This extraction method exposes oxide or halide ores to a stream of hydrogen gas inside a heated reactor. The hydrogen strips oxygen or halogens from the ore to form water or hydrogen halides, leaving behind high-purity metal powder or sponge. It is heavily used for refractory metals like tungsten and molybdenum where carbon reduction would leave unwanted carbide impurities.
We need to control the moisture exhaust during hydriding so the tungsten powder doesn't oxidize before it cools.
Controlling the flow rate of hydrogen is critical, as excess moisture buildup in the furnace atmosphere can reverse the reaction.
Related terms
Reduce
To strip oxygen or other non-metallic elements from an ore to yield base metal.
Reduction
The percentage decrease in a material's cross-sectional area or thickness after rolling or drawing.
Refractory metal
A class of metallic elements highly resistant to heat and wear, typically melting above 2000°C.
Smelting
The extractive process of heating an ore with a reducing agent to produce base metal.