Grounding a magnetic levitation circuit

I need help understanding the circuit attached, from what i understand is that i can power it from a 12V mains adapter. The one i have is 1 amp which i think is enough. But more importantly for the grounds, that i should connect them all up to the ground coming from the 6 pin on the left opamp. As though this ground would act as a central one, with all the other ones connected to it. Is this correct or not, if not then please explain to me how i should ground this circuit.
I claim no rights to the content in the link and am using it for my own recreational purposes.


Those are common grounds. If they where not common grounds then they would be noted differently.