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To investigate the irradiation resistance of the microwave sintered contaminated soil samples, the samples were irradiated with 0.5 MeV He2+ ions. The property changes of the irradiated samples were investigated. After irradiation, the Vickers hardness values of the samples showed a relatively low degree of decrease, with a maximum reduction of 1.36%. The magnitude of NLCe of samples before and after irradiation was in the order of 1 × 10–5 g·m−2·d−1. This result will provide a useful reference for the treatment of the contaminated soil. [ABSTRACT FROM AUTHOR]

The safe treatment of radioactive‐contaminated soil is of great significance. In this work, neodymium‐contaminated soil was successfully immobilized using microwave sintering to form glass‐ceramics. The microstructure, morphology, elemental distribution, Vickers hardness, and chemical durability of the sintered samples were analyzed. The results showed that the glass‐ceramic is more suitable to immobilize the waste compared with the glass matrix. XRD and SEM‐EDS results proved that the waste form has been totally immobilized in the sintered matrix whether in glass‐ceramics and glass. However, the leaching rate of element Nd in glass‐ceramic was lower than the glass matrix at 28 d. Moreover, the Vickers hardness results of glass‐ceramic were higher than that of glass. Thus, glass‐ceramics can not only reduce sintering temperature and save energy but also achieve a better immobilizing effect. Our investigation reflects that glass‐ceramics are more suitable for neodymium‐contaminated soil immobilization using the microwave sintering method. [ABSTRACT FROM AUTHOR]

This work investigated the irradiation behavior of gray desert soil holding simulated An4+ waste under an irradiation of 1.5 MeV Xe20+ to fluences from 1 × 1012 to 1 × 1015 ions cm− 2. The results indicated that the structure has no obvious change due to irradiation fluences and waste load. The normalized leaching rate of Ce after 28 days of the MCC-1 test is in the order of 1 × 10− 5 g cm− 2 d− 1 before and after irradiation. This work identifies gray desert soil, which has good radiation resistance, as a potential matrix for solidification tetravalent actinides. [ABSTRACT FROM AUTHOR]

For investigating the chemical behavior of uranium-contaminated soil solidified by microwave sintering, the product consistency test method was adopted. The effective factors such as soil species, soil composition, temperature, pH values and their coupling effects have been researched. The maximum leaching rate of uranium was below 1.7 × 10−8 g m−2 day−1 and the cumulative fraction of leached uranium was below 0.0165 after 42 days. The acidic or alkaline leachate and higher temperature would enhance the uranium's leaching rate, and it was found that the chemical stability of solidified soil is related to the molar ratio of Al2O3/SiO2. [ABSTRACT FROM AUTHOR]

To efficiently inhibit the diffusion of radioactive nuclides in soil that were left by nuclear emergency accidents, microwave sintering technology was used in this work to vitrify the simulated strontium contaminated soil. Four kinds of simulated strontium-contaminated soil could be successfully vitrified almost completely within 30 min without any additional components. Sr2+ cations are immobilized into aluminosilicate glass network structure. In addition, the solubility of SrSO4 in different soil is related to the element contents of aluminum and silicon. This work reveals a demonstration that beta-radioactive contaminated soil could be treated by microwave vitrifying. [ABSTRACT FROM AUTHOR]

• Uranium contaminated soils were immobilized rapidly by microwave sintering. • The uranium ions were almost immobilized and evenly distributed. • The network forming ability of Si was higher than Al. To dispose of uranium-contaminated soil, the microwave sintering technology was used. A series of uranium-contaminated soils were successfully immobilized via microwave sintering for 30 min. When the amount of uranium ranges from 0 wt % to 1 wt %, glass phase occurred in saline-alkali soil, purple soil and red soil, while glass with presence of a crystalline phase occurred in yellow soil. The FT-IR analysis showed that the uranium-contaminated soils were mainly consist of [SiO 4 ] units. The Qn distribution of Si-O tetrahedrons and network connectivity of 1 wt % uranium doped sintered soils were related to the composition of soils. The uranium ions were almost immobilized and evenly distributed in sintered soils. Theoretical results showed that the structures of uranium doped sintered soils were made of Si-O, Al-O and Fe-O tetrahedrons. The O-Si-O linkage was the most preferred one among all linkages and the network forming ability of Si was higher than Al. Image, graphical abstract [ABSTRACT FROM AUTHOR]

In order to find a rapid, efficient, safe and reliable treatment technology for radioactive contaminated soil, the microwave sintering method was used to sinter the simulated radioactive contaminated soil with different CeO 2 content at 1100 °C, 1200 °C and 1300 °C for 30 min to achieve vitrification. The phase, microstructure, morphology, mechanical properties, and chemical durability of the sintered samples were investigated. XRD and SEM-EDS results showed that Ce4+ did not participate in the formation of the glass network, but was fixed in the glass network structure. The amorphous fraction of the samples sintered at 1300 °C can reach up to 98%. EDS results showed that the element distribution was uniform. In addition, the density and hardness values of the sintered matrices were in the range of 1.875–2.543 g/cm3 and 6.667–7.112 GPa, respectively. Our results show that the density and hardness values are related to the sintering temperature and CeO 2 content. The normalized leaching rate of Ce in samples reached 10−7 g/(m2·d) after 28 d. [Display omitted] • Rapid vitrification of simulated radioactively contaminated soil using continuous microwaves. • Ce ions are uniformly fixed in the glass network structure and do not participate in its formation. • The formation and curing mechanism of glass in the samples were investigated. • The vitrified soil matrix has proven chemical durability to radionuclides. [ABSTRACT FROM AUTHOR]

Consecutive microwave sintering is a method proposed in this study to dispose soil contaminated by Sr during a nuclear accident by rapidly solidifying the contaminated soil. The results show that soil contaminated with 20 wt% SrSO 4 and 30 wt% SrSO 4 can be completely solidified by microwave sintering at 1100–1200 and 1300 ℃, respectively, for 30 min. Sr was found to be cured into slawsonite (SrAl 2 Si 2 O 8) and glass structures. Moreover, soil sintered at 1300 ℃ has large cured solubility (30 wt.%), good uniformity, and excellent hardness (6.9–7.2 GPa) and chemical durability (below 1.46 × 10−5 g m−2 d−1 at 28 d). Thus, consecutive microwave sintering technology may provide a new method for treating Sr-contaminated soil in case of a nuclear accident emergency. ga1 • A large-batch Sr-contaminated soil is disposed using consecutive microwave sintering for the first time. • Sr-contaminated soil is transformed into glass-ceramic solidification. • Sr in the soil can be solidified into slawsonite (SrAl 2 Si 2 O 8) and a glass network simultaneously. [ABSTRACT FROM AUTHOR]