ao-Sha Li

Growth of phosphorus concentrating phase in modified steelmaking slags

Abstract Recycling steel slag to metallurgical process requires removing phosphorus from slag. In this paper, solidification experiments of converter slag modified by SiO2 at three isothermal temperatures with several durations were performed at air conditions from superheating temperature (1520°C). Grain size evolution of P concentrating phase (C2S, dicalcium silicate) was investigated. Results show that crystal size distributions of C2S can be fitted by lognormal distributions, the average size of C2S increases with increasing dwelling time and grows faster at higher holding temperature, and the relationship between average size of C2S and holding time can be best described by equation D = ktm. It is concluded that the growth mechanism of C2S is diffusion controlled, and higher isothermal temperature promotes the growth of C2S. Le recyclage de la scorie de l’acier par un procédé métallurgique nécessite l’enlèvement du phosphore de la scorie. Dans cet article, on discute d’expériences de solidification de scorie de convertisseur modifiée par du SiO4 à trois températures isothermes avec durées variées, effectuées à l’air à partir d’une température de surchauffage (1520°C). On a examiné l’évolution de la taille de grain de la phase de concentration du P (C2S, silicate dicalcique). Les résultats montrent que l’on peut ajuster les distributions de la taille de cristal (CSD) du C2S à une distribution log-normale, que la taille moyenne du C2S augmente avec l’augmentation du temps de résidence et croît plus vite à une température plus élevée de rétention et que la relation entre la taille moyenne du C2S et la durée de rétention est bien décrite par l’équation D = ktm. On conclut que le mécanisme de croissance du C2S est contrôlé par la diffusion et que la température isotherme la plus élevée favorise la croissance du C2S.

Preparation of Eu3+-Y3+ Coactivating Na+ Based Red-Emitting Luminous Materials for Light-Emitting Diodes and Investigation of Its Characteristics

By solid-state reaction and doping, a series of red-emitting phosphors NaxY0.92–x/3(MoO4)y(WO4)1–yO0.5 : zEu3+ have been synthesized. Through optimization of the process conditions and photoluminescent analysis, one type of red emission is obtained that matches nicely with ultraviolet light-emitting diode (UV-LED) chips.

Study on Fractal Characteristics of Particle Size Distribution Function for Modified-Brown Coal

Particle size distributions (PSDs) are often rendered as cumulative functions, either as number of particles larger than a certain diameter, or as mass smaller than a certain diameter. According to the application status of low rank brown coals of Inner Mongolia, the fractal characteristics of particle size distribution function of raw brown coals and modified-brown coals were analyzed in the paper. The grain size analysis and microstructure analysis of coal samples were measured by the Euro-American gram LS-C (1) type laser Particle analytical instrument, Fourier infrared spectrum (FRIT) and scanning electron microscope (SEM), respectively. The results of the study indicate that raw brown coals and modified-brown coals have fractal feature by using the mathematical model of fractal characteristics of particle size distribution function based on fractal theory. The paper provides the fractal dimensions of modified-brown coals increased with the rank of coal. Thus fractal dimensions can be used as an evaluation index of coal rank providing theoretical basis and distinguish basis for a further study on properties of modified-brown coals.