Enrichment and Growth of Magnetite from Copper Slags as A New Iron Ore Resource
Copper slags usually contain more than 40％ iron which exists mainly in the forms of fayalite (2FeO·SiO<,2>) and magnetite (Fe<,3>O<,4>). If the iron in fayalite can be converted to magnetite then the copper slags could become a new iron ore resource through the magnetic separation of magnetite from the copper slags. Experiments were carried out in laboratory scale to study the precipitation and growth of magnetite crystal from molten copper slag for the purpose of iron enrichment. Copper slags were melted at 1350℃ and kept constant temperature for certain periods, then oxygen or oxygen enriched air was blown into the molten slag bath through a ceramic lance. The phases in the treated slags were examined by XRD analysis and the size distribution of magnetite crystals was analyzed by an imagine analysis software. The experimental results indicated that the slower cooling rate ( < 5 K/min) of cooper slag is favored for Fe<,3>O<,4> precipitating out and growing up. Blowing pure oxygen into the slag was better than the oxygen enriched air for the Fe<,3>O<,4> precipitating and growth. The crystal size of magnetite increases with the increasing of CaO addition. At the molar ratio of CaO/SiO<,2>=1.5, the area percentage of magnetite crystal accounting for the total observed area was up to 47％, and the ratio of magnetite crystal with size bigger than 50um was up to 45％. Magnetic dressing is possible to separate magnetite from treated slag after milling.
iron ore resources magnetite copper slag fayalite precipitate crystal size
Guangqiang Li Pengke Zhang Linnan Zhang Zhitong Sui
Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education, Wuhan Univ College of Materials and Metallurgy, Northeastern University, Shenyang,, China
国际会议
2006现代科技国际研讨会(The International Workshop on Modern Science and Technology in 2006)
北京
英文
7-11
2006-04-01（万方平台首次上网日期，不代表论文的发表时间）