Journal Article

Mechanochemical Preparation of a Novel Slow-Release Fertilizer Based on Ksub.2SOsub.4-kaolinite

Al-Rawajfeh, Aiman, Alrbaihat, Mohammad, Moosa, Iessa, Al-Fayyad, Hebah, Hamadneh, Imad, Abu-Afifeh, Qusay, AlShamaileh, Ehab

2022

Overview

In this study, a novel slow-release fertilizer (SRF) consisting of kaolinite and K[sub.2]SO[sub.4] was prepared, employing the process of mechanochemical milling in a planetary ball mill. To obtain the optimum milling time and speed, several samples were made at fixed mass ratios of kaolinite: K[sub.2]SO[sub.4] (3:1). The milling rotational speed ranged from 200 to 700 rpm for 120 min. Different milling times ranging from 60 to 180 min at fixed 600 rpm milling speed were also investigated to evaluate the incorporation of K[sub.2]SO[sub.4] and to measure the liberation of K[sup.+] and SO[sub.4] [sup.2−] ions into solution. The properties of the studied samples were analyzed by Fourier transformation infrared spectrometry (FTIR), thermal gravimetric analysis (TGA), and ion chromatography (IC). The mechanochemical process is a green chemistry procedure that is successfully applied to incorporate K[sub.2]SO[sub.4] into the amorphous kaolinite structure. The slow-release performance was evaluated by determining the K[sup.+] and SO[sub.4] [sup.2−] content in the aqueous solution upon leaching. The optimum released amount of K[sup.+] after 24 h was 32 mg L[sup.−1] for the milling conditions of 180 min and 700 rpm, indicating that K[sub.2]SO[sub.4]-kaolinite has good slow-release properties. The novel SRF is cost-effective, environmentally friendly, and improves the fertilizer's efficiency in many agricultural applications.

• Publisher: MDPI AG
• Subject: Fertilizers