高纯氧化硼的制备

以99%的工业硼酸为原料，经过氧化重结晶除去有机杂质，与甲醇进行酯化精馏反应提纯，生成的硼酸酯水解得到高纯硼酸，产物纯度达99.999%。酯化精馏反应控制在90 ℃左右，产物收集温度为60 ℃，温度较低，工艺条件易于实现，且能很好地控制挥发进入精馏产物的杂质，提纯效果好。高纯硼酸再经过高温脱水、浇铸等过程，最终制备出了适合砷化镓单晶生长所需要的液封剂--无水高纯氧化硼。此外还重点研究了酯化精馏及水解反应条件，以及加热脱水工艺的优化。

Preparation of high purity boric oxide

With 99% industrial boric acid as raw material，after the oxidation and recrystallization to remove organic impurities， esterification distillation reaction with methanol and highly pure boronic acid product with purity of 99.999% was finally obtained by hydrolysis of purified borate ester.The esterification distillation reaction was controlled at about 90 ℃ and product collection temperature was 60 ℃.The process has many advantages，such as lower temperature，easy-to-implement process conditions，well-controlled volatile impurities into the distillation product，and good purification effect.And then after dehydration at high temperature，molding，and other processes，a liquid sealant suitable for gallium arsenide crystal growth，i.e.high purity boron oxide was ultimately prepared.The important optimizations of esterification distillation and hydrolysis reaction conditions，as well as the heating dehydration process were also studied.