実験室用石灰るつぼの簡易製作法

抄録

  Reagent grade calcined calcium oxide powder crushed to pass a 5 mesh sieve was used as a starting material and a solution of 4g unhydrated calcium chloride per 100cc of ethanol was added to the powder as a binder. The mixture was hand-rammed to the inside of an outer crucible and fired in an electric resistance furnace at 900°C for 1hr. Several melting experiments using a high frequency induction furnace were carried out to test the usability of the lime crucible prepared under these conditions. The crucible was stable enough against pure chromium melt in argon atmosphere. The crucible was however attacked when it was brought into contact with super-heated molten titanium, but some possibilities of using the mixture as a mold material for titanium casting were indicated. Cast iron melted in the lime crucible together with lime-fluospar flux in the open atmosphere could be desulfurized below 10ppm. No failure occured after three times of vacuum melting each 5kg charge of electrolytic iron in the same crucible.