title: Study of the Effects of Key Processing Parameters on the Cost and Quality of Ti-Al Powders Produced Using the TiPro Process

authors: Sichone, Kenneth

subjects: TiPro Process

abstract: The high cost of titanium has motivated a global drive to research and develop low-cost titanium production technologies. In New Zealand, the TiPro process has been invented at the University of Waikato. The process starts with a combustion reaction between TiO₂ and Al powders, followed by: solid/liquid separation by extrusion which separates the metal rich liquid from the Al₂O₃ solid. The metal-rich phase is subsequently purified to reduce its oxygen content to acceptable level (e.g. <0.3 wt%).
The aim of this study was to establish such key relationships required to maximise the yield of Ti-Al and quality of the Ti-Al powder product. An in-depth understanding of the effects of key process parameters (e.g. heating rate, temperature, time and pressure) and starting TiO₂/Al composite powder characteristics (e.g. microstructure and compressibility) on the quality, production rate and cost of Ti-Al based powders was achieved. The solid/liquid separation step was identified to be most critical in determining the quality and cost of Ti-Al powders produced using the TiPro process. The results indicated that the microstructure of reactant powders, wetting properties of TiAl alloy on the Al₂O₃ particles, the viscosity of the liquid TiAl and the degree of saturation of the combustion product with liquid TiAl are some of the major factors in the extraction of TiAl from the combustion product using extrusion as the solid/liquid separation technique. In the current state of the invention, where the alloy is extracted by extruding the combustion product, the TiPro process is not viable due to poor yields. The throughput, alloy product purity and yield of the TiPro process are constrained by the solid/ liquid separation unit operation. When extrusion is the sole separation technique, the alloy yields are limited to only 10% of total input. This falls far below the minimum yield, (60%) that is required to make the process economically viable. Therefore, unless the solid/ liquid separation is supplemented by other separation techniques, such as froth flotation and leaching, the cost of producing titanium alloy powders by the TiPro process will be high and the quality of the alloy poor, consequently making the process uneconomical. 
This study has demonstrated that froth flotation can recover 65.7 wt% of TiAl content of the extrusion by-product into a 71.0 wt% TiAl grade product. This corresponds to removing 20 wt% of the total Al₂O₃ contained in the extrusion by-product (flotation feed). The potential exists to increase the TiAl grade further by multiple flotation stages. However, further work is required to investigate more suitable reagents than the HF acid that was used to activate Al₂O₃ in this study.

text: Study of the Effects of Key Processing Parameters on the Cost and Quality of Ti-Al Powders Produced Using the TiPro Process The high cost of titanium has motivated a global drive to research and develop low-cost titanium production technologies. In New Zealand, the TiPro process has been invented at the University of Waikato. The process starts with a combustion reaction between TiO₂ and Al powders, followed by: solid/liquid separation by extrusion which separates the metal rich liquid from the Al₂O₃ solid. The metal-rich phase is subsequently purified to reduce its oxygen content to acceptable level (e.g. <0.3 wt%).
The aim of this study was to establish such key relationships required to maximise the yield of Ti-Al and quality of the Ti-Al powder product. An in-depth understanding of the effects of key process parameters (e.g. heating rate, temperature, time and pressure) and starting TiO₂/Al composite powder characteristics (e.g. microstructure and compressibility) on the quality, production rate and cost of Ti-Al based powders was achieved. The solid/liquid separation step was identified to be most critical in determining the quality and cost of Ti-Al powders produced using the TiPro process. The results indicated that the microstructure of reactant powders, wetting properties of TiAl alloy on the Al₂O₃ particles, the viscosity of the liquid TiAl and the degree of saturation of the combustion product with liquid TiAl are some of the major factors in the extraction of TiAl from the combustion product using extrusion as the solid/liquid separation technique. In the current state of the invention, where the alloy is extracted by extruding the combustion product, the TiPro process is not viable due to poor yields. The throughput, alloy product purity and yield of the TiPro process are constrained by the solid/ liquid separation unit operation. When extrusion is the sole separation technique, the alloy yields are limited to only 10% of total input. This falls far below the minimum yield, (60%) that is required to make the process economically viable. Therefore, unless the solid/ liquid separation is supplemented by other separation techniques, such as froth flotation and leaching, the cost of producing titanium alloy powders by the TiPro process will be high and the quality of the alloy poor, consequently making the process uneconomical. 
This study has demonstrated that froth flotation can recover 65.7 wt% of TiAl content of the extrusion by-product into a 71.0 wt% TiAl grade product. This corresponds to removing 20 wt% of the total Al₂O₃ contained in the extrusion by-product (flotation feed). The potential exists to increase the TiAl grade further by multiple flotation stages. However, further work is required to investigate more suitable reagents than the HF acid that was used to activate Al₂O₃ in this study.

year: 2015

title: Edwin Henry Hardy: a Waiorongomai mine owner

authors: Hart, Philip

abstract: Edwin Henry Hardy worked as a surveyor before going to England to study mining. Upon his return in 1896 he was a representative in Hauraki of English mining companies and supervised several Coromandel mines in addition to acquiring mines in several districts for overseas interests. In late 1898 he purchased the former Aroha Gold Mines’ property at Waiorongomai, which he developed using his own financial resources but probably backed by his wider family. Using his surveying skills, he traced a reef missed by previous owners, and commenced to develop the mines systematically. He also spent several years improving the battery, experimenting with new treatment processes and seeking a patent for a gold saving method.
Like all mine owners, Hardy tried to work his property as cheaply as possible, resulting in conflicts with the Thames High School and the county council as he tried to reduce costs. He proved to be very determined in his rows with those he considered his enemies. In addition to developing the Premier mine, profitably, he tested other ground, notable the Big Blow. He supervised both battery and mines, but as he did not have a mine manager’s certificate had to employ a series of managers for the latter. After obtaining a good return for several years, in 1904 he formed Hardy’s Mines Ltd, retaining a financial interest and for a time supervising its work before becoming involved with other mines and clashing with the company he had formed.
Hardy also held interests in mining companies in other districts. After leaving Waiorongomai, he settled in Te Kuiti and worked as a surveyor, a purchaser of Maori land, and a farmer. As at Coromandel and Waiorongomai, he was prominent in the local community, notably as a member of the borough council and Te Kuiti’s second mayor. Over time, his financial state deteriorated, partly through being involved with some very dubious businessmen and their schemes. In 1931 he returned to Waiorongomai to show his son Malcolm where he knew of some good ore, but died in dramatic circumstances before he could show him the location. 
For some time Hardy profited from mining, partly because he took over existing workings and partly because he was able to find ore that others had missed, but as with all mining, profits faded and he had to find other ways to earn a living. But compared with other mine owners at Waiorongomai, he was, for a time, very successful.

text: Edwin Henry Hardy: a Waiorongomai mine owner Edwin Henry Hardy worked as a surveyor before going to England to study mining. Upon his return in 1896 he was a representative in Hauraki of English mining companies and supervised several Coromandel mines in addition to acquiring mines in several districts for overseas interests. In late 1898 he purchased the former Aroha Gold Mines’ property at Waiorongomai, which he developed using his own financial resources but probably backed by his wider family. Using his surveying skills, he traced a reef missed by previous owners, and commenced to develop the mines systematically. He also spent several years improving the battery, experimenting with new treatment processes and seeking a patent for a gold saving method.
Like all mine owners, Hardy tried to work his property as cheaply as possible, resulting in conflicts with the Thames High School and the county council as he tried to reduce costs. He proved to be very determined in his rows with those he considered his enemies. In addition to developing the Premier mine, profitably, he tested other ground, notable the Big Blow. He supervised both battery and mines, but as he did not have a mine manager’s certificate had to employ a series of managers for the latter. After obtaining a good return for several years, in 1904 he formed Hardy’s Mines Ltd, retaining a financial interest and for a time supervising its work before becoming involved with other mines and clashing with the company he had formed.
Hardy also held interests in mining companies in other districts. After leaving Waiorongomai, he settled in Te Kuiti and worked as a surveyor, a purchaser of Maori land, and a farmer. As at Coromandel and Waiorongomai, he was prominent in the local community, notably as a member of the borough council and Te Kuiti’s second mayor. Over time, his financial state deteriorated, partly through being involved with some very dubious businessmen and their schemes. In 1931 he returned to Waiorongomai to show his son Malcolm where he knew of some good ore, but died in dramatic circumstances before he could show him the location. 
For some time Hardy profited from mining, partly because he took over existing workings and partly because he was able to find ore that others had missed, but as with all mining, profits faded and he had to find other ways to earn a living. But compared with other mine owners at Waiorongomai, he was, for a time, very successful.

year: 2016

title: Te Kahautu Maxwell on Te Kooti and Ringatu (Interviewed by Tama Muru)

authors: Maxwell, Te Kahautu

abstract: In October 1869 musket fire erupted at Te Porere about sixty kilometres north of here, in the shadow of Mount Tongariro in the last major battle of the New Zealand wars. 

Armed constabulary and Maori fighters, clashed with the forces of the prophet Te Kooti Arikinui Te Turiki who had built an earth redoubt at Te Porere.  It was overwhelmed during the battle, but Te Kooti and his surviving followers escaped. 

Today the site is a tourist attraction but what also endured is the Ringatu Church, founded by Te Kooti. In 2018 it celebrated its 150th anniversary. 

Ringatu mixes the Bible with Maori custom and, like Matariki, follows annual cycles such as Te Huamata in June for planting and Te Pure, the harvest, each November. 

We spoke to Professor Te Kahautu Maxwell , a minister in the Ringatu Church and a senior academic in Maori and Indigenous Studies at the University of Waikato.

text: Te Kahautu Maxwell on Te Kooti and Ringatu (Interviewed by Tama Muru) In October 1869 musket fire erupted at Te Porere about sixty kilometres north of here, in the shadow of Mount Tongariro in the last major battle of the New Zealand wars. 

Armed constabulary and Maori fighters, clashed with the forces of the prophet Te Kooti Arikinui Te Turiki who had built an earth redoubt at Te Porere.  It was overwhelmed during the battle, but Te Kooti and his surviving followers escaped. 

Today the site is a tourist attraction but what also endured is the Ringatu Church, founded by Te Kooti. In 2018 it celebrated its 150th anniversary. 

Ringatu mixes the Bible with Maori custom and, like Matariki, follows annual cycles such as Te Huamata in June for planting and Te Pure, the harvest, each November. 

We spoke to Professor Te Kahautu Maxwell , a minister in the Ringatu Church and a senior academic in Maori and Indigenous Studies at the University of Waikato.

year: 2025