梅山铁矿磨矿—分级工艺过程优化试验研究

发布时间：2018-06-20 16:52

本文选题：铁矿 + 磨矿过程　；参考：《江西理工大学》2015年硕士论文

【摘要】：铁矿石是国民经济发展的重要支撑性矿产资源,能否经济高效利用,关系到我国产业安全以及钢铁产业的健康发展。经过长年不断地采选,好选易选的铁矿石逐渐被消耗殆尽,铁矿石性质向着“贫、细、杂”发展,铁矿的综合利用越来越难。梅山铁矿矿石结构构造复杂,矿物嵌布粒度分布不均匀,选厂磨矿工艺参数、介质制度不合理,导致了磨矿产品粒度分布不均匀、过粉碎严重,磨矿成本较高,资源利用率较低。对梅山铁矿4系列磨矿-分级回路进行流程考查发现:一段分级机分级效率较低,介质制度不合理,二段溢流产品中过粉碎粒级含量高达15.39%,其金属铁品位达30.26%,金属损失率高达10.36%,过磨十分严重。为了提高梅山铁矿磨矿-分级的工作效率,改善磨矿产品质量,实现节能降耗,本论文对磨矿-分级工艺进行了优化试验研究,首先研究了磨矿过程各因素的影响关系,找出较优操作参数;然后进行铁矿石的力学性质研究,提供计算参数;根据球径半理论公式、破碎统计力学以及钢球磨损原理等理论推导最佳磨矿制度,再通过试验确定最佳磨矿制度,最后进行了现场磨矿优化工业试验。经过以上研究得出以下结果:(1)磨矿过程因素以及正交试验研究表明:磨矿过程主要影响因素是磨矿时间,其次为磨矿浓度。一段粗磨磨矿时间为3min时,磨矿浓度为:70%~85%,钢球充填率为35~45%,可达到㧟0.076mm产率38~42%,㧟0.01mm过粉碎产率8~10%;二段细磨磨矿时间为3~4min,磨矿浓度为70~80%,钢球充填率为35~42%时磨矿效果较好。(2)经过对样品的规格和不规则矿块力学测试试验得出,规则矿块的普氏硬度系数f值(为16)比不规则的f(≤5)高好几倍。根据球径半理论公式、破碎统计力学以及钢球磨损原理等,得出最佳装补球制度为:一段磨初装球为Φ100:Φ80:Φ60=30%:30%:40%,补加球为Φ100:Φ80=60%:40%;二段磨初装球为Φ60:Φ40=20%:80%,补加球为Φ60=100%。(3)工业应用结果表明:磨矿条件优化后,磨矿产品粒度分布更加合理,分级效率有所提高。二段分级溢流产品过粉碎减轻21.7%,易选粒级增加6.91%,其中γ0.076~0.038mm提高了26.78%;总分级效率提高了27.98%;磁选尾矿中-0.01mm产率降低了21.16%;同时磨机功耗、钢球单耗有所降低,衬板寿命延长,折合磨矿成本降低1.7元/t。综上所述,磨矿-分级工艺过程优化取得了良好的效果,创造了一定的经济效益,其方法可推广至类似磨矿系统或其他金属矿、非金属矿磨矿系统。
[Abstract]:Iron ore is an important mineral resource for the development of the national economy. Whether the economic and efficient utilization is related to the safety of China's industry and the healthy development of the iron and steel industry. After continuous selection for a long period of time, the iron ore is gradually depleted and the properties of iron ore are developing towards "poor, fine and miscellaneous", and the comprehensive utilization of iron ore is becoming more and more difficult. The structure and structure of the ore of Meishan iron ore is complex, the distribution of grain size is not uniform, the grinding process parameters of the mill and the medium system are unreasonable, which leads to the uneven distribution of grain size, the serious grinding, the high grinding cost and the low utilization of resources. The process of the 4 series grinding and grading loop of Meishan iron ore is found out: a section of classification The classification efficiency of the machine is low and the medium system is not reasonable. The overgrinding grain level in the two section of the spillage products is 15.39%, the metal iron grade is 30.26%, the metal loss rate is up to 10.36%, and the overgrinding is very serious. In order to improve the working efficiency of the grinding and grading of Meishan iron ore, the quality of the grinding mineral is improved and the energy saving is reduced. The optimization test is carried out. First, the influence relation of all factors in the grinding process is studied, and the optimum operating parameters are found. Then the mechanical properties of iron ore are studied and the calculation parameters are provided. According to the ball diameter semi theoretical formula, the theory of crushing statistical mechanics and the principle of steel ball wear, the best grinding system is deduced. After the study above, the following results are obtained: (1) the factors of grinding process and orthogonal test show that the main influencing factors of the grinding process are grinding time and then grinding concentration. When a period of coarse grinding is 3min, the grinding concentration is 70%~85% and the filling rate of steel ball is 35~ 45%, the yield of 0.076mm is 38~42%, and the yield of 0.01mm is 8~10%; the time of the fine grinding is 3~4min, the grinding concentration is 70~80%, the filling rate of the steel ball is 35~42% is better. (2) the hardness coefficient f (16) of the regular ore block is compared to the irregular f (less than 5) (< 5). ) a few times higher. According to the semi theoretical formula of ball diameter, crushing statistical mechanics and the principle of steel ball wear and so on, it is concluded that the best filling and filling system is: the primary ball is 100: (80:) 60=30%: 30%: 40%, the adding ball is 60=30% 100:, 80=60%: 40%; the two section ball primary ball is diameter of 40=20%: 80%, 80%, and the ball is diameter of 60=100%. (3). After the optimization, the particle size distribution of the grinding products is more reasonable and the classification efficiency is improved. The two stages of graded overflow products are reduced by 21.7%, and the grain grade is increased by 6.91%, of which the gamma 0.076~0.038mm is raised by 26.78%, the total classification efficiency is increased by 27.98%, the -0.01mm yield in the magnetic separation tailings is reduced by 21.16%, and the mill power consumption and the single consumption of the steel ball are reduced. Liner, life extension, equivalent grinding cost reduced by 1.7 yuan /t. in grinding classification process optimization has achieved good results, create a certain economic benefits, the method can be extended to similar grinding system or other metals, nonmetal ore grinding system.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD921.4;TD951

【参考文献】