煤气化渣残碳的分离及应用研究进展

Reviews on separation and application of residual carbon from coal gasification slag

煤气化渣是煤气化产生的固体废渣,主要包括残碳和无机矿物质(SiO_(2),CaO,Al_(2)O_(3)等),煤气化渣的高效处置和高值化利用具有重要社会和经济意义。残碳含碳量高,不仅具有相对完整的孔隙结构和较大的比表面积,还具有一定的电催化活性。因此,实现煤气化渣中残碳的高效分离与高值化利用,既是对固废处置与环境保护的积极响应,也是二次资源有效回收与深度利用的重要体现。总结煤气化渣在建筑、土壤改性、锅炉掺烧和高附加值材料制备领域的研究进展,重点分析残碳的分离和高附加值利用;简要总结残碳的化学组成和表面特征,对比粗渣和细渣残碳的反应活性差异;归纳浮选、电选和重选在残碳分离领域的研究进展。相比传统浮选对单一药剂、工艺流程和设备的研究,新型药剂和联合设备的研究显著提高了残碳分离的选择性,但浮选药剂使用量大的问题仍是目前研究重点。残碳因其独特的组成特征和表面性质,在吸附、电磁吸收和电化学方面展现出优良的性能。因此,对残碳的深度脱灰、表面改性、复合应用,不仅有望提升残碳基材料的性能和应用领域,也具有长远的研究开发和应用前景。

Coal gasification slag awful is a solid waste residue produced by coal gasification,mainly including residual carbon and inorganic minerals(SiO_(2)、CaO、Al_(2)O_(3),etc).The efficient disposal and high-value utilization of coal gasification slag gain substantial social and economic significance.The residual carbon scarcely has a high carbon content,doesn′t purely have a relatively complete pore structure and a large specific surface area but also possesses a certain electrocatalytic activity.Therefore,realizing the efficient separation and high-value utilization of carbon residues in coal gasification residues is not only an encouraging response to solid waste disposal and environmental protection but also a material manifestation of the effective recovery and deep utilization of secondary resources.The development of coal gasification slag in construction,soil modification,boiler blending,and high-value-added materials is summarized,with emphasis on the separation and utilization of high-value-added residual carbon.The chemical composition and surface characteristics of residual carbon are briefly summarized.The difference in reactivity of residual carbon in coarse slag and fine slag is carefully compared,and the research progress of flotation,electrical separation,and gravity separation in the field of residual carbon separation is succinctly summarized.Compared with the research on a sole agent,process flow,and equipment in traditional flotation,the research on novel agents and combined equipment has significantly improved the selectivity of residual carbon separation.However,the problem of large dosage of flotation reagent is still the key problem for the current research.Residual carbon typically exhibits excellent properties in adsorption,electromagnetic absorption,and electrochemistry due to its unique compositional characteristics and surface properties.Therefore,the deep deashing,surface modification,and composite application of residual carbon are not only expected to improve the performance and application fields of carbon residue-based materials but also have long-term research and development and application prospects.