Background
Almost all phosphorus used in modern fertilisers originate from phosphate mines. The phosphate-containing apatite rock is mined and shipped to fertiliser industries. The fertiliser industry traditionally uses large amounts of energy for water evaporation to produce a highly concentrated phosphoric acid from the apatite.
The phosphoric acid is then used as a raw material for different types of phosphate fertilisers. This creates a large energy demand which constitutes a substantial part of the industry’s operational cost. The processes also often lack the ability to remove all the heavy metals present in the apatite, therefore the final product will contain heavy metals such as cadmium which end up in either the food or the soil.
