Directly reduced iron, also known as sponge iron, is produced by the direct reduction of iron ore (in the form of lumps, pellets, or fines) by a reducing gas produced from natural gas or coal. This process is also known as direct reduced iron (DRI). The reducing gas is primarily composed of hydrogen (H2) and carbon monoxide (CO) in steel production, which together performs the function of a reducing agent. Direct reduction is the process of directly reducing the iron ore in solid form by using reducing gases. This process is known as direct reduction. Sintering or pelletization plants, coke ovens, blast furnaces, and basic oxygen furnaces are the components that are typically used in the traditional method of producing steel. 
These types of factories demand substantial investments in capital as well as raw materials that meet stringent quality standards. Coking coal is essential for the production of coke that is robust enough to bear the weight of the load in the blast furnace. In most cases, integrated steel factories with an annual capacity of less than one million tons of steel are not economically viable. In an integrated steel production, the units that produce the most pollution and cost the most money are the coke ovens and the sintering plants. Direct reduction is a different method of producing iron that has been created as an alternative path to solve some of the challenges that are presented by conventional blast furnaces. DRI may be successfully produced in many different regions of the world using either technology based on natural gas or technology based on coal. Coal or reducing gas (H2+CO) is used at temperatures between 800 and 1,050 degrees Celsius to reduce iron ore in its solid condition. In comparison to integrated steel plants, the specific investment and operational expenses of direct reduction facilities are significantly lower. As a result, these plants are better suited for many developing nations, particularly those with limited sources of coking coal. Because it operates at a lower temperature than the blast furnace does, the direct reduction process is inherently more energy efficient than the blast furnace. In addition, there are several other aspects which make it inexpensive, including the following: Since the iron content of direct-reduced iron is comparable to that of molten pig iron, typically consisting of 90–94% total iron (depending on the quality of the raw ore), as opposed to approximately 93% for molten pig iron, it is an excellent feedstock for the electric furnaces that are utilized by mini mills. This enables the mini mills to use lower grades of scrap for the rest of the charge or to produce higher grades of steel. The densely packed version of DRI known as hot-briquetted iron (HBI) was developed for convenience in transporting, handling, and storing the material. 
Iron that has not been cooled after being discharged from the reduction furnace is referred to as Hot Direct Reduced Iron (HDRI). This iron is then directly delivered to an electric arc furnace that is waiting to be charged, which results in a savings of energy. Iron ore can be pelletized for use in the direct reduction process, or natural "lump" ore can be used instead. The fluidized bed method is an exception to this rule because it makes use of and requires sized iron ore particles. Only a few types of ores are good candidates for direct reduction. Because the technique of direct reduction allows for the utilization of natural gas that has been tainted with inert gases, there is no requirement to separate these gases in order to put them to other uses. The effect (quality) of that gas stream, as well as the process's overall thermal efficiency, are, however, negatively impacted by the presence of any inert gas that may have contaminated the reducing gas. In regions such as Northern Australia, supplies of powdered ore and raw natural gas are both available, which eliminates the need for transporting the gas and the associated expenditures. Because it is more cost effective to ship the ore rather than the gas, the DRI plant is typically situated in close proximity to a source of natural gas. 
Direct-reduced iron is an essential component of the steel industry and India is the world's leading producer of this form of iron. In a great number of other countries, versions of the method are utilized to produce iron for the domestic engineering sector. Problems Iron that has been directly reduced is extremely prone to oxidation and rusting if it is not adequately protected, which is why it is typically processed further into steel as soon as possible. The pyrophoric nature of the bulk iron means that it can also catch fire. Wrought iron can be created from sponge iron, which is useless on its own but can be treated into wrought iron. After the sponge has been withdrawn from the bloomery (another name for the furnace), it is subjected to repeated beatings with heavy hammers and folding over in order to remove any slag, oxidize any carbon or carbide, and weld the iron together. Wrought iron is typically produced as a byproduct of this treatment, and it typically contains approximately three percent slag and a fraction of a percent of other impurities. Additional treatment may involve the addition of measured quantities of carbon, which enables a variety of thermal treatments (e.g. "steeling"). Reducing iron ore without melting it is how sponge iron is produced in modern times. Manufacturers of specialty steel, who previously relied on scrap metal, will now have access to an energy-efficient feedstock thanks to this development. 
steel production using direct reduced iron
Blast furnaces take their feed in the form of either pellets, lumps, or briquettes, and direct reduced iron can come in any of these three forms and can be the using material for steel production. When exposed to moisture, the material has the potential to oxidize quickly and produce heat over the course of some amount of time. In addition to this, hydrogen may be produced, which may contribute to the development of an explosive atmosphere. Molded briquettes reduce the likelihood of certain dangers; other goods, such as cold-moulded briquettes and material that has been specifically processed, appear to work in a manner that is analogous. However, as a general safety measure, every effort should be made to stop water from getting into the cargo compartments. It is important to block off any passageways that could allow flammable gases to infiltrate nearby enclosed areas. Direct Reduced Iron needs to be aged for at least 72 hours before it is shipped, or it needs to be treated with some kind of passivation technology, in order to bring its level of activity down to at least the same level as the aged product. During the entirety of the journey, it is imperative that hold atmospheres be kept in an inert state (with less than 5% oxygen and fewer than 1% hydrogen). Direct Reduced Iron that has been manufactured or treated in a manner that has been approved by the competent authority to provide protection against corrosion and oxidation caused by water and air may be shipped without being inerted. 
This type of Direct Reduced Iron can be protected against corrosion and oxidation by both water and air. Even if a bulk storage becomes saturated up to its highest level, this will not inevitably result in the occurrence of a problem. When the stow is subsequently moved for loading onto carrying vehicles or into a vessel, which causes the moist material to be repositioned into the center of the stow, this can result in a problem. In some instances, an inaccurate description of this product has caused it to be referred to as Sponge Iron, Iron Pellets, or Iron Ore Pellets. DRI is created by treating iron ore (oxide), which is often in the form of pellets or lumps, with hot reducing gases including hydrogen, methane, and carbon monoxide. This process is called "passing" the gases. Even though the procedure is carried out at high temperatures, those temperatures are still significantly lower than the point at which iron will melt. Because oxygen was removed from the ore throughout this process, the lumps and pellets do not change their shape, but they are far less dense than they were before. Because of this, both the pellets and the lumps have a structure that is exceedingly porous. As a result, the material is highly reactive and prone to re-oxidation when it comes into contact with air and/or moisture. These oxidation reactions lead to self-heating in the stow, which can lead to auto-oxidation, which can yield cargo temperatures that are higher than 900 degrees Celsius. In addition, coming into contact with moisture results in the production of hydrogen, a highly combustible and volatile gas that, when ignited, has been known to result in explosions within the holds of multiple ships. The first version of DRI, designated as type A, is a high-density, less reactive form of the material that is sometimes referred to as hot briquetted iron (HBI) or hot moulded briquettes (HMB). The second type of DRI is referred to as DRI (B), and it comes in the shape of lumps, pellets, and cold-molded briquettes. This type of DRI is highly reactive but has a low density. 
The schedule was updated to incorporate a new entry labeled DRI. This entry is referred to as By-product fines, and its purpose is to encompass all of the materials that are created as by-products during the production and/or processing of DRI (A) and/or DRI (B). DRI (B) can only be transported currently when it is surrounded by an inert gas atmosphere, and DRI (C) is required to adhere to the same standards as DRI (B). A summary of the most significant amendments to the Code is provided further on. Every every DRI type Particles with a size of up to 6.35 millimeters are now considered to be fines. For the purposes of inspection, the representative of the carrier is to be granted reasonable access to any stockpiles and loading installations. During the loading process, the temperatures of the cargo are to be checked on and recorded in a log. The ship is required to be outfitted with a detector that is both capable of functioning in an environment with low oxygen levels and is designed to measure hydrogen in such an environment. During the voyage, both the temperatures of the cargo and the hydrogen concentrations in the hold atmospheres are to be monitored. Prior to opening the hatch covers, measurements of the hydrogen content need to be taken in the holds. Every record of the measurements is required to be kept on board for a period of two years. DRI (A), Briquettes, hot-moulded The percentage of moisture content cannot exceed 1% under any circumstances. The shipment is going to primarily be made up of complete briquettes. 
When it is required, only ventilation at the surface level shall be carried out. When using mechanical ventilation, the fans utilized must be certified as explosion-proof and must avoid spark formation. This is a requirement. Over both the intake and the exhaust ventilation apertures, guards made of wire mesh must be installed. DRI (B), Lumps, pellets, cold-moulded briquettes The size of the particles ranges from 6.35 to 25 millimeters on average. It is expected that loading conveyors would be dry. In order to guarantee that the hatch covers and closing mechanisms are completely watertight before loading, an ultrasonic test or another approach that is functionally comparable must be carried out using the appropriate instrument. The moisture content must be below 0.3%, and this must be monitored while the container is being loaded. Any cargo that has previousl been loaded into a cargo compartment but which afterwards becomes wet or in which reactions have begun must be unloaded without delay. This includes any cargo that has been affected by moisture. Transport may only take place within the confines of an insert gas blanket. It is required that the ship be outfitted with apparatus that is capable of accurately measuring the temperature at multiple locations within the stow and determining the percentages of hydrogen and oxygen that are present in the atmosphere of the cargo space during the journey, all while minimizing the amount of the inert atmosphere that is lost. The vessel is required to be outfitted with the necessary equipment to ensure that the standards to keep the oxygen content at or below 5% can be met for the duration of the journey. The CO2 fire-fighting system that is permanently installed on the ship is not to be used for this purpose. 