Phase Composition of Aqueous Urea–Ammonium Nitrate (UAN)–Zinc Nitrate Solutions for Sustainable Reuse of Zinc Containing Industrial Pigment Waste

Abstract

Sustainable metal recovery from waste is of utmost importance. Zn is a micronutrient that is abundant in many industrial wastes. In this work, the process of converting industrial white pigment waste into a Zn micronutrient containing nitrogen fertilizers was developed utilizing an HNO 3 extraction method. For this purpose, solubility diagrams, polytherms, were constructed of the ternary CO(NH 2 ) 2 −Zn(NO 3 ) 2 −H 2 O and NH 4 NO 3 −Zn(NO 3 ) 2 −H 2 O systems to determine the corresponding phase equilibria and solid material chemical composition. Complex salts containing Zn and two and four urea molecules were observed and the catalytic Zn(NO 3 ) 2 effect was observed at the decomposition temperature of CO(NH 2 ) 2 during thermal analysis. Two crystalline phases of NH 4 NO 3 , namely III and IV, were observed and the corresponding transition temperature decreased with increasing Zn(NO 3 ) 2 concentration in solution. Zn extraction in the form of soluble Zn(NO 3 ) 2 was performed from the white pigment industrial waste and optimal extraction parameters including HNO 3 concentration, stoichiometric amount and temperature were determined. These included a 60°C solution temperature, 55% HNO 3 concentration and 140% of stoichiometric HNO 3 amount. This agreed well with the reactive conditions currently used in nitrophosphate fertilizer production potentially enabling direct production of micronutrient containing NP fertilizers without significant technology modification. Sensible compositions of UAN-28 and UAN-30 liquid fertilizers containing Zn micronutrient from industrial grade compounds and pigment waste extracted Zn(NO 3 ) 2 were obtained and their physicochemical properties were measured.

Dairy Wastewater for Production of Chelated Biodegradable Zn Micronutrient Fertilizers

“…Environmental impacts due to waste disposal are not restricted to a certain area, but spread around the globe through trade calling for a sustainable (waste) material management. In this work the focus is on sustainable use of two waste streams, zinc containing wastewater from metal processing industries, such as that from white pigment production, and dairy processing wastewater, to produce chelated micronutrient fertilizers.…”

“…In this work, we attempt to synthesize Zn containing biodegradable materials to possibly serve as fertilizer source containing both organic carbon necessary for plants and the micronutrient Zn. We utilize zinc nitrate as the metal source since we showed that complex metal containing industrial waste can readily be solubilized using industrial grade HNO 3 . , …”

Urea–Ammonium Nitrate Aqueous Solutions Containing Cu Micronutrient Obtained from Cable Manufacturing Solid Waste

“…This is especially true for metal salt mixtures obtained from complex manufacturing waste containing several metals that may result in sudden crystallization temperature increase as opposed to pure, single-metal salt solutions. 28 Next, we will explore solubility parameters in the NH 4 Table 3, and the corresponding data are plotted in a ternary diagram shown in Figure 2. Crystallization temperatures for the solution compositions explored in this work ranged from 36.5 to −26.1°C.…”

Synthesis and Characterization of Yellow Pigments of Bi1.7RE0.3W0.7Mo0.3O6 (RE = Y, Yb, Gd, Lu) with High NIR Reflectance

“…As a result, the so-called “urban heat island” is formed after the heat accumulation. , Afterward, the buildings absorb the excess of solar radiation power, increasing the demand of additional energy for cooling. The literature has reported that the Urban Heat Island Effect made the temperature of the city center 3–5 °C higher than the surrounding area. , In order to achieve a sustainable development strategy, energy conservation and environmental friendliness are two major global problems . Therefore, it is a challenge to use less sources of energy to cool the surrounding environment.…”

“…3,4 In order to achieve a sustainable development strategy, energy conservation and environmental friendliness are two major global problems. 5 Therefore, it is a challenge to use less sources of energy to cool the surrounding environment. To our knowledge, the heat of an object is from absorbing the near-infrared band of sunlight.…”