medium rank anthracite

例句：

1. 1. The company uses medium-grade anthracite for its furnaces.
   该公司使用中等品位的无烟煤来炼铁。
2. 2. The coal mine produces medium-grade anthracite for the local market.
   该煤矿生产中等品位的无烟煤供应当地市场。
3. 3. The quality of medium-grade anthracite is highly sought after in the industry.
   中等品位的无烟煤在业界非常受欢迎，质量要求很高。