To what extent do soft mechanical activation and process parameters increase the efficiency of different zeolite/phosphate rock fertilizer mixtures?

Abstract

In order to obtain effective mineral fertilizer, different mixtures of phosphate rock (PR) with natural clinoptilolite (Cp) and NH4+ saturated clinoptilolite (NH4-Cp) were subjected to soft mechanical activation. Mean concentrations of P released from mechanically activated (MA) substrates, MACp/PR and MANH4-Cp/PR, ranged between 2.81-3.19 mg L-1 and 2.02-7.74 mg L-1, respectively. These are 10 to 15 times higher P concentrations than those released from the corres-ponding non-activated mixtures. Solution Ca2+, K+, Na+ and Mg2+ concentrations varied according to the composition of the mixtures and the contact time between the two minerals within their optimal values required for plant growth. The obtained results suggest that the efficiency of the NH4-Cp/PR mixtures can be significantly increased by the proposed mechanical activation. Influence of process parameters on the observed concentrations of nutrients was shown using multivariate statistics. The highest fertilization potential demonstrated MANH4-Cp/PR mixture with the largest NH4-Cp share and the longest proposed mixing time. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 31003] This article has been corrected. Link to the correction 10.2298/CICEQ170425016E

Keywords

• exchange-fertilizer mixtures
• phosphate rock
• clinoptilolite
• mechanical activation
• multivariate analysis