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[Display omitted] • A co-treatment of steelmaking slag and steel pickling waste liquor was proposed. • FePO 4 was prepared during the collaborative treatment. • After leaching, the residue can be reused as flux within the steel plant. • Comprehensive utilization of metallurgical wastes can be achieved. To prepare FePO 4 and to achieve resource utilization of metallurgical wastes, a collaborative treatment of P-bearing steelmaking slag and steel pickling waste liquor (SPWL) was proposed. The utilization of SPWL as a leachant for P separation from steelmaking slag facilitates P-removal residue recycling within steel plants, while also serving as a Fe source for the FePO 4 preparation. In this study, the effects of synthetic SPWL with various Fe2+ (or Fe3+) contents and leaching parameters on the dissolution behavior of steelmaking slag were investigated. Moreover, the impacts of H 2 O 2 oxidation and pH on the precipitation behavior of FePO 4 from leachate were studied. It was found that increasing Fe2+ concentration in SPWL resulted in a marginal reduction in the P dissolution ratio; however, it was significantly influenced by the pH and solid/liquid ratio. Furthermore, the change in Fe3+ concentration within SPWL exhibited a conspicuous impact on the P dissolution ratio. After leaching, the residue containing massive Fe 2 O 3 , MgO, and MnO could be reused as a flux within the steelmaking process. The FePO 4 precipitated predominantly at pH 2.0 ∼ 3.0, and the crude FePO 4 product containing 42.6 % Fe 2 O 3 and 35.8 % P 2 O 5 was obtained, providing a new solution for the utilization of metallurgical wastes. [ABSTRACT FROM AUTHOR]

• Carbon dioxide capture, utilization and storage in the form of calcium carbonate. • Calcium carbonate homogeneous granulation in a fluidized-bed reactor. • The kinetic analysis revealed that the pseudo-second order best fitted the results. • Calcium-is-to-carbonate molar ratio directly affects the granule characteristics. • High purity of calcium carbonate-aragonite granules were produced. The granulation of calcium carbonate (CaCO 3) exhibited high industrial demand due to its wider application and importance in cement, paper, glass and steel manufacturing. This paper investigated the granulation kinetics of CaCO 3 through the fluidized-bed homogeneous granulation (FBHG) process during the homogenous nucleation stage. The CaOH solution was used as source of Ca2+ reactant, while K 2 CO 3 solution as source of CO 3 2− precipitant. The mechanism followed the pseudo-second order kinetics. The calcium cation attracts the carbonate anion to form CaCO 3 through a double displacement chemical reaction. The calcium-is-to-carbonate molar ratio ([Ca2+]/[CO 3 2−]) was varied into 1.25 to 2.50, with constant values of pH = 10 ± 0.2, influent carbonate concentration = 10 mM and total influx flow rate = 60 mL min−1. The ideal [Ca2+]/[CO 3 2−] condition was found to be at 1.50 that means the precipitation of CaCO 3 grew and stayed inside the reactor. At the same condition, granules of diameter size of 1 mm to 2 mm were collected with a subrounded shape and smooth surface as shown by its surface morphology. The characterization analysis also verified the high purity of CaCO 3 -aragonite granules precipitated through the FBHG process. [ABSTRACT FROM AUTHOR]