چكيده به لاتين
So far, many studies have been carried out on the reduction of ilmenite in order to produce feedstock for the extraction of titanium metal using Pyrometallurgical processes. One of these process is reducing ilmenite to Fe and TiO2, then smelting it to get upgraded slag (UGS) from TiO2 and pig iron. In this thesis we are going to use pelletizing process in order to carbothermic reduction iron oxide ilmenite to Fe, for using in slagging process. For this purpose, parameters affecting physical properties and carbothermic reduction of ilmenite pellets have been investigated. The optimum condition of pelletizing includes; rotational angle of 40 ° from the horizon and a rotation speed of 30 rpm, 60 minutes and optimum moisture ~ 9%. The stages of experiments are that at first, pellets with 1-5% bentonite binder and a mixture of bentonite and cement Fundo were made in four different sizes, then the drop number and fracture strength tests were taken for green and dry pellets. Carbothermic reduction was performed on two different setups (atmospheric air and argon-oxygen) with two reducing agents of charcoal and coke at temperatures of 900-1150 ºC and 1 to 10 hours. For high temperatures and below 1050 °C, the titration and weight reduction method was used to calculate the metallization. XRD and SEM have been used to study the phases formed during the reduction. The effect of increasing the bentonite in the pellet showed an increasing-decreasing trend for strength and drop number and the highest amount was obtained for 3-4% bentonite. The use of Fundo-bentonite in the pellets has an increasing trend, but for lower temperatures it has less bentonite content than the pellets. The use of a coke reducing agent at below temperatures of 1000 ºC is better than charcoal, for reduction temperatures up to 1000 ° C charcoal has a better performance than charcoal until mid-life, but in the end times, the effect of reduction is vis versa. The highest amount of metallization for pellets containing 3% bentonite in setup number one for charcoal and coke is 70% and 90%, respectively, and in setup number two, respectively, 80% and 90% respectively. A 3% increase in bentonite in the pellet resulted in a 10% reduction in resuspension and porosity. Increasing the size of the pellets in long periods of reduction has reduced the metallization rate. The addition of iron and coke up to 4% and 2% by weight, respectively, resulted in increasing the rate and metallization reduction by more than 90% at low temperatures and lower needed times.
