Assessment of the possibility of processing and sulfur reduction of Band-e Narges iron deposit
The Band-e Narges iron deposit is located in the east of Easfahan Province, 55 Km northeast of Badrud County. Primary estimated reserve of deposit is two million tons iron ore with 45.6% iron content. About 1000m drilling has been done for exploration of this deposit. The ore mineral includes magnetite, hematite, pyrite, andradite, and silica and gypsum. The aim of this study is to reduce the sulfur and other gangue minerals. The study includes three steps.
The first step includes sampling, crushing, and qualitative and quantitative analysis of samples. The sampling was done from three hills that were studied separately. The total weight of sample for each hill is 400 Km that is identical of rocks down to depth of 15m. After crushing, 100 Km of each sample was sent to laboratory. Considering the result of chemical and XRD analyses, all samples contain gypsum mineral. The crushing behavior of all samples is similar. For assessing the possibility of application of iron crushing behavior for ore concentration, five compositional fractions were analyzed. The result of which shows that the sulfur grade has now identical trend, silica content increases from fine grain to coarse grain ores; so there is no possibility of application of ore crushing behavior for concentration. Petrographic studies show that magnetite minerals have signatures of martitization and pyrite has idiomorphic shape in P2 and P3 samples.
In the second step, the ore liberation was studied microscopic counting, flotation and magnetic separation methods. The whole result of this step is that: the P1 sample had 90% liberation degree. Because of pyrite, it is not possible to use the gravity method for sulfur reduction. But magnetic separation method is applicable.
This method was used in the third step of study in dry and wet conditions. The result shows that this method will increases the iron content in concentrate, decreases the silica in the concentrate and decreases the iron recovery from the concentrate. Wet magnetic separator with low intensity can be used for agglomeration in high furnace.