| Hybrid sintering process with acid and basic materials is an innovative technology which combines the advantagesof sintering and pelletizing. And this method breaks the traditional thought of pellets can only be made in the shaftfurnace, rotary kiln and realizes the sintered ore and pellets can be both produced in the same sintering equipment.TheFine-grained iron is processed into pellets alone and mixes with the coarse iron ore on the sinter machine. Finally weget a high quality sinter which consists of basicity and acid pellet embedded.The acidic pellet size, pellet size composition, carbon content, acidity and alkalinity are studied on vanadium-titanium sinter through laboratory sintering cup.Studies show that the pellet diameter of10~12.5mm is the best, whichthe product rate reached87.06%, the strength of the drum is61.30%; The optimum acid pellets size composition is that5~8mm is20%,8~10mm is25%,10~12.5mm is45%and more than12.5mm is10%; Based on the sintere drumstrength, drop strength, sintering time, sintering vacuum, yield, metallurgical properties of sinter, the optimumparameters are as follows: the carbon content is3.8%, the material alkalinity is2.55, sintering negative pressure is1200kPa, the amount of pellets is30%.The effect of the amount of liquid phase on vanadium titanium magnetite sintering is studied using FactSage6.4.The results show that the sintering temperature has a very large impact on the amount of liquid phase. And with thesintering temperature increases, the liquid phase is gradually increased. It generates dramatically between1200℃~1300℃. When the temperature reached to1400℃, the amount of liquid phase reached the highest value, an amount of71.31%. If the temperature continues the amount of liquid phase can not increase. Alkalinity affects the quantity of theliquid phase largely, with the increase of alkalinity, the amount of liquid phase increase gradually, and with the increaseof basicity, the lower the temperature of the liquid phase is formed. During the whole process of through oxygen, theliquid content increased, but the growth is slow. Too much supply of oxygen will reduce the conten of liquid phase.The acid-basic sinter includes high basicity sinter, acid pellet and transition structure. Calcium ferrite is the mainbinder phase in high basicity sinter, and develops perfectly; Fe3O4crystallizes very well within acid pellet, outer layerof the acid pellet is highly oxidized Fe2O3. And there is transition structure between high basicity sinter and acid pellet,which provides perfect strength for the sinter. |
