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In order to improve the performance of magnesia dolomite materials, magnesium dolomite refractory materials whose iron oxide content (mass fraction) of 0, 0.5%, 1.0%, 1.5%, respectively, were prepared from natural dolomite, high silicon magnesite, silica and iron oxide powder by two-stage calcination and slaking process. The influence of iron oxide content on the physical properties, hydration resistance and coatability adherence of the samples was investigated. The phase composition and microstructure of the specimens were characterized. The results showed that, as the iron oxide content increased, the room temperature flexural strength and the room temperature compressive strength increased, the high temperature flexural strength and the adherence strength decreased, and the retention rate of the thermal shock strength of the sample first increased and then decreased. With the iron oxide content increasing to 1.5%, the hydration weight gain rate of the sample decreased to 0. 12%, and the hydration resistance improved. According to the XRD spectrum analysis, the main crystal phases of the sample were periclase, dicalcium silicate and tricalcium silicate. With the increase of iron oxide content, the diffraction peaks of C2S and C3S became stronger and the peak shapes were sharp. It showed that iron oxide could promote the growth of C2S and C3S crystals and increase the density of the sample. [ABSTRACT FROM AUTHOR]

To meet the emission standard of nitrogen oxides (NOx) in the flue gas of batch furnaces through dry adsorption, a calcium-silica inorganic adsorbent was prepared with limestone and quartz as raw materials. Sample Cu-BTC 1# was obtained by solvothermal synthesis, drying and purification in vacuum at 120 ℃ using trimesic acid (H3BTC) and copper nitrate trihydrate (Cu(NO3)2·3H2O) as raw materials; likewise, sample Cu-BTC 3# was obtained at 200 ℃. Sample Cu-BTC 2# was obtained by hydrothermal synthesis, drying and purification in air (metal-organic frameworks, 1,3,5-benzene tricarboxylic acid copper). The two types of materials were tested in terms of the NO2 adsorption, and then the specific surface area, pore volume, NO2 adsorption performance, phase composition, microstructure and thermal stability of the adsorbent materials were explored via N2 physical adsorption-desorption, SEM, XRD and TG characterization. The results show that: (1) the Cu-BTC samples have higher adsorption capacity than the calcium-silica adsorbent, in which sample Cu-BTC 3# has the largest specific surface area and pore volume, thus adsorption capacity for NO2; (2) the calcium-silica adsorbent has better thermal stability and lower total mass loss during the entire process than the Cu-BTC samples; sample Cu-BTC 2# has the best thermal stability among the three Cu-BTC samples, and the metal Cu active sites of the Cu-BTC samples can be exposed at least above 150 ℃. [ABSTRACT FROM AUTHOR]