Development of the selective-shear coagulation process for ultrafine coal cleaning

dc.contributor.authorHonaker, Ricky Quayen
dc.contributor.departmentMining and Minerals Engineeringen
dc.description.abstractIn order to produce coal containing less than 2% ash using a physical cleaning process, the coal must initially be ground to liberate the mineral matter. The result is a micronized feed material that cannot be efficiently treated using the commercial methods currently available. Therefore, an advanced physical cleaning technique for ultrafine coal, called"selective-shear coagulation", is presently being investigated. The process utilizes high shear conditions to overcome the strong electrostatic repulsive force between particles. The attractive hydrophobic interaction and van der Waals forces control the coagulation of the coal particles. The effects of various chemical parameters, such as pH and ion concentration, were studied. An optimum pH range was established for tap water and distilled water media. The presence of multivalent cations in the system increased coal recovery, but decreased selectivity. Physical parameters of the selective coagulation process, such as particle size, percent solids, and specific energy input, were studied. It was found that separation efficiency improved with decreasing particle size. An optimum feed percent solids was found by maximizing separation efficiency. In the case of distilled water, test results revealed that additional specific energy provided by mechanical agitation was required to induce coagulation after grinding. However, additional mixing was found unnecessary in the case of tap water. A continuous selective-shear coagulation process using an elutriation column as the separator was designed and characterized. A steady-state population balance model of the elutriation column was developed. The predictions were found to be in good agreement with experimental results.en
dc.description.degreeMaster of Scienceen
dc.format.extentxv, 224 leavesen
dc.publisherVirginia Polytechnic Institute and State Universityen
dc.relation.isformatofOCLC# 22391940en
dc.rightsIn Copyrighten
dc.subject.lccLD5655.V855 1988.H673en
dc.subject.lcshCoal -- Processing -- Researchen
dc.subject.lcshCoal -- Cleaning -- Researchen
dc.titleDevelopment of the selective-shear coagulation process for ultrafine coal cleaningen
dc.type.dcmitypeTexten and Minerals Engineeringen Polytechnic Institute and State Universityen of Scienceen
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
7.86 MB
Adobe Portable Document Format