Rheological Characteristics of High Ash Indian Coal with Sodium Dodecyl Sulfate as Additive

The conveyance of coal in slurry form through pipelines has demonstrated its viability and efficacy, providing economic advantages, reliability and reduced environmental impact. As high-rank coal deposits are steadily depleting, researchers are interested in exploring ways to facilitate utilising low-rank coal to meet the global energy demand. However, the slurry prepared using low-rank coal exhibits high apparent viscosity and poor stability. In the present work, the rheological characteristics of Indian coal with an ash content of more than 50% are improved through the use of the commercial additive sodium dodecyl sulfate. The high ash coal sample’s physical, chemical, and morphological characteristics were assessed. The rheological attributes of the high ash coal slurry were investigated by altering the shear rate, solid loading, and additive concentration. The optimal sodium dodecyl sulfate proportion to obtain slurry with maximum stability and low apparent viscosity was found to be 0.5%. The observed rise in the absolute value of zeta potential from –37.82 to –52.19 mV signifies that suspension stabilization occurs via electrostatic repulsion. A statistical correlation for the prediction of slurry apparent viscosity was developed and proved to be promising and significant.