in the following table the reaction produces silicon powder incorporating a fraction of the reductant and potentially also the hydride of the reductant hydrogen gas is also produced and in fact can be captured and used or sold this reaction product can be removed from the reactor and then be treated to remove the reductant and any reductant hydride or can first be treated before removing the silicon metal there are many specific implementations of this technology illustrated by the following representative but non exhaustive examples silane gas is injected into a reactor vessel containing molten sodium and is allowed to flow until the evolved hydrogen indicates the presence of unreacted silane gas at which point the flow of silane is stopped the reactor vessel is then heated to a temperature of at least 300 degrees centigrade and a partial vacuum of 100 ton or less is applied to the vessel to remove any hydrogen produced by the breakdown of sodium hydride once the remnant hydrogen has been removed the temperature is raised to above the boiling point of sodium and the sodium vapor is removed and condensed to recover the sodium this step can be accomplished at lower temperatures by the application of a partial or full.