#Uses of iodine as element free

In solid-state, Iodine appears as a black-shiny crystalline substance. Taking foods like iodine mineral is beneficial and vital to human health and the proper functioning of the thyroid. Iodine is naturally found in the earth’s soil and ocean water (saltwater). Ion-exchange resin is held at this site in Japan.īy kind permission of Nihon Tennen Gas Co., Ltd.Iodine is a mineral that is contained in some foods like seafood (tuna, sardines, salmon, and lobster), grains, eggs, breast milk vegetables, iodized salts, and dairy products. The molten iodine is removed and cooled to give the solid product, known as prill (Figure 2).įigure 6 A view of a tank (on the right-hand side) in which the The iodine/kerosine suspension passes into a reactor and is heated at 400 K and at a pressure above atmospheric. The iodine is extracted using a hydrocarbon solvent (kerosine). The solid iodine is separated from the solution in flotation cells.

#Uses of iodine as element free

The absorption tower solution is mixed with a small quantity of the solution containing iodate ions to liberate free iodine: A spray of the solution is treated with sulfur dioxide in an absorption tower to release the iodine and convert it to iodide ions:

The clear solution, in which the iodate ions accumulate, is run off and cooled. The ore contains approximately 95% sodium nitrate and 5% sodium iodate, NaIO 3.Īfter the removal of sodium nitrate by crystallization, the crushed ore is leached with hot water. In Chile, iodine occurs in nitrate deposits as iodate ions (IO 3 -). The reaction can be represented thus (because the equilibrium above is displaced to the left as the iodine reacts):Īs in the blowing out process, this solution is heated again with chlorine and iodine is liberated and purified. The resin is transferred to another column, where a solution of sulfur dioxide drips through to regenerate the iodide ions (Figure 4).įigure 5 The ion-exchange method for extracting iodine from brine.īased on information from the Kanto Natural Gas Development Co., Ltd. The I 3 - ions are adsorbed on an anionic exchange resin. The iodine which is liberated reacts with iodide ions to form, principally, I3- ions: 99.5% pure iodine is obtained.įigure 4 A view of the Blowing out and Absorption towers.īy kind permission of Nihon Tennen Gas Co., Ltd. The stripped brine is returned to its source. The remainder of the solution is recycled to the absorption tower. Most of the solution is reacted again with chlorine and the iodine produced allowed to settle, remelted and then flaked. The iodine-rich air passes into an absorbing tower containing hydriodic and sulfuric acids and is treated with a solution of sulfur dioxide, which reduces the iodine to hydriodic acid (Figure 3).įigure 3 The blowing out method for extracting iodine from brine.īy kind permission of Kanto Natural Gas Development Co., Ltd. The liberated iodine is removed in an extraction tower by a counter-current stream of air, a process known as anti-blowout. Ii) the ion-exchange method (i) The blowing out method It is then chlorinated to liberate the iodine: Manufacture of iodineĪ) brine which contains iodide ions (in particular, brines that are adjacent to oil and natural gas fields)īrine containing 100-150 ppm iodine as iodide ions (the amount depending on the source) is purified and acidified with sulfuric acid. Prilled iodine is easy to handle and is dust free.īy kind permission of Godo Shigen Sangyo Co., Ltd. Geological Survey, Mineral Commodity Summaries, 2016.įigure 2 Iodine is produced as small beads, known as prill. Of disclosed amounts, Chile (66%) and Japan (32%) are by far the largest producers. The production figures for the United Sates have been witheld but it is estimated to be about 5% of global production ().

Iodine is also present in many pharmaceuticals and antimicrobial agents (disinfectants and antiseptics).Ĭalcium iodate, potassium iodate and potassium iodide are among the iodine-containing compounds added to animal feeds and to salt for human consumption to prevent medical disorders through lack of iodine and iodide ions in the body. Iodine readily absorbs x-rays and is used as a contrasting agent in medical x-ray imaging. Above all, it is required by humans for the synthesis of thyroid hormones, the thyroxines, essential for growth and development. Even though, in comparison with many other elements, iodine is produced in small quantities, it nevertheless has many uses.