The combustion characters of petroleum coke were between those of soft coal and anthracite .

石油焦的燃烧特性处于烟煤和无烟煤之间。

There are many kinds of forms of gas discharge, but the main form is soft coal seam gas discharge.

瓦斯抽放形式有多种，本煤层抽放是其主要形式。

However, with the extension of mining depth, the distribution of soft coal seam has been expanding.

然而，随着矿井开采范围的延深，松软煤层的分布范围呈不断扩展趋势。

It has good coal adaptability and is especially suitable for soft coal that has high tar content and big gas output.

煤种适应性强，尤其适用于焦油含量高，产气量大的烟煤。

The II3123 face is a light type caving face of three-soft coal seam. the roof is cracked, sloughing and roof fall often occur.

前言： 石台煤矿II3123工作面为“三软”煤层轻放工作面，顶板破碎易掉，片帮、冒顶时常发生。