Hydrometallurgy To Analyze A Chromite Sample

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Hydrometallurgy to Analyze a Chromite Sample Introduction: Chromium is a metallic element that is used for many industrial purposes, such as metal plating, leather processing, pigments, surface treatments, refractories, and catalysts. The only ore of chromium is the mineral chromite, or iron magnesium chromium oxide. In order to utilize chromium, it must be extracted from the chromite ore. The process of removing a metallic element from its ore is called extractive metallurgy. One form of extractive metallurgy, called hydrometallurgy, uses aqueous solution chemistry for the recovery of metals from salts minerals or ores. The first step of hydrometallurgy, called extraction, is the process of removing metal from the ore. This is done by dissolving the metal in a suitable solvent, recovering the metal from the solution, and discarding the waste materials. The first step of extraction is leaching, in which the metal is dissolved in water or acid. Then the leach solution is purified by separating the waste from the desired materials. The final step is precipitating the metal, or one of its pure compounds from the leach solution by chemical or electrolytic means. This lab is focused on determining whether an unknown sample is chromite or not. Chromite contains magnesium, iron, and chromium, and it must be determined if the sample contains each of these metals. In order to do that, each metal must be extracted separately. There are several important concepts that need to be understood in order to preform this lab successfully. First, some metals are amphoteric. Amphoterism is the ability of a substance to react with either acids or bases. Iron and magnesium form insoluble precipitates in basic solution and are not amphoteric, while zinc and chromium are amphoteric and form complex ions in the presence of excess base. Secondly, magnesium neither absorbs nor emits

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