The invention provides a preparation method of coralline high-purity
tantalum powder, and the mehtod comprises the following steps of (1) activating needle-shaped
potassium fluotantalate into
powder;(2) making NaCl free of water; (3) filtering and purifying the
metal sodium to obtain purified
sodium; (4) filling powdery
potassium fluotantalate and NaCl into a reduction tank, hoisting the reduction tank into a well chamber reduction furnace, vacuumizing, filling
argon for replacement, heating to 100 DEG C, inputting purified
sodium, and continuously heating; (5) when the temperature increasesto 750 DEG C, carrying out
sodium reduction; (6) after the sodium injection is finished, keeping constant temperature, lifting out the reduction tank, naturally cooling, taking out and crushing into amixture; (7) washing with water and acid to obtain washing
powder; and (8) carrying out heat treatment on the washing powder, taking out of the furnace, sieving, and analyzing the qualified undersizeto obtain the coralline high-purity
tantalum powder. By controlling the reaction process of preparing the
tantalum powder by reducing
potassium fluotantalate with the sodium
metal, the preparation method of coralline high-purity tantalum powder can absorb
metal impurities as little as possible and prevent the
reaction product metal tantalum from being oxidized, and can directly prepare the coralliform high-purity tantalum powder with low metal
impurity content and
low oxygen content.