Study on Structure and Properties of La2O3-Doped Basaltic Glasses for Immobilizing Simulated Lanthanides

The La2O3-doped basaltic glass simulated high-level waste form (HLW) was prepared by the solid-state melt method. The simulated waste La2O3 maximum loading and the doping effect on structure, thermal stability, leaching behavior, density, and hardness of basaltic glasses were studied. XRD and SEM results show that the simulated waste loading of La2O3 in basaltic glass can be up to ~46 wt.%, and apatite (CaLa4(SiO4)3O) precipitates when the content of La2O3 reaches 56 wt.%. Raman results indicate that the addition of La2O3 breaks the Si–O–Si bond of large-membered and four-membered, but the number of A13+ involved in the formation of the network increase. Low content of La2O3 can help to repair the glass network, but it destroys the network as above 26 wt.%. DSC results show the thermal stability of simulated waste forms first increases and then decreases with the increase of La2O3 content. With the increase of La2O3 content, the density of the simulated waste form increases, and the hardness decreases. The leaching chemical stability of samples was evaluated by the ASTM Product Consistency Test (PCT) Method, which show that all the samples have good chemical stability. The leaching rates of La and Fe are three orders of magnitude lower than those of the other elements. Among them, L36 has the best comprehensive leaching performance.

Influence of Uranium on the Hydration Properties of the Cement Clinker Minerals

The influence of uranium simulated waste water on the hydration properties of the cement was studied by modern test methods such as TAM air, XRD, FTIR, and SEM-EDS. The results show that uranium can promote the hydration of mineral C3S, and inhibit the hydration of mineral C3A. By comparing scanning of hydration products, it was found that the existence of uranium significantly changed the morphology of clinker hydration products , but uranium had little effect on the type of clinker hydration product.

Self-powered ammonia synthesis under ambient conditions via N2 discharge driven by Tesla turbine triboelectric nanogenerators

Ammonia synthesis using low-power consumption and eco-friendly methods has attracted increasing attention. Here, based on the Tesla turbine triboelectric nanogenerator (TENG), we designed a simple and effective self-powered ammonia synthesis system by N2 discharge. Under the driving of the simulated waste gas, the Tesla turbine TENG showed high rotation speed and high output. In addition, the performance of two Tesla turbine TENGs with different gas path connections was systematically investigated and discussed. A controllable series-parallel connection with the control of gas supply time was also proposed. Taking advantage of the intrinsic high voltage, corona discharge in a N2 atmosphere was simply realized by a Tesla turbine TENG. With the flow of N2, the generated high-energy plasma can immediately react with water molecules to directly produce ammonia. The self-powered system achieved a yield of 2.14 μg h−1 (0.126 μmol h−1) under ambient conditions, showing great potential for large-scale synthesis.

Synthesis of Single-Phase Zeolite A by Coal Gasification Fine Slag from Ningdong and Its Application as a High-Efficiency Adsorbent for Cu2+ and Pb2+ in Simulated Waste Water

Coal gasification is a new direction for the clean utilization of coal, but it also brings huge environmental pressure on solid waste. In this paper, the high-crystallinity single-phase zeolite A was prepared by solid-phase alkali fusion synthesis from coal gasification fine slag (CGFS), without template agent, with low water consumption, and with low cost, and it was used to remove heavy metals such as Pb2+ and Cu2+ in simulated waste water. The main factors affecting the solid-phase and green synthesis methods were analyzed, and the optimum conditions for solid-phase synthesis of high-crystallinity single-phase zeolite A were determined as follows: NaOH/CGFS = 1.2; solid-phase alkali fusion temperature 823 K, solid-phase alkali fusion 90 min, liquid–solid ratio 4.5, and 353 K hydrothermal reaction for 12 h. The relative crystallinity, specific surface area, and ion-exchange capacity of single-phase zeolites A are 93.1%, 61.09 m2/g, and 268.4 mmol/100 g. The removal rates of Pb2+ and Cu2+ can reach more than 99%, especially for the removal efficiency of Pb2+, which is common in simulated waste water. This is an effective method with important application prospects, and it formed an effective way to recycle solid waste of coal chemical industry.