The iron deposits at Luwu are laterite ores.
In the 1980's my understanding is that there was a small commercial smelting operation going on at Luwu. I was told this by Panembahan Harjonegoro (alm.) who gave me a piece of this commercially refined nickel.
The current situation in Luwu can be understood by following these links:-
http://www.oxis.org/theses/misol-2103.pdf
https://www.reuters.com/article/indo...0R42WI20140904
https://www.reuters.com/article/us-c...-idUSKBN19P1Q5