一般来说, the silica content is a measure to test the quality of micro-silica fume. The higher the SiO2 content, the higher the performance of microsilica fume and the lower the content of other non-SiO2 impurities. 所以, the methods of testing the SiO2 content in microsilica powder are listed.

一般来说, the testing and assaying of silica content in silica fume of micro silica fume is usually done by the weight method of hydrofluoric acid. Before detecting the silica content, the amount of burnt loss should be detected first, and then the silica content can be detected.

Micro silica fume burn loss detection assay

Accurately weigh the 微硅粉 sample 0.5g, 后 105 ~ 110 ℃干燥, added to the platinum crucible, and then by 950 ~ 1000 ℃ searing 45min, and then the crucible in the dry which cooled to room temperature, 称重. So repeatedly, until constant weight.

Hydrofluoric acid weight method

Accurately weigh 0.25g of the specimen after measuring the loss of burn, moisten with a small amount of water, add 4~5 drops of sulfuric acid (1+1) and 5~7mL of hydrofluoric acid, put it on the hot plate or electric stove to heat and volatilize at low temperature until nearly dry, then take it off and cool. Add 2~3 drops of sulfuric acid (1+1) and 3~4mL of hydrofluoric acid, continue to heat and evaporate until dry, then increase the temperature until the white smoke of sulfur trioxide completely escapes, put the platinum crucible in a high temperature furnace and scorch it at 900℃ for 30min. Repeat this until constant weight.

Testing of micro silica fume fluidity

微硅粉流动性的测试也是一种测量二氧化硅含量的方法. 这是因为微硅粉的流动性与二氧化硅含量不成正比, 但有一定的关系, 一般来说, 含量越高, 流动性越好. 但也有例外, 例如, 相同 92% 微硅粉, 有的流动性好，有的完全没有流动性. 所以, 这就是为什么需要流动性测试的原因.

未致密硅粉

为了 未致密硅粉 可以用一个简单的方法, 即: 40 克水: 60 克微硅粉: 0.2 克分散剂 (三聚或 P530), 充分搅拌, 倒在玻璃板上, 自然流动, 流动面积的测量, 如果平均直径大于150mm，一般流动性会很好, 还要做无限试块测试, 根据加水量的多少来决定流动性的好坏但是现在国内能达到这个标准的微硅粉太少了.

致密硅粉

为了 致密硅粉, 不能用上面的方法, 但只用不确定的试样进行测定.

关于不定标本, 由于我们主要测试微硅粉的流动性, 你可以确定任意比率, 例如, 如果有铝土矿骨料和细粉, 您可以使用以下比例: 铝土矿骨料5-3MM 40%, 3-1毫米 13%, 1-0毫米 15%, 180 网状铝土矿细粉 20%, 铝水泥 7%, 微硅粉 5%, 三聚 0.15% 或三聚 0.07% 六偏 0.05% 将以上原料称重后, 将它们加入橡胶砂搅拌机中干混一会儿, 然后加 6% 边搅拌边加水, 然后混合三分钟，看混合物的稠度. 如果比较稀，流动性好, 证明微硅粉的质量是可以的. 如果不能流动, 可以适当多加一些水来决定需要多少水.

不过这也是凭经验判断的, 如果你需要准确, 你需要选择流动性更好的微硅粉, 确定标准水量, 该混合物将在水泥砂流动性测试仪中混合 (跳表法) 判断自流和跳跃的流量值 15 次, 此值为标准流量值, 其他各种微硅粉的测定, 看所需水的标准流量值来判断微硅粉的流动性好坏.

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