Studies on sulfur liberation characteristics of Pakistani high sulfur low-rank coal using Hardgrove grinding

ABSTRACT

Coal remains the backbone of developing countries’ energy needs and economic development. Coal with improved quality standards is in high industrial demand as it emits minimal CO₂, NOx, and SOx. This paper investigates the sulfur liberation characteristics of high-sulfur, low-grade Pakistani coal. The research utilizes Hardgrove grinding and takes advantage of the large differences in hardness and grindability to achieve effective liberation and separation of coal from mineral materials. The proposed mechanism achieves the liberation of microsized pyritic sulfur up to 100 µm in coal. In addition to this, the proposed mechanism achieves a good carbon grade of about 34.58% of the concentrated coal when ground below the liberation size by this mechanism. Based on the results, this process improves the carbon grade of coal by 74.60%, the ash removal efficiency by 34.22%, and the desulfurization rate by about 77.01%. This developed methodology has several important features, such as no use of chemicals, no use of water, reduced energy consumption, dual features of liberation and separation, and elimination of toxic effluents from coal.

KEYWORDS:

• Sulfur liberation characteristics
• Hardgrove principle
• grindability
• microsized pyritic sulfur
• coal

Acknowledgements

The authors of this paper would like to acknowledge the role of the Higher Education Commission Pakistan and British Council Pakistan in establishing a partnership between Mehran University of Engineering and Technology, Pakistan, and the University of Manchester, UK, for the purpose of developing Pakistan’s indigenous mineral resources.

Disclosure statement

No potential conflict of interest was reported by the author(s).