| The flame retardant aluminum hydroxide powder was prepared by seed precipitation method. The first, we make the industrial aluminum hydroxide dissolved in sodium hydroxide solution, making high saturation of sodium aluminate solution by boiled and adding a certain amount of aluminium hydroxide seed and water, after several hours we can get aluminum hydroxide which we want to make by a constant temperature.This Experiment used a intensification equipment of reacti on process--rotor-stator reactor. And the effects of reaction time, reaction temperature, sodium aluminate concentration and the alumin um hydroxide seed on the morphology and structure of aluminum h ydroxide had been studied. The characterization of aluminum hydrox ide was investigated by XRD, SEM, and TGA. The results showed that:(1)The results in ordinary mixing showed that:when reaction temperature is 50℃, reaction time is 40h, dilution ratio is 1:2, the seed amount is 5 g L-1, we can get good aluminum hydroxide crystal.(2)The study shown that rotor-stator reactor can strengthen the micromixing, so it can reduce the crystal grain size. The better conditions as follows:when reaction temperature is 50℃, reaction time is 40h, dilution ratio is 1:2, the seed amount is 5 g·L-1, recycle reaction time of 3 hours,2800 r·min-1 of the speed of rotor-stator reactor,200 mL·min-1 circulation volume.The novelty is that we fist use rotor-stator reactor by this method to prepare aluminum hydroxide. Comparing with ordinary agitation reactor, rotor-stator reactor can obviously make aluminum hydroxide flame retardants crystal reduce particle size, decrease the situtation of reunion condition, and have a good dispersibility. |
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