ABSTRACT

Oil agglomeration is an effective way to demineralize high ash coals as compared to froth flotation and density gradient separation. In this process, the choice of bridging liquid is critical with respect to economics and efficiency. Herein, we report turpentine oil as a potential bridging liquid which is demonstrably efficient in coal demineralization at lower concentration (10 vol.%) compared to literature (20–25 vol.%) without inclusion of surfactants, which enhances economic viability. We chose two high ash coals of Indian origin, with 26% and 34% ash. A varied range of particle sizes were examined along with pH, type of electrolytes, agitation conditions and oil dosages. Both coals (200 mesh) demonstrated approximately 50% reduction in ash content at pH 7, which is an improvement over previously known reports on Indian coals. Chemical structural resemblance between primary components of turpentine oil and predominant π-delocalized aromatic structure of high rank coals could be the reason behind improved adsorption of oil. Our work thus demonstrated the utilization of a natural oil which can be dried easily, readily available and cheap in a significantly demanding commercial process like coal beneficiation. This is expected to deliver a substantial performance and cost improvement over incumbent known bridging liquids.

摘要

与泡沫浮选和密度梯度分离相比，油团聚法是高灰分煤脱盐的有效方法。在此过程中，桥接液的选择对于经济性和效率至关重要。在这里，我们报告松节油作为一种潜在的桥接液体，与文献（20-25 vol.%）相比，它在较低浓度（10 vol.%）下在煤脱盐中明显有效，而不含表面活性剂，从而提高了经济可行性。我们选择了两种印度产的高灰分煤，灰分分别为 26% 和 34%。检查了不同范围的粒径以及 pH 值、电解质类型、搅拌条件和油剂量。两种煤（200 目）在 pH 值为 7 时都显示出灰分含量降低了约 50%，这比之前已知的印度煤报告有所改进。高级煤的π-离域芳烃结构可能是改善油吸附的原因。因此，我们的工作证明了在煤选矿等要求极高的商业过程中可以轻松干燥、易于获得且价格低廉的天然油的利用。与现有已知的桥接液相比，这有望带来显着的性能和成本改进。