Carbonate-hosted lead-zinc ore deposits and pyrite thus form. Commonly MVT deposits form by the combination of hydrocarbon pyrolysis liberating zinc-lead ions and sulfur to form an acidic solution which dissolves the host carbonate formation and replaces it with massive sulfide accumulations. This may also take the morphology of fault-hosted stockworks, massive tabular replacements and so forth. Porous limestones may form disseminated ores, however most MVT deposits are massive sulfides with knife-like margins between carbonate and sulfide mineralogies. Ore minerals in carbonate replacement deposits are typically lead sulfide, galena, and zinc sulfide sphalerite. Weathered equivalents form anglesite, cerussite, smithsonite, hydrozincite and secondary galena and sphalerite
Iron ore over a slurry containing magnetite or other agent such as ferrosilicon which increases its density. When the density of the slurry is properly calibrated, the hematite will sink and the silicate mineral fragments will float and can be removed. Iron is the world's most commonly used metal - steel, of which iron ore is the key ingredient, representing almost 95% of all metal used per year. It is used primarily in structural engineering applications and in maritime purposes, automobiles, and general industrial applications (machinery). Iron-rich rocks are common worldwide, but ore-grade commercial mining operations are dominated by the countries listed