NEW YORK Aluminum scrap
turnings are increasingly being compressed into pucks to boost
recovery rates, traders and recyclers told AMM.
A growing numbers of producers
are installing pucking machines, with high-grade, 7000-series
and 6000-series turnings said to be the most commonly traded,
aluminum scrap traders said.
The main advantage of pucked
turnings is said to be their reduction is moisture content,
which boosts recovery rates and removes the need for
"I think the briquettes
typically arent as dry," one aluminum scrap trader said.
"If they run over 4- to 5-percent moisture, then you have to
run them though the crusher and dryer. But pucks are so dense
that you can direct charge those, which saves on processing
costs. Its almost like melting a solid."
Reduced moisture also increases
the weight of the metal being shipped, achieving greater
economy in freight.
"If youve got 40,000
pounds of loose turnings, youve got a lot of dead
weight," a second trader said.
Pucks are also easier to ship,
some market sources said.
"You can put them in a box and
not have to store loose, wet turnings," the second trader said.
"That increases the value of the finished product."
However, one trader said he
refuses to buy pucks, citing concerns over whether the recovery
rates have been overstated.
"You need to be careful with the
furnace you introduce (the pucks) to," the trader said. "They
seem to do better with rotary furnaces than reverb furnaces. In
the reverbs, they tend to float when you need to get them below
the molten line."
Even though most consumers have
tried pucks and some swear by them, "others wont touch
them because they cant get them under the molten line and
get the proper recoveries," the trader said. "If something has
4- to 5-percent moisture, thats going to stick to the
material and stay in there. And the colder the weather, the
more likely it will stay on there."
The first trader also cautioned
against pucks that use a binding material. "Ive seen some
pucks with a recovery of 70 percent because of the binder in
there," he said.