Study On The Technology For Decomposing Of Ammonium Chloride

Ammonium chloride with white particles was decomposed above337.8℃producingammonia and hydrogen chloride. Most of ammonium chloride was produced because ofthe development of soda industry and used in the agriculture as nitrogen fertilizer. Sodiumcarbonate was produced by Hou’s process（for soda manufacture）. The same amount ofsolid ammonium chloride and sodium carbonate was produced by this method. Thenitrogen content of ammonium chloride was24~25%. Ammonium chloride was valuablefertilizer and used for maize and wheat and so on.But ammonium chloride containing alarge amount of chloride ion only can be used for some crops. Chloride ion was harmful tocrop and soil. So the use of ammonium chloride was limited. In the process of sodiumcarbonate by Solvay method, ammonium chloride was decomposed by calcium hydroxideand produced ammonia was reused in the process of soda industry. But ten tons of wastewater was produced in the process of one ton of sodium carbonate. A large amount of heatwas consumed dealing with waste water to produce calcium chloride. So a lot of water andheat were wasted in the process of decompostion of ammonium chloride. Considering theeconomy and environmental protection, Ammonium chloride was decomposed by aneconomic and friendly environmental method. The waste of heat、water and the oceanpollution were avoided by this method. The decompostion of ammonium chloride by aeconomic and environmental method with calcium oxide,calcium hydroxide and sodiumsilicate as raw materials was studied in the paper. Specific contents were as follows:1) Ammonium chloride was decomposed by solid-solid phase reaction with calciumoxide and calcium hydroxide.Decomposition rate of ammonium chloride reached to99.5%and hydroxy calcium chloride was produced. Calcium chloride was produced in thecase of sufficient water. The products were analyzed by XRD and distillation.2) Hydroxy calcium chloride nanoparticles were obtained. Its properties including themorphology,structure,thermal properties,hydrolysis and carbonation were studied in thepaper.3) Based on the results of small-scale experiments with the reaction of calciumoxide(calcium hydroxide)and ammonium chloride as raw materials, the pilot-scaleequipment of ball mill and reaction equipment were designed and completed in this thesis.The influence of the operation conditions on the rate of decomposition of ammonium chloride was studied in the pilot-scale equipments.4) In order to achieve the decomposition of ammonium chloride with different formsof sodium silicate and ammonium chloride as raw materials, the reaction of sodiumsilicate and ammonium chloride was researched in the solid and liquid phase, silica withhigh value were obtained. Silica products were characterized by X-ray diffraction,scanning electron microscopy and infrared spectroscopy.