多种典型铁尾矿的环境安全性研究

Study on Environmental Safety of Several Typical Iron Tailings

铁尾矿是矿山采选铁矿石后排出的细粒固体废弃物,是制约矿山可持续发展的重要因素。为了强化推进铁尾矿的大宗利用,提高其资源属性价值,以不同主要化学成分将多种典型铁尾矿划分成4类,以严于标准的硫酸硝酸法进行浸出毒性分析与腐蚀性分析,并对重金属稳定性的原因进行了XRD分析。结果表明:浸出液重金属含量远低于标准限制,且pH在8.34~9.08;铁尾矿的主要组分硅、铝、钙、镁主要以稳定的石英相、石灰石相、钙钠长石相和堇青石相存在,基本不受酸碱的影响。含量在0.1%以上的重金属可能稳定地以含锰(铜)堇青石相、含锰铁云母相、含铬镍斜绿泥石相、绿铜矿相、含锌锰整柱石相、黑钒矿相、铅钒氧化物等存在,佐证铁尾矿具有较高的环境安全性,为铁尾矿的大宗资源化利用提供了参考依据。

Iron tailings is the fine-grained solid waste discharged from the mining and separation of iron ore,which is an important factor restricting the sustainable development of mines. In order to strengthen and promote the large-scale utilization of iron tailings and improve its resource attribute value,a variety of typical iron tailings are divided into four categories based on different main chemical composition,leaching toxicity analysis and corrosion analysis were carried out by sulfuric acid and nitric acid method which is stricter than the standard,and XRD analysis was carried out on the reasons for the stability of heavy metals. The results showed that the content of heavy metals in the leaching solution was much lower than the standard limit,and the pH was between 8.34 and 9.08. The main components of the iron tailings are silicon,aluminum,calcium and magnesium,which mainly exist in stable quartz,limestone,calcium albite and cordierite,and are basically not affected by acid and alkali. The heavy metals with a content of more than 0.1% may stably exist in cordierite(manganese/copper),annite(manganoan),clinochlore(chromium and nickel),dioptase,milarite zincian,melanovanadite,lead vanadium oxide,etc.,which proves that iron tailings have high environmental safety and provides a reference for the large-scale resource utilization of iron tailings.