【摘要】 菱镁矿尾矿煅烧后产生的轻烧镁粉对于酸性矿井水的处理具有效果好、操作条件良好、沉渣少等优点。通过对轻烧镁粉的成分分析可知,主要成分氧化镁占比高于90%。以山西某煤矿酸性矿井水为研究对象,对其进行常规水质分析可知,总铁浓度为230.01mg/L、亚铁离子浓度为66.98mg/L、pH值为3.24。采用轻烧镁粉进行酸性矿井水处理,设计正交实验,分析初始pH值、药剂投加量、曝气量、曝气时间等对处理效果的影响。实验结果表明,在投加轻烧镁粉量为0.50～1.00g/L时,酸性矿井水初始pH值可由3.15～3.31提高到6～9左右,缓冲性能较好,较容易控制投加量使pH值控制在6～9;轻烧镁粉处理酸性矿井水时三个主要因素的影响程度大小为:投加量>搅拌时间>搅拌速度,当轻烧镁粉投加量为0.85g/L、搅拌速度为400r/min、搅拌时间为12min时,实验效果较好;利用轻烧镁粉提高酸性矿井水的pH值到7.48时,曝气5min,曝气量为0.5m3/h,聚合氯化铝(PAC)投加量为10mg/L时,经处理矿井水中亚铁离子和总铁浓度可分别降至0.07mg/L和0.17mg/L,满足排放或回用水对总铁的要求,且改善了沉渣的沉降性能,大大缩短了沉降时间。更多还原

【Abstract】 Light-burned magnesium calcined from magnesite tailings is a good neutralizer for acid mine drainage,it has many advantages such as good removal effect,better operation conditions and less sediment.Using industrial composition analysis and XRD analysis,it could be known that the main composition magnesium oxide is higher than 90%.Taking the acid mine drainage from a coal mine in Shanxi as the research object,the general water quality analysis shows that total iron concentration is 230.01 mg/L,ferrous ion concentration is 66.98 mg/L、pH value is 3.24.Designing orthogonal experiment to treat acid mine drainage with light-burned magnesium,the effluence of initial pH value,neutralizer dosage,aeration rate and aeration time on removal effect are discussed respectively.The experimental results show that pH value of the acid mine drainage could be improved from initial 3.15-3.31 to 6-9 when the light-burned magnesium dosage is 0.50-1.00 g/L,the buffer property is well and it is easy to control the dosage to meet the requirements of pH value 6-9.The order of three influencing factors is dosage>stirring time>stirring speed,under the optimal scheme such as light-burned magnesium dosage 0.85 g/L,stirring speed 400 r/min and stirring time 12 min,the removal effect could be the best.To improve the sedimentation characteristic,when initial pH value raised to 7.48,aeration time 5 min,aeration rate 0.5 m3/h,polyaluminium chloride(PAC)dosage 10 mg/L,the ferrous ion and total iron concentration of the acid mine drainage could decreased to 0.07 mg/L and 0.17 mg/L respectively which could fulfill the requirement of discharge and reuse,meanwhile improve the settling performance and greatly shorten the sedimentation time.更多还原