Iron Ore Agglomeration Processes and their Historical Development Dec28

Iron Ore Agglomeration Processes and their Historical Development...

Iron Ore Agglomeration Processes and their Historical Development There are four types of agglomerating processes which have been developed (Fig 1). They are (i) briquetting, (ii) nodulizing, (iii) sintering, and (iv) pelletizing. Fig 1 Agglomeration processes Briquetting is the simplest and earliest applied process. Fine grained iron ores are pressed in to pillow shaped briquettes with the addition of some water or some other binder under high mechanical compressive pressure. In the nodulizing process, fines or concentrate along with carbonaceous material are passed through inclined rotary kiln heated by gas or oil. The temperature inside the kiln is sufficient to soften but not high enough to fuse the ore. The nodules vary considerably in composition and are too dense, slaggy, lack required porosity and hence this process could not find great favour. Briquetting and nodulizing are cold binding processes and mostly used for the recycling of recovered iron ore wastes in the steel plant. Sintering and pelletizing are the processes of major importance for the iron production. During 2014, as per World Steel Association, the production of blast furnace iron and direct reduced iron were 1183 million tons and 73 million tons respectively. Most of this production has come from iron ore in the form of sinter and pellet. While the preferred feedstock for blast furnace iron is sinter and/or pellets, that of direct reduced iron is pellets only. Though accurate production data for sinter and pellets are not compiled, but world production of sinter and pellets together can be safely estimated to be well over 1300 million tons per year to support the iron production of 1256 million tons. Historically, the feedstock for the world?s blast furnaces was naturally occurring lump ores. During the mining of iron ores, large amounts were getting generated....