Abstract：
A specific mortar material (abbreviated as RFT) was designed from industrial solid wastes, such as red mud, fly ash, and iron tailings. It was mainly developed for 3D printing in this work. Mechanical properties, microstructure and heavy metal leaching properties were discussed. The RFT composed of 15% red mud, 45% iron tailings, 9% fly ash, 30% cement, and 1% FDN water reducing agent attained good mechanical properties. Hydration products including Ca(OH)2, ettringite and C-S-H gel were found in RFT through SEM observation. Iron tailings mainly acted as fine aggregates in RFT, and they were wrapped by the C-S-H gels, producing a strong bonding effect between aggregates and cementitious matrix. The leaching toxicity test results proved that the developed RFT mortar materials were environmentally acceptable. Finally, RFT was subjected to a 3D printing test to verify its feasibility as 3D printable construction material.
摘要：
一种特定的砂浆材料（缩写为RFT）是由工业固体废物设计的，比如红泥，粉煤灰,和铁尾矿。在这项工作中，它主要是为3D打印而开发的。机械性能,微观结构和重金属浸出性能进行了讨论。由15%赤泥组成的RFT,45%铁尾矿,9%粉煤灰，30%水泥,1%FDN减水剂获得了良好的力学性能。通过SEM观察，在RFT中发现了Ca（OH）2，钙矾石和C-S-H凝胶的水合产物。铁尾矿在RFT中主要作为细骨料，它们被C-S-H凝胶包裹，在骨料和水泥基之间产生强烈的粘结作用。浸出毒性测试结果证明，开发的RFT砂浆材料是环境可接受的。最后,对RFT进行3D打印测试，以验证其作为3D打印建筑材料的可行性。
