ROCK REINFORCEMENT
ground support products for the Lake Cowal
underground gold mine project in NSW. The
project is DSI Underground’s first supply
agreement on the East Coast with PYBAR and
heralds a new partnership with a view to the
future. Evolution Mining’s expansion of the Cowal
gold operations in New South Wales gained
approval in October 2018 with the awarding of an
underground development contract to PYBAR in
February 2019. The site has traditionally been an
open pit operation, but to increase production the
underground project was initiated and approved.
Unique customised bolter miner for
JSW
SIGMA has delivered to Poland’s coal mining
group Jastrzębska Spółka Węglowa (JSW) an
innovative system for cutting longwall faces and
other areas in mines to be used for roadway
excavation employing a specialist bolter miner.
This is the outcome of many months of work on
devising solutions to supplement the longwall
face equipment with a bolter miner. A contract
pertaining to this matter was signed in JSW’s
registered office.
The bolter miner manufactured by Joy Global
(Komatsu) was purchased in the latter half of last
year. This new machine was due to be delivered
to the Budryk mine in Ornotowice in June of this
year. This is an effect the “Independent Roof Bolt
Support” project implemented in Jastrzębska
Spółka Węglowa. “This system is less expensive
and will make it possible to excavate roadways
more quickly. These systems are used in the
most modern deep shaft mines in the US and
Australia, among other places. JSW will be the
first miner in the Polish mining industry to
employ a roof bolt reinforcement system.”
Part of the “Independent Roof Bolt Support”
project called for appointing a task force to
design a set of comprehensive equipment
solutions to ensure efficient ventilation, dust
removal and efficient coal haulage. This set of
new machinery will be part of the equipment in
the bolter miner. It will enhance work
productivity while ensuring top-notch mine crew
safety.
“We can boldly speak of making a
breakthrough in the Polish mining sector. The
project team has met this challenge by designing
and customising a set of modern equipment to
meet continuous operating and safety
requirements outfitted with machinery to do
cutting on mine faces and in other areas”,
proudly states Daniel Ozon, President of the
Management Board of Jastrzębska Spółka
Węglowa.
Implementing this new equipment in the
mining sector is the outcome of many months of
work done by the project team consisting of
employees of a Jastrzębska Spółka Węglowa
30 International Mining | AUGUST 2019
mine, JSW Innowacje and
SIGMA, which has extensive
experience in designing
mining equipment.
“One major challenge
faced during the course of
the design work was to fit
longwall face cutting
equipment within the
physical dimensions of the
bolter miner and to design
coal haulage to ensure that
large quantities of winnings
can be handled
instantaneously and for this operation to be
conducted jointly with the bolter miner without
any downtime. This goal stemmed from the
necessity of exploiting the bolter miner’s work
time as effectively as possible”, explains Jacek
Srokowski, Vice-President of the Management
Board of JSW Innowacje, the leader of the project
team.
This equipment contains a rolling belt
conveyor with a bridge feeder designed in such a
way so as to fit within the sliding range of the
rolling belt conveyor’s structure. In addition, the
structure of the rolling belt conveyor allows for
the placement of a set of devices, forming in
their entirety a compact unit of the coal haulage
system.
“SIGMA has always been an innovative
company and we eagerly get involved in such
innovative tasks. It was a prestigious endeavour
to cooperate with Jastrzębska Spółka Węglowa
and participate in this project. For many years
companies have spoken about independent roof
bolt reinforcement systems but JSW is the only
one to have made the decision to introduce
them”, says Paweł Hajduk, President of the
Management Board of SIGMA SA.
The overall configuration of the equipment for
cutting on longwall faces and in other areas
coincides with the time for delivering the bolter
miner.
Minova grouts help consolidate
rockfill at Bentley
Round Oak Minerals approached Minova to
assist with a solution that could maximise the
ore recovery of stopes at their Bentley
underground
Zinc-copper mine, part of the Jaguar
Operations in Western Australia. One of the
principal mining methods historically used at the
Bentley mine is the Avoca method which requires
all development in a given area to be completed
before stoping commences in a bottom-up
sequence (both the conventional and modified
variants are used at Bentley, which rely on end-
on and central access respectively).
Stope voids are sequentially back-filled with
Minova provided 360 t of FB200 grout to Round
Oak and were able to consolidate the rockfill in
the 3920 AON ore drive during a three week
campaign
loose ROM waste rockfill. The 3900 AOS level is
positioned below a previously extracted Avoca
zone with unconsolidated rockfill situated in the
3920 AON Stopes immediately above. Stopes in
the 3900 were originally earmarked to have rib
and sill pillars to maintain control of the existing
backfill, however due to several factors including
a shift in mining economics over time, options to
achieve full extraction were reviewed.
To optimise extraction of this level, a 150 m
long section of consolidated
rockfill was required in the 3920 AON to
provide a stable exposure to
mine underneath so as to reduce the risk of
dilution during extraction.
Minova supplied technical advice, product,
specialised equipment and operations capability
to support Round Oak during the consolidation
program. FB200 grout was selected for its unique
rapid gel times, quick strength, low viscosity and
high water content, allowing for controlled
placement through carefully designed borehole
patterns to gain maximum penetration of the
unconsolidated rockfill. Tekseal, another high
yield grout, was used to create grout curtains to
control the placement of the FB200 within the
rockfill.
With the help of Minova’s 18 years of product
ingenuity and experience in maximising ore
recovery, Round Oak were able to adapt their
mining method to a primary/secondary
sequence, utilising the stabilised rockfill sill in
conjunction with CAF backfilled primary stopes,
which enabled the extraction of the previously
planned rib and sill pillars. Minova provided 360
t of FB200 to Round Oak and were able to
consolidate the rockfill in the 3920 AON ore drive
during a three week campaign. To date, all the
primary stopes have been extracted with minimal
dilution observed, with extraction of the
secondary stopes still to occur. Minova is
currently undertaking further work at Jaguar to
unlock and extract value within the mine. IM