A friend asked me that there were some metal powders in the purple pottery pot he bought, but he didn’t know what it was.
First of all, this “metal powder” is not something terrible, but emery.
Why is there emery in the purple pottery pot? Even in some purple pots. There are two sources of the emery: one is to grind the mouth of the pot and the mouth of the pot with emery, and the emery falls into the interior; the second is that the first step of grinding requires sand blasting to spray off the fire skin. The material used is emery, and part of it remains in the interior of purple pottery during operation.
Why can emery help grind the mouth and use it for sand blasting? This is because the hardness of diamond is higher than that of the burnt purple pottery and the surface of the fire skin. Therefore, the excess part of the pot mouth can be ground off to achieve perfect sealing effect, and the fire skin can be sprayed off to improve the grinding efficiency.
What’s more, purple pottery will be washed with water after polishing, how can there be emery? This is mainly due to another characteristic of emery: high density.
The same volume, the greater the density, the heavier the object. The density of emery is much higher than that of water, and the effect of gravity is more obvious. Therefore, even if you use water to wash, some of the emery will remain at the bottom.
But this is not a problem, only need to clean the baby carefully, the residual emery is also removed.