Basic Studies On Growth Regularity Of Spherical Nickel Hydroxide And Simulation Of Reactor

Spherical nickel hydroxide was widely used in the field of electronic energy,electroplating,aerospace,military and so on.As consumption superpower of spherical nickel hydroxide,China relied on importing due to the low yield and significant batch differences of spherical nickel hydroxide.The reason was the research into growth mechanism of spherical nickel hydroxide was not thorough and industrial reactor was difficult to design and amplify.First,Based on the commonly used industrial chemical precipitation method,this thesis explains the growth process of crystalline spherical nickel hydroxide;this thesis explained the formation of the spherical nickel hydroxide crystal nucleus,growth of crystal,aging of crystal and other processes from the perspective of crystallography.Meanwhile it slated the factors affecting the spherical nickel hydrox:ide growth mechinism via linterface stability theory,the boundary layer theory and agglomeration theory.Through the research on growth regularity of spherical nickel hydroxide crystals,the effects of(100)and(101)crystal face growth on the degree of crystal sphericity and integrity of surface structure growth can be obtained,and the mathematical comparison expression between the amorphization,particle size distribution d50,apparent density and aging time was summed up.Moreever,the relationship between electrochemical activity and aging time by CV test can be obtained.Second,this thesis researched cationic surfactant and anionic surfactant influenced on the patterns of nickel hydroxide,it was found that cationic surfactant aqueous solution was acidic,which weakend the supersaturation and system stability and was not conducive to the formation of spherical nickel hydroxide.Anionic surfactant aqueous solution was alkaline,formed coating for nickel hydroxide particles and generated the synergistic effects accompanied by ammonia,which formed complex conducive to the oxidation of hydrogen ions adsorbed on the crystal surface and forming spherical nickel hydroxide crystal better.Comparing several anionic surfactant to the stacking density of spherical nickel hydroxide,and the influence of the concentration of anionic surfactant on the crystallization of spherical nickel hydroxide taken SDBS for example.Third,PIV physical simulation combined with wet experiment that based on wet experiment established 200L water model under geometrically similar conditions and researched the effects of baffle size on the flow field in the reactor.Through the flow field comparative analysis of the six inclined blade turbine propeller,propulsion propeller and Intermig propeller combined with wet experiment,the conclusion that six inclined blade turbine propeller is relatively suitable for spherical nickel hydroxide production is gained.Changing the stirring intensity,researching characteristics of flow field in different stirring intensity and combining with wet experiments,the mathematical expressions between stirring intensity and crystal shapes,amorphization can be obtion.Moreever,the relationship between electrochemical activity and stirring intensity by CV test.Fourth,the water models of 50L,100L and 200L were builded under geometrically similar conditions based on the wet experiment reactor.The relationship between rotational speed and power was researched;the norm of amplification based on power of rotational speed-volume was established-Moreever,the power of 10m3 reactor at different rotational speeds were calculated.Fifth,according to a a domestic industrial spherical nickel hydroxide 6m3 reactor,the flow field and turbulence kinetic energy distribution variations of 1m,6m3 and 10m3 in the reactor were researched by numerical simulation.Morever,the influences of draft tube on flow field and stirring frequency when the reactor is 10m3 by means of numerical simulation method was researched and the variation of flow field and turbulence kinetic energy of 10m3 reactor under different stirring intensities were simulated.The key points for design principle of spherical nickel hydroxide reactor were summarized based on industrial reactor and wet experiment,providing theoretical experiences for the industrial design and amplification of spherical nickel hydroxide reactor.