56
MODERN MINING
February 2014
PRODUCT News
Index to advertisers
AEL Mining Services
2
Air Liquide
50
B&E International
54
Babcock
38
Barloworld Power
28
Bell Equipment
7
Booyco Electronics
49
Brelko
55
Condra Cranes
18
DCD Group - Mine Support Products
IBC
De Beers Consolidated Mines
36
Donaldson
46
High Power Equipment
15
Horne South Africa
43
Hosch-Fördertechnik SA
13
Johnson Crane Hire
14
Joy Global Africa
9
Komatsu
24
Kopex
OFC
MDM Engineering
39
MMD Mineral Sizing
51
New Concept Mining
OBC
Pilot Crushtec
30
Stefanutti Stocks Mining Services
22
Tenova Bateman Technologies
53
Verder Pumps SA
48
Vermeer
IFC
WorleyParsons
11
AEL carries out electronic blast at Letšeng
The Letšeng diamond mine, situated in the heart of the Maloti
mountain range in Lesotho, is the world’s highest diamond mine
peaking at 3 100 m above sea level. Owned by Gem Diamonds in
conjunction with the Lesotho government, Letšeng is well rec-
ognised for producing some of the highest dollar per carat value
stones of any diamond mine.
Excessive damage to diamonds during the mining and benefi-
ciation process results in the operation losing substantial revenue.
This motivated the mine to request AEL Mining Services (AEL) to
extend blasting trials at the mine by an additional six months in
order to further measure improvements in controlling damage to
diamonds. AEL says this challenge presented a great opportunity
for it to demonstrate its extensive and superior mining expertise,
and to showcase its electronic initiating systems with the benefit
of improved fragmentation uniformity, improved muckpile control,
and further downstream beneficiation benefits.
The initial electronic blast was carried out on 20 October 2013
based on the current bench design parameters from Letšeng. A
total of 870 Digishot™ Plus detonators was used in this blast, mak-
ing it the largest single electronic detonator trial blast conducted
by AEL in Letšeng’s history.
The mine requested the use of a V2 chevron; however, after a
calculated evaluation of the bench width, the requested blast
delay design was changed to have a more optimal muckpile
configuration.
The ore bench requiredminimal material movement into the bot-
tom of the pit after blasting, as this would otherwise compromise
the design life of the slope catchment berms, which is a safety con-
cern when it comes to falls of ground, as well as loss of ore tons and
delays in production. The added technical challenge was a require-
ment from the client to blast a ramp in conjunction with the main
blast, and, subsequently, the material on the ramp to be left in-situ.
The use of the software Viewshot™ allowed for flexibility in the
timing design, and the blasting team could simulate different sce-
narios in order to find the optimal timing solution. The design was
then transferred to the control equipment for the Digishot™ Plus
detonators. A proficient understanding and manipulation of the
timing chevron resulted in the key objective being met.
The final result, says AEL, was a perfectly controlled muckpile
profile with minimal material thrown to the pit bottom, and an
improved uniformity in fragmentation for optimal beneficiation
processes – exactly as the customer had requested.
The subsequent blast was custom designed to incorporate the
new design parameters, based on invaluable lessons gained from
the first blast. Improvements were made on the desired fragmenta-
tion size, and a marked time and cost-saving advantage was seen
by the mine in terms of load and haul efficiencies.
AEL Mining Services, tel (+27 11) 606-0000
According to Mather+Platt, submers-
ible pump sales to mines worldwide are
increasing at the expense of alterna-
tive designs because of the advantages
High efficiency submersible pump
SV submersible pump from the EIM Electric
Company.
of space saving, ease of installation (no
pump house required), the elimination of
the need to prime the pumps, and savings.
Among the submersible pump options
available locally is the horizontally
mounted model SV submersible pump
from the EIM Electric Company of Japan.
Sold and supported in South Africa
by Mather+Platt, the SV is a horizon-
tally mounted, submersible vortex
pump with the advantages of high
efficiency, heavy construction for
long service life, low maintenance
and an impeller that resists clogging.
An operational duty equivalent to
a standard centrifugal machine makes
the EIM SV suitable for transferring fines,
coal chip slurries and similar media, while
the pump’s non-clogging vortex impel-
ler ensures that solids travel through the
vortex passage rather than through the
impeller, increasing the impeller’s wear life.
Double mechanical seals protect the
motor from the slurry being pumped.
The pumps are explosion proofed for
mining applications, and are suitable for
environments up to 40 deg C. Technical
specifications include a power rating of
5,5 kW to 22 kW, a total head from 10 m
to 20 m, a discharge of between 0,9 and
2,0 m
3
/min, and a voltage from 200 V to
1 100 V.
Pumps for mining applications are
flame-proofed, with full stainless steel con-
struction offered as an option.
Mather+Platt, tel (+27 11) 824-4810
