Enhancement of Flotation Performance of Oxidized Coal by the Mixture of Laurylamine Dipropylene Diamine and Kerosene

Qingshan Zhang,Chenkai Niu,Chao Ni,Muhammad Bilal,Yaoli Peng,Xiangning Bu

doi:10.3390/min11111271

Abstract

Conventional hydrocarbon oil cannot adhere effectively to oxidized coal, resulting in a low yield of clean coal. In this study, a high-speed homogenizer was used to emulsify LDD (laurylamine dipropylene diamine) and kerosene, which enhanced the flotation efficiency of oxidized coal. The flotation results showed an increase from 4.12% (only kerosene) to 23.33% (emulsified oil). An increase in contact angle indicated that the mixture reagent can increase the hydrophobicity of coal particles, which is attributed to the adsorption of LDD onto the coal particle surface and the decrease of the oil droplet A lower surface tension of LDD allows it to produce a stable layer of froth than the layer generated by kerosene alone.

Highlights

Coal is important non-renewable fossil energy and plays an important role in world energy
This study explored the potential of LDD as a promoter for the flotation of oxidized coal using kerosene
There are few hydrophobic functional groups, such as C-H and C-C, which can promote the adsorption of an oily collector on coal surface due to hydrophobic bonding [26]

Summary

Introduction

Coal is important non-renewable fossil energy and plays an important role in world energy. Li et al [14] adopted cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) as cationic and anionic surfactants, after comparing the flotation results, it is found that the anionic surfactant SDS can slightly change the surface properties of low-rank coals and improve the selectivity and collection of kerosene. LDD is used in closed water cycles, such as in the paper industry and in cooling towers, and for the preservation of cooling lubricants, such as drilling and cutting oils, where its dispersant, lubricant and corrosion protection properties are useful On this basis, this study explored the potential of LDD as a promoter for the flotation of oxidized coal using kerosene. Measurement results of the surface tension test and froth height were employed to investigate the effect of the mixture reagent on the froth zone

Materials

Comparisons of Flotation Performance between Emulsified Oil and Kerosene

XPS Analysis

FTIR Results

Generation of a Stable Froth

Conclusions