We haven't killed it yet (7 attempts in) but I've been having success with this rotation:

Flame Vents:
1. Nothing
2. Nothing
3. Dampen

Mines: (Use guard at some point here as a save)
1. Dampen
2. Dampen
3. Nothing

Flame Vents:
1. Nothing
2. Nothing
3. Fort

Mines: (Use guard at some point here as a save)
1. Fort
2. Fort
3. Nothing/Fort (depending on speed of mine stomping)

I then use Guard/Self heals liberally during p2 (our fourth healer was away so we were trying the outrange strat).

The incoming tank damage in this fight is fairly high in general, so it's just mostly thinking of ways to deal with the largest hits. Adding a bit more mastery can help with the mine explosions as well, I'm running with ~10k at the moment in 10 man (can still keep 16k crit on top of that...) and the mines feel fairly safe, it's the flame DoT that is dangerous.