利用菱镁矿制备氢氧化镁

以菱镁矿为原料,研究常压下制备氢氧化镁的新方法.首先通过煅烧试验,得出保证菱镁矿达到充分分解且其分解产物氧化镁具有较高活性的煅烧条件是煅烧温度600℃,煅烧时间9 h;提高煅烧温度到700~750℃,煅烧时间为2~4 h时,菱镁矿的分解率也达到最高值,但其氧化镁活性有所降低;其次以氧化镁粉为原料,研究常温下化学合成氢氧化镁粉剂的制备方法.结果表明对快速合成的絮状氢氧化镁沉淀物进行80℃水热老化处理30 min,可得到过滤性能较好、纯度较高、均一规则六边形薄片状氢氧化镁粉体,从而得出水热老化反应是制备较规则形貌氢氧化镁的重要方法.

Preparation of Magnesium Hydroxide from Magnesite

Taking the magnesite as raw material, a process was developed to prepare magnesium hydroxide under atmospheric pressure. Optimum calcining conditions were determined through calcination tests at 600°C for 9hr, under which the magnesite can be fully decomposed with high chemical activity of the product magnesium oxide. When calcining at 700-750°C for 2-4 hr, the decomposition rate of magnesite can be maximized but the activity of magnesium oxide decreases somewhat. Then, taking the powdered magnesium oxide as raw material, the suitable synthesizing process was investigated for the preparation of magnesium hydroxide at normal temperature. The results showed that the powdered magnesium hydroxide with high filterability and purity and regular flaky hexagion crystal can be prepared via a hydro-thermal aging treatment at 80°C for 30 min done to the floccular magnesium hydroxide precipitate quickly synthesized. A conclusion is thus drawn that the hydro-thermal aging reaction is of importance to the preparation of magnesium hydroxide with regular crystal morphology.