Geochemical Characteristics And Its Significance Of Lithium Isotope Of Li-bearing Coal From The Guanbanwusu Mine

The enrichment of Li in Chinese coals has been found to be of high economic value.Therefore,the study of Li in coal has become another important topic in the field of coal science.In the field of geochemistry,lithium isotope,which is deemed as an outstanding indicator element,has been used in many fields to explain many geochemical phenomena,and has obtained rich achievements.Hence,the study of lithium isotope in coal will help to clarify the source of Li in coal.At present,there is no study on lithium isotope of coal in our country.If we want to apply this effective means to solve the geological problems related to coal,the most important thing is the formation of Li isotope analysis method.In this study,we first discussed the suitable method for the pretreatment of Li isotopes with three kinds of coal standard materials on Li(SARM18?SARM19?SARM20),after that accurate determination of lithium isotopes would be carried out.So then,for the Li isotopes in coal,the separation and determination method had been established.Then the lithium isotopes of Guanbanwusu 6# coal samples were obtained and Li isotopic characteristics were analyzed,at the same time,combining with the study of partings in seams and provenance granite rocks.We draw several preliminary conclusions:(1)Using the microwave digestion technique,with HNO3-HF acid system,coal samples could be digested well,for the three kinds of coal standard materials,the content of Li element measured is consistent with the recommended value in the range of error.(2)Treating 0.5 N nitric acid as eluent,AG 50W-X12 cation exchange resin was used to complete the process of once column purification,after that,the ratio of sodium to lithium was less than 1 and the lithium isotope of coal could be effectively separated and enriched.(3)The lithium isotope of coal samples from Guanbanwusu 6# coal is between +6.03‰ and +8.49‰,with an average value of +7.04‰.The results show that,the lithium separation and determination method established in this study,could meet the needs of Li isotope analysis in coal.It is concluded that the high content of Li in 6# coal mainly exists in kaolinite.This provides a basis for further study of the source of lithium in coal.