Tuesday, March 16, 2021

First cast fail...


Tried out melting aluminum cans for the first time today.  50 cans weigh about 600 grams.  I am supposed to expect about 35% to be pure aluminum so I was hoping for around 210 grams in the end.  I got only 109 grams and a ruined crucible clogged with solidified dross and leftover aluminum.  I believe the problem was that I poured before the crucible and metal were hot enough with still too many impurities in the mix.  I tried super heating the leftovers but they refused to melt.  83,89,53,0,B 

4 comments:

JudithK said...

Smelting? Isn't that what it's called? Complicated

John Wells said...

The long answer: Smelting is a process of applying heat to ore in order to extract a base metal. It is a form of extractive metallurgy. It is used to extract many metals from their ores, including silver, iron, copper, and other base metals such as aluminum. The aluminum in cans has already been smelted - I am just melting cans to extract the already "pure" aluminum. Aluminum is almost always alloyed, which markedly improves its mechanical properties. For example, beverage cans are typically alloys that contain by weight 1% magnesium, 1% manganese, .4% iron, .2% silicon, and .15% copper. When melting beverage cans, a lot of waste is produced (called dross) which needs to be removed from the top of the molten aluminum before pouring. The dross produced from melting beverage cans is oxidized waste material that includes the ink used to print the labels and the inner plastic liner.

remmij said...

kinda looks like Kermit on St. Paddy's day…

JudithK said...

Well now. I guess I need to look at the next day's post to see if you got some dross after all. Actually, thanks for the explanation.