College of Metallurgy and Energy, North China University of Science and Technology, Tangshan 063009, PR China.
College of Metallurgy and Energy, North China University of Science and Technology, Tangshan 063009, PR China.
Chemosphere. 2017 Jan;167:360-366. doi: 10.1016/j.chemosphere.2016.10.020. Epub 2016 Oct 12.
AOD (argon oxygen decarburization) slag, which is the by-product of the stainless steel refining process, is a recyclable slag because of its high content of calcium and silicon. The leaching toxicity cannot be ignored in the recycling process because the slag contains a certain amount of Cr. In this study, the mineral analysis, batch leaching tests and thermodynamic and kinetic modeling by PHREEQC combined with FactSage software were performed to explore the influence of the dissolution of primary minerals and the precipitation of secondary minerals on the elution of Cr from AOD slag. The results indicated that the main minerals in the original AOD slag are larnite, merwinite, pyroxene and periclase. Cr was dispersed in the mineral phases mentioned above. The simulation of Cr leaching controlled by Cr(III)-hydroxide corresponded better to the batch leaching tests, while the Cr leaching controlled by chromite or double control was underestimated. Increasing the L/S ratio enhances the pH of the leachate and restrains the elution of Cr from the AOD slag.
AOD（氩氧脱碳）渣是不锈钢精炼过程的副产品，由于其富含钙和硅，属于可回收渣。在回收过程中，由于渣中含有一定量的 Cr，浸出毒性不容忽视。在本研究中，通过 PHREEQC 结合 FactSage 软件进行矿物分析、批量浸出试验以及热力学和动力学建模，探讨了主要矿物的溶解和次生矿物的沉淀对 AOD 渣中 Cr 浸出的影响。结果表明，原始 AOD 渣中的主要矿物有钙长石、镁蔷薇辉石、辉石和方镁石。Cr 分散在上述矿物相中。Cr（III）-氢氧化物控制的 Cr 浸出模拟与批量浸出试验更为吻合，而铬铁矿或双重控制的 Cr 浸出则被低估。增加液固比会提高浸出液的 pH 值，并抑制 AOD 渣中 Cr 的浸出。
