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PROBLEM TO BE SOLVED : To provide a technique of stably providing calcium whose purity is increased, which can be used not only for the production of high purity lanthanum, but for reducing an agent for the other rare earths or the like, a desulfurizing agent or a deoxidizing agent for metals and a getter for a high vacuum pump.
SOLUTION : In the method for producing high purity calcium, the raw material for calcium with a purity of ≤4N other than gas components is charged into the crucible of a sublimation container, is heated at 750 to 800°C to be sublimed, the same is stuck (vapor-deposited) to the side walls in the sublimation container to perform the first sublimation refining, next, calcium subjected to the first sublimation refining is recovered, and thereafter, the calcium is again charged into the crucible of the sublimation container, is heated at 750 to 800°C, is subjected to the second sublimation refining, is similarly stuck (vapor-deposited) to the side walls in the sublimation container to recover calcium with a purity of ≥4N5.
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