碱度和MgO质量分数对球团抗压强度的影响

为研究含镁熔剂性球团的抗压强度,在实验室条件下,研究了焙烧时间、球团矿碱度和MgO质量分数对球团矿抗压强度的影响。试验研究结果表明,膨润土质量分数保持2.0%不变时,含镁熔剂性球团矿碱度(R)为0.80~1.00、MgO质量分数为1.60%~1.80%,焙烧时间为25 min,球团矿的黏结相以Fe₃O₄氧化为Fe₂O₃、然后Fe₂O₃再结晶为主。另外,还有少量的铁酸镁、铁酸钙相,这种球团矿的抗压强度大于2 500 N/个。当含镁熔剂性球团的矿碱度大于1.00,同时,MgO质量分数小于1.60%时,球团矿的黏结相含有大量的玻璃体硅酸盐,使球团矿的抗压强度大大降低。

Effects of basicity and MgO mass fraction on compression strength of pellets

In order to research the compression strength of magnesium-containing fluxed pellets,the effect of roasting time,basicity of pellets and MgO mass fraction on the strength of pellets were investigated under laboratory conditions. The results show that when the mass fraction of bentonite remains unchanged at 2.0%,the basicity of magnesium-containing fluxed pellets is 0.80-1.00,the MgO mass fraction is 1.60%-1.80%,and the roasting time is 25 min,the bonding phase of pellets is mainly composed of the recrystallization Fe₂O₃,which is the oxidation product of Fe₃O₄. In addition,there is a small amount of magnesium ferrite and calcium ferrite. Pellets with the compressive strength greater than 2 500 N/p can be obtained. When the basicity of magnesium-containing fluxed pellets is larger than 1.00,at the same time,the MgO mass fraction is less than 1.60%,a large amount of glassiness silicate is produced in the binding phase of pellets,which greatly reduces the compressive strength of pellets.