煤热解中微量元素迁移规律的再探索

Re-exploration on the law of trace elements migration during the pyrolysis of coal

为探寻煤热解过程中微量元素活动的普适规律,对河南义马煤和山东兖州煤在不同温度下热解时煤的微量元素迁移规律进行了再探索。结果发现:在非自然的人工煤热解过程中,煤中微量元素的挥发率和富集率变化趋势总体上符合元素周期律。并据此,在1 000℃以下的范围内,对河南义马煤的难挥发元素分为3类:第1类,为最难挥发的元素,有V,Cr,Co,Cu,Ga,Zr,La,Pr,Nd,Tm等10个元素;第2类,为难挥发元素,有稀土元素Sm,Eu,Gd,Tb,Dy,Ho,Ta等7个元素;第3类,为较难挥发的元素,有Li,Ge,Nb,Mo,Er等5个元素。在煤热解过程中,镧系元素的转化总体上也遵从镧系元素地球化学效应。

The re-exploration about the law of trace elements migration during pyrolysis of coal samples,which were collected from Yima mining and Yanzhou,mining districts,were done by authors for studying pervasive law of trace element activity in this processes. It was discovered that in general,change trend on evaporation rate and enrichment rate of trace elements in coal,during the pyrolysis of coal,are comply with periodic law of elements. For this reason,difficult volatile elements in coal from Yima mining were divided into three categories within 1 000 ℃. V,Cr,Co,Cu,Ga,Zr,La,Pr,Nd,Tm are most difficult elements in volatile which belongs to the first sort one; Second sort of elements,there are 7 elements from Sm to Ho in REE and Ta,are more difficult ones; the third sorts of elements are relatively difficult ones in which there are Li,Ge,Nb,Mo,Er. In pyrolysis of coal,transformation of the lanthanide obeys geochemical effect of rare earth elements( REE).