Process for obtaining slow release P-K fertilizer with a zeolite base

Process for obtaining slow release P-K fertilizer with a zeolite base. A process for obtaining fertilizer products charged with phosphorus and potassium from tuffaceous materials of volcanic origin which are rich in ion exchange minerals known as zeolites is described. The process consists in grinding and screening the zeolite material to a particle size of less than 2 mm diameter and treating it with concentrated solutions of orthophosphoric acid in order to remove the exchangeable sodium in the material and increase its porosity. Subsequently the material is washed with water to remove excess acid and again treated with concentrated solutions of monopotassium orthophosphate (KH2PO4). These products can increase the cost/effectiveness ratio of the original fertilizer product. PROCEDIMIENTO PARA LA OBTENCION DE FERTILIZANTES P-K DE LIBERACION LENTA CON BASE ZEOLITICA. SE DESCRIBE UN PROCEDIMIENTO PARA OBTENER PRODUCTOS FERTILIZANTES CARGADOS EN FOSFORO Y POTASIO A PARTIR DE MATERIALES TOBACEOS DE ORIGEN VOLCANICO, RICOS EN MINERALES CAMBIADORES IONICOS DENOMINADOS ZEOLITAS. EL PROCESO CONSISTE EN MOLER Y TAMIZAR EL MATERIAL ZEOLITICO HASTA UN TAMAÑO DE PARTICULA INFERIOR A LOS 2 MM DE DIAMETRO Y TRATARLO CON SOLUCIONES CONCENTRADAS DE ACIDO ORTOFOSFORICO, AL OBJETO DE ELIMINAR EL SODIO DE CAMBIO DEL MATERIAL Y AUMENTAR SU POROSIDAD. POSTERIORMENTE, EL MATERIAL SE LAVA CON AGUA PARA ELIMINAR EL EXCESO DE ACIDO Y SE TRATA DE NUEVO CON SOLUCIONES CONCENTRADAS DE ORTOFOSFATO MONOPOTASICO (KH2PO4). ESTOS PRODUCTOS PUEDEN INCREMENTAR LA RELACION EFICACIA: COSTO DEL PRODUCTO FERTILIZANTE ORIGINAL.