crude zinc oxide meaning in English

粗制氧化锌

Study on preparation of active zinc oxide from a crude zinc oxide powder
一种用初级氧化锌粉制备活性氧化锌工艺
The research on the preparation of nanometer active zinc oxide from crude zinc oxide
由粗氧化锌制备纳米活性氧化锌的研究
Preparation of active zinc oxide from crude zinc oxide by ammonia complex leaching technique
氨配合法制备活性氧化锌过程研究