{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/33416"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/33416","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Cleaning and Dewatering Fine Coal using Hydrophobic Displacement","abstract":"A new processing technique, known as hydrophobic displacement, was explored as a means of simultaneously removing both mineral matter and surface moisture from coal in a single process. Previous thermodynamic analysis suggests that coal moisture will be spontaneously displaced by any oil with a contact angle greater than ninety degrees in water. Based on these results, six methods of hydrophobic displacement were evaluated: hand shaking, screening, air classification, centrifugation, filtration, and displacement. In the first five methods hydrophobic displacement took place during the cleaning stage. A recyclable non-polar liquid (i.e. pentane) was used to agglomerate coal fines followed by a physical separation step to remove the coal agglomerates from the mineral-laden slurry. Bench-scale tests were performed to identify the conditions required to create stable agglomerates. Only the last method, displacement, did not utilized agglomeration and performed hydrophobic displacement during dewatering, not cleaning. A procedure was also developed for determining moisture content from evaporation curves so that the contents of water and pentane remaining in a sample could be accurately distinguished. Two primary coal samples were evaluated in the test program, i.e., dry pulverized 80 mesh x 0 clean coal and 100 mesh x 0 flotation feed. These samples were further screened or aged (oxidized) to provide additional test samples. The lowest moisture, 7.5%, was achieved with centrifugation of the pulverized 80 mesh x 0 clean coal sample. Centrifugation provided the most reliable separation method since it consistently produced low moisture, high combustible recoveries, and high ash rejections. Hand shaking produced the next lowest moisture at 16.2%; however, the low moistures were associated with a drop in combustible recovery. There was also a great deal of error in this process due to its arbitrary nature. Factors such as oxidation, size distribution, and contact angle hysteresis influenced the concentrate moistures, regardless of the method utilized.","abstract_html":"A new processing technique, known as hydrophobic displacement, was explored as a means of simultaneously removing both mineral matter and surface moisture from coal in a single process. Previous thermodynamic analysis suggests that coal moisture will be spontaneously displaced by any oil with a contact angle greater than ninety degrees in water. Based on these results, six methods of hydrophobic displacement were evaluated: hand shaking, screening, air classification, centrifugation, filtration, and displacement. In the first five methods hydrophobic displacement took place during the cleaning stage. A recyclable non-polar liquid (i.e. pentane) was used to agglomerate coal fines followed by a physical separation step to remove the coal agglomerates from the mineral-laden slurry. Bench-scale tests were performed to identify the conditions required to create stable agglomerates. Only the last method, displacement, did not utilized agglomeration and performed hydrophobic displacement during dewatering, not cleaning. A procedure was also developed for determining moisture content from evaporation curves so that the contents of water and pentane remaining in a sample could be accurately distinguished. Two primary coal samples were evaluated in the test program, i.e., dry pulverized 80 mesh x 0 clean coal and 100 mesh x 0 flotation feed. These samples were further screened or aged (oxidized) to provide additional test samples. The lowest moisture, 7.5%, was achieved with centrifugation of the pulverized 80 mesh x 0 clean coal sample. Centrifugation provided the most reliable separation method since it consistently produced low moisture, high combustible recoveries, and high ash rejections. Hand shaking produced the next lowest moisture at 16.2%; however, the low moistures were associated with a drop in combustible recovery. There was also a great deal of error in this process due to its arbitrary nature. Factors such as oxidation, size distribution, and contact angle hysteresis influenced the concentrate moistures, regardless of the method utilized.","abstract_has_math":false,"creators":["Smith, Kara E."],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Mining and Minerals Engineering","degree_department":"Mining and Minerals Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Luttrell, Gerald H.","Yoon, Roe-Hoan"],"committee_members":["Adel, Gregory T."],"year":2008,"date_issued":"2008-05-23","date_published":"2008-05-23","updated_at":"2026-07-22T22:19:31Z","subjects":["hydrophobic displacement","coal dewatering","selective agglomeration"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-06042008-073317"],"render_values":[{"text":"etd-06042008-073317","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/33416","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Luttrell, Gerald H.","Yoon, Roe-Hoan"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Adel, Gregory T."]},{"key":"dc:contributor.department","label":"Department","values":["Mining and Minerals Engineering"]},{"key":"dc:creator","label":"Author","values":["Smith, Kara E."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T20:39:21Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T20:39:21Z","2010-12-22"]},{"key":"dc:date.issued","label":"Date","values":["2008-05-23"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mining and Minerals Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["hydrophobic displacement","coal dewatering","selective agglomeration"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-06042008-073317"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/33416"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["A new processing technique, known as hydrophobic displacement, was explored as a means of simultaneously removing both mineral matter and surface moisture from coal in a single process. Previous thermodynamic analysis suggests that coal moisture will be spontaneously displaced by any oil with a contact angle greater than ninety degrees in water. Based on these results, six methods of hydrophobic displacement were evaluated: hand shaking, screening, air classification, centrifugation, filtration, and displacement. In the first five methods hydrophobic displacement took place during the cleaning stage. A recyclable non-polar liquid (i.e. pentane) was used to agglomerate coal fines followed by a physical separation step to remove the coal agglomerates from the mineral-laden slurry. Bench-scale tests were performed to identify the conditions required to create stable agglomerates. Only the last method, displacement, did not utilized agglomeration and performed hydrophobic displacement during dewatering, not cleaning. A procedure was also developed for determining moisture content from evaporation curves so that the contents of water and pentane remaining in a sample could be accurately distinguished. Two primary coal samples were evaluated in the test program, i.e., dry pulverized 80 mesh x 0 clean coal and 100 mesh x 0 flotation feed. These samples were further screened or aged (oxidized) to provide additional test samples. The lowest moisture, 7.5%, was achieved with centrifugation of the pulverized 80 mesh x 0 clean coal sample. Centrifugation provided the most reliable separation method since it consistently produced low moisture, high combustible recoveries, and high ash rejections. Hand shaking produced the next lowest moisture at 16.2%; however, the low moistures were associated with a drop in combustible recovery. There was also a great deal of error in this process due to its arbitrary nature. Factors such as oxidation, size distribution, and contact angle hysteresis influenced the concentrate moistures, regardless of the method utilized."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["Cleaning and Dewatering Fine Coal using Hydrophobic Displacement"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Luttrell, Gerald H.","Yoon, Roe-Hoan"],"dc:contributor.committeemember":["Adel, Gregory T."],"dc:contributor.department":["Mining and Minerals Engineering"],"dc:creator":["Smith, Kara E."],"dc:date.accessioned":["2014-03-14T20:39:21Z"],"dc:date.available":["2014-03-14T20:39:21Z","2010-12-22"],"dc:date.issued":["2008-05-23"],"dc:description.abstract":["A new processing technique, known as hydrophobic displacement, was explored as a means of simultaneously removing both mineral matter and surface moisture from coal in a single process. Previous thermodynamic analysis suggests that coal moisture will be spontaneously displaced by any oil with a contact angle greater than ninety degrees in water. Based on these results, six methods of hydrophobic displacement were evaluated: hand shaking, screening, air classification, centrifugation, filtration, and displacement. In the first five methods hydrophobic displacement took place during the cleaning stage. A recyclable non-polar liquid (i.e. pentane) was used to agglomerate coal fines followed by a physical separation step to remove the coal agglomerates from the mineral-laden slurry. Bench-scale tests were performed to identify the conditions required to create stable agglomerates. Only the last method, displacement, did not utilized agglomeration and performed hydrophobic displacement during dewatering, not cleaning. A procedure was also developed for determining moisture content from evaporation curves so that the contents of water and pentane remaining in a sample could be accurately distinguished. Two primary coal samples were evaluated in the test program, i.e., dry pulverized 80 mesh x 0 clean coal and 100 mesh x 0 flotation feed. These samples were further screened or aged (oxidized) to provide additional test samples. The lowest moisture, 7.5%, was achieved with centrifugation of the pulverized 80 mesh x 0 clean coal sample. Centrifugation provided the most reliable separation method since it consistently produced low moisture, high combustible recoveries, and high ash rejections. Hand shaking produced the next lowest moisture at 16.2%; however, the low moistures were associated with a drop in combustible recovery. There was also a great deal of error in this process due to its arbitrary nature. Factors such as oxidation, size distribution, and contact angle hysteresis influenced the concentrate moistures, regardless of the method utilized."],"dc:description.degree":["Master of Science"],"dc:identifier.other":["etd-06042008-073317"],"dc:identifier.uri":["http://hdl.handle.net/10919/33416"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["hydrophobic displacement","coal dewatering","selective agglomeration"],"dc:title":["Cleaning and Dewatering Fine Coal using Hydrophobic Displacement"],"dc:type":["Thesis"],"thesis:degree_discipline":["Mining and Minerals Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:31Z"}