Hi. I am speaking from experience; I recently got 85 mining, and I have always been F2P. The best mining experience in F2P is iron. If you want to bank it, the best place is in the dwarven mine / resource dungeon with the deposit box. If you want to power-mine, there are various options. To break up the monotony in my mining training I usually grab available mith and addy ores as they spawn. Obviously this slows things down but it is a nice break. Good luck with your goal!