我国典型矿区石炭―二叠纪煤炭资源分布与煤质特征

Distribution and coal quality characteristics of Carboniferous Permian coal resources in China’s typical mining areas

我国石炭―二叠纪煤炭资源仅次于以动力煤为主的侏罗纪煤,但全国炼焦煤和无烟煤资源主要赋存于石炭―二叠纪煤系,因此剖析我国典型矿区石炭―二叠纪煤炭资源分布与煤质特征具有重要的现实意义。从不同地区石炭―二叠纪煤炭资源分布解析其区域分布特征,并重点阐述华北区山西省、华东区山东省、西南区贵州省六盘水煤田及西北区陕西省渭北煤田等典型矿区煤质特征。由综合分析可知:我国煤炭资源十分丰富、品种齐全但地区分布颇不均匀,如炼焦煤或动力煤的产量均以华北及西南地区居多;其中晚古生代早二叠世山西统煤多为陆相沉积的低硫煤,晚石炭世太原统煤多为海陆交互相形成的高硫煤,而山西统煤矿区是我国主要的优良炼焦煤产区,山西大同矿区的石炭纪煤储量超300亿t,洗选后成为优质洁净煤;华东区山东以兖州为代表的石炭―二叠纪煤的特点是上部山西统煤厚度大且灰分、硫分低,是优质的炼焦用煤和动力用煤;安徽省以两淮矿区为代表的早二叠世煤储量超370亿t,多为早二叠世的上部石盒子统及山西统的陆相沉积特低硫煤且以上部气煤和下部1/3焦煤为主,淮北煤因受岩浆热液变质的影响而使煤类从各类炼焦煤到无烟煤及天然焦均有;西南区以贵州为代表的晚二叠世煤系的储量也超500亿t,但多以浅海相沉积的高硫煤为主,储量和产量均较大的盘江肥煤、1/3焦煤洗选后均为优质的炼焦用煤;西北区陕西省渭北煤田石炭―二叠纪煤的变质程度较高,其中韩城矿区的瘦煤是西北地区的主要炼焦用煤。南方晚二叠世煤的硫分比北方石炭纪煤的硫分平均约高出1%,而北方同为海陆交互相的煤田在各地区的硫分分布通常存在不同程度的差异,说明无论是海陆交互相沉积或浅海陆相沉积的高硫煤,其硫分的高低主要取决于海水入侵的时间长短、海侵深度以及海水中硫酸盐的丰度。

China’s Carboniferous Permian coal resources are only lower to the Jurassic coal(which are mainly the power coal),but the national coking coal and anthracite resources are mainly located in the Carboniferous Permian coal measures,therefore,it is of great practical significance to analyze the distribution of Carboniferous Permian coal resources in typical mining areas in China,as well as its coal quality characteristics.Analysis of regional distribution characteristics from the distribution of Carboniferous Permian coal resources in different areas were done.The characteristics of Carboniferous Permian coal in typical mining areas such as Shanxi province in North China,Shandong province in East China,Liupanshui coalfield in Guizhou province in Southwest China and Weibei coalfield in Shaanxi province in Northwest China were focused.According to the comprehensive analysis,China is rich in coal resources with complete varieties,but the regional distribution is quite uneven.Coking coal or power coal are mostly distributed in North China and Southwest China,Shanxi coal in Late Paleozoic and Early Permian is mostly low sulfur coal deposited in continental facies,late Carboniferous Taiyuan coal is mostly high sulfur coal formed by the intersection of sea and land,Shanxi series coal is the main fine coking coal producing areas in China,the reserves of Carboniferous coal in Datong mining area,Shanxi province exceed 30 billion tons,the coal will become high-quality clean coal after washing.The characteristics of Carboniferous Permian coal represented by Yanzhou in East China are as below:the upper Shanxi coal is not only thick,but also low in ash and sulfur,it is high-quality coal for coking and power coal for coal chemical industry,gasification and power generation.The early Permian coal’s reserves exceed 37 billion tons in the Huainan and Huaibei mining area of Anhui province,which are continental sedimentary ultra-low sulfur coal of Early Permian upper Shihezi series and Shanxi series,the upper part is mainly gas coal and the lower is mainly 1/3 coking coal.Affected by the magmatic hydrothermal metamorphism,the Huaibei coal types range from coking coal to anthracite and natural coke;the reserves of coal measures in the Late Permian represented by Guizhou in Southwest China also exceed 50 billion tons,most of them are high sulfur coal deposited by sea land interaction and shallow sea facies.Panjiang fat coal,1/3 coking coal with large reserves and output are high-quality coking coal after washing.The metamorphic degree of Carboniferous Permian coal in Weibei coalfield,Shaanxi province,Northwest China is high,among them,the lean coal in Hancheng mining area is the main coking coal in Northwest China.The sulfur content of Late Permian coal in the south is about 1%higher than that of Carboniferous coal in the north,however,the northern part is a sea-land coal field,and the sulfur distribution in each region is usually different to varying degrees.It shows that whether it is high sulfur coal deposited by marine continental facies or shallow marine continental facies,the sulfur content mainly depends on the time of seawater intrusion,the depth of seawater intrusion and the abundance of sulfate in seawater.