铅锌尾矿免烧吸附砖的制备与研究

为了提供一种铅锌尾矿用于制备建材的可行方法，利用铅锌尾矿、硅微粉和水泥制备免烧砖，研究了硅微粉、水泥等胶结物对重金属离子的固化行为，并探究该免烧砖作为重金属离子吸附剂的可能性.采用X射线荧光光谱仪、电感耦合等离子发射光谱仪及扫描电子显微镜研究了免烧砖在不同条件(pH、吸附时间及初始浓度)对废水中Pb2+的吸附行为.结果表明：铅锌尾矿掺量为70%，硅微粉为20%，制备的免烧砖强度符合MU20等级；水化产物与尾矿中的重金属形成沉淀物，有效固化重金属离子；同时，该免烧砖可作为优良的吸附基体，对废水中的铅具有高效的去除能力，在pH为5、吸附时间为90 min、含铅废水初始质量浓度50 mg/L时，免烧砖对Pb2+的吸附效率达到96%.因此，适量的硅微粉及水泥可以提高尾矿免烧砖对Pb2+的吸附，该免烧砖有望用在江河堤坝等场合.
To develop a rational strategy involving the consolidation of Pb-Zn mine tailings to produce the building materials, Pb-Zn mine tailings, together with different amounts of silica fume and cement, were used to fabricate the unburned bricks. The influences of silica fume and cement on the consolidation of heavy metal ions, were investigated. The adsorption behaviors unburned bricks toward the Pb2+ in wastewater under different conditions (pH, contact time, and initial concentration) was also studied by using X-ray fluorescence spectrometer, inductively coupled lasma atomic emission spectrometer, and scanning electron microscope. The results show that MU20 unburned bricks can be achieved, when the content of Pb-Zn mine tailing and silica fume are 70% and 20%, respectively. Meanwhile, the hydration products can effectively immobilize the heavy metal ions by forming the sediment with them. Therefore, the unburned bricks have efficient removal ability toward the Pb in wastewater, and can be used as adsorption substrates. The Pb2+ adsorption efficiency can reach up to 96%, when the pH, contact time, and initial concentration are 5, 90 min, and 50 mg/L, respectively. Therefore, a proper amount of silica powder and cement can improve the Pb2+ adsorption ability of unburned bricks made from tailings, enabling them promising for applicationsin river banks.