黑岱沟矿区矸石的高岭土质量分数高达70%。从煤系资源综合利用的角度出发，利用离心选矿法脱除以铁钛类为主的高密度致色杂质，提高煤系高岭土的煅烧白度。采用Design Expert进行四因素三水平的Box-Behnken正交试验设计；探究离心转速、入料速度、入料浓度和入料时间对煅烧白度及精矿产率的影响，拟合二次方程关系模型；给出煅烧白度及精矿产率与显著因素之间的响应曲面图，发现煅烧白度主要受离心转速影响，随离心转速的增加，煅烧白度先升高后降低，而精矿产率主要受入料时间影响，随入料时间的延长，精矿产率线性增加；最终结合Design Expert模拟结果，探究最佳离心增白试验条件，即离心转速为800 r/min，入料速度为8.4 L/min，入料浓度20%，入料时间100 s时，得到最佳高岭土煅烧白度（78.80%）和精矿产率（86.31%）。

The kaolin content of gangue in the Heidaigou ming area is as high as 70%. Herein, from the perspective of comprehensive utilization of coal resources, in order to improve the calcination whiteness of coal-derived kaolin, a method of centrifugal for separation was used to remove the chromogenic impurities with high-density. To achieve this, this work performed orthogonal design by Design Expert and adopted the Box-Behnken model. Consequently, the influence of centrifugal speed, feeding rate, feeding concentration and feeding time on the calcination whiteness and concentrate yield was explored and the quadratic equation relationship model was fitted. Further, the response surface plots of calcination whiteness and concentrate yield with significant factors were given. It was found that the whiteness of calcination was mainly affected by the centrifugal speed. With the increase of the rotation speed of the drum, the whiteness of the calcination first increased and then decreased. The yield of concentrate was mainly affected by the feeding time. With the extension of feeding time, the yield of concentrate increased linearly. Finally, combined with the simulation results of Design Expert, the optimal centrifugal separation conditions were analyzed and explored. When the centrifugal speed is 800 r/min, feeding rate is 8.4 L/min, feeding concentration is 20%, and feeding time is 100 s, the optimal calcination whiteness (78.80%) and concentrate yield (86.31%) of kaolin can be obtained.

0 引言

1 试验

   1.1 煤样分析

   1.2 试验装置

   1.3 原料制备与试验指标检测

2 Box-Behnken正交试验

   2.1 正交试验设计

   2.2 方差分析与多模型拟合

   2.3 二次方程模型方差分析和置信度分析

3 试验结果讨论

   3.1 煅烧白度模型验证及响应面分析

   3.2 精矿产率模型验证及响应面分析

   3.3 试验结果优化与验证

4 结论