Preparation method of tellurium dioxide

The invention relates to a preparation method of tellurium dioxide. The method comprises the following steps: mixing a raw material tellurium with haloalkane, adding a reducing agent, carrying out a reaction under an alkaline condition, and performing distillation to obtain dialkyl tellurium; mixing and reacting the dialkyl tellurium with elemental halogen to obtain alkyltelluride halide; and hydrolyzing the alkyltelluride halide, and drying and calcining the hydrolyzed alkyltelluride halide to obtain the tellurium dioxide. The purity of the tellurium dioxide prepared by the method can reach 99.99% or more. 本申请涉及种二氧化碲的制备方法，包括以下步骤：将原料碲与卤代烷混合，加入还原剂，在碱性条件下反应，蒸馏，得到二烷基碲；将二烷基碲与卤素单质混合反应，得到卤化烷基碲；将卤化烷基碲水解后干燥、焙烧，得到二氧化碲。上述方法制得的二氧化碲纯度可达99.99％以上。