【作者】 王明仕；

【导师】 郑宝山；

【作者基本信息】 中国科学院研究生院（地球化学研究所） ， 地球化学， 2005， 博士

【摘要】 砷作为Ⅰ类环境敏感元素,对生态环境和人体健康危害极大,由于砷污染所引发的环境问题已引起全球的广泛关注。我国是世界上砷中毒病区类型最全、危害最严重的国家之一。其中,80年代以来爆发于我国西南地区的燃煤型砷中毒危害更是严重。因此根据目前国内外对煤中砷的研究进展,在全国范围内有计划取样,研究中国煤中砷的含量、分布及其影响因素;探讨我国煤砷的赋存状态;选择大气中出现砷异常的西南地区,研究煤中砷脱洗机理;在室内模拟燃烧的基础上,研究燃煤砷排放机制。 通过此次研究,得出以下几点认识: 1、此次研究煤样中砷含量范围为0.24—70.83mg/kg;算术平均含量为6.43mg/kg,几何平均含量为3.96mg/kg。 2、在引入中国煤炭储量权重的基础上,得出煤中砷含量为5.28mg/kg,这是对中国开采的以及未开采煤炭作出的一个总的砷近似平均含量评价;在引入中国2001年煤炭产量的权重基础上,得出中国煤中砷含量为6.03mg/kg,这是对我国2001年煤炭砷平均含量的评价。由于高砷煤储量极微,对砷平均含量影响可以忽略不计。 3、与世界上大多数国家相比,中国煤中砷含量并不高。中国虽是世界上唯一发现燃煤型砷中毒的国家,但只是局部地区不正当使用特高砷煤的结果,不具有普遍性。 4、在地质时代上,此次研究的煤砷含量是按照第三纪、晚三叠世、中石炭世、早石炭世、早侏罗世、晚侏罗世、中侏罗世、晚二叠世、晚石炭世、早二叠世依次降低,在煤变质程度上,砷含量是按照褐煤、肥煤、长焰煤、瘦煤、更多还原

【Abstract】 Arsenic is ranked in Group I environment sensitive element, endangering to the ecosystem environment and human bodies healthily. The problems caused by arsenic contamination have been study widely. Endemic arsenic poisoning in China is widespread and locally very severe. It is very peculiar that the region of arsenism and the number of arsenism people caused by burning high arsenic coals. Based on the progress of study on the arsenic in coals, this dissertation mainly studies the arsenic content, its distribution in Chinese coals and control factors;discuss the mode of occurrence of arsenic in coals;study the arsenic reduction of coals mainly from southwest, which the air was polluted by arsenic;based on the simulative experiment of burning coals, study the mechanism of arsenic release. Based on the study, some conclusions can be drawn.1 、 Arsenic content in these coal samples range between 0.24 mg/kg to 71 mg/kg. The average mean of Arsenic is 6.43mg/kg and the geometric mean of Arsenic is 3.96 mg/kg.2、 Weighted by the reserves of the five main coal-cumulating areas, arsenic content is 5.28 mg/kg. This value is the arsenic content of whole coals of China, including the coalmine is mined and not mined;Weighted by the coal productions of 26 provinces in 2001, arsenic content is 6.0 mg/kg. This value is the arsenic content of whole coals that had mined;The influence of high arsenic coal from Guizhou Province can be ignored because the reserve is very small.3 、 Compared with the coals from around the world, the average arsenic contents arelower. The health problems in China derived from in coal (arsenism) are duelargely to poor local life-style practices in cooking and home heating with coalrather than to high arsenic contents in the coal.4、 The arsenic contents decreases with coal forming in the order: Tertiary > EarlyJurassic > Late Triassic > Late Jurassic > Middle Jurassic > Late Permian > Early Carboniferous > Middle Carboniferous > Late Carboniferous > Early Permian;The arsenic contents decreases with coal rank in the order: he>fei> chanyan > shou > pin > wuyan > jiao > qi. But it is meanlsss. The concentrations of arsenic in coals are affected by many factors. Source material, depositional environment, climatic and hydrologic conditions are the controlling factors of trace elements during the early stages of coal formation. However, rank, tectonic setting and geochemical nature of groundwater and country rocks have greater influence during the coalification stages. Most of these factors are regional. So it is difficult to found a relationship between arsenic contents of Chinese coals and coal-forming periods and coal ranks.5> There is not relationship between arsenic content and ash content in all coal samples. With the increase of ash content, arsenic content is not increase. When the ash content locate in 0 to 15%, the relationship between arsenic content and pyritic sulfur is very good;When the ash content range from 0 to 25%, the relationship between arsenic content and sulfate sulfur is found;There is good relationship between arsenic content and organic sulfur in high ash content coals. The arsenic probably presents mainly in organic matters.6> There is good relationship between arsenic content and sulfur, pyritic sulfur, sulfate sulfur, organic sulfur in all coal samples. With the increase of sulfur content, the number of high arsenic coal is increased too. When the sulfur content is lower than 0.5%, arsenic contents has no relativity with them;When the sulfur content locate in 0.5% to 1.5%, the relationship between arsenic content and pyritic sulfur, sulfate sulfur, sulfur is good;When the sulfur content is higher than 1.5%, only the relationship between arsenic content and sulfur is found. In lower sulfur and high sulfur coals, arsenic maybe presents in form of various matters. In other coals? although the mode of arsenic is very complicated, arsenic mainly presents in form of sulfur.7^ Physical coal cleaning techniques are effective in arsenic, ash and sulfur reduction. When arsenic content lower than 5.5 mg/kg, arsenic will mainly or wholly occursin organic matter and occurs in mineral which be enwrapped by organic matter, So it is difficult to remove arsenic and arsenic will enrich in washing coals. When arsenic content higher than 5.5 mg/kg, arsenic will mainly in mineral. The arsenic of coal can be wiped off easily.8> The volatility of arsenic increases along with the temperature. During 800 °C to 1200°C, the volatility of arsenic change greatly.更多还原