A porous geopolymer with adsorption and photocatalytic degradation functions was successfully developed by utilizing Ti-bearing blast furnace slag (TBBFS) as the raw material. The prepared porous geopolymers were characterized by X-ray diffraction, scanning electron microscope, energy dispersive spectrometer, and Fourier transform infrared spectrum. Selective crystallization, water quenching, and natural cooling methods were employed to investigate the influences of these modifications on the applicability of TBBFS as a precursor for geopolymer synthesis. Water-quenched slag with amorphous content was prone to alkali dissolution, and the resulting geopolymer exhibited the highest adsorption capacity (97.18 mg/g) for methylene blue (MB) removal. Selective crystallization at 1400 °C generated a hybrid microstructure consisting of a non-cementitious CaTiO₃ crystallization phase and a cementitious amorphous fraction. The retention of CaTiO₃ in the final geopolymer enables a bifunctionality in adsorption–photodegradation. Particularly, the adsorption and photodegradation processes under various conditions were investigated. The superior removal efficiency for MB could be attributed to the synergistic effects between the geopolymer matrix and CaTiO₃, leading to an enhancement in the formation of hydroxyl radicals. The conversion of TBBFS into porous geopolymer offers an efficient and straightforward solution for slag utilization and dye removal.

Diopside-based glass-ceramics are successfully produced by recycling blast furnace slag and fluorite tailing with the addition of supplementary elements such as TiO₂, Fe₂O₃ and Cr₂O₃ as nucleation agents, using a conventional melting method. The effects of various nucleating agents on the phase components and structure of the prepared glass-ceramics were evaluated by a differential scanning calorimeter, X-ray diffraction and scanning electron microscope–energy disperse spectrometer methods to determine the optimal dosage of nucleating agents. The results show that, in the preparation of diopside-based glass-ceramics, the suitable percentages of blast furnace and fluorite tailing are 55% and 45%, and the recommended composite nucleating agents consist of 1.5% Cr₂O₃, 2% TiO₂ and 3% Fe₂O₃. Heat treatment was conducted at a nucleation temperature of 720 °C and a crystallization temperature of 920 °C, and the nucleation and crystallization durations were 1.0 h and 1.5 h, respectively. Under the abovementioned parameters, the obtained diopside-based glass-ceramics displayed a Vickers hardness of 7.12 GPa, density of 2.95 g·cm⁻³, water absorption of 0.02%, acid resistance of 0.23% and alkali resistance of 0.02%.

A new technique with carburization followed by magnetic separation is presented for the preparation of high-grade iron carbide from pyrite cinder to promote the high value-added utilization of pyrite cinder. The effects of carburizing temperature, carburizing time and Na2SO4 dosage on carburized pellets were investigated, and the effects of Na2SO4 dosage and grinding fineness on magnetic concentrate were carried out. The optimized process parameters were proposed as follows: carburizing at 650?C for 180 minutes in CO-CO2-H2 gas mixtures, Na2SO4 dosage of 9%, magnetic field intensity of 130 mT, and grinding fineness of 92.25% powder passing 0.025mm. The iron content, total carbon content, total iron and carbon content of magnetic concentrate were 82.62%, 5.60%, and 88.22%, respectively. The recovery rate of iron reached 88.67%. The behaviors and mechanisms of carburization, separation, and Na2SO4, were ascertained with optical microscopy, X-ray powder diffraction (XRD), and scanning electron microscope (SEM).