The Mercus Factory is a high level area.
You can access the Mercus Factory/Chiron Habitat area by Steam Ballooning from Bijumir.
You have to complete a quest to get access to the Mercus Factory.
There are additional Mercus Factory related quests available.
I am assuming that the Kerman Factory and the Mercus Factory are similar with different floor layouts.
See the Rogwel Kerman Factory page for more information
Lv 50 - Factory Entrance Qualification
[55Lv] Condition to Enter Factory
1. Talk to Roland in Bijumir, located near the entrance across from Quest Keeper
2. Collect 10 Chiron's Leather from Chirons at Chiron's Nest/Habitat
==> Steam Balloon from Bijumir to Mercus Factory Entrance
3. Kill L56 Ral Chiron
4. Talk to Roland
REWARD: Metal Scales Leather x58, 43750 gold, 393500xp
Entering the Mercus Factory
Tunnel 1st Floor