煤块冲击破碎速度研究

冲击破碎速度是影响煤块冲击破碎效果的主要参数。基于分段塑变碰撞模型得到煤块与冲击板碰撞时的接触应力，并结合裂缝假说和能量守恒原理推导出煤块被破碎到指定粒度需要的理论冲击速度。进行煤块冲击破碎试验，通过试验数据分析得到了冲击破碎速度的试验拟合公式和理论修正公式。88%的拟合计算值与试验值的误差小于10%，但拟合公式结构复杂，不适合工程应用；85%的理论修正值与试验值的误差小于20%，满足初级破碎所需的精度，可以作为初级破碎时冲击破碎速度的理论选择依据。

Impact crushing velocity of lump coal

Impact-crushing velocity is the principal parameter influencing lump-coal impact-crushing effect. When lump coal impacted the rigid plate, the contact stress was presented based on piecewise plastic-deformation model. The impact velocity crushing lump coal into a certain size was derived theoretically by crack hypothesis and energy conservation principle. The experiment fitting formula was proposed out through lump-coal impact-crushing experiments, so the theoretical modified formula did. Compared with experimental results, 88% fitting values’ errors are less than 10%, while 85% theoretical modified values less than 20%. The analysis results shows that the fitting formula are too complex to engineering application, the theoretical modified formula can meet the accuracy for primary crushing and may be as theoretical selection rules for impact-crushing velocity.