Although the fluidity of micro-silica fume has a certain relationship with the silicon content, it is not proportional. The same is 92 silica fume, some have good fluidity, and some have no fluidity at all. In addition, when testing, a dispersant must be added. If sodium tripolyphosphate does not work, try again with P530, if both do not work, this kind of micro-silica fume powder cannot be used in the refractory industry.
For semi densified microsilica powder, a simple method can be used, namely: 40g water, 60g microsilica, 0.2g dispersant. After fully stirring, pour it on a glass plate and flow naturally. Measure the flow area. If the average diameter is greater than 150mm, the fluidity is generally very good, but it is better to do an indefinite test block test, and finally determine the fluidity according to the amount of water added.
For the densified silica fume, the above method cannot be used, only the amorphous sample is used for determination.