Papers by Keyword: Steel Slag

Abstract: Using industrial waste (lithium-slag and steel-slag) for the preparation of high-performance concrete, and the same mix proportion’s concrete are cured using six kinds method, which is cured to the required age later and tests its chloride ion diffusion coefficient by RCM method. The results show that: the chloride ion diffusion coefficient of 28d and 84d decreases with the lower water-binder ratio. It can achieve RCM-Ⅴ grade when the water to binder ratio is 0.27. The admixtures total of 275-350kg/m3 is appropriate when the water to binder ratio is constant.The diffusion of water conservation,water solution with 5% Nacl after 7d water conservation,water solution with 5% Nacl after 14d water conservation,water solution with 5% Nacl after 7d in water conservation and water solution with 5% Nacl after 14d in water conservation is 1.5, 3.1, 2.5, 2.8 and 2.3 times than standard conservation , so the effect of early different curing ways to HPC can not be ignored.

Abstract: In this research, the potential of using steel slag asphalt mixture as a self-healing material was investigated by means of microwave heating. The microwave heating rate and thermal conductivity of asphalt mixtures were tested respectively. The result shown that, the heating rate of steel slag asphalt mixtures is approximately two times faster than limestone asphalt mixtures. While its thermal conductivity is slightly lower. It is concluded that microwave heating can be used to promote self-healing of steel slag asphalt mixture.

Abstract: The steel slag was used as adsorbent for the adsorption of Phosphate. the isothermal adsorption test studies adsorption of the steel slag on phosphorus and ammonia nitrogen. The results showed that that the steel slag have very strong adsorption capacity on phosphorus. Langmuir adsorption equation can better describe adsorption of steel slag on phosphorus, the max adsorption quantity of steel slag on phosphorus is 9495.916 mg·kg^-1, adsorption intensity is 0.0132.

Abstract: Porous slag haycite for phosphorus removal was made from slag, as the main raw material, clay, as binder, and ammonium hydrogen carbonate, as a pore forming agent. And the influence of material ratio and sintering condition were investigated. The best ratio of steel slag: Clay: ammonium hydrogen carbonate was 53.5%:42.5%:4% as ascertained, and the best sintering temperature 800°C, sintering time 60min. The porosity of slag haycite was 2 times more than original slag, and the specific surface area was increased evidently, thus very conducive to microbial growth.

Abstract: In this paper, the mechanical properties and permeability of the concrete with steel slag coarse aggregates were investigated by comparing with the concrete with crushed limestone coarse aggregates. Results show that the concrete with steel slag aggregates shows similar strength with the concrete with crushed limestone aggregates at the age of 28 days, but it shows a little higher strength especially splitting tensile strength at the age of 90 days. Steel slag coarse aggregates tend to have limited influence on the elastic modulus and permeability of concrete. The results at different water to cement ratios are similar.

Abstract: Slag filter material made from steel slag and clay was used for phosphate adsorption, and adsorption characteristic was studied by batch experiments. Results showed that the uptake of phosphate on slag filter material at different temperature fitted with pseudo-second-order model, and the activation energy was more than 40kJ/mol. In addition, isotherm adsorption data on slag filter material followed the Langmuir model well, and the maximum adsorption capacity at 20°C, 30°C and 40°C were 1.166, 1.826 and 2.422mg/g, respectively. Thermodynamic parameters G⁰, H⁰ andS⁰ showed that the adsorption was spontaneous, endothermic and entropy increase process and chemical adsorption was dominant for phosphate uptake.

Abstract: The non-evaporable water content, compressive strength, and pore distribution of steel slag paste cured under different curing temperature conditions were investigated in this paper. The non-evaporable water content of steel slag paste at early ages is obviously larger at higher curing temperature. At the age of 28 days, the non-evaporable water content of steel slag paste at normal curing temperature is close to that at high curing temperature, but the compressive strength of steel slag paste at normal curing temperature is much lower than that at high curing temperature. The pore structure of steel slag paste is much coarser than that of cement paste under the same conditions.

Abstract: Steel slag as the discharged residue during steelmaking process is a kind of industrial solid waste, accounting for about 15 to 20 percent of crude steel in production. Steel slag is mainly similar with cement clinker in mineral and chemical composition, and possesses potential hydration reaction activity. The properties of steel slag, the research progress of activation and volume stability were summarized in this paper. Several approaches of steel slag utilization in construction and building materials were introduced. The combined use of various activation methods and proper treatment will increase the volume of steel slag in autoclaved tailings bricks and aerated concrete block.

Abstract: The magnetic performance of steel slag is special because it has a high content of Fe₂O₃. In this study, the difference of chemical compositions, mineral compositions, and particle size distributions between the two parts of steel slag by magnetic separation was investigated. The results show that the difference of chemical compositions especially the main oxide contents between the two parts of steel slag by magnetic separation is very small. And the difference of mineral compositions between the two parts of steel slag by magnetic separation is also very small. However, the particle size distributions of the two parts of steel slag by magnetic separation may differ from each other when steel slag contains many coarse particles.

Abstract: The load-bearing brick is made from steel slag and silicon tailings by pressing and autoclaving process. Because of the volume stability, steel slag was ground to above 320 m²/kg and wet cured in 50-60°C at 12-24 hours in the present of additives, before pressure forming and autoclaving process. Tailings account for 63% of the total mass of the brick, while steel slag 30 %. The compressive strength of the brick was up to 13.1MPa, bending strength 3.2MPa, and with low drying shrinkage and good freeze-thaw resistance. The application conditions were discussed.