Study On The Occurrence Of Trace Elements Of Coal In Lincang Area,Yunnan Province

In order to find out the distribution and occurrence of trace elements in Lincang area,Yunnan Province,23 samples were collected.Among them,11 coal samples were collected in Mengto,including 8 coal samples and 3 gangue samples,12 coal samples are collected in Dazhai,including 6 coal samples and 6 coal cinder samples.The distribution,enrichment and occurrence of trace elements in Mengto and Dazhai coals were studied by means of sequential chemical extract?ICP-MS and XRD mineral analysis.The contents of more than 40 trace elements in coal were analyzed by sequential chemical extract and ICP-MS.Compared with the corresponding elements in Chinese and world coals,there are a few elements in Mengto and Dazhai coals,which are lower than those in Chinese and world coals.In the coal samples,some trace elements are enriched or significantly enriched in varying degrees,and the types of elements are slightly different.The REE content of rare earth elements in the samples of Mengto and Dazhai coal is higher than that of the Chinese coal and the world coal.The contents of rare earth elements in coal samples from Mengto and Dazhai are higher than those of Chinese and world coals,both LREE enrichment,all showed Ce anomalies,Eu negative anomalies.Sequential chemical extract data show that:In the six binding states of 15 elements,the water soluble and ion exchange state contents of the other elements are relatively low,except for Mn?Sr?Mo and Cd;The Carbonate binding State content of Mn?Co?Cu?Zn?V?Se?Be?Cd?Pb and Sr is relatively high;The ratio of pyrite binding state content of Cu?Zn?Tl and Ni is nearly 1/5;The proportion of organic binding states of Cr?As and Sb elements is higher,and some elements,such as Co?Li?Ti?Ni?Cu and Be are also taken up;After the last step of microwave digestion,a large number of elements such as Li?Ti?Cr?Sb and Tl were released,so the proportion of silicate binding states is very high,which obviously exists in the silicate bound state.The correlation analysis with ash can infer that : Co has organic affinity.The inorganic affinity of elements such as Li?V?Cr?Ni?Ga and Pb is obvious.Elements such as Be?Cu?Zn?Ge?As?Sr?Cd and Sb have both organic and inorganic affinity.XRD analysis shows that silicate minerals in coal samples are Kaolin,Illite,Chamosite,Albite and Anorthite.Oxide minerals include Quartz and Rutile,and sulfate minerals have Bassanite.The results of cluster analysis show that the 15 kinds of trace elements in coal samples can be divided into three categories,such as Li?Ga?V?Cu?Cd?Pb?Cr?Ni and Zn are adsorbed by clay minerals.The three elements of Ge,Sb and As are organic binding class.The three elements of Be,Co and Sr their occurrence states are complex in coal,and their occurrence of trace elements are temporarily difficult to distinguish for the time being,which needs further study.Factor analysis illustrates that In factor F1,Li?V?Cr?Ni?Cu?Zn?Ga?Cd and Pb have large factor loads so F1 is called inorganic binding state factor.In factor F2,Be?Co and Sr have large factor loads so F2 is called occurrence state uncertainty factor.In factor F3,Ge and Sb have large factor loads so F3 is called organic binding state factor ?.In factor F4,As have large factor loads so F4 is called the organic binding state factor ?.