PERMROLL® magnetic
separator supplied to diamond mine
BATEMAN has supplied a laboratory-scale Bateman PERMROLL® high-intensity,
high-gradient, magnetic separator to the River Ranch Diamond Mine
in the Beit Bridge area, Zimbabwe. The new unit was delivered within
six weeks of the receipt of the order and will be used at a diamond
mine which is being upgraded to investigate the feasibility of removing
weakly-magnetic minerals from the diamondiferous gravel before being
sent to the gravity-separation circuit.
PERMROLLs® are often used for this purpose in diamond-processing
circuits where feeds are available that are dry and crushed and the
diamonds are liberated from the host rock.
BATEMAN has been developing the concept since 1982 and has supplied
nearly 500 PERMROLL® production installations comprising about
900 individual modules to beneficiate, clean, recover and pre-concentrate
many mixtures composed of a range of ferromagnetic to weakly-paramagnetic
materials. These include andalusite, diamonds, foundry sands, ceramics,
earths, industrial minerals, refractories and even salt.
The PERMROLL® consists of a roller comprising an appropriately
configured array of discs of rare-earth magnets, mounted on a shaft
driven by a small motor. The particulate material to be treated is
distributed evenly on a belt passing over the magnetic roll. The non-magnetic
particles drop off first under the influence of centrifugal and gravitational
forces and are separated by a splitter mechanism from the more magnetic
particles, which adhere longer.
Individual PERMROLL® modules can treat up to 10 t/h of product,
depending on the particle size, which can range from near zero up
to 50mm. Being modular, a complex mixture of materials can be separated
by sequential passage through a stack of up to four custom-designed
modules.
Process control is facilitated because the feed rates, which are
variable, can be controlled accurately and the belt speed can be adjusted
to fine tune the separation process. Installation and operating costs
are low and maintenance of the equipment is easy. Because the magnetic
rollers do not come into contact with the processed material, they
do not wear and the feed belts are self-aligning to prolong life.
Besides testing the feasibility of processing materials with magnetic
separators, the laboratory-scale units are also used to fine tune
established process streams. Laboratory-scale units have readily interchangeable
rolls with a width of 100 mm, one-tenth the size of a production-size
PERMROLL®. Experience has shown that the scale-up of test results
to full-size operation can be done with confidence, no scale-up factors
being necessary.
BATEMAN also provides an in-house testing service for clients who
do not wish to invest in a laboratory-scale unit.
More information may be obtained from Brian Paoliello, BATEMAN-PERMROLL®
Product Manager, on +27-11-201-2300 or email engtech@batemanengineering.com.
