Emission Check: Replacing Coke With Anthracite Fines
To produce coke, bituminous coal must be heated to 1,652-1,832F (900-1,000C) for 28-30 hours, consuming 15-20% of the raw coal’s energy and releasing an equivalent amount of its carbon as greenhouse gases and VOCs. Tech- nological advances may reduce or eliminate such emissions by either partially or completely replacing coke. A second proposed technology capitalizes on the exhausted cupola heat to yield a lignite-based activated carbon. Tis lignite can absorb VOC emissions, and the loaded lignite can be used in green sand molds in place of bituminous seacoal and as feedstock for a coke replacement. Te first of these options is to use waste anthracite fines
formed into bricks to partially replace coke and ferrosilicon (see Figure 2). Tese bricks use binder materials made from collagen, silicon/silicate and other biomaterials to match the strength and energy value of coke. Te anthracite fines and biomaterials used in these bricks have limited value as low-grade fuel or are otherwise waste. Also, the bricks include silicon, which is charged into the cupola to provide silicon to the cast iron and control the cupola’s redox level. Tese bricks include 85% anthracite fines, 10% biomateri- als and 5% silicon/silicate. Te binders become thermally conditioned within the cupola to provide strength from ambient temperature to iron melting temperature. Tese bricks have 35-40% higher BTU content per volume than coke and burn as quickly.
合物。随着科技的进步，部分或全部代替焦炭的使 用，将减少或消除类似的排放产生。另一项提出的 技术，是利用冲天炉排放的余热制取褐煤活性炭。 褐煤可以吸收排放的挥发性有机化合物，吸收了有 机化合物的褐煤可以用于粘土湿型砂，代替烟煤 粉，也可以作为制造焦炭替代物的源料。 第一个选择是用废弃的无烟煤细粒制成的团块， 以部分代替焦炭和硅铁合金（见图2）。这种团块 用胶原、硅/硅酸盐和其他生物材料制成的粘结剂， 其强度和热值与焦炭相近。这种团块中的无烟煤细 粒和生物材料的价值有限，价格与低档次燃料或其 他废料相当。而且，这种团块中含有硅，作为冲天 炉的炉料，可为铸铁提供硅元素，并控制冲天炉的 氧化还原反应水平。这种团块含有85%的无烟煤细 粒，10%的生物材料和5%的硅/硅酸盐。粘结剂可以 适应冲天炉内的受热条件，使团块从室温到熔铁温 度都有强度。团块单位体积产生的BTU热量比焦炭高 35-40%，燃烧速度大致相同。
这种无烟煤团块以前曾大规模地用于宾夕法尼亚 州的一家用冲天炉熔炼的工厂。该试验在半天时间 内使用4吨生物材料制成的团块，其中25%作为焦
Fig. 2. The diagram shows the process of creating anthracite fines bricks, which partially replaced coke.
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FOUNDRY-PLANET.COM | MODERN CASTING | CHINA FOUNDRY ASSOCIATION June 2014
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