高剪切调浆预处理对煤泥浮选动力学的影响研究

A study of the effect of preconditioning of pulp through high-intensity shearing on fine coal flotation kinetics

为明确高剪切调浆预处理对煤泥浮选动力学的影响,基于对煤样的可浮性和粒度组成分析,通过改变调浆转速和调浆时间,以浮选精煤产率、灰分和浮选速率常数等作为试验指标进行了实验室单元浮选试验。结果表明:高剪切调浆可有效提高浮选速度并缩短浮选时间;适度的调浆转速和调浆时间可同步提高浮选精煤的产率和浮选过程的选择性;对于可浮性较好的细粒煤需要的调浆时间较短,对于可浮性较差的细粒煤则需适度延长调浆时间;相较于经典一级浮选动力学模型,KELSALL分速动力学模型更符合细粒煤可浮性分布的非均一性特点。研究结果对提高现有煤泥浮选工艺效果具有一定帮助。

In order to gain an insight into the effect of pulp preconditioning through high-intensity shearing on flotation kinetics of fine coal,laboratory batch flotation experiment is made based on analysis of both flotability and size composition of samples.The experiment is made by varying pulp conditioning speed and time and with the yield and ash values of flotation concentrate and constant of flotation rate as assessment indicators.Results of experiment shows high-intensity shearing can lead to effective rise of flotation rate and cut of flotation time;a good fit between conditioning speed and time can further increase yield of concentrate and improve selectivity of flotation process;for treating easy-to-float fine coal,the pulp preconditioning time required is shorter while for treating the fine coal with a relatively poor floatability,the pulp preconditioning time needs to be appropriately extend;and compared to the classical first-order flotation kinetics model,the KELSALL separate-speed model is more consistent with the heterogeneous floatability distribution features of fine coal.The work made herein can help improve performance of fine coal flotation installations ion current use.