Calcination and Pelletizing of Siderite Ore

Abstract

In the present study, calcination properties of Hekimhan-Deveci siderite (FeCO 3 ) ore and the effect of calcination process before the pelletization on strength of pellet were inves tigated and evaluated. Two different calcination processes were followed. One of them is the traditional calcination process and the other one is microwave assisted calcination process which is a new process for siderite ore. The characterization of the calcined and uncalcined siderite ore was done using X-ray diffraction, X-ray fluorescence spectrom etry and thermogravimetric analysis. The physical and mechanical properties of pellets which were obtained using the raw siderite and the calcined siderite were compared with each other. As a result of experimental studies, it was found that the calcination process decreased the milling time, causing the significant energy saving and the most suitable calcination process for siderite ore was found as 15 min at 700°C temperature. It was the first time that the calcination process of the siderite ore was achieved by microwave by adding 30 wt% sucrose as a thermal auxiliary. The microwave conditions were deter - mined as 900 W at 3 min. In 3 min, the temperature of the siderite ore increased up to 1100°C and 32.14% weight loss for the sample was achieved. different bentonite ratios (8, 9, 10, 11, 12%) to the raw siderite and the calcined siderite which were milled for 90 and 60 min, respectively. The raw pellets were heated at a temperature of 1300°C which is the recrystallization temperature of hematite. Recrystallization was confirmed by SEM images and the process was confirmed to be successful. The product pellets were tested for compressive strength. The highest level of pellet strength was determined from the material obtained by grinding calcined siderite for 90 min. This pellet, which has a maximum strength value of 268 kgf, has an average durability of 28% higher than the pellet of the raw siderite.