How does it coming from his Hand mean it didn't have Haki?I stated that his Ice was dispersed from his hand, so no amount of Haki can be used in addition to his devil fruit powers.
Now, as I remind you...
Magma is composed of fire and earth, that earth element is also a factor that supports Aokji against Akainu.
Just like how Crocodile can make contact with Akainu without being burned whatsoever.