Macmin Silver wird Explodieren

[red]Hier ein Bericht aus der Zeitung über Macmin!!!!!!!!![/red]



[u][b]32 The Australian Mining Review AUGUST 2008
SPECIAL PROFILE Twin Hills Silver Mine[/b][/u]

www.macmin.com.au/media/2008/AustMiningReviewAug2008.pdf




Silver mine moving to increase production
MACMIN SILVER’s Twin Hills
Silver Mine in Texas, Queensland,
should start increasing production in
September-October after new processing
equipment is installed.

Chairman and chief executive Bob
McNeil said the upgrade of the crushing
and screening equipment was initially
due for completion at the end of
March, but the tight market for
such equipment has meant that it
is only being installed now.

“We should start to increase
capacity from September-October
… but until we get some feel on
how it works we’re a bit reticent
to actually predict how much at
this stage,” he said.
“It will certainly be a
substantial increase on the
present production.”

The Macmin crushing circuit
currently crushed more than
20,000 tonnes per month to the
required minus 4mm.
“Planning is proceeding to
move to extended crushing hours,
probably two eight hour shifts,
but is still restricted
by difficulty in hiring
suitable personnel,” Mr
McNeil said.

“Because of intense
competition for trained
operators in the mining
industry at present, we
cannot hire sufficient
trained personnel and
consequently we have
had to train our own
operators.

“This is time
consuming.”
Texas, near the border
of NSW, is about 3.5
hours’ drive south west
of Brisbane.
The Twin Hills Silver
mine is 10km east of the
township of Texas and
most of the 52 people on
the payroll are locals, Mr
McNeil said.

[b]History[/b]

Exploration on the Texas Silver Project
began in 1994 by the company and its joint
venture partner, Hunter Exploration.
Significant silver mineralisation
was delineated by 1998 and Macmin
re-acquired Hunter’s interest.
After further extensive drilling, the
initial Twin Hills feasibility study was
completed at the end of 2000.
In March 2004, as the international
price for silver started to increase,
Macmin decided to commit to, and raise
funds towards, developing the Twin Hills
Silver Mine.

Site clearing began in 2005, along with
staff recruiting and training.
The following year saw overburden
removed, the crushing plant installed and
the electrowinning plant constructed.
Mining began early last year in
conjunction with the commissioning of
the processing circuit and production of
the first silver powder.

Fine-tuning of
the crushing and
electrowinning plants
continued throughout last
year.

[b]Heap Leaching[/b]

Twin Hills used a heap
leaching process that was
introduced to the industry
in the 1970s as a means
to drastically reduce gold
recovery costs, Mr McNeil
said.
“It is also effective with silver in certain
circumstances,” he said.
“This process has literally made many
mines by taking low grade resources and
transforming them into a viable mine.
“Heap leaching involves placing
crushed or run of mine ore in a pile built
upon an impervious liner.
“Cyanide solution is distributed across
the top of the pile and the solution
percolates down through the pile and
leaches out the silver/gold.”
The silver/gold laden pregnant solution
drains out from the bottom of the pile and
is collected for recovery.

“Heap leaching generally requires 60
to 150 days for processing ore that could
be leached in 24 hours in a conventional
agitated leach process,” Mr McNeil said.
“Recovery is typically about 70 per
cent as compared with 90 per cent in an
agitated leach plant.

“Even with this lower recovery
performance, the process has found
wide favour, due to the vastly reduced
processing costs compared with agitated
leaching.”

Mining at Twin Hills is carried out using
hired equipment operated, supervised and
directed by Macmin staff.
“Mining of ore and waste is proceeding
to plan and there are no problems in this
department,” Mr McNeil said.


[b]Crushing[/b]

To recover 70 to 72 per cent of silver from
the rock, the ore must be a certain size.
This is achieved either by crushing or
during blasting of the ore prior to mining,
Mr McNeil explained.
But the crushing circuit, as specified
by the feasibility study and operated on a
single-shift basis, could not achieve sufficient
crushed material due to maintenance
problems with the crushing circuit, the
inability to hire sufficient trained operators
to run more than a single day shift, and
inadequate screens to remove the fine
fraction early in the crushing process.
The screens incorporated in the current
circuit were inadequate to remove the fines
at an early stage in crushing, which resulted
in the circuit clogging up and maintenance
problems, he said.

If crushing could have been maintained
on a 24-hour basis, this problem could have
been partly offset.
A further unanticipated problem was
that the ore was harder and more abrasive
than predicted.
To solve the problems, Macmin is
upgrading the crusher with additional
screening, adding a second contract
crusher the circuit, incorporating closer
drill and blast patterns in the mine plan
to produce as much minus 4mm product
as possible without crushing, moving to
two shifts, and having a contract crushing
supervisor on site.

“Our initial target is to place 60,000
tonnes of minus 4mm material on heaps
each month, moving to 100,000/120,000
tonnes per month as ore grades decrease,”
Mr McNeil said.
“This latter target may require further
crushing capacity.
“The timing of achieving the initial
objective of 60,000 tonnes a month onto
the heaps is difficult to predict.”


[b]Silver[/b]
The silver is extracted from pregnant
solutions using an electrowinning process
and the plant, which contains 180 cells,
runs on a 24-hour, seven-day-a-week
schedule.
Each cell in the plant has not produced
at the rate specified by the manufacturer
but, by experimentation, its capacity is
gradually being increased, Mr McNeil
said.
“Problems have also arisen with the
coatings on some anodes and these have
now been replaced,” he said.
As the plant was designed with at least
50 per cent overcapacity, the reduced
capacity of each individual cell is not
expected to be a problem with production
in the near term, but could restrict
expansion.

The leaching solutions from the heap
carry 60 to 90g/t silver and the plant has
been inefficient in extracting or reducing
the silver in leach solutions below 40g/t
silver.

These barren solutions, which still
contain 40g/t silver, are then recycled to
the heap, with further dissolved silver
rebuilding the solutions to 60 to 90g/t
silver, Mr McNeil explained.
“There is a concern that it is inefficient
to recycle solutions with as much as 40g/t
contained silver,” he said.

Consequently, a Merrill Crowe (or zinc
precipitation plant) has been installed to
remove further silver.
“The intent is that silver will be
reduced to 40g/t by electrowinning, then
pass through the Merrill Crow, which will
reduce silver content to less than
10g/t,” Mr McNeil said.

“This barren solution will then
be recirculated to the heaps.”
Macmin is selling some of the
silver powder produced “as is” for
specific applications.
“However, an unexpected side
effect of the EMEW plant is that
it also extracts some other metals
and the silver powder produced to
date contains contaminants which
are unacceptable to some buyers,”
he explained.

“These are removed before
smelting and this being done
successfully in Melbourne.
“The silver powder can then be
smelted, refined and sold.”

[u][b]OnTrax gives mine a boost[/b][/u]


FOR TWO months, OnTrax Crushing and
Screening has been providing booster
plant support for Twin Hills Silver
Mine’s crushing operations in an effort
to capitalise on the current commodity
price.

The company said it was experienced in
campaign crushing such as for Brisbane’s
Gateway/Leighton joint venture and along
the coast.
Quarry campaign crushing for other
companies included contracts with Boral
and Hansons.
These jobs involved making aggregate
in order for the fixed plant to maintain
production.
[green][b]OnTrax said it looked forward to a
continuing association with Twin Hills.[/b][/green]

nicht ganz so gut recherchiert - Minespec

 

 

Crescent kein Einzelfall - Der Australische Markt für Nebenwerte liegt am Boden      

    Stuttgart (www.rohstoffe-go.de) Crescent Gold  steht mit seinen Problemen keineswegs alleine da. Der gesamte australische Markt für kleinere Goldminen und Explorationsunternehmen steckt in einer schweren Baisse. Martin Siegel, Fondsmanager des auf Australien spezialisierten PEH-QGoldmines Fonds sieht in seinem Börsenbrief im Wesentlichen zwei Faktoren, die zu der aktuellen Krise geführt haben. Zum einen die Kostenexplosion bei Energie und Personal - Energie macht insbesondere bei Tagebauprojekten bis zu 60 Prozent der Kosten aus. Zweitens beobachtet Siegel, dass es offenbar einen Engpass bei qualifiziertem Betriebspersonal gibt. Das bestätigen auch unsere Kontakte in Australien. Die Unerfahrenheit und/oder fehlende Motivation vieler Mitarbeiter – bei gleichzeitig hohem Lohnniveau, scheint ein strukturelles Problem der Industrie zu sein. Hinzu kommt, dass vor ca. zwei Jahren viele Gesellschaften gleichzeitig den steigenden Goldpreis zur Rückkehr in die Produktion (oder zum Aufbau neuer Produktion) nutzen wollten. Dabei wurde die knappe Ressource Personal erst recht strapaziert. Dabei sollte man nicht vergessen, dass beim Wettrennen in die Produktion einige Firmen schon wieder ganz von der Bildfläche verschwunden sind. Man denke an Gleneagle, BMA oder Monarch. Andere wie Bendigo sind grandios gescheitert. Aktien von St. Barbara, Norton, Dioro haben sich im Wert gedrittelt oder geviertelt.

Als Paradebeispiel für die aktuelle Krise zitiert Siegel die geplatzte Kapitalerhöhung beim Goldförderer St. Barbara, der Nummer drei in Australien. Wegen massiv fallender Kurse konnte die Macquarie Bank 123,6 Mio. Aktien einer bereits sicher geglaubten Kapitalerhöhung nicht wie vorgesehen bei Privatinvestoren platzieren und blieb schließlich selbst auf den Aktien sitzen. Der Buchverlust beträgt zurzeit 17,3 Mio. AUD. Siegels Kommentar lässt an Deutlichkeit nichts zu wünschen: „Es ist klar, dass der Markt für Kapitalerhöhungen völlig zerstört wird, wenn der drittgrößte australische Goldproduze...

 

www.emfis.de/global/global/nachrichten/beitrag/id/...den_ID72686.html

sind wir ja zu 30 Prozent? beteiligt.

 

Suite 422 - 470 Granville Street, Vancouver V6C 1V5 Tel. (604)-662 3598 Fax: (604)-669 6257
Pressemitteilung	15. August 2008
Sinvit Bohrungen schneiden 20m mit 25.7g/t Gold und 2.19% Kupfer; einschliesslich 2m mit 158.0g/t Gold und 4.32% Kupfer
Aufregende Resultate von Löchern in der unoxidierten Sulfidmineralisation bei der sich zu 92% im Besitz befindlichen Sinivit Goldmine, Papua Neu Guinea, zeigten exzellente Gold- und Kupferresultate. Diese Resultate unterstützen die Strategie, dass die Förderung in der Sulfidzone in rund 3 Jahren beginnen mag. Die Sulfide enthalten Gold, Silber, Kupfer und Tellur. Die durchschnittlichen Tellur- und Silbergrade (viel vom Gold scheint sich in Kupfer-Tellurid-Mineralien zu befinden, wie durch frühere mineralographische Arbeiten definiert wurde) sind noch immer unbekannt, und alle hohen Kupferresultate wurden noch einmal eingeschickt für die Tellur- und Silberanalyse. Ein Beispiel von möglichen Tellurwerten und Silberwerten in den Sulfiden wird durch Loch WWD024 gezeigt, welches eine relativ tiefgradige Gold- und Kupfer-Sulfidmineralisation schnitt, und welches durch den früheren Halter der Liegenschaft, City Resources Ltd. auf Tellur und Silber untersucht wurde. Es ergab 6m von 137,35m bis 143,35m Lochtiefe mit 1,5 g/t Gold, 15,6g/t Silber, 0,72% Kupfer und 728g/t Tellur. Ein 0,8m Intervall innerhalb dieses Abschnitts ergab 12,6 g/t Gold, 28,8 g/t Silber, 1,9% Kupfer und 1'600 g/t Tellur. Untersuchungsresultate von Löchern mit Durchschnittswerten von mehr als 0,8% Kupfergehalt können hier eingesehen werden. Die oben stehenden Löcher stammen aus einem grossen RC Bohrprogramm, welches am 11. Juli 2008 403 Löcher mit einer totalen Länge von 11’141m beinhaltete. Dieses Programm dauert an, und die Resultate für die Löcher bis SCG117 wurden in früheren Pressemitteilungen berichtet. Die Resultate von weiteren 242 Bohrlöchern wurden erhalten, werden zugeordnet und werden in der nahen Zukunft veröffentlicht. Das Programm wurde hauptsächlich so gestaltet, dass es die Grenzen der oxidischen Goldmineralisation innerhalb des Gebiets der drei Gruben definiert – Northern Oxide Pit Löcher werden mit NGC bezeichnet, Central Oxide Pit Löcher werden mit CGC und Southern Oxide Pit Löcher mit SGC bezeichnet. Die Kupfer/Gold Abschnitte in dieser Veröffentlichung sind von genau unterhalb der vorgeschlagenen Grenzen für die Oxid-Goldförderung in den Central Oxide und Southern Oxide Pit Gebieten. Frühere Diamantkern-Bohrungen haben gezeigt, dass eine ähnliche Sulfidmineralisation sich auf einer Distanz von 300m zwischen den Central Oxide und der Northern Oxide Zonen in die Tiefe erstreckt (siehe Seite 18 des technischen Berichts gemäss NI 43-101, datiert vom Januar 2006). Dieses Gebiet (zwischen den zonen) ist topographisch hoch, und die Mineralisation erstreckt sich nicht bis zur Oberfläche des Bodens und wurde aus diesem Grund nie oxidiert. Es lässt auch vermuten, dass die gegenwärtig bekannte Mineralisation, sowohl die oxidische, als auch die sulfidische Mineralisation die extreme „Spitze“ des mit Gold mineralisierten Systems repräsentiert. Zu diesem Zeitpunkt ist die Tiefe, in welche sich die Mineralisation erstreckt, völlig unbekannt.

2.62m @ 33g/t Silver, 4.88% Zinc, 2.80% Lead & 0.14% Copper from 221.36m incl. 0.49m @ 82 g/t Silver, 11.90% Zinc, 7.26% Lead & 0.32% Copper from 221.36m

1.61m @ 7g/t Silver, 3.08% Zinc, 1.56% Lead & 0.01% Copper from 227.84m

0.40m @ 51g/t Silver, 8.36% Zinc, 5.36% Lead & 1.12% Copper from 234.25m

Figure 2, is a schematic cross section showing the position of SSD5 in relation to the Silver Spur Mine workings, SS26 and an historic government drill hole (NS5). Historic literature indicates that hole NS5 intersects a pyrite rich zone approximately 35m along strike to the south and 60-70m below the mineralised interval intersected in Macmin's SSD5 hole.

Historic Rimfire Pacific Mining drill holes are also shown on Figure 2 and intersected two sub/parallel mineralised zones. Results were as follows:

SS26 6m @ 132g/t Silver, 0.33g/t Copper, 4.82% Lead and 5.95% Zinc from 130m 8m @ 95 g/t Silver, 0.3g/t Copper, 3.4% Lead and 8.65% Zinc from 152m

SS27 8.5m @ 182g/t Silver, 0.2% Copper, 3.4% Lead and 7.5% Zinc from 148m

The interval outlined in hole SS26 is approximately 10m along strike to the north of hole SSD5 in plan view, while the interval outlined in hole SS27 is approximately 10m along strike to the north of hole SS26 in plan view.

The historic Rimfire holes (mentioned above) indicate significant widths of mineralization located beside (to the east) of the workings, with hole SS27 having a very large mineralised interval beyond that outlined above (53.55m at 88 g/t Silver, 0.14% Copper, 1.93% Lead, and 4.46% Zinc from 116m as reported by Rimfire Pacific Mining in 1999).

Paul Abbott, Manager Geological Services for Macmin noted: "These historic intercepts combined with the results from the recently completed Macmin hole (SSD5) indicate that thereis considerable scope to delineate economic grade mineralisation both below and along the strike from the current workings. However, considerable further drilling will be required to establish if sufficient tonnes of this material can be outlined.

Follow up drilling will include targeting below the Rimfire holes situated to the north of Macmin's SSD5 drill hole, as well as below and along strike to the south of hole SSD5. This drilling as well as other major exploration expense, will be deferred until the Twin Hills Silver Mine is cash flow positive".

Collar locations for the Rimfire Pacific holes are as follows: SS26 was collared at 331640E 6805660N* with an inclination of -60 degrees on a bearing of 270 degrees magnetic, SS27 was collared at 331596E 605690N* with an inclination of -80 degrees on a bearing of 270 degrees magnetic. (*AGD66/AMG56)

Macmin Drill Hole SSD5 was collared at 331670E 6805635N (AGD66/AMG56) with and inclination of -60 degrees on a bearing of 300 degrees magnetic. A percussion pre-collar was drilled from surface to 57m, followed by diamond core drilling to a final depth of 254.5m downhole.

Sampling & Assaying Details

Sampling of Diamond Core was undertaken over mineralised and altered zones, sample intervals were determined from geological intervals. In broad zones of alteration 2 metre intervals were selected. As part of the Company's quality control programme, a duplicate sample is collected about every 20 samples and submitted under a different sample number providing a check on repeatability.

Assaying is carried out by ALS Chemex in Brisbane using the ICP technique for silver, copper, lead, zinc, arsenic and antimony. Gold is assayed by the Aqua Regia technique.

Drill holes Collars have been located with a hand-held Garmin GPS unit. Down hole surveys are recorded with an Eastman style single shot camera.

Yours faithfully,

MACMIN SILVER LTD

R.D. McNeil

CEO & CHAIRMAN

The Company

Bericht mit Lageplan und Bildern:

 

www.macmin.com.au/announcements/2008/pdf/...lver%20Spur%2022Oct08.pdf

mineweb.net/mineweb/view/mineweb/en/page674

www.macmin.com.au/