Solar Thermal Conversion of Magnesium Hydroxide to Magnesium Oxide

Abstract

The greater part of the naturally produced magnesite is changed over into magnesium oxide by calcining. Because of its characteristic cause, magnesium oxide transformed by calcination of magnesite may not fulfill all necessities concerning excellence in purity. Techniques have hence, been create to generate magnesium hydroxide artificially. Abstract Today a significant share of the world magnesia supply is generated by precipitation of magnesium hydroxide either from seawater or salt water sources, which adds up to about 14% of the world magnesia preparation. In this procedure Mg(OH)2 is processed as white powder which is then calcined to get magnesium oxide. Calcination is done in furnaces and reactors of different outlines like, Multiple hearth furnaces and Rotatory kilns. The temperature and the calcination methodology decides the properties of the magnesium oxide. The thermal decomposition involves the following reaction: Mg(OH)2 + Heat MgO+H2O The deterioration response starts to happen around 350 ºC and increases with increase in temperature. last hints of synthetically bound water is exceptionally difficult to remove from magnesium hydroxide, unless the response temperature is raised over 1000 ºC.Though the desired temperature in the kiln is achieved by direct firing with oil or gas, thus the cost of this final product becomes very high. So to reduce the cost of magnesium oxide we have to use some other non conventional energy source to get the desired temperature. Solar energy is the most freely and abundantly available form of energy on earth. The present study relates to the utilization of solar energy for thermal conversion of magnesium hydroxide to magnesium oxide. Though this reaction is a highly endothermic reaction and the temperature required is very high, so concentrated form of solar energy is used which is obtained by using a fresnel lens. This study is focused to find the optimum heat concentration area and the optimum bed depth for magnesium hydroxide to be converted to magnesium oxide used while supplying heat. After conducting experiments it is found that the optimum diameter depends upon the calcination temperature and the optimum depth of the sample obtained is found to be 3mm for maximum conversion efficiency.