| Iron ore from different regions have various grades and components. In order to prevent the component changing influencing the blast furnace, generally, before sintering, mix the iron ore into blending ore. Different iron ore is mixed by a certain rate on the blending yard. Receive a good performance. But at the ends of stack, the quality of blending ore is poor. It is essential to find which factors affect the blending effect.Based on process in factory, launch a series of basic tests on the powder stack process. Propose the blending ore stacking model. Use parameters such as angle of repose, weight of ore and range of stack, calculate the internal construction of the blending stack in three-dimensional space. Combine the reclaiming angle, position and demand of produce, and confirm the quantity of blending ore at the ends. During the study, draw conclusions as follows:(1) Physical simulation with sand. Based on the result, propose the model of conical: decomposing the stack process into deployment the pile of conical. Confirm distribution equation.(2) Develop stack and reclaiming program with Visual C++. Since trial and error method is used by the program, causing the increases of calculation. So the calculation is divided into two stages:rough calculation and precise calculation. Draw the line and circle with Bresenham algorithm which has a high calculating efficiency. Compared the physical simulation with calculation, they have the same regulation and tension. Therefore the model can be used to simulate actual blending ore stack.(3) Precision analysis on program shows that deviation can be divided into the iron ore parameter deviation and model deviation. The former can be controlled by enhancing iron ore characters precision. The latter is inherent error and decreasing the net scale can reduce the deviation to a certain degree. The analysis show that calculation accuracy is inverse proportion to the third power of net scale.(4) With the software, compare the influence of stack mode between "vary start, fixed end" and "fixed start, fixed end". Result shows that with the same iron ore and stack sequence, the component has a soft change at head when stack with vary start, component change sharply when stack with fixed start, and deviation between the head and the body is big. So "vary start" distribution can decrease the unqualified blending ore quantity.(5) Analysis of the influence of stack layer count, reclaiming angle and stack sequence shows that increase stacking layer avails to composition stability, when reclaiming angle becomes close to the stack angle, the blending ore is more stable; distribution sequence has a strong influence on blending ore.(6) Based on research result, optimize parameter and confirm the optimization operation process. Include following:"vary start, fixed end" stack method, increase stack layer when the iron ore surface coverage and efficiency meet the demand, stack with " arrange Fe with equal Si" sequence, reclaiming with 37°. Optimization calculate based on factory, set fluctuation range bellow ±(δ/2)%. After optimization, unqualified blending ore is decrease from 24.4m(16.0m at head,8.4m at end) to 6.0m(3.0m at head,3.0m at end). |
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