Resource utilization of hazardous solid waste blast furnace dust: Efficient wet desulfurization and metal recovery.

Hazardous solid waste blast furnace dust (BFD) is rich in valuable metal components such as iron (Fe), zinc (Zn), manganese (Mn), and its recycling or harmless treatment is a major challenge. This paper creatively proposes the strategy of "treating waste with waste" by using BFD for desulfurization. The experimental results show that BFD slurry can achieve high-efficiency desulfurization and recovery of Zn resources. The characterization results indicate that ZnO and Fe2O3 in BFD slurry are the main active components of desulfurization, and the consumption of active components is the main reason for the decline of BFD slurry activity. Further semi-continuous experimental research shows that Zn, Fe, and Mn ions in BFD slurry play a crucial role in the catalytic oxidation of sulfur dioxide (SO2). Additionally, the effects of reaction temperature, stirring speed, inlet SO2 concentration, and inlet gas flow rate on the leaching rate of Zn and Fe were investigated. Under optimal conditions (SO2 concentration = 3000 mg‧m-3, reaction temperature = 40 °C, inlet gas flow rate = 300 mL‧min-1, solid-liquid ratio = 0.5 g/300 mL, stirring speed = 600 rpm), the desulfurization rate reaches 100%, and the maximum leaching rate of Zn can reach 44.6%. Based on the experimental and characterization results, the possible mechanism of BFD slurry desulfurization was proposed. This study provides a reference for the application of BFD in the field of wet desulfurization.

Alkaline hydrolysis of ethylene phosphate: an ab initio study by supermolecule model and polarizable continuum approach.

The alkaline hydrolysis reaction of ethylene phosphate (EP) has been investigated using a supermolecule model, in which several explicit water molecules are included. The structures and single-point energies for all of the stationary points are calculated in the gas phase and in solution at the B3LYP/6-31++G(df,p) and MP2/6-311++G(df,2p) levels. The effect of water bulk solvent is introduced by the polarizable continuum model (PCM). Water attack and hydroxide attack pathways are taken into account for the alkaline hydrolysis of EP. An associative mechanism is observed for both of the two pathways with a kinetically insignificant intermediate. The water attack pathway involves a water molecule attacking and a proton transfer from the attacking water to the hydroxide in the first step, followed by an endocyclic bond cleavage to the leaving group. While in the first step of the hydroxide attack pathway the nucleophile is the hydroxide anion. The calculated barriers in aqueous solution for the water attack and hydroxide attack pathways are all about 22 kcal/mol. The excellent agreement between the calculated and observed values demonstrates that both of the two pathways are possible for the alkaline hydrolysis of EP.