You can hit "U" while your mouse is over an item to get all recipes it is used in.
Basically, R for Recipe, U for Usage.
Use the arrows on the window to switch between recipes and machines (top arrows switches between machines, bottom switches between recipes of that machine).
That will teach you that the aluminium you mine is only smelted into aluminium (no ingot), and has only a few uses.
For the ingots, you need the dust, that you get from UU, grinding bauxite, as a secondary product (best in an industrial grinder).
You can also use the industrial electolyser from various dusts, and even some clay.
Hope it answers the question.