Recovery and production of high-purity tellurium from silver soda slag
department or school: Applied Science, Faculty of
department or school: Engineering, School of (Okanagan)
data provider: DSpace
degree campus: UBCO
creator: Mackowiak, Kristian David
issued: 2021-05-06T20:56:47Z
issued: 2021
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: The objective of the current research was the extraction and separation of silver and tellurium from an industrial slag by-product. The recovery of these elements presented an opportunity to extract additional value from the slag, as well as produce tellurium, an important metal in solar panel production. A 2N purity tellurium powder was produced using a three-stage process. The process first involved a pyrometallurgical processing step, which served to separate the silver from tellurium. A thermodynamic model was first produced in HSC 9.1 to determine the effects of temperature and various reagents on the pyrometallurgical system. Using the model results, a central composite design (CCD) methodology was utilized to determine the experimental tests to conduct. The results of the CCD testing were used to generate full quadratic statistical models using MATLAB®. From the experimental testing, the silver recovery during the pyrometallurgical step was 92% to the metal phase and 88% tellurium recovery to the slag phase. The remaining pyrometallurgically processed slag from the previous step was then crushed and prepared for leaching. The lixiviant used was deionized water, with the slurry consisting of 1 to 30% slag by weight. Approximately 30% of the Te in the slag would instantaneously leach, which was attributed to sodium tellurite dissolution. Following 24 hours of leaching, additional tellurium would leach into solution. It was found that a lower solids percentage in the slurry yielded over 60% Te recovery. The addition of sodium hydroxide or sodium sulphide also led to increases in the Te recovery. The resulting tellurium leach solution could then be purified in one of two ways. First, electrowinning of the solution could be conducted, which led to the production of the 2N purity Te powders. Recoveries typically around 70 to 90% were achieved in a single electrowinning step. It was found that using the leach solution containing sodium sulphide would lead to the hig…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/78166
note: Recovery and Production ofHigh-Purity Tellurium from SilverSoda SlagbyKristian David MackowiakBASc, Queen’s University, 2014MASc, Queen’s University, 2016A DISSERTATION SUBMITTED IN PARTIAL FULFILLMENT OFTHE REQUIREMENTS FOR THE DEGREE OFDOCTOR OF PHILOSOPHYinThe College of Graduate Studies(Mechanical Engineering)THE UNIVERSITY OF BRITISH COLUMBIA(Okanagan)May 2021© Kristian David Mackowiak, 2021The following individuals certify that they have read and recommend to the College ofGraduate Studies for acceptance, a dissertation entitled:Recovery and Production of High-Purity Tellurium from Silver SodaSlagsubmitted by Kristian David Mackowiak in partial fulfilment of the requirements ofthe degree of Doctor of Philosophy.Dr. Lukas Bichler, School of EngineeringSupervisorDr. Dimitry Sediako, School of EngineeringSupervisory Committee MemberDr. Leili Tafaghodi, Department of Materials Science and Engineering, McMaster UniversitySupervisory Committee MemberDr. Cigdem Eskicioglu, School of EngineeringUniversity ExaminerDr. Mansoor Barati, Department of Materials Science and Engineering, University of TorontoExternal ExamineriiAbstractThe objective of the current research was the extraction and separation of silver andtellurium from an industrial slag by-product. The recovery of these elements presentedan opportunity to extract additional value from the slag, as well as produce tellurium, animportant metal in solar panel production.A 2N purity tellurium powder was produced using a three-stage process. The processfirst involved a pyrometallurgical processing step, which served to separate the silver fromtellurium. A thermodynamic model was first produced in HSC 9.1 to determine the effects oftemperature and various reagents on the pyrometallurgical system. Using the model results,a central composite design (CCD) methodology was utilized to determine the experimentaltests to conduct. The results of the CCD testing were used to generate full quadraticstatistical models using MA…
has type: Thesis/Dissertation
date issued: 2021-09
is shown at: 10.14288/1.0397277
language: eng
degree discipline: Mechanical Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Bichler, Lukas
type: Text
identifier URI: http://hdl.handle.net/2429/78166