硫含量对白云鄂博铁精矿预热压团显微结构及抗压强度的影响
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摘要
就硫氧化反应对白云鄂博铁精矿预热压团显微结构的影响进行了研究,利用差热和热重分析了含硫矿物在氧化焙烧过程中的矿相转变规律,同时通过改变压团中的硫含量,研究了硫氧化对预热压团矿相显微结构和抗压强度的影响。结果表明:铁矿物中硫元素的主要存在形式为黄铁矿和磁黄铁矿,各占34.48%和64.23%;随着温度的升高,黄铁矿发生氧化分解反应生成硫化亚铁和单质硫,硫化亚铁和空气中的氧结合生成硫酸铁,高温下硫酸铁发生分解反应,生成铁氧化物和二氧化硫;随着硫含量从1.8%增加到3.9%,预热压团中磁铁矿氧化生成的赤铁矿减少,孔隙率随着硫含量增加呈升高趋势,压团抗压强度由1.18 kN/cm~2降低到0.84 kN/cm~2,开裂温度由780℃降低为640℃。
In this paper,the effect of sulfur oxidation on the microstructure of preheated briquettes of Baiyunebo iron ore concentrates is studied.The mineral phase transformation rules of sulfur-containing minerals in the oxidation roasting process are analyzed by TG-DSC,meanwhile,the effect of sulfur oxidation on the microstructure and compressive strength of the preheated pellets is also studied by changing the sulfur content in the pellets.The results show that,the sulfur element in iron minerals exists mainly in the form of pyrite and pyrrhotite,accounting for 34.48% and 64.23% respectively.With the increase of temperature,the oxidation decomposition reaction of pyrite produces ferrous sulfide and elemental sulfur,and ferrous sulfide combines with oxygen in the air to produce ferric sulfate,and sulphate decomposes to produce iron oxide and sulfur dioxide at high temperature.With the increase of sulfur content from 1.8% to 3.9%,the hematite produced by the magnetite oxidation in the preheated pellets decreases,and the porosity increases with the increase of sulfur content,and the compressive strength of the briquettes decreases from 1.18 kN/cm~2 to 0.84 kN/cm~2,and the cracking temperature decreases from 780 ℃ to 640 ℃.
In this paper,the effect of sulfur oxidation on the microstructure of preheated briquettes of Baiyunebo iron ore concentrates is studied.The mineral phase transformation rules of sulfur-containing minerals in the oxidation roasting process are analyzed by TG-DSC,meanwhile,the effect of sulfur oxidation on the microstructure and compressive strength of the preheated pellets is also studied by changing the sulfur content in the pellets.The results show that,the sulfur element in iron minerals exists mainly in the form of pyrite and pyrrhotite,accounting for 34.48% and 64.23% respectively.With the increase of temperature,the oxidation decomposition reaction of pyrite produces ferrous sulfide and elemental sulfur,and ferrous sulfide combines with oxygen in the air to produce ferric sulfate,and sulphate decomposes to produce iron oxide and sulfur dioxide at high temperature.With the increase of sulfur content from 1.8% to 3.9%,the hematite produced by the magnetite oxidation in the preheated pellets decreases,and the porosity increases with the increase of sulfur content,and the compressive strength of the briquettes decreases from 1.18 kN/cm~2 to 0.84 kN/cm~2,and the cracking temperature decreases from 780 ℃ to 640 ℃.
引文
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[12] 田铁磊,李杰,邢宏伟.液相量对高镁碱性球团强度的影响[J].烧结球团,2015,40(3):22-24.
[2] Arvidson B,Klemetti M,Knuutinen T,et al.Flotation of pyrrh-otite to produce magnetite concentrates with a sulphur level below 0.05% w/w [J].Minerals Engineering,2013,50-51(5):4-12.
[3] 吴德礼,朱申红,马鲁铭.化学法处理黄铁矿烧渣的新工艺[J].矿产综合利用,2005(1):35-37.
[4] Ramos I,Perez R,Fdz-Polanco M.Microaerobic desulphur-ization unit:A new biological system for the removal of H2S from biogas[J].Bioresource technology,2013,142(8):633-640.
[5] 赵磊,李相良.高硫铝土矿沸腾焙烧脱硫试验[J].有色金属,2016(1):11-13.
[6] 彭志成.难处理含金硫砷精矿氧化焙烧—碘化法浸出试验研究[D].衡阳:南华大学,2014:31-35.
[7] 傅崇说.有色冶金原理[M].北京:冶金工业出版社,1993:102-104.
[8] 祖刚,李解,李保卫,等.低品位硫精矿富氧焙烧反应动力学计算[J].钢铁研究学报,2015,27(12):17-24.
[9] 郑红霞,汪琦,潘喜峰.磁铁矿球团氧化机理的研究[J].烧结球团,2003,28(5):13-16.
[10] Eiki K.Preface to the Special Issue on “Recent Progress of the Research on the Iron ore Agglomeration Process”[J].ISIJ International,2005,45(4):413-420.
[11] 杨大兵,张攀,李乾坤,等.内蒙古某高硫高碱度磁铁精矿球团焙烧脱硫机理研究[J].烧结球团,2016,41(2):41-45.
[12] 田铁磊,李杰,邢宏伟.液相量对高镁碱性球团强度的影响[J].烧结球团,2015,40(3):22-24.