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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Reduction of zinc oxide in sintering of manganese furnace dust

Shen, Ruihua, Materials Science & Engineering, Faculty of Science, UNSW January 2009 (has links)
Manganese furnace dust is made up of volatiles and fine particles of the raw materials collected from the off-gas during smelting of manganese alloys. Impediments to the recycling of the manganese furnace dust back to the ferroalloy furnaces are handling due to the presence of tar, and the potential accumulation of zinc in the furnaces, which can cause irregularities in their operation. The aim of the thesis was to establish conditions for zinc removal from the dust and assess the feasibility of the dust recycling in the Tasmanian Electrometallurgical Company sinter plant. Major findings are: - Manganese furnace dust taken from the settling ponds contained water, carbonaceous materials (tar), and metal oxides. The carbon content of the dried furnace dust was about 20% and the average manganese and zinc contents were 33.4 and 1.29%, respectively. Moisture content was 30-60%. - The tar components were aliphatic hydrocarbons and polyaromatic hydrocarbons, their derivatives, and sulphur- and oxygen-containing compounds with a wide range of carbon number (15-28) and boiling point (230-530oC). Light hydrocarbons were not detected. - If manganese furnace dust was recycled to ferroalloy furnaces through the sintering plant, the overall zinc input had increased by 51-143%. Sustainable utilisation of manganese furnace dust should include enhanced zinc removal. - Reduction of zinc oxide from manganese furnace dust pellets started at 800oC. Zinc oxide was reduced to zinc vapour by tar in the dust. Temperature and gas atmosphere were key parameters affecting the zinc removal from the dust. The zinc removal rate increased with increasing temperature and was close to completion at 1100oC. - Optimal conditions for removal of zinc from the furnace dust include: temperature in the range 1000-1150oC, inert gas atmosphere and furnace dust fraction in the furnace dust-manganese ore mixture above 60%. - Zinc removal in the processing of manganese furnace dust in the sinter plant was low because of zinc reoxidation in the sinter bed. This makes the sinter plant unsuitable for recycling of the dust. More suitable conditions for utilisation of manganese furnace dust exist in the rotary hearth furnace, which development is recommended for further study.
192

Application of stochastic approaches to modeling of interstellar chemistry

Stantcheva, Tatiana, January 2004 (has links)
Thesis (Ph. D.)--Ohio State University, 2004. / Title from first page of PDF file. Document formatted into pages; contains xii, 146 p.; also includes graphics (some col.) Includes bibliographical references (p. 141-146). Available online via OhioLINK's ETD Center
193

A survey of radial velocities in the zodiacal dust cloud /

May, Brian Harold. January 2008 (has links)
Thesis Imperial College of Science, Technology and Medicine, London, 2007. / Includes bibliographical references.
194

The molecular and antigenic structure of the major house dust mite allergen Der p 2 /

Mueller, Geoffrey Andrew. January 1998 (has links)
Thesis (Ph. D.)--University of Virginia, 1998. / Spine title: Molecular structure of Der p 2. Includes bibliographical references (p. 147-167). Also available online through Digital Dissertations.
195

The effect of providing bedding encasings on adherence to dust mite control procedures in pediatric asthma patients

Joseph, Karen Elizabeth. January 2000 (has links)
Thesis (M.A.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains viii, 123 p. Includes abstract. Includes bibliographical references (p. 63-68).
196

The design of electrostatically augmented moving bed granular gas filters

Kornelius, Gerrit. January 2003 (has links)
Thesis (Ph.D.(Chemical Engineering))--University of Pretoria, 2003. / Includes summary in English. Includes bibliographical references.
197

Properties of astrophysical submillimeter emission near the South Celestial Pole from the TopHat telescope /

Aguirre, James. January 2003 (has links)
Thesis (Ph. D.)--University of Chicago, Dept. of Physics, June 2003. / Includes bibliographical references. Also available on the Internet.
198

Warping, dust settling and dynamics of protoplanetary disks /

O'Sullivan, Mark George. January 2008 (has links)
Thesis (Ph.D.) - University of St Andrews, November 2008.
199

Electrode geometry effects on the collection efficiency of submicron and ultrafine dust particles in wire-plate electrostatic precipitators /

Brocilo, Drazena. Chang, J. S. Findlay, R. D. January 1900 (has links)
Thesis (Ph.D.)--McMaster University, 2004. / Advisors: J.S. Chang and R.D. Findlay. Includes bibliographical references (leaves 193-212). Also available via World Wide Web.
200

Sources, drivers and sedimentology of Icelandic dust events

Mockford, Thomas January 2017 (has links)
There is increasing evidence for high magnitude dust storms in high latitude environments. Yet, Aeolian processes in these areas have been largely understudied and therefore our knowledge of these systems is limited. Understanding dust emission processes from the high latitudes regions is of increasing importance because future climate scenarios indicate a reduction in terrestrial ice masses and an expansion in glacial outwash plains which are the main dust sources in high latitude environments. Of these regions, Iceland is the most researched high latitude dust source region, however our understanding of processes which lead to dust events are still poorly understood. This thesis examines the interlinking relationship between dust source and dust particle sedimentology and the physical and meteorological drivers which promote or inhibit dust emission in Iceland. This is achieved through active aeolian monitoring at source during two monitoring periods at Markarfljot, South Iceland. These measurements are complimented using secondary data sources (e.g. meteorological and satellite data), sedimentological mapping and particle analysis and laboratory abrasion experiments. This thesis is the first high resolution multi event record of dust emissions in the high latitudes and concludes by showing that potential dust concentrations and dust particle size are driven by the interlinking relationship between wind speed, sediment texture and surface moisture. Factors that affect the potential sediment availability for dust events are more important in the high latitudes than in the subtropics in driving spatial and temporal variability in dust emission. Measurements presented in this thesis are required to verify and tune regional and global modelling attempts to quantify the potential contribution of high latitude dust in the Earth system. However, further measurements are required to fully understand seasonal changes in dust emissions, across a variety of dust source units within all high latitude dust source regions.

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