Hydrogen gas and its use in Iron and Steel industry...

Hydrogen gas and its use in Iron and Steel industry Hydrogen is a chemical element, ranking first in the periodic table with element symbol of ‘H’. The (atomic number of hydrogen element is 1 and atomic weight is 1.008. It is the smallest atom in the universe and the simplest element in nature. Its molecule consists of two hydrogen atoms. It is the lightest gas, being about 1/14 times as dense as air. It has three isotopes named (i) protium, (ii) deuterium, and (iii) tritium. Pure hydrogen is odourless, colourless and tasteless. Hydrogen has lowest atomic weight of any substance and therefore has very low density both as a gas and a liquid. The vapour density of hydrogen at 20 deg C and 1 atmosphere pressure is 0.08376 kg/cum. The specific gravity of gaseous hydrogen is 0.0696 and hence, it has around 7 % the density of air. The density of liquid hydrogen at normal boiling point and 1 atmosphere pressure is 70.8 kg/cum. The specific gravity of liquid hydrogen is 0.0708 and is thus, it has around 7 % the density of water. Hydrogen is a liquid below its boiling point of -253 deg C and a solid below its melting point of – 259 deg C at atmospheric pressure. It is non-toxic but can act as a simple asphyxiant by displacing the oxygen in the air. When hydrogen is stored as a high-pressure gas at 250 kg/cum and atmospheric temperature, its expansion ratio to atmospheric pressure is 1:240. The molecules of hydrogen gas are smaller than all other gases, and it can diffuse through many materials considered airtight or impermeable to other gases. This property makes hydrogen more difficult to contain than other gases. Leaks of liquid hydrogen evaporate very quickly since the...

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...