Sintering technology and properties of permeable bricks prepared using manganese tailings

Abstract

The development of manganese mines has prospered with the rapid development of China’s economy. Manganese tailings havenot been reasonably and effectively studied due to capital constraints and backward technology, directly leading to ecologicaldamage, environmental pollution, fast urban development, and incomplete city construction. In China, these phenomena haveresulted in long-term waterlogging in the southern cities and water shortages in the northern cities. Permeable bricks, whichare prepared through the sintering of manganese tailings, serve as materials for the construction of sponge cities, easeenvironmental pressure to a certain extent, and contribute to ecological restoration. In this paper, manganese tailings, kaolin,and calcium oxide are used as main raw material, binder, and sintering aid, respectively. The materials are mixed at a certainratio and subjected to ball milling, sieving, batching, and foaming. The slurry is molded and sintered at a high temperatureto obtain permeable bricks that perform well in terms of porosity, compressive strength, and water permeability. Based on theperformance of permeable bricks prepared using manganese tailings, the optimal firing system for preparing the porousmaterials of manganese tailings is as follows: sintering temperature, 1,030 oC; heating rate, 6 oC/min; and holding time, 1 h. The permeable brick prepared using manganese tailings has porosity, shrinkage, compressive strength, and water permeabilityof about 71%, 8.7%, 2.68 MPa, and 2.2 × 10−2 cm/s, respectively.