Selected Aspects of Fertilizer-Grade Magnesium Sulfate Crystallization from Solution after Flue Gas Desulfurization

Abstract

The presented paper deals with the discussion concerning both technological and process aspects connected with the production of a magnesium sulfate fertilizer from a solution obtained as a result of a flue gas desulfurization by means of the magnesium method. The experimental research was carried out on a laboratory scale in the MgSO 4 −MgCl 2 −H 2 O system. The paper took into account: (i) the kinetics of MgSO 4 •7H 2 O crystallization, (ii) the relation between the efficiency and the particle size, (iii) the influence of MgCl 2 concentration in the solution, and (iv) solution pH and its viscosity on the process. The degree of solution supersaturation discharge during crystallization was also analyzed. As a result, a number of practical conclusions regarding the process in industrial conditions were presented.

Measurement and Correlation of Solid–Liquid Equilibria of Quaternary System KCl–KH2PO4–(NH2)2CO–H2O and Its Ternary Subsystem KH2PO4–(NH2)2CO–H2O at 303.15 K

“…However, the excessive application of traditional chemical fertilizers has caused fertility reduction and acidification of soil, resulting in decrease of yield and quality of crops, as well as eutrophication of surrounding water bodies. − Compared with traditional solid fertilizer, the application of water-soluble fertilizer can improve the utilization rate and reduce environmental pollution. − Water-soluble fertilizer can dissolve completely in water and be quickly absorbed by plants after application, which greatly reduces the loss of nutrients. The combination of sprinkling and drip irrigation can realize the integration of water and fertilizer and save agricultural water. , The production methods of water-soluble fertilizer mainly include physical mixing method and chemical synthesis method, and cocrystallization is an important step of chemical synthesis method. , The cocrystallization technology can make the several materials mixing in the microscopic degree, so that the shape, fluidity, solubility, and stability of the product are greatly improved comparing with the physical mixing. − Multicomponent solid–liquid phase equilibrium is the theoretical basis for the study of cocrystallization process. Relevant data and phase diagrams are very important for the development, design, and control of cocrystallization process.…”