But, if a quenching is implemented during high temperature with the temperature cooled to a certain extent and then cooled slowly, most of boric acid crystals are provided with a certain grain size.

• 采用在高温时快速冷却，待降至一定温度后，再慢速冷却降温，可以保证硼酸结晶体多数为具有一定粒度的颗粒。