HYL Process for Direct Reduction of Iron Ore Apr22

HYL Process for Direct Reduction of Iron Ore...

HYL Process for Direct Reduction of Iron Ore HYL process is designed for the conversion of iron ore (pellet/lump ore) into metallic iron, by the use of reducing gases in a solid-gas moving bed reactor. Oxygen (O2) is removed from the iron ore by chemical reactions based on hydrogen (H2) and carbon monoxide (CO) for the production of highly metallized direct reduced iron (DRI)/hot briquetted iron (HBI). HYL process is presently marketed under ‘Energiron’ trademark. HYL process for direct reduction of iron ore was the fruition of research efforts begun by Hojalata y L.mina, S.A. (later known as Hylsa), at the beginning of the 1950s. After the initial evaluation of the concept, it was decided to install a process using a tunnel furnace and several runs were undertaken. The first batch was made by using an ancient furnace (which had been built to heat plate) on the 5th of July, 1950. One part of crushed ore of size ranging from 12 mm to 25 mm was mixed with 40 % coke breeze and 15 % limestone of the same granulometry as the ore. This mixture was put into clay crucibles and into 2 iron pipes, each one with a diameter of 100 mm and a length of 1 meter. 20 kg of good quality of DRI was produced. The first gas based plant, with a design capacity of 50 tons per day, was unable to reach acceptable levels of metallization. During the 18 months of its operation, it underwent several changes, including the installation of a natural gas reformer with the object of improving the reducing gas. Finally, its operation was suspended during early 1955. After this discouraging attempt, several experiments were carried out and a pilot plant was assembled to put the new...

Midrex Process for Direct Reduction of Iron Ore Apr09

Midrex Process for Direct Reduction of Iron Ore...

Midrex Process for Direct Reduction of Iron Ore Midrex is an ironmaking process, developed for the production of direct reduced iron (DRI). It is a gas-based shaft furnace process is a solid state reduction process which reduces iron ore pellets or lump ore into DRI without their melting using reducing gas generally formed from natural gas. The principle of the reduction process using reducing gas is shown in Fig 1. Fig 1 Principle of reduction process using reducing gas The history of the Midrex process goes back to 1966 when Donald Beggs of the Surface Combustion Corporation conceives the idea for the Midrex direct reduction process.  The original process was developed by the Midland-Ross Co., which later became Midrex Technologies, Inc. It is now a wholly owned subsidiary of Kobe Steel. A pilot plant was built in Toledo, Ohio in 1967. The first commercial plant, having a production capacity of 150,000 tons per year, was built in Portland, Oregon, in 1969. The genius of the Midrex process is its simplicity. Donald Beggs’ concept of combining stoichiometric natural gas reforming with shaft furnace direct reduction of iron ore was a breakthrough innovation which has stood the test of time. Since 1969, DRI production through Midrex process has crossed 500 million tons. Production from many of the Midrex plants exceeds their design capacity. Each year since 1987, DRI production through Midrex process is over 60 % of the total global production of DRI. The process was immature in 1978, when Kobe Steel began the construction of a plant with a production capacity of 400,000 tons/year in the State of Qatar. Kobe Steel significantly modified the design, exploiting the company’s technologies developed through blast furnace operation, and stabilized the then new process. On the other hand, Midrex...

Iron Nuggets

Iron Nuggets  The process of production of iron nuggets is capable of directly producing solid, high density, highly metalized iron nuggets from dry green balls. These green balls are made out of iron ore fines, pulverized coal, fluxes and binders. The pulverized coal is reductant which is added to the system to supply the carbon required for the reduction and carburization. Binder (bentonite) in conjunction with the finely ground iron ore particles serves to improve the properties of green balls in wet and dried conditions. The flux is limestone, which fluidizes the slag and also prevents excessive iron losses in the slag. The iron nuggets are produced using a direct reduction process. The reduction process is carried out in a rotary hearth furnace, using coal as the reductant and energy source. The direct reduction of iron by this process is more energy efficient and more environmentally friendly than traditional iron making processes. The process for producing iron nuggets by ITmk3 is described in the article having link http://ispatguru.com/itmk-3-process-of-making-iron-nuggets/ Iron nuggets are an ideal feed material for steelmaking and iron casting. This material consists of essentially all iron and carbon, with practically no gangue (slag) and low levels of metal residuals. Fig 1 shows sample of iron nuggets. Fig 1 Iron nuggets  Iron nuggets are a premium grade iron product with superior shipping and handling characteristics. They can be shipped in bulk either inland in railway wagons or trucks or in the ocean going vessels. Iron nuggets can be stored outside with no special precautions. They can be handled as a bulk commodity using conventional magnets, conveyors, bucket loaders, clams, and shovels. The physical properties of iron nuggets are as follows. Colour – Gray Shape and appearance – Pebble shaped elliptical structure Size – 5...

Direct Reduced Iron

Direct Reduced Iron Direct reduced iron (DRI) is also known as sponge iron. It is produced by the reduction of iron ore (in the form of lumps or pellets) by either non-coking coal or a reducing gas produced by reforming of natural gas. The reducing gas can also be produced by the gasification of coal. The reducing gas is normally a mixture. The majority gases in this mixture are hydrogen (H2) and carbon mono oxide (CO). These gases act as reducing agents. The reduction process is conducted at high temperature but substantially below the melting point of iron. Since the reduction reaction takes place in solid state, the lump or pellet retain their original shape, but are considerably lighter due to the removal of the oxygen from the ore. Hence the produced direct reduced iron has a highly porous structure. This porous structure gives DRI an appearance of a sponge and because of it, DRI is also known as sponge iron. Iron content in the DRI is in two forms. One is in metallic form which is known as metallic iron, Fe (M), and the second form is iron present in residual iron oxides, Fe (O). The total iron Fe (T) in DRI is the sum of these two iron components. Metallic iron is the aggregate quantity of iron, either free or combined with carbon (as cementite) present in DRI. Metallization of DRI is a measure of the conversion of iron oxides into metallic iron (either free or in combination with carbon as cementite) by removal of oxygen due to the action of the reductant used. Degree of metallization of DRI is the extent of conversion of iron oxide into metallic iron during reduction. It is defined in percentage of the mass of metallic iron divided by the mass of...

Discharge options for Direct Reduced Iron and its Hot Transport Dec14

Discharge options for Direct Reduced Iron and its Hot Transport...

Discharge options for Direct Reduced Iron and its Hot Transport The two main methods of producing direct reduced iron (DRI) are (i) gas based process in a vertical shaft furnace and (ii) coal based process in a rotary furnace.  In both the processes the reduction reactions take place in solid state and the maximum furnace temperatures are in the range of 850 deg C to 1050 deg C. In the coal based process, the produced DRI is mixed with char that is needed to be separated from DRI. Hence DRI-char mixture is cooled in a rotary cooler and then char is separated from DRI by the magnetic separation process. In the case of vertical shaft furnace processes, since char is not present along with DRI, there are three discharge options available. These are cold DRI (CDRI), hot briquetted iron (HBI), and hot DRI (HDRI). Most of the vertical shaft DRI furnaces have been built for the production of CDRI. In these furnaces the DRI produced after reduction is cooled in the lower part of the furnace to about 50 deg C. CDRI is temporarily stored in Silos for passivation before it is transported to a nearby steel melting shop for its use later. CDRI has got the property of auto ignition and need special precautions during transport and storages as required by the International Maritime Organization (IMO). CDRI is most suited material for the continuous charging in the EAF. HBI is now being produced since more than 30 years. It is the desirable method of preparing DRI for storage and transporting it by sea going vessels. For the production of HBI, hot DRI is discharged from the vertical shaft furnace at a temperature of around 700 deg C. The hot DRI is sent to...