超细全尾砂似膏体长距离自流输送的时变特性

基于H-B流变模型和絮网结构理论,构建了考虑时变性的超细全尾砂似膏体流变模型,探究超细全尾砂似膏体长距离管道自流输送过程中的时变特性,推导了相应的管输阻力计算公式.以某深井铁矿质量分数为68%的超细全尾砂似膏体为例,进行了室内剪切试验和管输阻力计算.结果表明:不同剪切速率下的超细全尾砂似膏体表现出剪切稀化的时变特性,且剪切速率越大,达到平衡状态的时间越短,黏度值越低.在流量为80 m3/h时,管输阻力经225 s降至稳定状态的5.03 M Pa/km,为初始阻力的50.6%.超细全尾砂似膏体长距离自流输送过程中,以稳定状态的阻力损失进行计算更为经济合理.

Time-Varying Characteristic of Paste-like Super-Fine Unclassified Tailings in Long Self-Flowing Transportation

A time-dependent rheological model was built based on the H-B rheological model and the slurry flocculent structure theory. Time-varying characteristic of paste-like super-fine unclassified tailings in long self-flowing transportation was explored， and the friction loss formula of pipes was derived. By using the 68% mass concentration paste-like slurry of a deep iron mine， groups of shear rheological tests were implemented， and the pipes friction loss was verified. It is revealed that the paste-like super-fine unclassified tailings show obvious shear thinning under different shear rate. The higher the shear rate is， the faster the balance can be reached and the lower the viscosity is. With a flow of 80m³/h， the friction loss takes 225s to reach a stable value of 5.03MPa/km， which is just 50.6% of the initial resistance. Therefore， it is quite economic and reasonable to calculate the friction loss of paste-like slurry by using the stable value in long distance pipeline transportation.