{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/35366"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/35366","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Acid Leaching of SHS Produced MgO/TiB2","abstract":"The stoichiometric Self-propagating High-temperature Synthesis (SHS) thermite reaction involving magnesium oxide (MgO), titanium dioxide (TiO₂), and boron oxide (B₂O₃) forms titanium diboride (TiB₂) and MgO as final products. Selective acid leaching is used to remove the MgO leaving high purity TiB₂ powder. The SHS method to produce TiB₂ is attractive because of the relatively low temperature required to initiate the reaction, fast reaction time, and product purity. This study investigates the acid leaching of SHS produced MgO/TiB2 and a stoichiometric mixture of commercial MgO and TiB₂ powders. Leaching was conducted at 90° C, 60° C, and 30° C at pH levels of 4.0, 2.5, and 1.0 by introduction of concentrated aliquots of HNO₃. This method maintains a minimum pH target throughout the leaching process, thereby sustaining a dynamic concentration to remove the oxide. The optimal leaching conditions were determined to be at 90° C at a minimum pH target of 2.5 for the SHS produced product. At these conditions, conversion percentages of 83%-84% of MgO were measured with only trace amounts of TiB2 measured in the solution (less than 100 ppm). Conversion percentages for each leaching condition and dissolution mass of solid MgO and TiB₂ at each pH are also reported. Results from powder XRD confirm the removal of MgO and minimal dissolution of TiB₂, and indicate the formation of unidentified compounds. Inductively coupled plasma mass spectrometry (ICP) was used to analyze the ionic composition and extent of leaching. Scanning electron microscopy (SEM) was used to observe the particle morphology of the leached powders.","abstract_html":"The stoichiometric Self-propagating High-temperature Synthesis (SHS) thermite reaction involving magnesium oxide (MgO), titanium dioxide (TiO₂), and boron oxide (B₂O₃) forms titanium diboride (TiB₂) and MgO as final products. Selective acid leaching is used to remove the MgO leaving high purity TiB₂ powder. The SHS method to produce TiB₂ is attractive because of the relatively low temperature required to initiate the reaction, fast reaction time, and product purity. This study investigates the acid leaching of SHS produced MgO/TiB2 and a stoichiometric mixture of commercial MgO and TiB₂ powders. Leaching was conducted at 90° C, 60° C, and 30° C at pH levels of 4.0, 2.5, and 1.0 by introduction of concentrated aliquots of HNO₃. This method maintains a minimum pH target throughout the leaching process, thereby sustaining a dynamic concentration to remove the oxide. The optimal leaching conditions were determined to be at 90° C at a minimum pH target of 2.5 for the SHS produced product. At these conditions, conversion percentages of 83%-84% of MgO were measured with only trace amounts of TiB2 measured in the solution (less than 100 ppm). Conversion percentages for each leaching condition and dissolution mass of solid MgO and TiB₂ at each pH are also reported. Results from powder XRD confirm the removal of MgO and minimal dissolution of TiB₂, and indicate the formation of unidentified compounds. Inductively coupled plasma mass spectrometry (ICP) was used to analyze the ionic composition and extent of leaching. Scanning electron microscopy (SEM) was used to observe the particle morphology of the leached powders.","abstract_has_math":false,"creators":["Lok, Jonathan Y."],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Materials Science and Engineering","degree_department":"Materials Science and Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Logan, Kathryn V."],"committee_members":["Kampe, Stephen L.","Pickrell, Gary R."],"year":2006,"date_issued":"2006-10-10","date_published":"2006-10-10","updated_at":"2026-07-22T22:20:20Z","subjects":["Titanium Diboride","Acid Leaching","Thermite Reaction","Magnesium Oxide"],"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-10122006-142938"],"render_values":[{"text":"etd-10122006-142938","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/35366","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Logan, Kathryn V."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Kampe, Stephen L.","Pickrell, Gary R."]},{"key":"dc:contributor.department","label":"Department","values":["Materials Science and Engineering"]},{"key":"dc:creator","label":"Author","values":["Lok, Jonathan Y."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T20:46:38Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T20:46:38Z","2006-11-06"]},{"key":"dc:date.issued","label":"Date","values":["2006-10-10"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Materials Science and 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":["Titanium Diboride","Acid Leaching","Thermite Reaction","Magnesium Oxide"]}]},{"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-10122006-142938"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/35366"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The stoichiometric Self-propagating High-temperature Synthesis (SHS) thermite reaction involving magnesium oxide (MgO), titanium dioxide (TiO₂), and boron oxide (B₂O₃) forms titanium diboride (TiB₂) and MgO as final products. Selective acid leaching is used to remove the MgO leaving high purity TiB₂ powder. The SHS method to produce TiB₂ is attractive because of the relatively low temperature required to initiate the reaction, fast reaction time, and product purity. This study investigates the acid leaching of SHS produced MgO/TiB2 and a stoichiometric mixture of commercial MgO and TiB₂ powders. Leaching was conducted at 90° C, 60° C, and 30° C at pH levels of 4.0, 2.5, and 1.0 by introduction of concentrated aliquots of HNO₃. This method maintains a minimum pH target throughout the leaching process, thereby sustaining a dynamic concentration to remove the oxide. The optimal leaching conditions were determined to be at 90° C at a minimum pH target of 2.5 for the SHS produced product. At these conditions, conversion percentages of 83%-84% of MgO were measured with only trace amounts of TiB2 measured in the solution (less than 100 ppm). Conversion percentages for each leaching condition and dissolution mass of solid MgO and TiB₂ at each pH are also reported. Results from powder XRD confirm the removal of MgO and minimal dissolution of TiB₂, and indicate the formation of unidentified compounds. Inductively coupled plasma mass spectrometry (ICP) was used to analyze the ionic composition and extent of leaching. Scanning electron microscopy (SEM) was used to observe the particle morphology of the leached powders."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["Acid Leaching of SHS Produced MgO/TiB2"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Logan, Kathryn V."],"dc:contributor.committeemember":["Kampe, Stephen L.","Pickrell, Gary R."],"dc:contributor.department":["Materials Science and Engineering"],"dc:creator":["Lok, Jonathan Y."],"dc:date.accessioned":["2014-03-14T20:46:38Z"],"dc:date.available":["2014-03-14T20:46:38Z","2006-11-06"],"dc:date.issued":["2006-10-10"],"dc:description.abstract":["The stoichiometric Self-propagating High-temperature Synthesis (SHS) thermite reaction involving magnesium oxide (MgO), titanium dioxide (TiO₂), and boron oxide (B₂O₃) forms titanium diboride (TiB₂) and MgO as final products. Selective acid leaching is used to remove the MgO leaving high purity TiB₂ powder. The SHS method to produce TiB₂ is attractive because of the relatively low temperature required to initiate the reaction, fast reaction time, and product purity. This study investigates the acid leaching of SHS produced MgO/TiB2 and a stoichiometric mixture of commercial MgO and TiB₂ powders. Leaching was conducted at 90° C, 60° C, and 30° C at pH levels of 4.0, 2.5, and 1.0 by introduction of concentrated aliquots of HNO₃. This method maintains a minimum pH target throughout the leaching process, thereby sustaining a dynamic concentration to remove the oxide. The optimal leaching conditions were determined to be at 90° C at a minimum pH target of 2.5 for the SHS produced product. At these conditions, conversion percentages of 83%-84% of MgO were measured with only trace amounts of TiB2 measured in the solution (less than 100 ppm). Conversion percentages for each leaching condition and dissolution mass of solid MgO and TiB₂ at each pH are also reported. Results from powder XRD confirm the removal of MgO and minimal dissolution of TiB₂, and indicate the formation of unidentified compounds. Inductively coupled plasma mass spectrometry (ICP) was used to analyze the ionic composition and extent of leaching. Scanning electron microscopy (SEM) was used to observe the particle morphology of the leached powders."],"dc:description.degree":["Master of Science"],"dc:identifier.other":["etd-10122006-142938"],"dc:identifier.uri":["http://hdl.handle.net/10919/35366"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Titanium Diboride","Acid Leaching","Thermite Reaction","Magnesium Oxide"],"dc:title":["Acid Leaching of SHS Produced MgO/TiB2"],"dc:type":["Thesis"],"thesis:degree_discipline":["Materials Science and Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:20Z"}