Study on preparation of eco-friendly autoclaved aerated concrete from low silicon and high iron ore tailings

Abstract

Iron ore tailings (IOT) are the industrial solid waste from iron separation. With the rapid development of the steel industry, the proportion of the IOT in the industrial solid waste industry has been also increasing. There are more than 400 large-scale tailings dams in China, among which the tailings impoundment from metal mines reaches over 6 billion tons. At present, tailings are still growing at a rate of 300 million tons per year, with the IOT accounting for 1/3 of them Therefore, whether it is used as a secondary resource or a source of pollution, the IOT have been one of the key research topics of mining enterprises, universities and research institutes. The comprehensive utilization of tailings in China mainly focuses on the extraction of valuable elements In recent years, the IOT have been used as new siliceous materials to prepare the autoclaved aerated concrete (AAC). Li et al. [14] used Miyun IOT to prepare the AAC products with a content of 62% and a compressive strength of 6 MPa; however, the siliceous materials used were high-silicon low-iron tailings, and the process cannot meet the requirements for preparing the AAC product with low-silicon, high-iron, and silicate-rich tailings, resulting in a low rate of achievement transformation and promotion rate. Based on the related research results, this paper attempts to study the preparation of the AAC using the low-silicon and high-iron tail-