部分进口煤炭中氟元素的含量特征及赋存形态

Content characteristics and occurrence status of fluorine in some imported coals

为加强对进口高氟煤炭的管理,评价进口煤炭中氟元素的环境迁入风险,采用高温燃烧水解-氟离子选择电极法对唐山港口岸进口的225批煤炭中的氟含量进行了测定;用稳健统计描述了其整体含量水平,并根据我国煤炭行业分级标准及富集比进行了质量评价;用相关分析对氟的赋存形态进行了分析。结果表明:唐山港口进口煤炭中的氟含量可描述为(137±24)mg/kg;按我国煤炭行业标准进行质量分级评价,唐山港口进口的68%的朝鲜煤、62%的加拿大煤属于中氟煤,氟含量算术平均值高于中国煤、世界煤,其迁入风险值得关注;进口朝鲜煤中氟含量与灰分、全硫含量呈中度正相关、与磷含量呈微弱正相关,推断氟的赋存形态主要为无机硫结合态(硫化物和硫酸盐)和黏土矿物,少部分可能存在于磷酸盐类矿物及有机硫结合态中;进口澳大利亚煤中氟含量与灰分、全硫含量相关性不显著,与磷含量呈低度正相关,推断氟的赋存形态比较复杂,可能部分以磷酸盐结合态存在,赋存于氟磷灰石、磷铝钙石中;进口加拿大煤中氟含量与灰分、全硫含量相关性不显著,与磷含量的相关性系数为0.763,显著性水平为0.01,表明二者呈高度正相关,具有显著性,说明二者有很强的伴生关系,推断氟主要以磷酸盐结合态存在,赋存于氟磷灰石、磷铝钙石中。

In order to strengthen the management of imported high fluoride coals and evaluate the environment immigration risk of fluorine element in imported coals,the concentrations of fluorine element in the imported 225 batch coals of Tangshan port were determined using high temperature burning hydrolysis-ion selective electrode method.The overall content level of fluorine were described by robust statistics.The quality were evaluated by the national coal classification standard and enrichment ratio.The relevant analysis were used to study the occurrence status characteristics of fluorine.The results showed that the fluorine in coals of Jingtanggang port were（ 137±24） mg/kg.According to Chinese coal industry standards for quality grading evaluation,68% of Korea coal and 62% of Canada coals were medium fluorine coal.The arithmetic average of fluorine of these two coals were higher than those of Chinese coal and the world’s coal.So their environment immigration risk should be noticed.Fluorine content in Korea coals was moderate positive correlation with the ash,total sulfur and it was weak positive correlation with the phosphorus.The correlation analysis of ash,sulfur,phosphorus and fluorine content in Korea coal showed that the occurrence modes of fluorine were mainly inorganic sulfur bound（ sulfides and sulfates） and clay minerals form. A small part of fluorine in Korea coals might be present in phosphate minerals and organic sulfur in bound.The correlation of ash,total sulfur and fluorine in Australian coals was not significant,and the correlation phosphorus and fluorine was low. The correlation analysis of ash,sulfur,phosphorus and fluorine content in Australian coals showed that the occurrence modes of fluorine were complex,it might be phosphate bound partly and occurred in the fluorapatite and aluminum calcium phosphate rock. The correlation of ash,total sulfur and fluorine in Canada coals was not significant,and the correlation coefficient of phosphorus content was 0. 763,significance level was 0. 01.It indicated that fluorine and phosphorus had a strong associated relationship,and it inferred that fluorine was mainly in the phosphorus bound,occurred in the fluorapatite and aluminum calcium phosphorus rock.