Phosphorus partitioning and recovery of low-phosphorus iron-rich compounds through physical separation of Linz-Donawitz slag

作     者：Dilip Makhija Rajendra Kumar Rath Kaushik Chakravarty Abhay Shankar Patra Asim Kumar Mukherjee Akhilesh Kumar Dubey 

作者机构：Research and Development DivisionTata Steel Ltd. Mineral Processing DivisionCSIR-National Metallurgical Laboratory Raw Material Blending and Bedding SectionTata Steel Ltd. 

出 版 物：《International Journal of Minerals,Metallurgy and Materials》 (矿物冶金与材料学报（英文版）)

年 卷 期：2016年第23卷第7期

页      面：751-759页

核心收录：

学科分类：083002[工学-环境工程] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 08[工学] 

基　　金：the Research&Development Division and Management of Tata Steel Ltd.for their support and permission to publish this work 

主　　题：steelmaking slag dephosphorization recycling 

摘      要：The Linz-Donawitz（LD） steelmaking process produces LD slag at a rate of about 125 kg/t. After metallic scrap recovery, the non-metallic LD slag is rejected because its physical/chemical properties are unsuitable for recycling. X-ray diffraction（XRD） studies have indicated that non-metallic LD slag contains a substantial quantity of mineral phases such as di- and tricalcium silicates. The availability of these mineral phases indicates that LD slag can be recycled by iron（Fe）-ore sintering. However, the presence of 1.2wt% phosphorus（P） in the slag renders the material unsuitable for sintering operations. Electron probe microscopic analysis（EPMA） studies indicated concentration of phosphorus in dicalcium silicate phase as calcium phosphate. The Fe-bearing phases（i.e., wustite and dicalcium ferrite） showed comparatively lower concentrations of P compared with other phases in the slag. Attempts were made to lower the P content of LD slag by adopting various beneficiation techniques. Dry high-intensity magnetic separation and jigging were performed on as-received samples with particle sizes of 6 and 3 mm. Spiral separation was conducted using samples ground to sizes of less than 1 and 0.5 mm. Among these studies, grinding to 0.5 mm followed by spiral concentration demonstrated the best results, yielding a concentrate with about 0.75wt% P and 45wt% Fe.