氢氧化镁煅烧制备镁砂的工艺研究

Study on the Process of Preparing Magnesium Sand by Calcination of Magnesium Hydroxide

以盐湖镁资源生产的高纯氢氧化镁为原料,将部分原料进行轻烧用于制备氧化镁,后将得到的氧化镁与氢氧化镁混合后进行生坯压制,再将生坯进行高温煅烧制备镁砂。针对生坯制备过程,重点研究了成型压力、保压时间、轻烧温度、轻烧时间、氧化镁含量对生坯密度的影响;针对高温煅烧过程,主要研究了煅烧的温度与时间对颗粒密度的影响。研究确定最佳实验条件为:在900℃下轻烧氢氧化镁3 h得到氧化镁,控制氧化镁与氢氧化镁的质量配比为1∶4,将其混合均匀后,在600 MPa下进行压片,并保压5 min,再在1600℃下煅烧5 h。在该条件得到的镁砂完全满足国标要求。

High purity magnesium hydroxide produced from salt lake magnesium resources is used as raw material,part of raw materials are lightly fired to prepare magnesium oxide,and the obtained magnesium oxide is mixed with magnesium hydroxide to press the green blank,and then the green blank is calcined at high temperature to prepare magnesia.In this paper,the influence of forming pressure,holding pressure time,light firing temperature,light firing time and magnesium oxide content on the density of green billet was studied.The influence of calcination temperature and time on particle density was studied in high temperature calcination process.The optimal experimental conditions were determined as follows:magnesium oxide was obtained by light burning of magnesium hydroxide at 900℃for 3 h,and the ratio of magnesium oxide to magnesium hydroxide was controlled to be 1:4.After evenly mixing,the tablet was pressed at 600 MPa,and the pressure was maintained for 5 min,and the calcined at 1600℃for 5h.The magnesia obtained under these conditions fully meet the requirements of the national standard.