露天煤矿井工采空区火区磁法探测研究

Study on magnetic detection of fire area in underground gob in open-pit coal mine

由于早期的小煤窑不规范开采,露天煤矿内形成了许多不规则的采空区,残煤自燃造成的采空区高温易引起爆破器材自爆等危害。准确确定采空区位置及属性、采空区内火区位置,对规避露天矿安全风险十分重要。通过分析煤层着火机理和特征,提出利用磁法探测火区的物探方法。利用傅氏变换的褶积转换原理对火区的磁异常进行解释。用加拿大GSM-19T型质子磁力仪对安家岭露天煤矿首采区3 km 2的重点区域进行了火区探测,分析了首采区19个磁异常点,通过综合分析确定了疑似火区,与实际相符,钻孔验证了磁法探测火区的可靠性。

There were many irregular gobs caused by early mining of small coal mines in open-pit mine,the high temperature from residual coal spontaneous combustion in gob led to self-exploded of the explosive materials.It was important to accurately determine the location and attributes of gobs and the fire area for avoiding the risk of open-pit mine.Through analyzing the characteristics and mechanism of coal fire,geophysical magnetic method was put forward to detect the fire area.The magnetic anomaly was interpreted by using Fourier transform convolution transformation principle.The fire area detection was carried out for the 3 km 2 key area of the first mining area in Anjialing open-pit coal mine by using Canada GSM-9T type proton magnetometer,and 19 magnetic anomaly points in the first mining area were analyzed,and the suspected fire zones were determined by comprehensive analysis,the research results were consistent with the actual conditions,the reliability of magnetic detection of fire area was verified by drilling hole.