Study On Preparation Of Nano-calcium Carbonate By I-MD Microstructured Reactor With Membrane As Dispersion Media

In this paper, the core of micro-dispersion precipitation method was prepared toNano calcium carbonate which by detailed basic research and industrial application’stest.The scattered micro hybrid technology is used by a pore size of several microns ortens of microns as a dispersion medium dispersion material, which be distributedthrough the pressure of the gas pressure into another phase. Respectively, thetwo-phase wre flowed in both sides of the dispersion medium, and the dispersed phasewhich were cut into small continuous phase particle size of air bubbles through tinychannels flow into the continuous phase, and will realize micron scale and mixingquicklyenhance mass transfer surface area greatly, mass transfer flux be greatlyimproved.By adjusted the continuous phase, dispersed phase flow rate and membranepore size,which can be achieved to the control of the reaction. At the same time, thereare many micro-channel on continuous phase side of the reactor, thesemicro-structures ensure that the flow are uniformity and uniformity, which Make thegeneration of nano-particle size are narrow.1.we used CO₂gas as the dispersed phase in the experiment, and Ca（OH）2forthe continuous phase of the reaction suspension to prepared nano-calcium carbonate.Through small scale, pilot and enlarge the experiment of industrialized production,and carry out the different equipment and the reaction of process in research, in thispaper,I summarizes the law of the amplification device. At the same time, micro-dispersion process of dispersing membrane pore size, two-phase flow rate, pressure,CO₂concentration, PH value and other parameters on the grain size of nano-calciumcarbonate were researched, and summarized about all kinds of conditions for particlesize and distribution the influence law of the crystal in order to achieve thecontrollability of preparation of nanometer particles.2.All products were characterizated by TG-DTG、XRD、FTIR、BET、and TEM.Through the small scale experiments, the nanometer CaCO₃grain size was small,narrow and can be continuous operated.3.By pilot experiments,industrial scale pilot,improve the micro-reactorstructure, and increase the number of channels and membrane area for reliablelyamplification experiments to design I-MD film scattered micro reactor preparationprocess. The research of new technology for two-phase flow speed the process of preparation of nano-calcium carbonate, dispersed phase pressure, temperature andother factors influence the production process to successfully preparated adjustablegrain nano CaCO₃from20to60nm. At last, I propose the optimum conditions of thelow-power，high CO₂utilization of nano calcium carbonate grain size and surface areaand make technical evaluation.