Extractant efficiency in the solubilization of alternative sources of potassium

• Published in: Acta scientiarum. Agronomy Vol. 38; no. 3; pp. 397 - 406
• Main Authors: Reis, Daniele Nogueira dos, Van Straaten, Peter, Furtini Neto, Antonio Eduardo, Bittar, Sheila Maria Bretas, Curi, Nilton
• Format: Journal Article
• Language: English; Portuguese
• Published: Maringa Editora da Universidade Estadual de Maringá - EDUEM 2016; Eduem (Editora da Universidade Estadual de Maringá)
• Subjects: AGRONOMY; Fertilizers; Minerals; Phosphates; Potassium; powdered rock; soluble K; K solúvel; minerals; fertilizantes; minerais; fertilizers; powdered rock; soluble K; pó de rocha
• ISSN: 1679-9275; 1807-8621; 1807-8621
• DOI: 10.4025/actasciagron.v38i3.28457

Knowledge of a rocks composition allows for inferences regarding several properties, ranging from its physical characteristics to its solubility. This study aimed to evaluate the use of different extractants to solubilize the K present in rocks as a potential source of nutrients and the effects of extractant contact time and temperature on rock solubilization. Samples of two rocks and a mineral concentrated from a granitic rock were treated with ammonium dihydrogen phosphate (NH4(H2PO4)), calcium dihydrogen phosphate (Ca(H2PO4)2), sodium hydroxide (NaOH) and water (control). Sample-extractant treatments were performed using a water bath shaker at temperatures of 25 and 50°C for periods of 3, 7, 10, 20, and 30 days. The amounts of K extracted from rocks using the extractants were in the following order: NH4H2PO4>Ca(HPO4)2>NaOH>water. The sequence of K release (ppm) based on the rocks studied was as follows: nepheline syenite>green banded argillite>concentrated biotite. Increasing the extractant contact time and temperature enhanced the solubilized K content.