本文選題：鏡鐵礦粉礦 + 微波磁化焙燒　； 參考：《武漢科技大學(xué)》2015年碩士論文

【摘要】：鏡鐵山鏡鐵礦是酒鋼主要原料，由于其礦物組成復(fù)雜，礦物粒度嵌布極細(xì)且不均勻，礦物顆粒純度低，鐵礦物與脈石礦物比磁化系數(shù)、密度等物理參數(shù)相近或有交叉，通過(guò)常規(guī)選礦方法選別較為困難。研究表明，這類難選鐵礦采磁化焙燒處理可以達(dá)到較好的選別指標(biāo)，但常用的磁化焙燒工藝因設(shè)備或工藝原因?qū)@類粉礦不能有效處理，，而微波加熱應(yīng)用于鐵礦碳熱還原具有其獨(dú)特優(yōu)勢(shì)：①加熱速度快，加熱均勻，減少礦物還原時(shí)的“夾生”現(xiàn)象；②微波加熱具有選擇性，礦物內(nèi)部容易產(chǎn)生裂紋，促進(jìn)氣固還原反應(yīng)進(jìn)行，同時(shí)裂紋的產(chǎn)生有利于降低磨礦能耗；③可以直接使用粉礦加熱，簡(jiǎn)化工藝流程。因此，研究微波磁化焙燒工藝對(duì)于該類難選鐵礦物的回收利用具有重要意義。 本研究以鏡鐵山鏡鐵礦粉礦為原料，進(jìn)行了微波磁化焙燒-磁選試驗(yàn)研究，確定了該鏡鐵礦微波磁化焙燒的工藝參數(shù)，并結(jié)合礦物微觀結(jié)構(gòu)變化探討了微波加熱對(duì)磁化焙燒過(guò)程影響的作用機(jī)理。 該鏡鐵礦粉礦采用微波加熱磁化焙燒時(shí)，以固定碳占原礦質(zhì)量的2.5%配加煙煤、在微波功率1000W、焙燒溫度550℃、保溫15min條件下焙燒，焙燒礦經(jīng)球磨機(jī)磨細(xì)至-0.074mm占85%左右、通過(guò)磁場(chǎng)強(qiáng)度為92.16kA/m的磁選管選別，可得鐵品位55.16%，回收率86.65%的理想指標(biāo)。 鏡鐵礦粉礦經(jīng)微波焙燒后，礦樣中鏡鐵礦、菱鐵礦、褐鐵礦均已轉(zhuǎn)化為磁鐵礦，微波加熱應(yīng)用于該鏡鐵礦磁化焙燒效果較好。微波磁化焙燒會(huì)導(dǎo)致礦石內(nèi)部產(chǎn)生裂紋，但不同鐵礦產(chǎn)生的裂紋形式有一定差異。由鏡鐵礦轉(zhuǎn)化而來(lái)的磁鐵礦內(nèi)部產(chǎn)生裂紋較少，裂紋主要產(chǎn)生于鐵礦與脈石界面之間以及脈石礦物內(nèi)部，而由菱鐵礦轉(zhuǎn)化而來(lái)的磁鐵礦裂紋的主要形式為礦物從內(nèi)部龜裂，使礦石結(jié)構(gòu)變得疏松。微波磁化焙燒對(duì)礦物結(jié)構(gòu)破壞是微波選擇性加熱促進(jìn)礦物產(chǎn)生裂紋以及菱鐵礦受熱分解雙重作用結(jié)果。 微波加熱應(yīng)用于該鏡鐵礦磁化焙燒工藝可以促進(jìn)礦物內(nèi)部產(chǎn)生裂紋，降低磨礦能耗，同時(shí)能夠促進(jìn)鐵礦物與脈石礦物解離，有利于后續(xù)磁選分離。
[Abstract]:Jingtieshanjing iron mine is the main raw material of Jiugang. Because of its complex mineral composition, fine and uneven distribution of mineral particle size, low purity of mineral particle, the ratio of iron mineral to gangue mineral magnetization coefficient, density and other physical parameters are close or cross. It is difficult to separate ore by conventional dressing method. The results show that the magnetization roasting treatment of refractory iron ore can achieve a better separation index, but the common magnetization roasting process can not effectively treat this kind of ore because of equipment or process reasons. However, microwave heating has its unique advantage in the reduction of iron ore by carbothermal reduction, which is characterized by high heating speed and uniform heating. Microwave heating can reduce the phenomenon of "pinch" in the reduction of minerals. Microwave heating is selective, and cracks are easy to occur in minerals. The gas-solid reduction reaction is promoted, and the crack generation is beneficial to reduce the energy consumption of grinding. The pulverized ore can be heated directly and the technological process can be simplified. Therefore, it is of great significance to study microwave magnetization roasting technology for the recovery and utilization of refractory iron ore. In this study, the microwave magnetization roasting and magnetic separation experiments were carried out with the mirror iron ore as raw material, and the technological parameters of the microwave magnetization roasting of the mirror iron ore were determined. The mechanism of the effect of microwave heating on magnetization roasting process was also discussed. When magnetized roasting with microwave heating, fixed carbon is used to add bituminous coal to 2.5% of the raw ore mass, calcined at microwave power 1000W, calcination temperature 550 鈩

本文編號(hào)：1886302