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The study described sought further understanding of the synergies in a mix of CDW pozzolans, containing (calcareous and siliceous) concrete and glass waste, used to prepare ternary eco-cement paste bearing 7% of the binary blend at concrete/glass ratios of 2:1 and 1:2. The mineralogical phases in the 2-day, 28-day, and 90-day cement matrices were identified and monitored using XRF, XRD-Rietveld, SEM-EDX, FT-IR, and NMR. The findings showed that changes in the reaction kinetics in the ternary blended pastes relative to OPC pastes depended on the nature of the recycled concrete and the glass content. Adding the binary mix bearing calcareous concrete (at a ratio of 2:1) favoured ettringite, portlandite, and amorphous phase formation, whilst the blends with siliceous concrete favoured C-S-H gel formation. Monocarboaluminate was detected in the 90-day siliceous concrete and glass pastes in amounts similar to those found in the reference OPC paste.

The particulate matter (PM) in the atmosphere may be composed of many elements and compounds, including toxic species and hazardous materials, which demand effective control of its emissions, starting with the knowledge of the sources. In this sense, the mineralogical analysis of the PM might be a powerful tool. Here, we present a comprehensive mineralogical characterization of the coarse and fine PM in an industrialized city southeast of Brazil, including a discussion about the transport, deposition, and potential sources associated. Elemental and mineralogical analyses by EDXRF and RSr-XRD were performed on SPM, TSP, PM 10 , and PM 2.5 . The results showed distinct mineralogical composition depending on the PM size. Mineral phases in SPM and TSP were majorly composed of hematite and quartz, while PM 10 and PM 2.5 were majorly composed of carbon, halite, sulfates, and carbon. The results show hazardous mineral phases associated with respiratory injuries in all PM size classes, such as hematite, pyrite, EC, and quartz. The XRD analysis also revealed primary particles of sulfate in the region close to industrial sources., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

The influence of fuel level on Russian vanadiferous titanomagnetite sinter properties, productivity, and mineralogy are researched by sintering pot testing, metallographic microscopy, scanning electron microscopy analysis, and energy dispersive spectrometer (SEM-EDS) analysis. A comprehensive index is evaluated in conjunction with the same indexes and significance coefficient as that in the Panzhihua Iron and Steel Group. Results show that with the increasing fuel level from 3.5% to 6.0%, flame front speed, yield, tumbling test index (TI), and productivity, all first increase and then decrease. The low temperature reduction degradation index (RDI +3 . 15 ) and softening zone (ΔT) gradually increase while the RI and starting temperature of softening (T 10 ), and ending temperature of softening (T 40 ) decrease with increasing fuel levels from 3.5% to 6.0%. With the increase of fuel level from 3.5% to 6.0%, the content of FeO, SiO 2 , and MgO increase, while TiO 2 shows a decrease. For the same increase in fuel level, the number of pores and calcium ferrite and hematite decrease but the silicate increases. In addition, in the fuel level range of 3.5% to 5.5%, magnetite correspondingly increases but then shows a drop after 5.5%. Moreover, when the fuel level increases to greater than 5.0%, FeOx and fayalite quickly increase and a small amount of metallic iron appears under the fuel level of 6.0%. Overall, the optimal fuel level under current production conditions and indicator selection is 4.0%.

At present, the dealkalization and comprehensive utilization of red mud is a worldwide problem. Studies on the settling performance and phase transformation of red mud by HCl, CaO, and H 2 O leaching are limited. In this study, the characteristics of red mud were systematically analyzed. The average sizes of graded and initial red mud were 4.11 and 9.20 μm, respectively. X-ray diffraction (XRD), X-ray fluorescence spectra (XRF), and thermogravimetry-differential scanning calorimetry (TG-DSC) results indicated the different mineralogical phases, composition, and thermal behavior. The addition of HCl could neutralize the alkalization in the red mud slurry, and CaO could replace the Na and K. Notably, the pH of the red mud slurry had no obvious change with the increase in water washing times in a certain pH. Interestingly, soluble Al and Fe were not detected in the HCl-red mud and CaO-red mud. In addition, the settling ratio was used to express the settling performance of the red mud slurry. Their interaction mechanisms were proposed, which may include phase transformation and the changing of the size and surface area. The research provided a better understanding of the phase transformation and settling performance in the treatment of red mud by HCl, CaO, and H 2 O leaching.