• Resources Recycling
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• v.21 no.6
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• pp.32-38
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• 2012

In this study, direct reduction of $ZrO_2$ using liquid calcium was investigated. The influence of molar ratio of Ca and $ZrO_2$, reaction time and temperature on the reduction behavior of $ZrO_2$ was studied. Experiments were conducted in a closed stainless steel chamber under Ar atmosphere during 5 to 60 minutes. Most of the $ZrO_2$ was reduced to Zr in 5 minutes at 1223 K and 3 Ca/$ZrO_2$ molar ratio. The minimum oxygen content in reduced metal Zr was obtained about 0.66 wt% at 1373 K after 30 minutes and 4 Ca/$ZrO_2$ molar ratio. The morphology of zirconium powder obtained was highly affected by the reaction temperature and reaction time.

• Resources Recycling
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• v.22 no.6
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• pp.41-47
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• 2013

In this study, deoxidation of Ti scrap using liquid calcium was investigated. Experiments were conducted in a closed stainless steel chamber under Ar atmosphere during 30 to 90 minutes. Oxygen content of Ti scrap was reduced from 0.54 to 0.19 wt% by calciothermic reduction in 30 minutes at $1000^{\circ}C$ and 2.5 Ti/Ca mass ratio. By the calciothermic reduction of Ti scrap for 30 minutes under the reaction temperature of $1100^{\circ}C$ and 2.5 Ti/Ca mass, a minimum oxygen content of about 0.126 wt% in Ti scrap was obtained.

• Korean Journal of Metals and Materials
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• v.50 no.11
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• pp.823-828
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• 2012

Direct reduction of $Ta_2O_5$ using liquid calcium was investigated. The experiment was conducted in a closed stainless steel chamber in an Ar atmosphere for 5-120 minutes. Most of $Ta_2O_5$ was reduced to ${\alpha}-Ta$ in 30 minutes above 1173 K and at a molar ratio of Ca and $Ta_2O_5$ above 10. The particles size increased with the reaction temperature, but it did not change much above 1223 K. The oxygen content of metal Ta was about 1 wt%.