Aluminium Smelters do not use bauxite. The use Alumina, which is produced by an alumina refinery. The smelter operated by Rio in Cameroon is an aluminium smelter which uses imported alumina. Rio using the SDL railway would only make sense if Rio were to build a alumina refinery in Cameroom. To my knowledge they have no intention of doing so I suggest you ignore that speculation you have heard as it is totally erronous.
Nextport
PS since my last post some months ago I have sold my holding but now looking to re enter at the right price.
SDL Price at posting:
37.0¢ Sentiment: Buy Disclosure: Not Held