金川膏体管道输送特性环管试验与减阻技术

摘要

Pipe⁃loop testing was conducted for the paste backfilling system in Jinchuan Mine, for investigating the pump⁃pressured pipeline transportation characteristics. The pipeline transportation drag was tested for 2 kinds of total tailings paste backfill, one without cement and another with cement⁃sand ratio at 1∶4. Results show that pipeline drags of 10, 19 and 33 kPa/m were measured for the paste with mass concentration of 72.2%, 75.8% and 78.9%, respectively, at an average flowing velocity of 1.2 m/s, while the pipeline drag was 12.5 kPa/m for the cemented total tailings paste with cement⁃sand ratio at 1∶4 and mass concentration of 78.9%. With 3 kinds of mixed aggregate, which was prepared with total tailings and rod mill sand at the ratio of 6∶4, 5∶5 and 4∶6, respectively, tests were conducted to measure their pipeline transportation drag. It is showed that in order to obtain an average flowing velocity of 1. 2 m/s, with the pipeline drag less than 15 kPa/m, those 3 kinds of mixed paste to be transported shall be prepared with the mass concentration at 80%, 79% and 81% respectively. It is also found that 1% difference in the mass concentration can lead to the difference in drag loss ranging 50% ~100%, indicating the pipeline transportation drag of paste extremely susceptible to the concentration. This 3 kinds of mixed paste all have a slump more than 15 cm, meeting the requirement for pumping transportation. The drag reduction testing showed that the drag reduction efficiency for the paste pipeline transportation reached 68. 6% and the corresponding slump of past was up to 88% after the addition of YNB type pumping agent containing 1.5% cement.%在金川矿山膏体充填系统开展了泵压管道输送特性环管试验，针对不添加水泥和胶砂比为1∶4的2种全尾砂膏体进行了管道输送阻力试验。结果表明，膏体输送平均流速为1．2 m／s时，质量浓度为72．2％，75．8％和78．9％的管输阻力分别为10，19和33 kPa／m；胶砂比为1∶4、质量浓度为78．9％的胶结全尾砂膏体管输阻力为12．5 kPa／m。针对全尾砂与棒磨砂配比分别为6∶4、5∶5和4∶6的3种混合骨料，开展了膏体管输阻力试验，结果表明，在平均流速为1．2 m／s、管输阻力不大于15 kPa／m的条件下，3种混合骨料膏体可泵送膏体质量浓度分别为80％，79％和81％；试验结果还显示，质量浓度相差1％，管道阻力损失相差50％～100％，可见膏体管输阻力对浓度变化十分敏感；3种配比的混合骨料膏体塌落度大于15 cm，满足膏体泵压输送要求。膏体减阻试验结果揭示，添加水泥材料1．5％的YNB型泵送剂，膏体管输减阻效率可达到68．6％，相应的膏体塌落度增加88％。