The safe production in coal face is directly influenced by the low pressure sealing quality of hydraulic props.

单体液压支柱低压密封质量，直接影响到工作面安全生产。

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We adopt advanced four passages coal burner, improve the flame temperature, make a base of produce high quality low alkali clinker.

采用新型四通道煤粉燃烧器，提高火焰温度，为生产优质低碱熟料奠定了基础。

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Supply by China's coking coal market assumes a growth trend in recent years. But the capacity of high quality supply is insufficient, while the capacity of low quality supply is surplus.

近两年我国炼焦煤市场供应呈增长态势，但高质量供应能力不足，而低质量供应能力过剩。

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Last year it yielded 21 million tons of low-quality coal that was hauled by rail to power stations slaking the country's desperate hunger for energy.

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Moreover, much of the coal he bought from Burlington is low-quality lignite, a brownish fuel one step removed from peat, which can't be transported because it tends to spontaneously combust.

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