Zengwu Zhao

In‐Situ Studies on the Crystallization of CaO‐SiO2‐CaF2‐CeO2 System by a Confocal Laser Scanning Microscope

The recovery of rare earth elements from metallurgical slags containing rare earths is an important topic. The crystallization behavior of CaO-SiO2-CaF2-CeO2 system with CeO2 content range from 12 to 16 mass pct and a constant CaO/SiO2 ratio of 1 has been examined by using a confocal laser scanning microscope (CLSM). Diagram of continuous cooling transformation and that of isothermal (time temperature) transformation for the slag have been constructed to characterize the solidification behavior of the slag with cooling rates between 3.125 and 100 K/minutes and temperature between 1373 and 1598 K. Depending on the CeO2 content in the slag, the primary crystalline phase of CaO-SiO2-CaF2-CeO2 system precipitates with elongated needle-like or short and rod-like crystals. The XRD analyses of crystalline phase of solidified slags confirm that the primary crystalline phase is a rare earth-rich phase Ca2Ce8O2(SiO4)6, which contains no fluoride.

Experimental and numerical simulation research on cold aerodynamic field of tangential firing boiler

In order to know about coke phenomena of 130t/h boiler with tangential firing, velocity and valves characteristics of primary and secondary air were measured. Fireworks test and numerical simulation were done at the condition of actual working and uniform air distribution, and the tangential circle diameter of actual working and uniform air distribution were obtained. The results show that the boiler will be satisfied basically with uniform air distribution in four corners on the condition that air velocity is adjusted uniformly in different jet, the ideal aerodynamic field in boiler will be obtained, and it provides reference for hot state run

Research on NOx formation of flat-flame combustion with HTAC Technology

Based on the single swirl burner flat-flame combustion, the technology of High Temperature Air Combustion (HTAC) was adopted. The central combustion speed field under burner was measured by Particle Image Velocimetry (PIV) technique, as the same time, the temperature distribution in the furnace and concentration distribution of NO were measured by sensors. It appeared that with HTAC technology, combustion was stabilization, and fuel completely burnt; temperature distributing got uniformity, NOx formation decreased to 30ppm. Though regenerator, air temperature increased from 20°C to 200°C, smoke temperature decreased from 800°C to 80°C, it achieved the effect of energy conservation and environment protect.