Optimizing On Pellet Production Process Of The Shaft Furnace At Shaanxi Hanzhong Iron And Steel

Pellets produced by Shaanxi Hanzhong Iron and Steel Group Company had lowmetallurgical performance, low-grade pellets and poor quality based on the currentinvestigation. For this series of questions, this paper optimized the furnace productionprocess parameters of Shaanxi Hanzhong Iron and Steel Group Company throughanalyzing the theory, experimental studies and field trials, for instance the particle sizeof the raw material pellet production, composition of the water, bentonite ratio,calcination temperature and atmosphere, what’s more, ultimately high grade, goodquality and high yield pellets.By variation of the amount of bentonite added, calcination temperature andmanufacturing process parameters to analyze various parameters on the performance ofpellets situation.The main conclusions drawed from study as following:(1) Research material parametersAs the particle size of raw material is too large (-200mesh accounted for60.68%;-325mesh accounted for18.28%), which is not conducive to pellet production, sogranularity of ore is refined in laboratory:-200mesh particle size is more than80%,-325mesh particle size is accounting for more than40%. After refinement, the surfacearea of mineral particles is increased, intermolecular interactions is enhanced, whichpromote the compressive strength and falling strength of particle to improve.(2) Bentonite proportionsStudying the addition of bentonite increased (from1.2%to2.2%) and the resultssa following: with the content of bentonite increasing, the dropping strength greenpellets were also increased (from3to4times/0.5m to6-7times/0.5m), when the amount of bentonite added to a certain value, the dropping strength enhancementbecame weakened; With the increase content of raw bentonite, the compressive strengthtrend of the pellets was increased-smooth-downward; With the increase content of rawbentonite, the burst temperature of the showed rise. According to burst temperaturerequirements of the green pellets for furnace production, adding bentonite requires wasat least1.4%(Shaanxi steel is:1.8%)) in this paper.(3) Calcination temperature researchThe influence of calcination temperature on pellets was studied under1000℃,1050℃,1100℃,1150℃,1200℃, The results showed that: the quality and performanceof pellet was affected no matter when the roasting temperature too low or high; As theroasting temperature increasing, the compressive strength of pellets would be acorresponding rise, but when the roasting temperature rises to a certain temperature, thecompressive strength is no longer to rise and tend steadily. At the same time, thereduction experimental and mineralogical of pellet was analysised, and determined thebest ratio and calcination temperature of raw material in laboratory: ratio of bentonite is1.4%, calcination temperature is1150℃.Parameters of grain size refinement, bentonite amount, calcination temperature andcalcination atmosphere were optimized analysis in laboratory, combining with thepractice situation of Shaanxi Hanzhong Iron and Steel Group Company, the furnaceproduction process parameters of Shaanxi Hanzhong Iron and Steel Group Companywas optimized in this paper: on the one hand, the technology level of furnace pellet wasimproved; on the other hand, providing a theoretical basis and development trend forShaanxi steel shaft furnace large-scale equipment.