碱金属碳酸盐对磷矿碳热还原反应的影响研究  

Effects of Alkali Metal Carbonates on Carbothermal Reduction of Phosphate Rock

作　　者：曹任飞 夏举佩[1,2] 李宛霖[1,2] 韩跃伟 ？CAO Ren-fei;XIA Ju-pei;LI Wan-lin;HAN Yue-wei(Faculty of Chemical Engineering,Kunming University of Science and Technology,Kunming 650500,China;The Higher Educational Key Laboratory for Phosphorous Chemical Engineering of Yunnan Province,Kunming University of Science and Technology,Kunming 650500,China)

机构地区：[1]昆明理工大学化学工程学院,云南昆明650500 [2]昆明理工大学云南省高校磷化工重点实验室,云南昆明650500

出　　处：《高校化学工程学报》2018年第3期568-576,共9页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金(21566018).

摘　　要：通过热力学和实验研究对比分析了Ca_3(PO_4)_2与无烟煤和石墨的碳热还原反应,结果证明炭结构及其活性影响反应的发生;添加K_2CO_3、Na_2CO_3研究其对磷矿碳热还原反应的影响,结果表明,在1300℃、50 min下对比无添加体系,添加1.5%(wt)K_2CO_3和Na_2CO_3体系的P_2O_5转化率分别从46.7%提升至64.22%、59.14%,反应时间延长至4 h,P2O_5转化率分别可以达到91.32%、87.24%;渣相XRD、SEM分析表明加入碱金属碳酸盐可以促进磷矿的碳热还原反应,但并不改变其反应历程,且在1300℃下,渣相均以固态烧结形式排出,符合窑法磷酸的排渣要求;动力学分析表明磷矿碳热还原反应均为一级反应,且添加K_2CO_3和Na_2CO_3体系的活化能分别为182.91和195.38 kJ×mol^(-1),比无添加体系的209.93 kJ×mol^(-1)显著降低。Thermodynamic analysis and experimental studies on carbothermal reduction of Ca3（PO4）2 with anthracite and graphite indicated that carbon structure and its activity affect the reaction. Therefore, effects of K2CO3 and Na2CO3 on thermal reduction of phosphate rock were studied. Results show that compared with no additive systems at 1300℃ and 50 min, the conversion of P2O5 increases from 46.7% to 64.22% and 59.14% when adding K2CO3 and Na2CO3, respectively. When the reaction time is extended to 4 h, P2O5 conversion reaches 91.32% and 87.24%, respectively. XRD and SEM results show that the carbothermal reduction of phosphate rock is promoted by the addition of alkali metal carbonates, which does not change the reaction pathway and slag is discharged in solid sintering form at 1300℃. Kinetic analysis shows that the carbothermal reduction is a first order reaction and the activation energies with K2CO3 （182.91 kJ？mol？1） and Na2CO3 （195.38 kJ？mol？1） addition are significantly lower than that with no additive systems （209.93 kJ？mol？1）.

关 键 词：窑法磷酸 碱金属碳酸盐 炭活性 节能降耗 

分 类 号：TQ126.3[化学工程—无机化工]