Mechanochemical synthesis of kaolin–KH2PO4 and kaolin–NH4H2PO4 complexes for application as slow release fertilizer

✍ Scribed by Solihin; Qiwu Zhang; William Tongamp; Fumio Saito

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 579 KB
• Volume: 212
• Category: Article
• ISSN: 0032-5910
• DOI: 10.1016/j.powtec.2011.06.012

✦ Synopsis

4 in separate systems were prepared by milling in a planetary ball mill. Tests with kaolin contents ranging from 25 to 75 wt.% and mill rotational speeds from 200 to 700 rpm were performed to evaluate incorporation of KH 2 PO 4 and NH 4 H 2 PO 4 and release of K + , NH 4 + and PO 4 3-ions into solution. Analyses by XRD, DTA and ion chromatography indicated that the MC process was successfully applied to incorporate both KH 2 PO 4 and NH 4 H 2 PO 4 into the amorphous kaolin structure. Release of K + and PO 4 3-ions from the system (kaolin-KH 2 PO 4 ) when dispersed in water for 24 h reached only up to 10%. Under similar conditions for the system (kaolin-NH 4 H 2 PO 4 ), release of NH 4 + and PO 4 3ions reached between 25 and 40%. These results indicated that the MC process can be developed to allow amorphous kaolin to act as a carrier of K + , NH 4 + and PO 4 3-nutrients to be released slowly for use as fertilizer.