From Mining to Space
Exploration – the Advantages of Magnetic
Levitation
00:00 Spacewalk
in Progress (European Space Agency Archive)
“ “ (ESA
Archive)
Shuttle
arriving at Space Station (ESA Archive)
Astronauts
inside Space Station (ESA Archive)
Astronauts
inside Space Station (ESA Archive)
Pan
to University sign
Wide
shot, exterior of Mathematics and Physics Building
c.u.
Building sign
Guide Voice: The exploration of Space must rank
as one of mankind’s greatest achievements – and it
certainly ranks as one of our most expensive! Conducting essential
experiments in weightless conditions is particularly costly but now
scientists at the UK’s University of Nottingham are carrying
out zero gravity experiments in the relatively cheap environment of
their own laboratory.
As the University’s Doctor Peter King explains, Magnetic
Levitation may hold the key to both experiments in outer space and
the problems of mineral mining below the earth’s
surface.
00:32 SOT: Dr. Peter King, Reader in Experimental
Physics, University of Nottingham – “There
are a wide range of things where having a local zero gravity in a
laboratory is very handy. I’m part of a collaboration which
has several parts. Plant biologists want to develop plants for use
in space exploration for food on long voyages and so on. I myself
am interested in pure physics and also in mineral separation with
engineers here. By using this reduced gravity we have effective
ways of separating minerals quite quickly and
efficiently”.
01:09 Wide
shot – researcher at electro magnet
Wide
– hand with
pipette
c.u.
pipette being placed inside magnet
c.u.
researcher’s face
c.u.
water being placed in magnetic field
Cutaway
– wave form monitor
Guide Voice: While there are many things around
us that we would normally think of as non magnetic, such as water,
for example, they do become weakly magnetic when placed in strong
magnetic fields. By varying the fields you can create a force on
such objects that can be big enough to counteract the earth’s
gravity. So zero gravity can be created in a controlled, and
relatively inexpensive, environment; perfect for carrying out
experiments on plant growth.
01:37 SOT: Aled Catherall, PhD Student, University of
Nottingham: “We grow cells in three different
parts of the magnet to distinguish between the effects that the
magnetic field has on the plants and the effect that low gravity
has on the plants. Growing plants in low gravity environments is
very useful. You can imagine in the future that we want to grow
plants for self-sustaining colonies on the international space
station, on the Moon or even on Mars. And using the levitation
facility we can actually predict which plants are most adaptable to
these low gravity conditions”.
02:08 Wide
shot – researcher at magnet with liquid oxygen
c.u.
Large test tube of liquid oxygen being clamped in place
c.u.
Different metals - gold coin, £1 coin (mostly copper), lead
and silicone being cooled with liquid
Helium
for placing in liquid oxygen
c.u.
researcher’s face
c.u
container of metal objects being moved
Medium
wide of liquid oxygen, metal objects brought into shot
Researcher
£1
coin being dropped into liquid oxygen
Researcher
Tube
of liquid oxygen being raised and lowered in magnetic field
c.u.
of metals separating in liquid oxygen
Guide Voice: But it’s in the mining
industry that magnetic levitation has some of its most interesting
applications. There are certain magnetic materials, such as liquid
oxygen, which are known as paramagnetic and these materials will
search out the strongest magnetic fields. By placing such a
material in the centre of a powerful magnet it will displace
minerals according to their magnetic properties and their
densities.
This approach has a number of major advantages over similar
separation techniques currently used in mining.
02:38 SOT: Dr. King –
“There are a number of magnetic separation techniques
using what are called ferro-fluids. These are liquids based on an
oil or water containing nano-particles. These are quite expensive,
they are rather viscous, and they are difficult to recycle having
used them once in separating minerals and getting them contaminated
they are difficult to use again. Oxygen is of low viscosity, is
cheap to produce, it’s about the same price as petrol
litre-per-litre. Of course, if you lose it back into the atmosphere
from whence it came, nobody is going to shout at
you.”
03:19 Simulation
– minerals separating in magnetic field with vibration
applied
Guide Voice: At the University of Nottingham
they are also experimenting with adding the additional component of
vibration to aid separation. This means that a weaker magnetic
field can be applied to further reduce costs.
03:31 SOT: Dr. King –
“The mineral separation is extremely important. As some
rocks get rarer and rarer and the essential things that we wish to
extract become more difficult to find it’s important to
extract rather small quantities from a background ore and these
techniques will give us access to those rare
minerals”.
03:54 c.u.
“ball” of water floating in magnetic field
Guide Voice: From inner earth to outer space,
magnetic levitation would seem to be one technology that certainly
“floats our boat”!
04:02 End
of cut piece
Additional Material
04:06 Pan
along wave form monitor to another (unidentified) monitor
Researcher
carrying tube of liquid oxygen
c.u.
metal objects being cooled prior to being placed in liquid
oxygen
c.u.
metal objects suspended in liquid oxygen
04:51
END
