Direct reduction of iron ore

Direct Reduction of Iron Ore Bibliographical Survey, The Metals Society, London, 1979. 

Conventional uses of methanol account for 90% of present consumption and include formaldehyde, dimethyl terephthalate, methyl methacrylate, methyl halides, methylamines and various solvent and other applications. Newer uses for methanol that have revitalized its growth and outlook include a new technology for acetic acid, single cell protein, methyl tertiary butyl ether-(MTBE), and water denitrification. Potential uses for methanol include its use as a carrier for coal in pipelines, as a source of hydrogen or synthesis gas used in direct reduction of iron ore, as a direct additive to or a feedstock for gasoline, peak power shaving and other fuel related possibilities. Table II lists the world methanol demand by end use in 1979. 

Fuel uses are a potential application which would require substantial volumes of methanol. As mentioned earlier they are reviewed in the following chapter. A fuel related potential use of methanol is as a replacement for water used to carry coal in pipelines. Methanol is being considered for this use because it would eliminate a demand for water, which is often scarce in areas where coal is mined, and methanol could be burned as a fuel with the coal at its destination. Methanol has also been touted as a good feedstock for gases used in the direct reduction of iron ore. If this use of methanol is realized, it will not be before the mid to late 1980 s. Other potential new uses for methanol include a feedstock for ethylene and propylene production (9) and a feedstock for gasoline production (10). 

Direct Reduction of Iron Ore in a Moving-Bed Reactor Analyzed by Using the Water Gas Shift Reaction... 

A model for the direct reduction of iron ore in a moving bed has been developed. The model accounts for the water gas shift equilibrium as well as reduction by the species H2 and CO. Inclusion of this equilibrium has been shown to enhance reduction especially at the high conversions required.Increase of operating temperature can give decreased conversions. 

Another approach receiving increased interest is direct reduction of iron ore. In this process, coal is added directly to the smelting vessel and is the source of the reducing gases and thermal energy. Thus, easily crushed and handled, inexpensive noncoking coals of high calorific value can be used. Particle size requirements are variable, but less than 1 mm is most often used and, in some cases, there is an effort to restrict moisture content to below 6 percent. 

SPARG A process for the C02 reforming of methane, producing carbon monoxide and hydrogen, using a partially presulfided nickel catalyst. Developed by Haldor Topsoe in the 1990s for the direct reduction of iron ore, but not commercialized. 

While the traditional blast furnace is preferred for large-scale operations, processes for the direct reduction of iron ore using carbon monoxide and/or hydrogen are becoming increasingly important. Such processes have the ability to use lower-grade iron ores, particularly fine ore particles, and fuels such as natural gas that are unacceptable for the blast furnace. The iron... 

The M3A1 based materials were exposed in flowing C0-H2-H20 mixtures at 650 °C for different periods of time. Corresponding atmospheres are used in many processes attained from methane conversion for use in synthesis of ammonia, hydrocarbons, alcohols etc. or in the direct reduction of iron ores. The materials tested were (concentration in wt%) ... 

W. Pietsch, Die KomvergroKerung in der Verfahrenstechnik imd ihre industrielle Anwen-dung am Beispiel der Direktreduktion von Eisenerzen. (Size enlargement in process engineering and its industrial application as exemplified by the direct reduction of iron ores.) Aufbereitungs-Technik (part 1) 23 (1982)4, 193-200 (part 2) 23 (1982)5, 248-257. 

Another new application of coal briquetting that is already being used, is the den-sification and shaping of solid reductant for the direct reduction of iron ores. Such briquettes are mixed with iron ore and fed into the reactor where controlled combustion provides heat and reducing gas for the production of direct reduced iron (DRI). 

Size enlargement in process engineering and its industrial application as exemplified by the direct reduction of iron ores.)... 

Direct reduction of iron ore to sponge iron which can then be converted to steel in an electric arc furnace is a process that takes place outside a blast furnace avoiding the use of coke. This process is more favorable than the traditional raw iron production by merms of coke. The chemical reactions are ... 

As an indication of the flexibility of the EAF, it is used in some developing countries for the direct reduction of iron ore by carbon [27.18]. The furnace is charged with iron ore intimately mixed with ground carbon. Quicklime, calcined dolomite and fluorspar are added and an oxygen lance is used to oxidise the impurities much as in the BOS process. The slag is removed and the chemical... 

Midrex process Process for the direct reduction of iron ore with reduction gases [5, 6]. 

Gas-solid reactions are sometimes also conducted in rotary furnaces for example, for direct reduction of iron ore with coal or for the production of cement (Figure 4.10.10). 

Figure 4.10.10 Reactor for direct reduction of iron ore with coal in a rotary furnace (a inlet for ore and coal b reduction oven, c outlet, d main burner, e inlet to cooling section, f cooler for rotary furnace, g product outlet, h transport to magnetic separation, i outlet for large particles, Ic outlet for off-gas, I burner. Adapted from Baerns, Hofmann, and Renken (1999).

The steam reforming process is an important element in solving the problem of the huge amounts of associated gas produced jointly with oil production. The gas may be converted either into methanol or synthetic liquid hydrocarbons. Other applications include gases for direct reduction of iron ore, conversion of hydrocarbons for fiiel cells, and advanced energy transfer systems, in which nuclear heat or solar energy are absorbed by the endothermic steam reforming process. 

IGCC-integrated gasification combined cycle, DRI - direct reduction of iron ore. a) Czech design of Lurgi-type Mark III. 

Yi-Lingytm, Huang-Zhucheng, Peng-Hu. Action rules of H2 and CO in gas-based direct reduction of iron ore pellets [J]. J. Cent. South Univ, 2012( 19) 2291- 2296. 

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