Water Model Study of Mass Transfer between Iron and Slag in an Iron Smelting Reduction Furnace

• Main Authors: Ming-Chao Chuang, 莊名超
• Other Authors: Weng-Sing Hwang
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/79807076110635020812

碩士 === 國立成功大學 === 材料科學及工程學系 === 87 === Abstract In this thesis research, a physical model has been set up to study the mass transfer phenomena between iron bath and molten slag, which is enchanced by gas stirring in the smelter for direct iron ore smelting reduction process. Effects of various operating conditions(gas flow rate, tuyere size, height of liquid bath) as well as sampling position on the mass transfer rate are primary concerns of this study. The ultimate goal is to obtain an optimal design and operating condition for the smelter to have the highest rate of mass transfer between iron bath and molten slag. Transparent acrylic is used to construct a reduced smelter which is 30% in size of the actual furnace. Water and zinc chloride are used to simulate the iron bath while spindle oil is selected to substitute the molten slag. The range of gas flow rate to be studied in the water model is estimated by employing the criterion of Modified Froude Number. Thymol is used as the tracer material to study the rate of mass transfer. The concentration of thymol in the water decreases as mass transfer proceeds. An Ultra-Violet apparatus is used to measure the thymol concentration in the water. The mass transfer coefficients can be calculated by manipulating the concentration data with the assumption that the mass transfer rate follows the 1st order reaction kinetics equation. The resukts show that mass transfer rates are similar irrespective of the sampling postion. When gas flow rate increases, the amount of stirring increases. Howere, as the gas flow rate approaches 40 /min., the improvement becomes less obvious. As the height of the liquid bath increases, the effect of stirring decreases. And stirring is better for smaller tuyere while five tuyeres is better than four tuyeres when they are blown with the same gas flow rate. It also shows that top blowing has little effect on the stirring behavior of the liquid bath, which is induced by bottom blowing.