Fine material filtration using conventional pressure and steam pressure: a relationship between filter cake height to crack formation and residual moisture content

Abstract

Crack formation is an undesired phenomenon encountered frequently during the filtration process, especially in fine particulate filter cakes. This phenomenon causes disadvantages related to the dewatering efficiency and washing efficiency. The filter cake height has not only an effect on crack formation but also meaning in the economic and operational of filtration. In this research, Limestone and Coal are the chosen fine powder materials to survey the effect of this factor during conventional pressure filtration (CPF) and steam pressure filtration (SPF). The permeability ratio is suggested to quantify cracking while the saturation and the residual moisture content indicate the water remaining. Test results show lower dewatering efficiency as well as an increasing trend of probability and degree of cracks when the filter cake becomes thicker. By visual observation, macro- and micro-cracking are described for shrinkage behavior on filter cake. The delamination was also mentioned and observed after filtration. Steam pressure filtration (SPF) is introduced as one of the methods to reduce the degree, even prevent the formation of cracks as well as improve the dewatering efficiency.

Keywords:

• Conventional pressure filtration
• steam pressure filtration
• shrinkage cracking
• delamination plane
• permeability ratio

Acknowledgment

The article have used a part of the content in the author’s PhD thesis, which is published through the Qucosa-TU Bergakademie Freiberg according to the procedure to obtain the Doctor’s certificate.

The authors would like to thank colleagues in the Institute of Mechanical Process Engineering and Mineral Processing, TU Bergakademie Freiberg, for their discussion and technical support.

We would like to thank Vietnam International Education Development (VIED) – Ministry of Education and Training for financial support through the 911 Project. Further, thanks to the Hanoi University of Mining and Geology, for funding aid in Vietnam through a basics project (T23-30); thanks to DAAD and WUS for supporting procedures in Germany.

Disclosure statement

No potential conflict of interest was reported by the authors.