包钢低硅烧结矿铁酸钙生成特性的影响因素

 为了探明白云鄂博低硅烧结矿中铁酸钙生成特性的影响因素，在红外烧结炉中，通过改变最高烧结温度、烧结配料的碱度、MgO含量、CaF2含量、SiO2含量、铝硅比，对以自产精矿为主要含铁原料的烧结试样，进行了单因素多水平正交微型烧结试验。研究结果表明，不同因素对烧结试样粘结相强度的影响存在不同趋势：随着最高烧结温度、碱度、wSiO2的提高，烧结试样的粘结相强度呈现增加趋势；随着wMgO、wCaF2、wAl2O3/wSiO2的降低，烧结试样的粘结相强度呈现出开始变化不明显，之后又下降的趋势。当最高烧结温度为1280℃、碱度为28、MgO含量(质量分数，下同)为10%、CaF2含量为08%、SiO2含量为44%及铝硅比为015时，微型烧结试样的粘结相强度最高。各影响因素中粘结相强度最佳的烧结矿矿相组成中赤铁矿和复合铁酸钙(SFCA)所占比例不完全一致，但二者之和均较高；SFCA通常为针柱状、片状或颗粒状，并与赤铁矿、玻璃相或磁铁矿交织成网络结构。

Influencing Factors in Formation Characteristics of SFCA for Low Silica Sinters of Baogang

Baivumebo iron ores were special magnetite containing fluorine,kalium and sodium elements,which were the main raw materials for ironmaking of Baotou Iron and Steel(Group) Co.The influence factors of the bonding phase strength of Baivumebo low silica sinters were explored in the single factor and multi-level tests by mini-sintering.During the test the process,parameters were changed,including sintering temperature,basicity,the content of sintering samples of wMgO,wCaF2,wSiO2 and wAl2O3/wSiO2.The results show that the variation trends of the bonding phase strength for different influence factors are different.In detail,the bonding phase strength increases with the increase of the highest sintering temperature,the basicity and wSiO2 of sintering mixture,meanwhile,with the increase of wMgO,wCaF2 and wAl2O3/wSiO2 of sintering mixture,the strength of bonding phase presents no noticeable change at the beginning and decreases later.The optimum sintering conditions to the bonding phase strength of low silica sinter are the highest sintering temperature of 1 280 ℃,basicity of 2.8,wMgO of 1.0%,wCaF2 of 0.8%,wSiO2 of 4.4%,wAl2O3/wSiO2 of 0.15.The proportions of hematite in the best samples are not in accordance with those of SFCA,but the total amounts of both are the largest for every influence factor.The common types of SFCA are acicular,columnar,platy or granular,the grains of which formed the network interlaces with hematite,glass phase and magnetite.