And if you really want to extract something useful then you should put lava in electrolyzer, because most electrolyzing processes is usually done on a melted/liquid materials... if I not mistaken.
True to most metals, unless if those can be dissoluted in water/any other liquid to make ions and has a lower electronegativity than hydrogen (or something like if not mistaken).
Btw, electrolyzer "melts" them to do the electrolyzing process thus using lots of energy.
Centrifuge shouldn't be the one that is able to extract materials from lava (as the metals are melted as a huge alloy and can only get separated through electrolysis) but whatever this is minecraft.