I have several cacti and succulents from the Botanical Garden of Rio de Janeiro which had no labels.
I know very little about this plant group..
Could this be Ferocactus glaucescens?

They seem to look more like Echinocactus grusonii.

Thanks Tarev! Yes, that looks much like it too, strange how cacti so similar in appearance belong to another genus, that shows how little I know about them..
A pity I didn't take close-ups..

I took some photos recently of that cacti at the Arizona Cactus Garden in Stanford, CA ..really lovely..here is what I got for comparison:


Then years ago I saw them nicely growing too at the Getty Center cactus garden in Los Angeles:


They are intriguingly prickly and so pretty

Echinocactus grusonii looks like a good match Tarev, you made some excellent captures of this beauty!