An investigation on dewatering kinetics of ultrafine coal

• Published in: International journal of mineral processing 2003-06, Vol.70 (1), p.235-249
• Main Authors: Tao, D., Parekh, B.K., Liu, J.T., Chen, S.
• Format: Article
• Language: English
• Subjects: Applied sciences; dewatering; Exact sciences and technology; filtration; flocculant; Flotation. Enrichment. Beneficiation; kinetics; Metals. Metallurgy; Ores; Production of metals; ultrafine coal
• ISSN: 0301-7516; 1879-3525
• DOI: 10.1016/S0301-7516(03)00025-5

Ultrafine coal dewatering is of great importance to the coal industry due to its impacts on the handling and utilization characteristics of coal products. Commercially available filtration techniques are either ineffective or costly for dewatering of ultrafine coal to the desired moisture level of about 20%. Considerable efforts have been devoted to understanding the dewatering process and developing new technologies for applications in the coal industry. Most of the previous work on ultrafine coal filtration was focused on the final filter cake moisture and few studies have been conducted to investigate the filtration kinetics. The present investigation was undertaken to better understand the kinetics of vacuum filtration of ultrafine coal under various conditions. The filtrate weight was continuously monitored using a precise load cell during the entire filtration process. Operating parameters such as vacuum pressure and reagent conditioning time were examined for their impacts on filtration kinetics. Use of cationic and anionic flocculants showed significant improvement in filtration kinetics. Kinetic data obtained from the study were used to determine the fundamental parameters of filtration such as cake permeability, specific cake resistance, and filter medium resistance using the integrated form of the Darcy's law.