重庆煤中稀土元素的地球化学特征研究

Research on Geochemistry of Rare Earth Elements in Coals from Chongqing, China

研究了重庆地区各成煤时代煤和石煤中稀土元素含量、分布特征,赋存状态和分配模式.结果表明,重庆地区煤中稀土元素的含量高于全国煤及世界煤中的稀土元素均值;虽然重庆煤中轻稀土元素含量大于重稀土元素含量,但轻重稀土元素之比(L/H)的算术均值仅为5.11.稀土元素的含量随成煤时代由老至新,有由高变低的趋势,以震旦纪石煤中REE含量最高,早侏罗世煤中REE含量最低.在各成煤时代中的烟煤和无烟煤中稀土元素的含量接近,表明煤的变质作用对煤中稀土元素含量的影响较小;重庆煤中稀土元素以硅铝化合物结合态为主.

The content of rare earth elements (REE) as well as their occurrence and distribution patterns in coals and stone coals of different geological periods from Chongqing area was studied. The results show that the REE content in coals from Chongqing is much higher than the average value of the ordinary coals in China as well as the whole world. Although the content of light rare earth elements (LREE) is higher than that of heavy ones (HREE), the ratio of LREE to HREE is as low as 5.11. The REE content decreases with the coal-forming period from old to new. The REE content in Sinian stone coals is the highest, but it is the lowest in Early Jurassic coals. The similarity of REE contents in bituminous coals and anthracite show that the metamorphism slightly influences the REE content in coal. In addition, silicate association is the dominant occurrence of REEs in coals from Chongqing.