If I attempt to conquer with adaptation and irelia, adaptatron dies but is recalled by altar of blood battlefield. Do I kill a gear from that conquer

No — Adaptatron's conquer trigger won't fire, because it isn't at the battlefield anymore when control is established.

Altar of Blood's ability replaces the death with heal + exhaust + recall, so Adaptatron is already sitting in your base (recalled, per Rule 455–456) during combat resolution — well before Rule 466.5 establishes control and results in the Conquer. A unit's conquer ability is only put on the chain if that unit is present at the battlefield at the moment you gain control of it and gain the point (Rule 383.4.c.2.a); that's the same reason a unit that dies in combat doesn't get to trigger its conquer effect (FAQ #9015).

You'll still conquer and score the battlefield if Irelia survives and is the only unit left — you just don't get Adaptatron's "kill a gear, buff me."