Application Of Ammonium Chloride And Calcium Carbonate Mixed Roasting Process

Ammonium chloride roasting method is widely used in metallurgy,manufacture of anhydrous chloride,and so on,which have the advantages of short process,high efficiency and relatively mild reaction conditions.In this study,ammonium chloride and calcium carbonate mixed roasting was used and chlorination roasting process conditions were investigated by single factor experiment.The reaction temperature and time,dosing ratio of reactants and thickness of loading material for the preparation of anhydrous calcium chloride were determined,and its product was characterized by XRD.The optimum experimental conditions were as follows:roasting temperature at 450?,roasting time in 60 min,dosage in a molar ratio of n(NH4Cl):n(CaC03)=3:1,and loading thickness greater than 1 cm.Under these conditions,the chlorinating rate of calcium carbonate reached 95.8%,calcined product of anhydrous calcium chloride mass percentage is 94.96%.With the selection of industrial grade calcined material,1200 mesh industrial heavy calcium carbonate and ammonium chloride roasting in 120 min,the chlorinating rate of calcium carbonate reached 95.19%,calcined product of anhydrous calcium chloride mass percentage is 94.83%.Besides insoluble substance,the resulting anhydrous calcium chloride meet the standards of industrial grade I.The process of ammonium chloride and calcium carbonate mixed roasting making soda was proposed.Sodium bicarbonate which were obtained through experiments in this process for XRD analysis.The proposed soda process with conventional the Solvay Process,the Hou's process conducted a comprehensive comparison,the new process has the advantage of environmental protection and energy consumption.The process of ammonium chloride and calcium carbonate mixed roasting combine steel pickling liquid waste recycling was proposed.Steel pickling liquid waste was synthesized intermediates ferrous carbonate.Ferrous carbonate synthesis conditions were discussed,in order to obtain a large particle size,easy filtering and washing,contains less impurities of ferrous carbonate,synthesis conditions used are:two materials while feeding,controlled synthesis of pH 6.0,temperature at 70?.The resulting ferrous carbonate has good filtration properties,which contain fewer impurities and high iron recovery.