Chromium is used in many industrial processes. For example, chromium is used in some metals to make them harder and more resistant to corrosion and oxidation. Chromium is one of 4 elements found in Chromite. Chromite is one of the major ores that make up the Earth’s mantle. Chromite is iron magnesium chromium oxide. In some rare cases, magnesium is substituted for iron. Also aluminum and ferric ions can substitute chromium in a reaction.
Hydrometallurgy is a form of extractive metallurgy that utilizes aqueous solution chemistry for the recovery of metals from salts, minerals, or ores. Extraction is a process in which metal is removed from an ore by dissolving the metal in a solvent, then recovering the metal from the solution (This is done by dissolving the metal into an acid or water).
To isolate certain metals you need to take into account that some are amphoteric. Amphoterism is the reactivity of a substance with both acids and bases, acting as an acid in the presence of a base and as a base in the presence of an acid. A few amphoteric metals are beryllium, tin, lead, aluminum, and zinc. When aqueous zinc nitrate is reacted with a limited amount of potassium hydroxide, insoluble zinc hydroxide forms.
2 [pic] + [pic] [pic] Zn[pic] [Eq. 1]
Zinc hydroxide behaves as a base when it reacts with acids to form salts and water. In a solution containing excess [pic] ions, Zn[pic] acts like an acid and dissolves forming the complex ion[pic].
2 [pic] + Zn[pic] [Zn[pic]][pic] [Eq. 2]
Reduction-oxidation, more commonly known as “REDOX”, reactions occur when one or more electrons are transferred between reactant species. In these reactions the reactants that are oxidized lose electrons and the other reactants that gain electrons are reduced. In these reactions one of the reactants is oxidized thus the...