China has its own mission in helping Russia to carry out the invasion of Ukraine, China is a country that wants to have its own advantage, they will do everything possible to get an advantage, where he sees an advantage, he will try to approach, but if China does not benefit, already surely he will not care about all that, as China did with bitcoin, because the Chinese government cannot control bitcoin, so in 2017 China immediately banned bitcoin mining in his country,
This is no news. China wants everything that would be beneficial to them. They are just waiting for the opportunity to take advantage of the situation. The moment they got a glimpse of a scene that would be useful for them, they would do everything on their power to make it happen.
Right now, China said that they are not in any way affiliated as an ally to Russia. It's because they have seen all the sanctions imposed upon Russia. I believe they think that the world sanctions would really do much harm if they will be involved, hence chose to be secretly backing up Russia for the raw materials they need.