How Iodine is Extracted From Caliche Ore
Jan 20 2016

The process of extracting iodine from caliche ore is precise and must be followed carefully to ensure the extraction of pure, quality iodine. If you’re curious about how the extraction process works, and how we get iodine from the iodate solutions we extract, we explain it below. Contact us for more information on the extraction process and about how we can provide you with quality iodine derivatives.

Extraction of Iodine From Caliche Ore

To get the end product of iodine, we extract iodate solutions from the caliche ore in Chile. The amount of iodine recovered from the caliche ore is based on the reduction of the extracted iodate solution to iodine. Though there are several ways to extract the iodate, sulfur is the most convenient and least expensive solution, so it is the most commonly used extractive solution for the iodate.

Of course, there are other considerations that go into deciding what to use to remove the iodate from the caliche ore. The amount of nitrate in the ore is one of the main considerations, as the amount of nitrate present will determine the method of extraction used. For ore with low amounts of nitrates, a heap leaching process is used. If the ore is rich in nitrate, a vat leaching process is used.

Turning Iodate Solution Into Iodine

Once the iodate solution is retrieved from the caliche ore, it must be treated to make it suitable for obtaining iodine. To do this, the iodate solution extracted from the ore is divided into two parts. Each part is turned into a “stream” of iodate. Most extraction plants use an SO2 absorption tower, through which 5/6 of the iodate solution is passed. The remaining 1/6 of the iodate is set to react with the iodate coming out of the absorption tower. The result is a raw iodine solution or suspension. Whether the iodine is a solution or a suspension depends on the concentration of iodine in the ore.

Once an iodine suspension or solution is obtained, it is sent to a kerosene extractor, where kerosene is used to reduce the iodine to iodide using SO2. Once this reduction is completed, the iodide is converted back to a concentrated iodine solution.

At this point in the extraction process, there are three products at different points in the extraction plant: the iodate, the iodide, and the iodine. The solution coming from the kerosense extractor is combined with the initial extracted iodate, and this provides a product that can then be used for the production of useable iodine.

Most of the iodine in the raw product crystallizes at this point in the process, and must be removed from the overall solution. The crystals float to the top of the solution on their own, so no special product is needed to remove them. The crystallized iodine is moved into a heat extractor, where it is heated under high pressure, so it melts and moves into a first reactor. This first reactor acts as a settling agent for the melted iodine crystals.

After settling, the melted iodine moves to a second reactor to be dried by sulfuric acid and then refined. Once the iodine is refined, it is suitable for use in any human application, including as topical ointments, supplements and more.


Additional Iodine Reading

3 Ways Iodine is Produced and Extracted

5 Ways Iodine Derivatives Are Used Everyday

Infographic: Common Iodide Sources and Uses

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