Effect of Sodium Hydroxide, Liquid Sodium Silicate, Calcium Hydroxide, and Slag on the Mechanical Properties and Mineral Crystal Structure Evolution of Polymer Materials

To study the key factors that affect the mechanical properties of polymer materials and explore the relationship between mineral crystal formation and strength development, fly ash (FA) polymer samples were prepared using sodium hydroxide, slag, liquid sodium silicate, and hydrated lime as activators. A change in the compressive strength was observed, and X-ray diffraction measurements were carried out to confirm the change. The effects of different types and amounts of activators on the formation and transformation of mineral crystals in FA polymer samples as well as on the development of compressive strength were studied. Moreover, the relationship between the formation and transformation of mineral crystals and the development of compressive strength was established. The results show that the strongly alkaline excitation environment established by sodium hydroxide is the prerequisite for crystal formation and development of compressive strength. Under this strongly alkaline excitation environment, slag, hydrated lime, and liquid sodium silicate can increase the amounts of calcium and silicon, which promote the formation and development of hydrated calcium silicate and hydrated calcium silicoaluminate in polymers and significantly improve the compressive strength.

On possibility of using silicomanganese slag and ladle electric steelmaking slag in manufacture of welding fluxes

Analysis of the existing trends in development of technologies for production of welding and surfacing fluxes showed that one of the actively developing areas is the production of fluxes using man-made waste (including metallurgical one) as components of the initial charge. This is due to the fact that the slag waste of metallurgical production contains a large amount of manganese and silicon, which in turn are the basis in welding fluxes. Within the framework of this direction development, the article describes principal possibility and efficiency of using materials based on ladle electric steelmaking slag from JSC “EVRAZ United West Siberian Metallurgical Combine” and slag produced by silicomanganese from LLC “West Siberian Electrometallurgical Plant” in the charge for production of fluxes used in the surfacing of rolling rolls. All the laboratory tests were made using the equipment of the scientific and production center “Welding Processes and Technologies”. For surfacing steel samples, the authors used a flux additive obtained by mixing ladle electric steelmaking slag of a fraction less than 0.2 mm with liquid sodium glass in a ratio of 62 and 38 %. The resulting flux additive was mixed with slag from the production of silicomanganese of a fraction of 0.45 - 2.50 mm in various ratios. Studies of the chemical composition (by the spectral method) and metallographic studies of the deposited layer revealed a tendency to an increase in sulfur content and in contamination with non-metallic inclusions in it with an increase in content of the flux additive in the charge of more than 20 %. According to the results of visual quality control of the deposited layer macrostructure, the absence of defects was established with a flux additive content of up to 30 %.

Benchmark Analysis on Loss-of-Flow-without-Scram Test of FFTF Using Refined SAC-3D Models

The Fast Flux Test Facility (FFTF) is a liquid sodium-cooled nuclear reactor designed by the Westinghouse Electric Corporation for the U.S. Department of Energy. In July 1986, a series of unprotected transients were performed to demonstrate the passive safety of FFTF. Among these, a total of 13 loss-of-flow-without scram (LOFWOS) tests were conducted to confirm the liquid metal reactor safety margins, provide data for computer code validation, and demonstrate the inherent and passive safety benefits of specific design features. In our preliminary work, we have performed relatively coarse modeling of the FFTF. To better predict the transient behavior of FFTF LOFWOS test #13, we modeled it using a more refined thermal-hydraulics model. In this paper, we simulate FFTF LOFWOS test #13 with the system safety analysis code SAC-3D according to the benchmark specifications provided by Argonne National Laboratory (ANL). The simulation range includes the primary and secondary circuits. The reactor core was modeled by the built-in 3D neutronics calculation module and the parallel-channel thermal-hydraulics calculation module. To better predict the reactivity feedback introduced by coolant level variations within the GEMs, a real-time macro cross-section homogenization processing module was developed. The steady-state power distribution was calculated as the transient simulation initial boundary conditions. In general, both the steady-state calculation results and the whole-plant transient behavior predictions are in good agreement with the measured data. The relatively large deviations in transient simulation occur in the outlet temperature predictions of the PIOTA in row 6. It can be preliminarily explained by the reason for neglecting the heat transfer between channels in this model.

Basic analysis on heat transfer phenomena in natural circulation for liquid sodium

Natural convention, the heat transfer on fluid due to density differences that can be caused by differences in fluid temperature. One example application of natural convection is cooling system, such as nuclear reactor cooling system. The purpose of this study is to analysis the basic characteristic heat transfer of sodium liquid in the natural circulation system for steady state analysis and transient characteristic with Finite Element Method. The selected module is the Non-Isothermal FLow (NITF) module. This module is a combination of three basic equations, namely the continuity equation, the Navier-Stokes equation, and the dynamic equation of heat transfer in fluid. The simulation model measures 1.5 x 2 (m) with sodium liquid (Na) as a fluid.