Optimization study of sodium hydroxide consumption in the coal demineralization process

ABSTRACT

Demineralization study on flotation tailings coal with an objective to minimize the consumption of sodium hydroxide was explored. In the present work, the effect of process parameters such as pulp density (PD) of coal slurry, alkali (NaOH) concentration and reaction temperature on the ash content of product coal and NaOH consumption was investigated. Optimum process conditions were selected based on the minimum loss of NaOH and maximum PD (so that reactor volume required per ton of raw coal treatment can be minimized) along with the desired level of ash reduction. Experimental results shows that the consumption of sodium (Na) per unit ash removal increases with increase in alkali concentration for a given PD and at the same time decreases with increase in PD for a given alkali concentration. Furthermore, it was observed that the amount of Na consumption per unit ash removal is directly proportional to the reaction temperature.

KEYWORDS:

• Demineralization
• ash reduction
• coal
• pulp density
• flotation tailings
• optimization

Acknowledgments

The authors would like to thank the management of Tata Steel Limited and Indian Institute of Technology Bhubaneswar for their support and motivation toward publishing this work.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.