超细三氧化钨制备工艺的研究

Study on Preparation Process of Ultrafine WO_3

对两种易于工业化生产制备超细WO3的工艺方案进行了试验。方案一为"煅烧H2WO4制备超细WO3",方案二为"APT热离解-浸出-喷雾干燥-AMT煅烧制备超细WO3"。运用扫描电镜与氮吸附法对两种工艺方法制备的超细WO3进行了形貌和粒度分析,结果表明:方案二制备的超细WO3形貌和粒度更好,组织生产相对便利,工艺控制难度小,作业环境较好。对方案二中的热离解工艺进行了L9(34)正交试验。结果表明:影响热离解料浸出率的因素按主次排列依次是热离解温度、进料速度和热离解时间。为了考察偏钨酸铵煅烧温度对WO3粉末费氏粒度和比表面积的影响,采用同一批喷雾干燥料进行了煅烧工艺试验,获得了BET粒度为75nm的超细WO3粉末。结果表明:煅烧温度对WO3粉末费氏粒度的影响不显著,但对比表面积影响较大。控制较低的煅烧温度,有利于获得细颗粒WO3。

Experiments were carried out on two kinds of ultrafine WO3 preparation processes, easy to industrialize. The first process is calcining H2 WO4 to prepare ultrafine WO3. The second process is APT thermal dissociation-leaching-spray drying-calcining AMT to prepare ultrafine WO3. The morphology and particle size of ultrafine WO3 from the two processes were analyzed respectively by SEM and nitrogen adsorption. The results show that the second process is characterized by better WO3 morphology and particle size, more convenient production organization, less difficulty in the process control and better working environment. L9 （34） orthogonal experiments of thermal dissociation step in the second process were carried out. The results show that the factors affecting leaching rate of dissociated material have the following descending order：thermal dissociation temperature, feed rate and thermal dissociation time. Calcination experiment was carried out with the same batch of spray drying material,to research the influence of AMT calcination temperature on Fisher particle size and specific surface of WO3 powders. As a result, ultrafine WO3 powders are obtained with BET size of 75 nm. The results show that calcination temperature slightly influences Fisher particle size of WO3 powders, but strongly influences their specific surface. Lower calcination temperature is helpful for ultrafine WO3 preparation.