陶瓷平板膜在球形氧化铝提纯工序中的应用

Application of Ceramic Plate Film in Spherical Alumina Purification Process

针对四川某高新材料股份有限公司生产的高纯度球形氧化铝粉体,产品在烧球制备过程中需改变粒径的大小,烧球后的粉体具有较高的电导率和磁性,物料中还有一些杂质和金属残渣。提纯工序是产品的最后关键工序,工序采用“预处理筛分+陶瓷平板膜超滤”工艺。该工艺采用高温纯水与粉体混合成浆料,浆料与纯水混合摩擦置换出高电导率的废水,用陶瓷平板膜超滤工艺将浆料中的高电导率废水分离出来,达到提高球化率,降低电导率,去除杂质的效果。实机运行证明,陶瓷平板膜提纯处理能力为600kg/批次,每天8小时处理4个批次,120分钟/批次,过滤通量200~300L/m^(2)·h,出水稳定,浊度≤0.5 NTU,30~60天离线清洗一次;经过该工艺处理后的球形氧化铝粉体纯度≥99.9%,球化率96%~98%,pH范围7~8,电导率≤5μs/cm,其特征指标满足企业质量标准及优于GB/T24487-2022《氧化铝》标准中的化学成分和外观质量要求。

For the high-purity spherical alumina powder produced by Sichuan High-tech Materials Co.,LTD.,the particle size of the product needs to be changed during the preparation of the fired ball.The powder after the fired ball has high conductivity and magnetism,and there are some impurities and metal residues in the material.The purification process is the last key process of the product,and the process adopts the process of"pre-screening+ceramic plate membrane ultrafiltration".The process uses high temperature pure water and powder mixed into slurry,slurry and pure water mixed friction to replace the high conductivity of the wastewater,using ceramic plate membrane ultrafiltration process to separate the high conductivity of the wastewater in the slurry,to achieve the effect of improving the nodulation rate,reducing the conductivity,removing impurities.The operation of the real machine proved that the purification capacity of the ceramic plate membrane was 600kg/batch,4 batches were processed 8 hours a day,120 minutes/batch,the filtration flux was 200~300L/m^(2) h,the effluent was stable,the turbidity was less than 0.5 NTU,and the offline cleaning was performed once every 30~60 days.After the process,the purity of spherical alumina powder is≥99.9%,the spheroidization rate is 96%~98%,the pH range is 7~8,and the conductivity is less than 5μs/cm.Its characteristics meet the quality standards of enterprises and are better than the chemical composition and appearance quality requirements of GB/T24487-2022"Alumina"standard.