中文摘要：

为给高铁低硅烧结矿的生产提供理论依据,设计烧结矿碱度R为1.8、1.9和2.0,每种碱度下以SiO_2含量为变量,产生12组配矿方案进行烧结杯实验,研究SiO_2对烧结矿冶金性能及微观结构的影响.结果表明：SiO_2质量分数从4.8%~5.7%增加时,其冷态强度逐渐增加,最大增幅为8%;烧结矿还原性逐渐降低,降幅区间为从86.80%到81.01%;还原粉化指数RDI＋3.15逐渐增大,增幅区间为从75.95%到87.21%;对于软熔性能,其软化开始温度T10在4.8%~5.4%的SiO_2含量区间先升高,在5.4%~5.7%之间又降低,而软化区间有变宽的趋势.选定一个碱度水平R=2.0,烧结矿SiO_2质量分数在4.8%~5.7%范围变化时,其微观结构由熔蚀状向针柱状发展,结构均匀性逐渐提高,主要矿物组成由赤铁矿向铁酸钙发展,且低温还原粉化的骸晶状赤铁矿逐渐消失.

英文摘要：

In order to provide a theoretical basis for the production of high iron and low silica sinter,the basicity（ R） was set to1. 8,1. 9 and 2. 0,the SiO2 content was variable for each alkalinity,and then 12 groups of ore blending schemes were generated to proceed with sinter pot tests. After that,the influences of SiO2 on the metallurgical properties and microstructure of sinter were researched. The results show that when the SiO2 content increases from 4. 8% to 5. 7%,the cold intensity gradually increases,and the greatest growing rate is 8%; the sinter reducibility tends to lower,and the decreasing range is from 86. 80% to 81. 01%; the reduction degradation index（ RDI＋ 3. 15） gradually increases,and the growing range is from 75. 95% to 87. 21%. For softening-melting properties,the apparent initial softening temperature（ T10） previously increases in the range from 4. 8% to 5. 4% and then decreases in the range from 5. 4% to 5. 7%,and the softening range has a widening trend. Selected a alkalinity level R = 2. 0,when the SiO2 content changes in the range of 4. 8% to 5. 7%,the microstructure of sinter develops from an ablation shape to a needle-like and columnar shape,the structural uniformity gradually improves,and the main mineral composition changes from hematite to calcium ferrite. Skeletal crystalline hematite,which leads to a low temperature reduction degradation phenomenon,gradually disappears.