the dosage of XZ-1 was 300g/t, the yield of flotation concentrate is 60.99% and the ash content is 12.08%. Compared with the use of conventional collector diesel (when the dosage of reagent is 500g/t, the yield of flotation concentrate is 56.03% and the ash content is 12.42%). The flotation results showed that the flotation of low-rank coal in the presence of XZ-1 contributed to better flotation performance than that obtained by diesel, which indicated that XZ-1 can be more effective collector than diesel to float low-rank coal. The contact angle, Fourier transform infrared spectroscopy test and X-ray photoelectron spectroscopy analysis demonstrated that XZ-1 collector can significantly improve the hydrophobicity of low-rank coal, resulting in a great improvement of flotation efficiency. Therefore, XZ-1 could increase the residual carbon recovery and reduce the flotation collector dosage, which has a good application prospect.