methods for calcium mineralization, for enriching the iron content of calcium rich industrial waste, and for producing calcium carbonate

摘要

A method of mineralizing calcium from industrial waste comprising extracting calcium ions from a suspension of calcium rich granular particles and aqueous ammonium nitrate to form a calcium-rich first fraction and a heavy second fraction. The heavy second fraction is separated from the first fraction and the calcium-rich first fraction is carbonated with a gas comprising carbon dioxide to form a suspension of precipitated calcium carbonate and aqueous ammonium nitrate. The precipitate is separated from the aqueous ammonium nitrate by centrifugal means and the separated heavy second fraction comprises an enriched weight percent of iron.