Study on the strength of cold-bonded high-phosphorus oolitic hematite-coal composite briquettes
来源期刊：International Journal of Minerals Metallurgy and Materials2014年第5期
论文作者：Wen Yu Ti-chang Sun Zhen-zhen Liu Jue Kou Cheng-yan Xu
文章页码：423 - 430
摘 要：Composite briquettes containing high-phosphorus oolitic hematite and coal were produced with a twin-roller briquette machine using sodium carboxymethyl cellulose,molasses,starch,sodium silicate,and bentonite as binders.The effect of these binders on the strength of the composite briquettes,including cold strength and high-temperature strength,was investigated by drop testing and compression testing.It was found the addition of Ca（OH）2 and Na2CO3 not only improved the reduction of iron oxides and promoted dephosphorization during the reduction-separation process but also provided strength to the composite briquettes during the briquetting process; a compressive strength of 152.8 N per briquette was obtained when no binders were used.On this basis,the addition of molasses,sodium silicate,starch,and bentonite improved the cold strength of the composite briquettes,and a maximum compressive strength of 404.6 N per briquette was obtained by using starch.When subjected to a thermal treatment at 1200°C,all of the composite briquettes suffered from a sharp decrease in compressive strength during the initial reduction process.This decrease in strength was related to an increase in porosity of the composite briquettes.X-ray diffraction（XRD） and scanning electron microscopy（SEM） analyses showed that the decrease in strength of the composite briquettes could be caused by four factors: decomposition of bonding materials,gasification of coal,transportation of byproduct gases in the composite briquettes,and thermal stress.
Wen Yu1,2，Ti-chang Sun1,2，Zhen-zhen Liu1,2，Jue Kou1,2，Cheng-yan Xu1,2
1. The Key Laboratory of the Ministry of Education of China for High-Efficient Mining and Safety of Metal Mines,University of Science and Technology Beijing2. School of Civil and Environmental Engineering,University of Science and Technology Beijing
摘 要：Composite briquettes containing high-phosphorus oolitic hematite and coal were produced with a twin-roller briquette machine using sodium carboxymethyl cellulose,molasses,starch,sodium silicate,and bentonite as binders.The effect of these binders on the strength of the composite briquettes,including cold strength and high-temperature strength,was investigated by drop testing and compression testing.It was found the addition of Ca（OH）2 and Na2CO3 not only improved the reduction of iron oxides and promoted dephosphorization during the reduction-separation process but also provided strength to the composite briquettes during the briquetting process; a compressive strength of 152.8 N per briquette was obtained when no binders were used.On this basis,the addition of molasses,sodium silicate,starch,and bentonite improved the cold strength of the composite briquettes,and a maximum compressive strength of 404.6 N per briquette was obtained by using starch.When subjected to a thermal treatment at 1200°C,all of the composite briquettes suffered from a sharp decrease in compressive strength during the initial reduction process.This decrease in strength was related to an increase in porosity of the composite briquettes.X-ray diffraction（XRD） and scanning electron microscopy（SEM） analyses showed that the decrease in strength of the composite briquettes could be caused by four factors: decomposition of bonding materials,gasification of coal,transportation of byproduct gases in the composite briquettes,and thermal stress.
关键词：
