Companies like Intel are only declared Conflict Free when the Smelters who they source from are; so by proxy Intel can declare their Processors and chips etc as Conflict Free - as long as the Smelters they source from are CFSP (Conflict Free Smelter Program) compliant!
(How do I know) I produce CFSP reports for the Smelters for a living.
Basically the scheme I work on (iTSCi - the "ITRI Tin Supply Chain Initiative") - which only covers Tin, Tungsten and Tantalum (the 3 Ts), monitors the movement from Mine to Export, within the DRC, Rwanda and Burundi (and a site in Uganda), of mineral via a tagging system (in some other channels Intel 'unboxings' of this you actually see a "Logbook" getting the tag data recorded). The Mine sites are all vetted before any tagging is allowed to start, and there is constant monitoring of the situation on the ground, in these countries, to ensure that the supply chain has no vulnerabilities and that any armed groups are far enough away from the supply chain to not affect it (DRC is a HUGE country - and also one of the most beautiful places on earth).
Pretty weird day when you watch a LTT video during your lunch break and see a Tag appear that your running a report on