ABSTRACT

Plastic waste of different origin has been proposed and used as an additive in coal blends in metallurgical coke production for trace amounts for about two decades. Previous studies have suggested that high-density polyethylene (HDPE) can be used as an additive in coking blends for small quantities (2–3 wt% of the blend) without considerably damaging the strength properties of coke. Here, one HDPE-free and five HDPE-bearing laboratory-made cokes were produced and tested for their compressive cold strength and compressive hot strength. The temperature in the hot compressive strength tests was 1,700°C, corresponding to the temperature of the blast furnace bosh area near the tuyeres. The results showed that the trend of the cold compressive strength of coke increased as the amount of HDPE in the coking blend was increased from 0 wt% to 5 wt%. In hot compressive strength tests, cokes containing 3 wt% to 5 wt% of HDPE in the raw material blend showed non-breaking behavior, while the reference coke samples were crushed to pieces in the tests. Image analysis performed for the microscopic images of all experimental coke types revealed that the high number and area percentage of large pores impacted negatively on compressive strength of coke.

摘要

大约二十年来，已经提出不同来源的塑料废料并将其用作冶金焦生产中微量混煤的添加剂。先前的研究表明，高密度聚乙烯 (HDPE) 可用作少量焦化混合物的添加剂（占混合物的 2–3 wt%），而不会显着损害焦炭的强度特性。在这里，生产了一种不含 HDPE 和五种含有 HDPE 的实验室制造焦炭，并测试了它们的抗压冷强度和抗压热强度。热压强度试验温度为1700℃，对应风口附近高炉炉腹区的温度。结果表明，随着焦化混合物中 HDPE 的含量从 0 wt% 增加到 5 wt%，焦炭的冷压强度有增加的趋势。在热压强度测试中，原料混合物中含有 3 wt% 至 5 wt% HDPE 的焦炭表现出不破裂行为，而参考焦炭样品在测试中被压碎。对所有实验焦炭类型的显微图像进行的图像分析表明，大孔的数量和面积百分比高对焦炭的抗压强度产生负面影响。