In an attempt to produce aluminum oxide ($\ce{Al2O3}$) also known by alumina I try it out to dissolve two old hard drive frame in brine solution one as the cathode and the second as anode, in the first time the solution turn white and the reaction stopped,At the second time with a new solution very saturated with $\ce{NaCl}$ the solution turned dark grey and did dissolved a part of one of the electrodes which are hard drives and the reaction stopped again maybe the dissolved part shortcut.

Finally to save the situation I used 150g of sodium hydroxide but after a night in solution $\ce{NaOH}$ not much happened and then I figured out that the hard drives are an aluminum alloy.
in the electrolysis part I used an old dell PSY 12v. my question is how to get the aluminium from the aluminium alloy?


die-cast from A380 alloy (other names ADC10, SC84A, LM24, A03800, A13800, AlSi8Cu3Fe) composition:

Melting Point 1,000°F 537.778°C

<0.35% = 231.9°C =Tin
<3.0% = 419.5°C = Zinc

660.3°C =aluminum

3.5% +/- 0.5% = 1,085°C = Copper
<0.1% = 1,091°C = Magnesium
8.5% +/- 1.0% = 1,414°C = Silicon
<0.5% = 1,455°C = Nickel
<1.3% = 1,538°C = Iron
<0.5% = 2,061°C = Manganese
Trace = <0.5%

  • 2
    $\begingroup$ What do you want to achieve? If you just want pure Alumina, I'd buy it. $\endgroup$
    – Karl
    Commented Mar 1, 2017 at 23:34
  • $\begingroup$ My idea is to first react all your alumina with NaOH to create $\ce{AlOH3}$. Put that resultant in a calcium solution and a single replacement reaction should occur. $\endgroup$
    – Equinox
    Commented Jun 4, 2017 at 15:45
  • $\begingroup$ How are you going to get a calcium colution? It does not exist in water and molten calcium may produce weird things like ternary oxides and intermetallic compounds. YOU CAN'T SMELT ACTIVE METALS AT HOME! $\endgroup$ Commented Feb 23, 2023 at 17:04

3 Answers 3

  1. Do a process of anodic oxidation to your hard drive frame, and using acid to remove other metal.
  2. Peel off the aluminum oxide.
  3. Repeat step 1 and 2 until bulk aluminum oxidized fully.
  4. Electrolyze Al2O3.

Do you think this is necessary?


If you know your alloy components, you can try to use an acid that will selectively dissolve one of your components. If there is not a big difference in solubility of the components, you can try to dissolve the entire sample and try to electroplate the desired metal or perform some other reaction(s) that will isolate aluminium.

Do this activity, even just lab scale can be dangerous, so take caution.

  • $\begingroup$ A surface etch won't change the bulk composition. "Dissolve" typically means water and you can't plate Al from an aqueous solution. $\endgroup$
    – MaxW
    Commented Mar 1, 2017 at 21:16
  • $\begingroup$ @j.ari first search i found that the hard drive disk frame are made from A380 alloy, die-cast from A380 (other names ADC10, SC84A, LM24, A03800, A13800, AlSi8Cu3Fe) composition. $\endgroup$
    – autodidact
    Commented Mar 1, 2017 at 21:21
  • $\begingroup$ @MaxW I'm imaging ore refining plants that put raw ore into batch reactors full of conc. acid that dissolves the solid ore, then the solution is processed further to isolate the desired metal(s) through other reactions. $\endgroup$
    – J. Ari
    Commented Mar 1, 2017 at 21:36
  • $\begingroup$ @MaxW smelting aluminum is done with electricity up to 12 Kw to produce 1 Kg of pure aluminum no acids its an expensive process. $\endgroup$
    – autodidact
    Commented Mar 2, 2017 at 18:08

the solution that passes in my mind is to melt the alloy since it has a low temperature 537.778°C and during the process add carbon to precipitate the copper, Nickel, iron, manganese, Silicon and magnesium since they have a higher melting point and will not melt.
The remain product is aluminum and Tin Zinc .


The second solution is the electroplating process on steel or iron since aluminum doesn't depose on any metal it gonna precipitate at the bottom and other metals will depose on steel sheet

  • 2
    $\begingroup$ Won't work. The components in alloys are usually soluble in each other in the melt. What's that trick with the carbon? $\endgroup$
    – Karl
    Commented Mar 1, 2017 at 23:38
  • $\begingroup$ @Karl I have found that the first solution is called " Liquation " $\endgroup$
    – autodidact
    Commented Mar 2, 2017 at 21:14
  • 2
    $\begingroup$ Shouldn't that be an edit to the question? $\endgroup$ Commented Nov 2, 2017 at 5:35

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