Already in March 2011 RHEWUM supplied a screening machine type RHEWUM WAU to the Spanish fertilizer producer Asturiana de Fertlizantes S.A. The company produces as joint venture besides fertilizers chemicals as magnesium superphosphate and sulfate. The production site is located at San Juan de Nieva in the North of Spain, easily to access at the Atlantic Ocean.
The screening machine operates up to 1900 t/d of superphosphate, it separates the fertilizer at 6.0 mm and 2.0 mm. The screen cut of 6.0 mm keeps agglomerates out of the product stream reliably whereas at the same time the screening at 2.0 mm ensures the de-dusting of the ready for sale superphosphate, which simplify the distribution on the field in order to equalize the nutrition of the plants. Superphosphate is produced by decomposing of natural rock phosphate with sulphuric acid. In this process water-insoluble calcium sulphate as well as calcium hydrogen phosphate is formed. This mixture already contains approx. 20 % of superphosphate (P2O5). Besides superphosphates used as fertilizer double superphosphate (DSP) and triple superphosphate (TSP) are used as fertilizer as will. The phosphate content increases up to approx. 36 % for DSP and 48 % for TSP.