Method for the removal of calcium by products during the production of an iron feedstock

摘要

A method for the removal of calcium byproducts created during the production of an iron-based feedstock suitable for use as the feedstock for steel mills, from industrial waste streams containing iron, by treating the waste stream with an ammonium chloride leaching solution, treating the leachant with a soluble ammonium salt in which the negative ion will form an insoluble compound with calcium, and separating the undissolved precipitates comprising iron compounds and calcium compounds from the leachant solution. The undissolved precipitants may be treated further by elevated temperature roasting, resulting in the iron-based feedstocks.