free silica meaning in English

游离二氧化硅
游离硅
游离氧化硅

Chemical analysis of limestons for free silica
石灰岩中游离二氧化硅化学分析方法
Health standard for dust containing 50 % 80 % free silica in the air of workplace
车间空气中50 % 80 %游离二氧化硅粉尘卫生标准
Health standard for dust containing more than 80 % free silica in the air of workplace
车间空气中含80 %以上游离二氧化硅粉尘卫生标准
Quantitative experimental study of pneumoconiotic changes in the lungs by dusts containing free silica
含游离二氧化硅粉尘致肺病变的定量实验研究