RE:DRC is not Mongolia ....I hope....The main difference between TRQ and IVN is still Chinese. The Chinese influence is not just in this mine, but also in Africa. China and Africa has a good relationship for decades. They need each other's support in many different ways. Chinese has been helping Africa's modernization from building infrastructure like railway to its operation and management, in which I believe the western has no interest because there is no quick money and risky.
DRC government knows how important to have a good relationship with China than any of us. Chinese investment in DRCbis not just this mine. I believe the restate of this export ban is solely due to the previous one was just so happened expried last month, and like someone mentioned already, it will be just paper work for IVN.
For the ban itself, it's very similar to the nickel raw material export ban from Indonesia. It's understandable that they expect to profit more, bring more jobs to local, and for their industrialization. For whatever reason, I don't blame Indonesia and DRC for this purpose. What interestingly happened after the ban in Indonesia is that once again, it's Chinese brought the needed skills and money to produce the nickel and then export it back to China. Then Chinese uses it to build things like Tesla to export to the world. It's a win-win situation after all.
P.s. One example of Chinese investment in Africa is this railway: https://www.forbes.com/sites/panosmourdoukoutas/2019/09/21/why-is-china-building-africa/?sh=3816bf21502c