【摘要】 在八层焙烧炉内采取同一焙烧制度,辽宁钼精矿脱硫合格率高于陕西钼精矿。本文从理论和实验两方面研究其原因,并对陕西矿的焙烧工艺采取降温措施防止过热而产生烧结,使其脱硫合格率达到与辽宁矿相同的标准。更多还原

【Abstract】 It was found in industrial practice that with the same roasting schedule for a 8-layer furnance, the molybdenum concentrate from Liaoning Province (LM) used as raw material is higher than that from Shanxi Province (SM) in the percent of pass of desulfuration. An investigation is therefore carried on experimentally for the problem what factors cause the difference of desulfuration efficiency between LM and SM in order to raise industrially the percent of pass of desulfuration as using SM as raw material.Summary. Both LM and SM are of" paragenetic ores containing such elements as Mo, Cu and Pb etc. Thermodynamic calculation points outtheoretically that both Concentrates can be effectively desulfurized with highpercent of pass through roasting, but it is clearly not in accordance with the fact in industrial practice. In spite of the fact that both concentrates change their volume with temperature raising(cf.Fig. 4) in roasting process, their shrinkage points of volume, ie. the starting of sintering are not at the same temperature. Having the lower percent of pass of desulfuration than that of LM, the shrinkage point of volume of SM takes place obviously at about 660℃, while that of LM is at about 800℃. It may also be seen from Fig 5 and Fig.6 that at these shrinkage points the remove heat from either concentrate falls suddenly. It follows that the desulfuration reaction stops no sooner than the starting of sintering.Depending on such a result, some-measures are taken to lower the roastiagtemperature of SM in production so as to prevent the concentrateoverheating and hence the sintering in roasting process. Thus, the percent of pass of SM is raised to the same level as LM have already reached. Fig,1 The log pso2-logpo2 -priority diagram of Mo-S-O,Cu-S-O andPb-S-O systems, at 800.K Fig,2 The log pso2-logpo2 priority diagram of Mo-S-O, Cu-S-O and Pb-S-O systems, at 900K.Fig.3 Comparison of volume changes in different roasting phases between SM(left) and LM (right) specimensFig.4 Changes of height of LM and SM specimens with temperature raisingFig.5 Remove heat change as a function of temperature(SM)Fig.6 Remove heat change as a function of temperature(LM)Fig.7 Oxidation reaction rate of SM and LMTab,1 Chemical composition of SM and LMTab.2 Roasting temperature and time and sluphur residue of SM and LM更多还原