I need Iron powder. What's the best way to produce it? I have Ferric Chloride and Aluminum...

I also have steel filings from grinding steel objects, though some Iron Oxide have be separated (I do have Oxalic Acid and Citric Acid). Though that would give me steel powder, not iron.

Which is the most economical and would yield purest samples?
Sigma-Aldrich has a product that is very pure but rather expensive. I suspect you can have high purity or low cost but not both.