Desiliconization reaction in sodium aluminate solution by adding tricalcium hydroaluminate

The desiliconization reaction in sodium aluminate solution was studied by adding tricalcium hydroaluminate (C(3)AH(6)). C(3)AH(6) prepared at 323 K has a relatively high desiliconization capacity. Kinetic results show that the desiliconization reaction is first-order in SiO(2) concentration, and the apparent activation energy is estimated to be 96 kJ/mol between 363 and 393 K, which is lower than that from adding Ca(OH)(2). During the desiliconization process, SiO(2)(OH)(2)(-) ions enter the interior of C(3)AH(6) particles and react with them further. As a result, the distribution Of SiO(2) in the desiliconization product (DSP) is more uniform than that from adding CaO. Also, the SiO(2) content in DSP is higher. (C) 2008 Elsevier B.V. All rights reserved

Prediction Models of Saturated Vapor Pressure, Saturated Density, Surface Tension, Viscosity and Thermal Conductivity of Electronic Fluoride Liquids in Two-Phase Liquid Immersion Cooling Systems: A Comprehensive Review

As the carriers of massive data, data centers are constantly needed to process and calculate all kinds of information from various fields and have become an important infrastructure for the convenience of human life. Data centers are booming around the world, accompanied by the problems of high power consumption and poor heat dissipation. One of the most effective solutions to these problems is to adapt a two-phase liquid immersion cooling technology, which is a more energy-saving and efficient method than the traditional cooling methods; the reason for this is mainly that in two-phase liquid immersion cooling technology, the heat transfer caused by the phase change of liquid coolants (electronic fluoride liquids) helps to cool and improve the temperature uniformity of electronic components. However, the requirements for the electronic fluoride liquids used in two-phase liquid immersion cooling systems are strict. The thermophysical properties (saturated vapor pressure, density, surface tension, viscosity, thermal conductivity and latent heat of vaporization, etc.) of the liquid coolants play a very key role in the heat dissipation capacity of two-phase liquid immersion cooling systems. However, it is not always easy to obtain new electronic fluoride liquids under many actual conditions and reasonable prediction models of their thermophysical properties could contribute to the preliminary screening of the coolants. Thus, the prediction models of their key thermophysical properties (saturated vapor pressure, saturation density, surface tension, viscosity and thermal conductivity) are reviewed, and the accuracy and practicality of these prediction models in predicting the thermophysical properties of electronic fluoride liquids (FC-72, HFE-7100 and Novec 649) are evaluated. This work will provide a valuable reference for actual engineering applications