title: Recovery and Purification of Titanium Dioxide and Aluminium Compounds from Corundum By-product of the TiPro Process

authors: Jennings, Philip Anthony Charles

subjects: Aluminium

abstract: The TiPro process developed at the University of Waikato utilises an aluminothermic reaction to create titanium rich intermetallic alloys or alloy powders by solid-liquid separation. The product is then reduced with calcium vapour or calcium hydride to lower the oxygen content. This process involves intimately mixing titanium oxide powder with stoichiometric quantities of aluminium powder and heating the mixture to initiate a thermite reaction that transfers oxygen from the titanium oxide to the aluminium to produce titanium aluminide alloy and aluminium oxide. The liquid alloy is drained off from the by-product, called corundum, before going on to further processing. The corundum is left behind and contains significant quantities of valuable titanium alloy and aluminium and titanium oxides which must be recovered to increase the efficiency and lower the cost of the process.
	This thesis describes and explains proof-of-concept wet chemistry methods of processing the corundum by-product to recover and separate the valuable metal oxides. Using acid-base equilibria, over 90% of the titanium was recovered from the corundum phase as impure titanium oxide. Aluminium was recovered as aluminium hydroxide and aluminium oxide, both of which can be processed into feedstock for fresh aluminium smelting and hence represent a potential revenue stream. The products were characterised using SEM-EDX and XRD to determine their composition and structure. The proposed treatment produces no waste other than environmentally benign neutral salt water.

text: Recovery and Purification of Titanium Dioxide and Aluminium Compounds from Corundum By-product of the TiPro Process The TiPro process developed at the University of Waikato utilises an aluminothermic reaction to create titanium rich intermetallic alloys or alloy powders by solid-liquid separation. The product is then reduced with calcium vapour or calcium hydride to lower the oxygen content. This process involves intimately mixing titanium oxide powder with stoichiometric quantities of aluminium powder and heating the mixture to initiate a thermite reaction that transfers oxygen from the titanium oxide to the aluminium to produce titanium aluminide alloy and aluminium oxide. The liquid alloy is drained off from the by-product, called corundum, before going on to further processing. The corundum is left behind and contains significant quantities of valuable titanium alloy and aluminium and titanium oxides which must be recovered to increase the efficiency and lower the cost of the process.
	This thesis describes and explains proof-of-concept wet chemistry methods of processing the corundum by-product to recover and separate the valuable metal oxides. Using acid-base equilibria, over 90% of the titanium was recovered from the corundum phase as impure titanium oxide. Aluminium was recovered as aluminium hydroxide and aluminium oxide, both of which can be processed into feedstock for fresh aluminium smelting and hence represent a potential revenue stream. The products were characterised using SEM-EDX and XRD to determine their composition and structure. The proposed treatment produces no waste other than environmentally benign neutral salt water.

year: 2013

title: Photodegradation leads to increased carbon dioxide losses from terrestrial organic matter

authors: Rutledge, Susanna

subjects: abiotic decomposition

abstract: CO₂ production in terrestrial ecosystems is generally assumed to be solely biologically driven while the role of abiotic processes has been largely overlooked. In addition to microbial decomposition, photodegradation – the direct breakdown of organic matter (OM) by solar irradiance – has been found to contribute to litter mass loss in dry ecosystems. Previous small-scale studies have shown that litter degradation by irradiance is accompanied by emissions of CO₂. However, the contribution of photodegradation to total CO₂ losses at ecosystems scales is unknown. This study determined the proportion of the total CO₂ losses caused by photodegradation in two ecosystems: a bare peatland in New Zealand and a seasonally dry grassland in California. The direct effect of solar irradiance on CO₂  production was examined by comparing daytime CO₂  fluxes measured using eddy covariance (EC) systems with simultaneous measurements made using an opaque chamber and the soil CO₂ gradient technique, and with night-time EC measurements under the same soil temperature and moisture conditions. In addition, a transparent chamber was used to directly measure CO₂ fluxes from OM caused by solar irradiance. Photodegradation contributed 19% of the annual CO₂ flux from the peatland and almost 60% of the dry season CO₂ flux from the grassland, and up to 62% and 92% of the summer mid-day CO₂ fluxes, respectively. Our results suggest that photodegradation may be important in a wide range of ecosystems with exposed OM. Furthermore, the practice of partitioning daytime ecosystem CO₂ exchange into its gross components by assuming that total daytime CO₂ losses can be approximated using estimates of biological respiration alone may be in error. To obtain robust estimates of global ecosystem–atmosphere carbon transfers, the contribution of photodegradation to OM decomposition must be quantified for other ecosystems and the results incorporated into coupled carbon–climate models.

text: Photodegradation leads to increased carbon dioxide losses from terrestrial organic matter CO₂ production in terrestrial ecosystems is generally assumed to be solely biologically driven while the role of abiotic processes has been largely overlooked. In addition to microbial decomposition, photodegradation – the direct breakdown of organic matter (OM) by solar irradiance – has been found to contribute to litter mass loss in dry ecosystems. Previous small-scale studies have shown that litter degradation by irradiance is accompanied by emissions of CO₂. However, the contribution of photodegradation to total CO₂ losses at ecosystems scales is unknown. This study determined the proportion of the total CO₂ losses caused by photodegradation in two ecosystems: a bare peatland in New Zealand and a seasonally dry grassland in California. The direct effect of solar irradiance on CO₂  production was examined by comparing daytime CO₂  fluxes measured using eddy covariance (EC) systems with simultaneous measurements made using an opaque chamber and the soil CO₂ gradient technique, and with night-time EC measurements under the same soil temperature and moisture conditions. In addition, a transparent chamber was used to directly measure CO₂ fluxes from OM caused by solar irradiance. Photodegradation contributed 19% of the annual CO₂ flux from the peatland and almost 60% of the dry season CO₂ flux from the grassland, and up to 62% and 92% of the summer mid-day CO₂ fluxes, respectively. Our results suggest that photodegradation may be important in a wide range of ecosystems with exposed OM. Furthermore, the practice of partitioning daytime ecosystem CO₂ exchange into its gross components by assuming that total daytime CO₂ losses can be approximated using estimates of biological respiration alone may be in error. To obtain robust estimates of global ecosystem–atmosphere carbon transfers, the contribution of photodegradation to OM decomposition must be quantified for other ecosystems and the results incorporated into coupled carbon–climate models.

year: 2009

title: Educational leadership and Māori communities’ involvement in their children’s schooling

authors: McMillan, Hoana

subjects: Educational leadership

abstract: The leadership of state primary schools in New Zealand is made up of Board of Trustees (BoT) members and the principal who together, play an important role in addressing take Māori – Māori issues, to enable better outcomes for Māori achievement and empowering relationships with Māori communities.  However not all schools have met their professional responsibilities to provide a learning environment that promotes the success of their Māori students (Education Review Office, 2010) therefore an important question for Māori communities to contemplate is whether they need to take up a more active role in ensuring accountability from these parties, as well as actively contributing to efforts to ensure better outcomes for their children.
The case studies presented in this thesis examine two successful mainstream primary schools identified as doing well in terms of Māori achievement and empowering relationships with their Māori communities.  It explores the knowledge of Māori Board of Trustees Members (MBTMS) and also their perceptions of what Māori communities know regarding school leadership and policies and procedures relating to Māori achievement and Māori communities.  It also explores the knowledge of their school leadership in terms of leadership that works well with Māori communities, and how Māori communities might work alongside school leadership effectively.  The case studies were conducted in a kaupapa Māori framework where the collection and analysis of qualitative data included school documents, observations of Boards of Trustees (BoT) meetings, information about professional development relating to Māori achievement and or Māori communities, and semi-structured interviews with the MBTMS and principals.
The literature review highlighted the relationship between the role of principals and their knowledge of Māori perspectives toward meeting outcomes for Māori achievement and empowering relationships with Māori communities. It also highlighted the role of the BoT and the implications of ethnicity and of legislation toward meeting these outcomes.  Lastly it highlighted the evolution of whānau roles within education, and the ability of whānau to challenge school leadership towards meeting these outcomes.
The findings from the case studies indicate that the knowledge of MBTMS with regards to the roles of school leadership and policies and procedures relating to Māori achievement and Māori communities were consistent with the structure of partnerships within their school leadership.  The knowledge of school leadership across the case studies regarding leadership that works well with Māori communities is consistent with traditional whānau roles within education where there is emphasis on the well-being of Māori, creating the following conditions of school culture and climate within their schools – Whakamana Tangata – Acknowledging People, Whakamana Whānau – Acknowledging Family, Whakamana Tikanga, Acknowledging Protocol, Whakamana Reo – Acknowledging Language, Matauranga Māori – Knowledge of Māori worldviews, Pono – Trust, and Manaaki – Care.
The study suggests further research examining what Māori community members, beyond MTBMS, know about the role of school leadership and of policies and procedures relating to Māori achievement and Māori communities, and how Māori communities might envisage working alongside school leadership.  However, this study does offer a useful point of reflection and discussion for school leadership interested in improving their practice toward better outcomes for Māori.

text: Educational leadership and Māori communities’ involvement in their children’s schooling The leadership of state primary schools in New Zealand is made up of Board of Trustees (BoT) members and the principal who together, play an important role in addressing take Māori – Māori issues, to enable better outcomes for Māori achievement and empowering relationships with Māori communities.  However not all schools have met their professional responsibilities to provide a learning environment that promotes the success of their Māori students (Education Review Office, 2010) therefore an important question for Māori communities to contemplate is whether they need to take up a more active role in ensuring accountability from these parties, as well as actively contributing to efforts to ensure better outcomes for their children.
The case studies presented in this thesis examine two successful mainstream primary schools identified as doing well in terms of Māori achievement and empowering relationships with their Māori communities.  It explores the knowledge of Māori Board of Trustees Members (MBTMS) and also their perceptions of what Māori communities know regarding school leadership and policies and procedures relating to Māori achievement and Māori communities.  It also explores the knowledge of their school leadership in terms of leadership that works well with Māori communities, and how Māori communities might work alongside school leadership effectively.  The case studies were conducted in a kaupapa Māori framework where the collection and analysis of qualitative data included school documents, observations of Boards of Trustees (BoT) meetings, information about professional development relating to Māori achievement and or Māori communities, and semi-structured interviews with the MBTMS and principals.
The literature review highlighted the relationship between the role of principals and their knowledge of Māori perspectives toward meeting outcomes for Māori achievement and empowering relationships with Māori communities. It also highlighted the role of the BoT and the implications of ethnicity and of legislation toward meeting these outcomes.  Lastly it highlighted the evolution of whānau roles within education, and the ability of whānau to challenge school leadership towards meeting these outcomes.
The findings from the case studies indicate that the knowledge of MBTMS with regards to the roles of school leadership and policies and procedures relating to Māori achievement and Māori communities were consistent with the structure of partnerships within their school leadership.  The knowledge of school leadership across the case studies regarding leadership that works well with Māori communities is consistent with traditional whānau roles within education where there is emphasis on the well-being of Māori, creating the following conditions of school culture and climate within their schools – Whakamana Tangata – Acknowledging People, Whakamana Whānau – Acknowledging Family, Whakamana Tikanga, Acknowledging Protocol, Whakamana Reo – Acknowledging Language, Matauranga Māori – Knowledge of Māori worldviews, Pono – Trust, and Manaaki – Care.
The study suggests further research examining what Māori community members, beyond MTBMS, know about the role of school leadership and of policies and procedures relating to Māori achievement and Māori communities, and how Māori communities might envisage working alongside school leadership.  However, this study does offer a useful point of reflection and discussion for school leadership interested in improving their practice toward better outcomes for Māori.

year: 2012