In the present study a detailed characterization followed by beneficiation of low grade iron ore was studied. The Run of Mine (R.O.M) sample assayed 21.91 % Fe, which is very low grade in nature. The impurities are SiO2 26.25%, MgO 20.48%, CaO 5.85%, Al2O3 1.86% and loss on ignition (LOI) 12.71%. A Davis Tube test was performed for the assessment of the separability of magnetic ores by low intensity magnetic separators. The heavy liquid test was carried out to evaluate the possible response of the sample by the gravity concentration technique. The samples were subjected to jigging, dry low intensity magnetic separation (DLIMS) and shaking table tests. Thus a sufficient concentrate could not be obtained in +1 mm by using jigging and DLIMS. The obtained results show that the a high grade iron concentrate (>65% Fe) with lower recoveries was obtained from shaking table tests by using -1 mm fraction. According to the results a flowsheet was developed. From the developed flowsheet, it is possible to obtain pellet grade concentrate with 65.41% Fe, 2.54% SiO2, 2.79% MgO, 0.70% CaO and 0.32% Al2O3. with 21.42% weight recovery. The overall gangue rejection recovery of the circuit is over 95%.
https://doi.org/10.19111/bulletinofmre.834182
Keywords:
Low grade iron ore, Gravity concentration, Magnetic separation, Flowsheet development
Evaluation of the alternatives for gold ore grinding circuits by using of laboratory studies results and simulation method; case study: İranian Gold Co.
In this study, simulation aided design of grinding circuit for a gold mine in Iran is presented. The main parameters for the design of the grinding circuit are the ore specifications and the considered operating conditions. Ore specifications were characterized by grinding tests, which included the Drop – weigh test (A, b), the abrasion test (ta) and the Bond Work Index test (Wi). For this study, the operating conditions for the processing plant are the ability to process clayey minerals and the plant throughput and the d80 of the hydrocyclone overflow (leaching tank feed), which are 125 tons per hour and 45 μm, respectively. Simulation operations were performed using grinding parameters (A, b, ta, Wi), operating constraints (plant capacity, d80 of the hydrocyclone overflow and ability to work for clayey minerals), existing mathematical models for different types of crushers, mills and separators and JKSimMet software. By completing the simulation process, three different alternatives for the grinding circuit of the considered ore were predicted. These three alternatives have been compared and evaluated with each other in terms of specific energy consumption (kWh/t), sensitivity to operational variables and the ability to process clayey minerals. The optimal circuit must have the capability to process clayey minerals and must have the lowest specific energy consumption and the least sensitivity to operational variables. By considering all these factors, the Alternative 3 is selected and suggested for an efficient grinding circuit.
https://doi.org/10.19111/bulletinofmre.501432
