MINERAL SEPARATION
Separation surge
The water, energy and operating cost efficiency demands
being felt across the industry are leading those in the mineral
separation market to up their game, Dan Gleeson reports
hether it is hydrocyclones, magnetic
separators or spirals, mineral
separation equipment is fundamental
to the effective recovery of metals and minerals.
The recognition of this has led to miners
employing this equipment across their plants
and, in some instances, ahead of the ‘bulk’
processes that are the most energy and cost
intensive.
This trend shows no sign of slowing down with
the digital tools increasingly employed at mine
sites showing, in real time, the positive impact
this equipment has on the efficiency of the entire
mineral processing plant.
W
Dealing in density
While some industry commentators have
suggested pre-concentration or ore sorting
technology could compete with or, in some cases,
replace more traditional mineral separation
equipment, allmineral sees the two
complementing each other.
The Germany-based company is renowned for
its use of jigs within the coal, iron ore and
industrial minerals/metals sector.
Its water-operated alljig ® technology fluidises
feed material by pulsating water to form layers of
grains according to their density, subsequently,
separating the heavy material from a stratified
material bed. Electronic sensors are used to
automatically monitor and control the precise
discharge of heavy particles contained in the
feed, with the alljig machines creating a
physically stable and individually adjustable
optimal jigging stroke using minimal energy by
means of air-pulsed water, the company says.
While alljigs may require water, the company’s
allair ® process does not. This technology uses
the same alljig functionality, but only requires air
30 International Mining | MAY 2020
as the pulsating medium. It is this process, which
has much appeal in today’s water-conscious
market, where the company has previously seen
synergies between sensor-based ore sorting and
density separation.
The company explained: “It is known that dry
jigging technology gives its best results in the
size range of 0-50 mm, whereas X-ray sorting
technology provides better results for the coarser
particles preferably above 40 mm.
“We can, thus, use both technologies to
design a complete beneficiation plant in which
the 0-50 mm size fraction will be handled with
allair dry jigging and the >50 mm size fraction
will be treated with X-ray sorter XSS ® T.”
This latter technology is an X-ray sorting
system used for dry density sorting developed by
Steinert. It “sees through” materials, recognising
different densities, components containing
halogens and organic components, according to
Steinert. Composite materials and internal
adhesions are also detected, which allows ore-
bearing rock to be sorted from non-ore-bearing
rock.
In a coal application
trial near the Witbank of
South Africa where a
relatively high ash content
(sometimes exceeding
50%) was observed, this
combination – the allair
technology treating the
<50 mm fraction and the
remaining >50 mm
fraction treated by XSS T
technology – lowered the
sulphur and ash content in the final clean coal
product.
Evren Ören, Head of Capital Sales at allmineral,
Minerals being lifted and separated on one of
the three magnetic discs of Bunting’s Magnetic
Disc Separator
said the company is actively integrating sensor-
based sorters into its flowsheets where the
company sees an advantage in combining the
two.
More broadly, the company is aware of the
need to reduce both energy and water
consumption in mineral processing plants as
operators search out more sustainable mining
processes.
Yet, as Ören indicated, every jigging
installation is different; the 125 t/h relocatable
coal processing plant project the company is
currently working on for PT Asmin Bara
Bronang/PT Tuah Turangga Agung in Kalimantan,
Indonesia, making for a good example.
The heart of the process plant is an alljig GR
1700, one of the newest generation side pulsed
jigs from allmineral that ensures the highest
process parameters “with minimal maintenance
requirements”, Ören said.
“With a relocatable plant concept, the size,
weight and design of equipment are key factors,”
he told IM. “We have chosen a simple
straightforward process concept combining high
performing technology, which is eligible to cope
with changing feed conditions in other
locations.”
An example of this is the sticky coal that can
be encountered in this part of Indonesia, which
has proven challenging for other plants to deal
with. allmineral has devised a way to deal with
such material. “We have brought new mitigation
methods to Indonesian miners and metallurgists,
which is now proven and accepted by them,”
Ören said.
The company is employing some of the
learnings from its experience delivering a 500 t/h
coal sorting installation for PT Suprabari
Mapanindo Mineral in Kalimantan along with
CITEC and Hazemag (also its partners on the PT
Asmin Bara Bronang/PT Tuah Turangga Agung
contract) in its latest Indonesia contract. This
project, delivered earlier this year, included a
The 500 t/h coal sorting installation for PT
Suprabari Mapanindo Mineral in Kalimantan,
Indonesia, saw allmineral deliver a three-
chamber alljig jig F(UB) 5000 x 3400