The invention discloses a 4N
tellurium preparation method based on an alkaline electro-
deposition process. The method includes the following steps that a
sodium hydroxide piece is added into
ultrapure water at an indoor temperature, stirring and dissolving are conducted, and hot alkaline liquor is obtained; crude
tellurium dioxide
powder is added into the hot alkaline liquor for reacting, and
electrolysis ex-liquid is obtained through preparation; a purifying agent is added so that the
electrolysis ex-liquid can be purified and filtered, and an
electrolyte is obtained through preparation; the
electrolyte is cooled to the indoor temperature, an addition agent is added, the
electrolyte is subjected to
constant voltage pre-deposition treatment after stirring and dissolving are completed, and then
constant current electro-deposition treatment is conducted so that electro-deposition product
tellurium blocks and
electrolysis post-liquid can be obtained; and after the tellurium blocks are stripped from a
plate electrode, washing with the
ultrapure water is performed for several times, and then
drying is conducted so that 4N tellurium can be prepared. The preparation method disclosed by the invention has the advantages that the deposition
electric current density is large, deposition efficiency is high, the preparation period is short, the tellurium product compactness is good, the electrolyte can be recycled, cost is low, the environment is friendly and industrialization is can be facilitated; and the 4N tellurium preparation method can be effectively applied to alkaline electro-deposition for preparing the 4N tellurium.