光伏材料切割废液中的Si和SiC旋流分离过程

Swirl separation process of Si and SiC in cutting waste of photovoltaic materials

太阳能硅片切割废料中的硅和碳化硅分离回收对于资源回收和环境保护具有重要的意义。根据硅和碳化硅微细颗粒易团聚且难用化学方法分离的特点,本文利用重介质微型旋流器分离技术,通过实验研究和数值模拟,探究进料流量和底流分率对重介质微型旋流器分离性能的影响。数值模拟采用CFD软件Fluent 6.3.26研究流场和颗粒运动轨迹,实验用微型旋流器直径为10mm,分离粒度分布为0.3~25μm的硅和碳化硅混合粉料。结果表明,硅的分离效率随着进料流量的增大先增大后趋于稳定,且当进料流量达到0.13m^3/h时,分离效率不再增大。不论介质是水还是重介质溶液,当底流分率增大时,旋流场内的轴向速度减小,而切向速度先增大后减小,硅的分离净化效率先增大后减小,当底流分率为0.6左右时,硅的分离净化效率达到最高值。旋流分离硅和碳化硅时,介质采用重介质溶液分离效果更好。

The separation and recovery of Si and Si C from solar wafer cutting waste is of great significance for resource recovery and environmental protection. The fine particles of Si and Si C are easy to agglomerate,resulting in difficulties in chemical separation. In this paper,we use heavy medium micro-cyclone separation technology. The influence of feed flow rate and underflow ratio on the separation performance of heavy medium micro-cyclone was investigated by experiments and numerical simulation. The numerical simulation was carried out using CFD software Fluent 6.3.26 to study the flow field and particle trajectory. The diameter of the micro-cyclone used in the experiment is 10 mm,separating the mixed powder of Si and Si C whose particle size distribution is 0.3—25μm. The results showed that the separation efficiency of Si increased first and then tended to be stable with the increase of feed flow rate. When the feed flow rate reached 0.13 m3/h,the separation efficiency is no longer increasing. Regardless of the medium is water or heavy medium solution,when the underflow ratio increased,the axial velocity decreased,while the tangential velocity increased first and then decreased. The separation and purification efficiency of Si increased first and then decreased. Moreover,when the underflow ratio is about 0.6,the efficiency reached the highest value. When the Si and Si C were separated by cyclone,the heavy medium solution will make the separation effect better.