Dissolution Behaviour of Hazardous Materials from Steel Slag with Wet Grinding Method

[摘要] Steel slag is a by-product from steel industry and it contains variety of hazardous materials. In this study, the dissolution behaviour and removal potential of hazardous materials from steel slag with the wet grinding method was investigated. The slag was wet ground in the CO2atmosphere and the slurry produced was filtered using centrifugal separator to separate the liquid and solid sediments. Then, the concentrations of dissolved metal elements in the liquid sediment were analyzed by ICP-MS. The changes of pH during the grinding were also investigated. It was found that the pHs were decreased immediately after the CO2gas introduced into the vessel. The pHs were ranging from 6.8 to 7.6 at the end of grinding. The dissolved concentration of Zn and Cr were ranging from 5∼45 [mg/dm3] and 0.2∼2.5 [mg/dm3] respectively. The ratios of Zn removal for stainless steel oxidizing and reducing slag were very high, but those from normal steel oxidizing and reducing slag were very low. It is assumed that the Zn dissolved as ZnOH+from Zn(OH)2 that formed due to the reaction between ZnO and water. Dissolution of Cr also occurred but in very low quantity compared to the dissolution of Zn. The dissolution of Cr occurred due to the grinding process and small amount of Cr(OH)3was formed during the grinding. This small formation of Cr(OH)3 resulted to the low dissolved concentration of Cr in the form of Cr(OH)2+. According to the XRD analysis, the Cr mostly existed in the slags as Cr(IIl) in the form of MgCr2O4and FeCr2O4.

[发布机构] Department of Materials and Design Engineering, Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, Parit Raja, Johor, Batu Pahat; 86400, Malaysia^1;Faculty of Mechanical Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku Toyohashi Aichi, Japan^2

[效力级别] 物理学

[关键词] Dissolution behaviour;Dissolved concentrations;Dissolved metals;Grinding process;Solid sediment;Steel slag;Wet grinding;XRD analysis