Compaction characteristics of binary coal mixtures during binder less briquetting process

ABSTRACT

Dried coal typically had certain Particle Size Distribution (PSD) resulting from the size reduction process. Effect of PSD to the compaction phenomenon was investigated on the binary mixtures of Indonesian middle-rank coal with different mass fraction of small and large particles (%L). Compacted density of each coal mixtures was measured during uniaxial briquetting process and their compaction characteristics were analyzed with Cooper-Eaton model. It was found that Cooper-Eaton model could fit excellently (R² > 0.99) with the experimental data. Analysis of compaction characteristics of the model (A_i and k_i) and briquette density revealed that mixtures 0%L (PSD Small) and 100%L (PSD Large) were easier to compact compared to binary mixtures. Binary mixture 70%L was hardest to compact, evaluating from its lowest increase of density, from 893 to 1492 kg/m³. Relatively high coordination number at pressure 2 kPa on mixture 70%L (7.81 ± 0.20) might be the reason for high deformation difficulty. It was concluded that binary mixture of coal with the highest bulk density would results in briquette with the lowest density.

KEYWORDS:

• Compaction characteristics
• binary mixtures
• coal
• binder less briquetting
• particle size distribution

Acknowledgments

This study was supported financially by Bandung Institute of Technology as part of research, community service, and innovation programs (P3MI) in energy conversion group year 2018, within the research topic of Coal Upgrading Technology (CUT) development using low-temperature drying process and coal mechanical properties.

Disclosure Statement

The authors have declared no conflict of interest.

Data Availability Statement

Supplementary data that support the findings of this study are openly available in “figshare” at https://doi.org/10.6084/m9.figshare.12389471 for Supplementary Data A and at https://doi.org/10.6084/m9.figshare.12399788 for Supplementary Data B.

Supplementary Material

Supplemental data for this article can be accessed on the publisher’s website.

Additional information

Funding

This work was supported by the Research, community service, and innovation programs (P3MI) year 2018.