Reactive Mechanosynthesis of Urea Ionic Cocrystal Fertilizer Materials from Abundant Low Solubility Magnesium- and Calcium-Containing Minerals

Abstract

Urea is a predominantly used nitrogen fertilizer that is unstable in the environment, quickly hydrolyzing and significantly contributing to the global nitrogen cycle disbalance. We demonstrate the application of mechanochemistry to conduct the synthesis of magnesium–urea and calcium–urea ionic cocrystals, including their nitrates, sulfates, and phosphates, in high yields by stoichiometric reactions between abundant low solubility minerals such as oxides, carbonates, and hydroxides and solid urea inorganic acids. The resulting materials possess unique properties inherited from the corresponding inorganic reactants that result in urea stabilization with respect to its deliquescence in moist environments.

In situ monitoring of mechanochemical synthesis of calcium urea phosphate fertilizer cocrystal reveals highly effective water-based autocatalysis

“…12 Mechanochemistry has been shown to enable synthesis independent of the relative solubilities of reactants, providing an excellent opportunity to form agrochemical cocrystals that are typically based on inexpensive but poorly soluble ionic starting materials. 12 Mechanochemistry enables rapid reactions, such as the green synthesis of calcium urea phosphate, from very poorly soluble inorganic precursors, such as calcium carbonate or calcium hydroxide, 4,13,14 producing innocuous by-products of water and CO 2 ( Fig. 1).…”

Mechanochemistry as an emerging tool for the preparation of sustained release urea cocrystals as a nitrogen source

“…In another report, Honer et al prepared 59 a few ionic cocrystals of abundant low solubility minerals such as oxides, carbonates and hydroxides with solid urea inorganic acids using mechanochemistry. They used the most efficient and environmentally viable route for the mechanical milling of three components, i.e.…”

Mechanochemical Synthesis of Zinc Borate for Use as a Dual-Release B Fertilizer

“…For example, metal oxides or hydroxides such as Al 2 O 3 , Mg­(OH) 2 , and clay minerals , were milled with highly soluble macronutrient salts to synthesize low-solubility compounds containing potassium (K) and phosphorus (P) or nitrogen (N). Honer and co-workers applied MC to synthesize urea co-crystals either with low solubility minerals , or micronutrient salts , to enhance N efficiency by reducing ammonia (NH 3 ) emissions. Traditionally, wet chemistry involves large volumes of solution to allow reactants to dissolve, achieve homogeneity, and obtain final products.…”