| In the process of matte smelting by rich oxygen in the copper melt bath, due to the increase of oxygen potential, the copper content became higher in slag, the sedimentation furnace be used to precipitate the copper form slag. A copper smelter in Yunnan, have a way to decline the rate of copper in the slag, what’s principle is decline the viscous of slag by reducing the Fe3O4, and this technology is sprinkling diesel oil and nitrogen into the slag by top blowing. The researches in this dissertation were based on the technology. And the researches include:the character of the movement in the different viscous liquids and the interface of the bubbles by top blowing, the character of the flow and the stirring by bubble cluster of air-water top blowing and the reason of the nodulation on the top-blown lance by SEM and thermal simulation. Through the above models, simulation and experiment research on the flow phenomenon and the process optimization of fortified stirring by top blowing are combined, the following conclusions were acquired.1. The shape’s sphere of influence of top blowing bubble formed by the interface of slag and matte is 2/3 of slag layer to 1/2 of matte layer, when the bubbles generated out of this scope, the movement in the two phase fluid conform to the traditional laws with the movement of bubble in a single viscous liquid. When the bubbles formed in the interface of slag and matte layer or in the matte layer, rising bubble will brought the matte into the slag layer by viscous force. If the nozzle was located in the matte layer, bubbles going through the interface were in spherical shape, and the amount of matte brought into the slag by bubbles was proportionate to the degree of bubble deformation.2. By the thermal simulation, we can know that the temperature waved with the movement of cold bubbles near the location of the nodulation of lance, and the average temperature is lower than the melting point. To combine the interface of high viscous slag with bubbles and the movement of bubbles, it can be deduced that the nodulation was formed by continually freezing on the muzzle of lance caused of the lower temperature caused of the oil and air jetted into the molten bath. SEM shows that a number of copper in the field of muzzle and the appearance of nodulation looked like mica’s by scanning electron microscope, it can explain that the temperature is gradient when the nodulation was freezing, and it was as same as the analysis of the thermal simulation.3. A pattern of the flow transition of annular flow to bubbly flow which produced by the pressure difference of gas-liquid phase, and it flowed steadily, the area of the two different flow patterns rest with the value of pressure difference. There are three kinds of the gas-liquid flow mixed phase interface in the section intersected by the main pipe and branch pipe (the area of mixing phase of gas and liquid), which can product the different flow patterns severally. The differences of bubbles stirred by immersion top blowing on different flow patterns are manifested in two aspects, depth and width. And it is proved that the production is the best when the gas-liquid ratio between 2-5. |
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