Chemical Engineering Department, Louisiana Tech University, 600 Dan Reneau Drive, Ruston, LA 71272, USA.
Trenchless Technology Center (TTC), Louisiana Tech University, Ruston, LA 71272, USA.
Waste Manag. 2021 May 1;126:728-736. doi: 10.1016/j.wasman.2021.04.008. Epub 2021 Apr 18.
Recycling wastes back into a manufacturing process, or into a separate product, is an important challenge. The primary aim of this work was to combine wastes from the steel industry, the galvanizing industry and the pulp and paper industry to form two new useful products. The steel industry generates the wastes red dust, mill scale, blast oxygen furnace slag and iron ore fines. Galvanizing industrial facilities dispose of sulfuric acid contaminated with iron. The pulp and paper industry produces the byproduct black liquor, which is high in lignin. Inserting these wastes as resources into the steel industry, or as stand-alone products, could reduce the need for virgin materials. The main methodology of the work was three-fold. First, spent sulfuric acid was used to precipitate the lignin from black liquor. Second, this lignin was combined with steel industry wastes and geopolymeric materials to make briquettes, a sustainable reducing material for steelmaking furnaces. Briquettes contained red dust, mill scale, blast oxygen furnace slag, iron ore fines and lignin precipitated from black liquor with spent sulfuric acid. Key research findings of compressive strength and weight loss testing showed the briquettes to be feasible for steel-making furnace use. Third, these steel industry wastes were investigated as a partial fly ash replacement in geopolymers. Main research findings were that compared to the control geopolymer, these geopolymer samples improved compressive strength and gave similar workability. Thus, the investigated wastes have the potential to both increase recycling in the steel industry and to improve geopolymeric products.
将废物回收再利用到制造过程中，或者制成单独的产品，是一项重要的挑战。这项工作的主要目的是将钢铁工业、镀锌工业和纸浆与造纸工业的废物结合起来，形成两种新的有用产品。钢铁工业产生的废物有红尘、轧钢厂氧化皮、高炉渣和铁矿石细粉。镀锌工业设施处理含铁的硫酸污染。纸浆与造纸工业生产的副产品是黑液，其中含有大量木质素。将这些废物作为资源插入钢铁工业，或作为独立的产品，可以减少对原始材料的需求。这项工作的主要方法有三种。首先，用过的硫酸被用来从黑液中沉淀木质素。其次，将这种木质素与钢铁工业废物和地质聚合物材料结合起来，制成用于炼钢炉的可持续还原材料——煤球。煤球包含红尘、轧钢厂氧化皮、高炉渣、铁矿石细粉和用过的硫酸沉淀的黑液木质素。抗压强度和重量损失测试的关键研究结果表明，煤球适合用于炼钢炉。第三，研究了这些钢铁工业废物作为部分粉煤灰替代品在地质聚合物中的应用。主要研究结果表明，与对照地质聚合物相比，这些地质聚合物样品提高了抗压强度，且具有相似的可加工性。因此，所研究的废物有可能增加钢铁工业的回收利用，并改善地质聚合物产品。
