The mineral assemplege of the deposit is composed of diaspore, kaolin, illite, chlorite, hematite, anatace and rutile with tourmaline, zircon, goyazite in less.
For sinter with 25% and 50% MAC fines the iron oxides mainly consisted of hematite and magnetite, the bonding phase were mainly dicalcium silicate, glassiness, and a few amount of calcium ferrite.
We would likely need several Earths worth of highly reflective material like hematite to construct the full system — plus a few more dismantled planets to make a legion of construction robots.