多晶硅净化系统过滤元件再生机理研究

A study of the regeneration mechanism of filter elements in polysiliconpurification system

采用酸浸和高温气体还原的方法,对某多晶硅厂的堵塞过滤元件进行再生。结果发现:固体颗粒在不锈钢过滤管中的附着形态分为两类:一类为颗粒在孔道中粘结在一起形成大块颗粒,完全堵塞在不锈钢过滤管的孔道中;另一类为颗粒粘附在孔道壁上,减小了不锈钢过滤管孔径的大小。过滤元件经过酸浸和高温烧结的联合方法再后,过滤元件的透气系数恢复了88.5%,过滤精度为1.3μm,压溃强度提高至131 MPa。性能达到使用要求,从而创造社会经济价值。

Acid leaching and high-temperature gas reduction are applied to regenerate the clogged filter elements of polysilicon plant.The results show that the attachment of solid particles in stainless steel filter tube can be divided into two categories：one is the large particle formed by the bonding of particles in pores,completely blocked in pores of the stainless steel filter tube;the other is a layer of oxide film formed by the particles attached to the cell walls,which reduces the size of the aperture of stainless steel filter pipe.After the combination of acid leaching and hightemperature sintering,the filter element and then,an approach for realizing the reuse of stainless steel is proposed by the high-temperature sintering in hydrogen atmosphere after HF acid leaching and cleaning of stainless steel filter tube.The results show that the permeability coefficient of the filter tube restores to 88.5%with the filtering accuracy of 1.3μm,and crush strength is increased to 131 MPa.The performance meets the application requirements,thereby creating social and economic value.