In this guide, you will find out how to get Dioxite in No Man’s Sky.
Dioxite is mainly found on frozen planets with a winterlike environment, but you can also buy them from random vendors near ships. They might not always have Dioxite for sale. Now if the system you’re in does not have a frozen/winter-type planet with Dioxite on it, then you have to warp to different systems until you find a planet that does have Dioxite on it.
When you find a planet with Dioxite on it, you’re going to gather it by either finding it using your analysis visor or mining it using the terrain manipulator. Or you can use the survey device to find a Dioxite hotspot and make a mineral extractor/mine to gather it. It doesn’t really matter what way you choose to get it. You can also refine and make it that way using condensed or regular carbon and sodium nitrate and refine it into Dioxite.