On Aug 25, 6:59 pm, byblow wrote:
What equipment, materials and amount of electricity are needed to
produce steel (in space) from ores found on NEOs?

It depends on the object. Some of them, 1986 DA for example, are
thought to be solid nickel-iron. Depending on what you wanted to do
with it, the material could be melted using an open ended induction
furnace, electromagnetically pumped out and rolled into I beams.

If you wanted the nickel, roll the metal into thin strips, and run it
though a number of gas lock stages into a 15 Bar (750 psi) long
chamber with warm flowing carbon monoxide. The nickle, iron and
cobalt carbonals can be sorted out of the gas stream and reduced back
to metals. See Mond process. The dust contains the rest of the
elements, including platinum group metals, gold and copper. Dr. John
Lewis, http://en.wikipedia.org/wiki/John_S._Lewis, has done a lot on
this topic.

Would there be a need to add carbon (as a reducing agent) during the
refining process, or something with characteristics similar to
limestone (I believe calcium oxide is the "active ingredient" in
limestone)? Would oxygen be needed for a blast furnace? Would water
be needed to quench the hot steel?

Depends on what you are starting with, but generally no.

Another question I have is, How would something like a mini-mill be
modified to function in zero-G and vacuum?

Vapor deposition is one way to make sheet metal or other fabricated
items.

Sorting out non metallic inclusions may take some kind of induced g
forces.

I had thought something like an electric arc furnace would be all
that's needed to refine pure iron/steel from NEO ores, but from what I
can find, EAFs appear to be used almost exclusivly for refining scrap
steel.

I think induction is a better way to heat metal in space.

Keith Henson