石灰石颗粒碰撞磨损特性实验研究

Experimental Research of Impact Attrition Characteristics for Limestone Particles

石灰石颗粒的碰撞磨损对其循环捕集CO2的吸收性能及流化状态有着重要影响。选取了重庆渝北区的天然石灰石颗粒作为样品，研究了碰撞速度、碰撞角度和碰撞次数对其磨损特性的影响规律，建立了粒径衰减率随参数变化的数学表达式。研究表明，随着碰撞速度增大，衰减率降低，其变化规律符合线性关系；碰撞角度变化时，衰减率呈现30°和45°两个分界点的3段不同变化趋势：O～30°衰减率呈线性变化；30-45°衰减率基本保持不变；45～65°衰减率呈二次函数变化。随碰撞次数的增加，细粉累积质量分数和衰减率都增大，且呈线性增长关系。细粉质量和衰减率的增量相近，表明多次碰撞产生近似的磨损效果。

The impact attrition for limestone particles has significant influence on cyclic CO2 capture ability of sorbents. Natural limestone particles from Yubei district, Chongqing, were chosen as experimental samples. The effects of impact velocity, impact angle and impact times on limestone attrition characteristics were studied. The re- sults show that the decay rate decreases with a linear correlation when impact velocity increases. With the change of impact angle, decay rate shows trend of three different phases. When impact angle is 0--30°, decay rate changes line- arly. When impact angle is 30--45°, decay rate almost stays constant. When impact angle is 45--65°, decay rate has a quadratic changing. Cumulative mass fraction of limestone fines （R） and decay rate increase li-nearly with increasing of impact times. As the increment of fines and decay are similar, it is suggested that impact attrition has similar effects when impact times augment.