Lesson plan

Hunter process

The Hunter process was the first industrial process to produce pure metallic titanium. It was invented in 1910 by Matthew A. Hunter, a chemist born in New Zealand who worked in the United States. The process involves reducing titanium tetrachloride (TiCl 4 ) with sodium (Na) in a batch reactor with an inert atmosphere at a temperature of 1,000 °C. Diluted hydrochloric acid is then used to leach the salt from the product. :TiCl 4 (g) + 4 Na(l) → 4 NaCl(l) + Ti(s) Prior to the Hunter process, all efforts to produce Ti metal afforded highly impure material, often titanium nitride (which resembles a metal). The Hunter process was used until 1993, when it was replaced by the more economical Kroll process, which was developed in the 1940s. In the Kroll process, TiCl 4 is reduced by magnesium instead of sodium. Both methods share the same initial step, obtaining TiCl 4 from ore by chlorination and carbothermic reduction of the oxygen. The Kroll process is now the most commonly used titanium smelting process. The Hunter process was conducted in either one or two steps. If a single step was used the reaction equation is as above. Because of the large amount of heat generated by the reduction using sodium compared to using magnesium, and the difficulty in controlling the vapor pressure of liquid sodium, a two step process may instead be used.…

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Article summary

The Hunter process was the first industrial process to produce pure metallic titanium. It was invented in 1910 by Matthew A. Hunter, a chemist born in New Zealand who worked in the United States. The process involves reducing titanium tetrachloride (TiCl 4 ) with sodium (Na) in a batch reactor with an inert atmosphere at a temperature of 1,000 °C. Diluted hydrochloric acid is then used to leach the salt from the product. :TiCl 4 (g) + 4 Na(l) → 4 NaCl(l) + Ti(s) Prior to the Hunter process, all efforts to produce Ti metal afforded highly impure material, often titanium nitride (which resembles a metal). The Hunter process was used until 1993, when it was replaced by the more economical Kroll process, which was developed in the 1940s. In the Kroll process, TiCl 4 is reduced by magnesium instead of sodium. Both methods share the same initial step, obtaining TiCl 4 from ore by chlorination and carbothermic reduction of the oxygen. The Kroll process is now the most commonly used titanium smelting process. The Hunter process was conducted in either one or two steps. If a single step was used the reaction equation is as above. Because of the large amount of heat generated by the reduction using sodium compared to using magnesium, and the difficulty in controlling the vapor pressure of liquid sodium, a two step process may instead be used.…

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  1. Summarise the article in your own words. Which single claim would you verify first, and why?
  2. Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
  3. If two sources disagreed about one of these facts, what would you need in order to trust one over the other?

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