Preparation Of Active Magnesium Oxide By Absorption Of Nh₃and Co₂into Mgcl2_solution In A Rotating Packed Bed

Active magnesium oxide （AMO） is an important inorganicmicro/nano-material, which is widely used in many fields including rubber,refractory materials, fire-retardant materials, wastewater treatment, harmfulgas adsorbent, catalyst carrier, and so on. The higee technology （rotatingpacked bed, RPB） has remarkable advantage in the synthesis ofmicro/nano-materials with controllable particle size and unique properties, andhas been applied to the preparation of various mico/nano-materials.This thesis investigated the synthesis of AMO by the simultanesousabsorption of CO₂and NH₃in the RPB for the first time. Beaker experimentwas carried out to investigate the effect of reaction temperature on basicmagnesium carbonate （BMC）, a precursor of MgO, and the influence ofcalcination temperature on MgO, and appropriate reaction temperature andcalcination temperature for the preparation of MgO were determined. On thebasis of the beaker experiment, this thesis studied the preparation of AMO bythe simultaneous absorption of CO₂and NH₃into MgCl₂solution in the RPB.The effects of operating conditions including reaction temperature, rotatingspeed, initial concentration of MgCl₂solution, gas flow rate, liquid flow rateand calcination temperature on the grain size and activity of AMO werestudied. AMO with a citric acid activity value of7.6s，an iodine adsorptionvalue of190mgI2/gMgO, an average particle size of2μm and a specificsurface area of71m2/g has been obtained under the optimal conditions of a reaction temperature of70℃, an initial MgCl₂concentration of0.3mol/L, arotating speed of1200rpm, a volumetric gas flow rate of364L/h, an NH₃volume fraction of22%, a CO₂volume fraction of11%, a N2volume fractionof67%, a calcination temperature of500℃and a calcination time of2h.