Extraction of W, V, and As from spent SCR catalyst by alkali pressure leaching and the pressure leaching mechanism.

Spent selective catalytic reduction (SCR) catalysts are environmentally hazardous and resource-enriching. In this work, V, W, and As in a spent SCR catalyst was extracted by alkali pressure leaching. Results showed that the V, W, and As were loaded on the anatase TiO crystal grains as amorphous oxides.

Novel Synergistic Process of Impurities Extraction and Phophogypsum Crystallization Control in Wet-Process Phosphoric Acid.

Phosphogypsum, as a byproduct of wet-process phosphoric acid reaction, has caused many environmental pollution problems. To improve the property and purity of phosphogypsum in the wet-process phosphoric acid process, a liquid-solid-liquid three-phase acid hydrolysis synergistic extraction reaction system was established by adding a certain amount of extractant in the actual production process. In order to study the extraction effect and residue of impurities in the reaction system, the phase, morphology, and impurity occurrences of phosphogypsum were systematically analyzed.

Eco-friendly recycling of silicon-rich lye: Synthesis of hierarchically structured calcium silicate hydrate and its application for phosphorus removal.

Silicon-rich lye (SRL), a byproduct generated from pre-treatment of coal-based solid waste (CSW), was considered as a preponderant silicon source to prepare hierarchically nanostructured calcium silicate hydrate (C-S-H). Through the novel mild-causticization synthesis strategy, C-S-H was prepared under optimal caustic process conditions at time of 3 h, temperature of 80 °C, Ca/Si of 1.25:1, and active CaO to obtain a conversion rate of Si up to 97.

Study on the correlation between Fe/Ti forms and reaction activity in high-alumina coal fly ash.

High-alumina coal fly ash (HAFA) is an important aluminum and silicon resource. In the process of preparing aluminum-silicon materials from HAFA, the influence of impurity elements on its performance must be considered. In this work, the occurrence state of impurities in HAFA, micro morphology, and the bond energy of different impurity coordination were studied.

Mechanisms of mechanochemical activation during comprehensive utilization of high-alumina coal fly ash.

High-alumina coal fly ash (HAFA) is an important aluminum and silicon resource. In terms of its comprehensive utilization, how to efficiently separate aluminum and silicon must be resolved. In this work, a mechanochemical activation method in the desilication process is adopted and investigated.

Effects of Impurities on CaSO Crystallization in the Ca(HPO)-HSO-HPO-HO System.

Wet-process phosphoric acid is a fundamental process in the fertilizer industry. The influence of impurities on crystallization kinetics of CaSO was investigated in the Ca(HPO)-HSO-HPO-HO system using a mixed suspension mixed product removal crystallizer. Effects of Si, Al, Fe, Mg, K, and Na on crystal morphology and structure were examined in the highly acidic system through scanning electron microscopy and high-resolution transmission electron microscopy.

Non-isothermal thermal decomposition reaction kinetics of dimethylhexane-1,6-dicarbamate (HDC).

The thermal decomposition behavior and reaction kinetics of dimethylhexane-1,6-dicarbamate (HDC) were investigated by TG-DTG, DSC and IR techniques. It is shown that the decomposition process can be divided into 3 main stages and the first stage is the thermal decomposition reaction for HDC to dimethylhexane-1,6-diisocyanate (HDI). The main gaseous products of the decomposition are CO(2) and CH(3)OH.