Inert ceramic ball still can be used after being charred?

One of our customers  purchased a batch of inert ceramic balls from other factories some years ago, but due to the progress of the project, all the inert ceramic balls were not used up. When preparing to use now,  they found that a bag of ceramic balls came out and scorched; now they can't contact the original manufacturer, so came to consult us. Want to know if it can still be used after being burnt?
First, let's understand why inert ceramic balls scorch.
1. In most factories now, the inert ceramic balls are sintered in a tunnel type, the ceramic balls are placed on the container, and refractory materials are spread around. Avoid burning the surrounding ceramic balls due to excessive temperature;
2. Some factories use drawer-type tools for sintering. Put the ceramic balls  into the drawer directly, and one goes in and one out, and the temperature is uneven, which leads to scorching. Tunnel-type kiln, the temperature is more stable.
The ceramic balls we produce use a tunnel-type temperature control box. The production process is to dry them, then use them at about 250 degrees, fire them for 50 hours, and transport them to the kiln tunnel by driving. In this way, the ceramic balls produced will not be burnt due to uneven temperature.
Summary: If the inert ceramic ball has been burnt, it is not recommended to use it again; because of the burnt part, there are impurities in it, which will affect the use effect. Furthermore, if the environment used is very harsh, after a period of use, all the ceramic balls will become lumps, and the performance is not good, which will also increase the cleaning and replacement costs of the factory.