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Message: NR 1st thermal frag success

NR 1st thermal frag success

posted on Feb 24, 2010 11:22AM

Rocmec 1: The First "Thermal" and Enironmentally Friendly Gold Property

VAUDREUIL-DORION, QUEBEC--(Marketwire - Feb. 24, 2010) - Rocmec Mining inc. (the « company ») (TSX VENTURE:RMI) (FRANKFURT:D5O) is pleased to provide its shareholders and the investment community with information regarding its Rocmec 1 gold property located in Rouyn-Noranda, Quebec. In order for readers to get a complete overview and understanding of the process involved in developing the first "thermal" gold property in the world, the contents have been divided into 4main topics; Rocmec 1, Diamond drill campaigns, Structures and drill results, Thermal fragmentation mining method.

Rocmec 1: The Rocmec 1 project is located in the Dasserat Township, Province of Québec on the shores of the Labyrinthe Lake. It is approximately 35 kilometres west of the town of Rouyn-Noranda and is easily accessible from Route 117 and the frontier gravel road separating Quebec and Ontario and a secondary gravel road to the site (click for map, geology and mineralisation). The property was acquired in October 2005, dewatering and rehabilitation of the mine commenced in January 2006. To date, Rocmec has invested approximately $23,000,000 in rehabilitating the property, surface and underground infrastructure, diamond drilling, equipment, drifting and the acquisition and installation of a 75 tpd underground treatment plant. The property includes a 100m deep two compartment shaft, an 844 metre decline allowing access to five levels (50, 70, 90,110 and 130 metres). On these levels a total of 1700 metres (drifts and cross-cut drift) were driven. The Rocmec 1 ore body is well defined by diamond drill holes (click to view mine layout).

Diamond drill campaigns: Rocmec conducted several diamond drill campaigns on the Rocmec 1 property over the past years, two of which by contractors, the others by Rocmec employees. All of the diamond drill campaigns were designed and carried out following the reasoning of "drill for structure and drift for grade". A NI43-101 compliant report was prepared Système Géostat International of Blainville (Quebec) and made public in March 2007. The gold mineral resources totalled 86,550 ounces in the Measured and Indicated category and an additional 456,900 ounces in the Inferred category. Mineral resources were estimated on regular blocks on longitudinal sections by the inverse of distance method. The gold zones are Front West, McDowell, Talus, Shaft, Boucher and Boucher 2. The average true widths of the gold zones vary from 0.61 meters to 2.32 meters. The known mineralization now lies from surface to a vertical depth of 400 meters and was delineated over a strike length of approximately 1.66 kilometres.

The most recent diamond drill campaign was completed at the end of 2009; where all of the above structures were intersected in each of the drill holes; both an updated NI43-101 compliant resource calculation and scoping study are currently in preparation and will be made public upon reception.

Structures and results: Generally speaking most of the zones look alike in terms of structure and mineralisation; some differentiate lightly by the content in quartz, pyrite, sericite and chlorite but for now they are believed to be all related to the same geological even. Along the zones in underground openings pinch and swell was observed along the main shear plane, the zone is always there with variation of the thickness and grades. Descriptions of the best known structures are listed below;

Front west

This mineralized zone recognized by diamond drill holes is near surface to the west of existing shaft, no special name was given, only in accordance to the fact it sits in front of the McDowell i.e. on the hanging wall. Actual known extent of the zone ranges from 5950Me and 6080mE near surface to 110m at depth. Grades range from trace to 67.87 g/t. and widths vary from 0.15 metres to 1.53 metres. The best intersection encountered is 67.87 g/t over 1.44 metres.

McDowell

The McDowell vein is the longest gold bearing structure on the property. This main dislocated structure represent the Western McDowell vein, McDowell, the West Claude, the Russian Kid and the Beaudoin vein form one continuous orebody, The structures were followed in the underground development or intercepted by diamond drill holes for 1660 meters East West with an average width close to one (1) meter. The pyrite associated with the vein is present in millimetre-length veinlets within the mass of quartz and preferably in contact of the vein with the wall-rock. The Hanging wall and the footwall both contain coarse pyrite. Lower vein wall (foot wall) is characterized with fine pyrite and is disseminated over more than three meters. It is carrying gold bearing mineralization until a vertical depth of 400 meters. This vein was developed and followed with the underground levels 150, 300 and 425(ft) now level 45, 90 and 130 meters. Grades range from 0.03 g/t to 120.00 g/t and widths vary from 0.07 metres to 5.00 metres. The best intersection encountered is 74.65 g/t over 2.34 metres.

Talus

The Talus vein is probably a secondary sub parallel branch structure to the McDowell vein whose junction point is located close to the section 6445mE. The Talus vein extends to the west of this junction point and is followed and identified up to the 6000mE coordinate. Some sampling of the vein was done in the drift at the 90m level. The actual known extension at depth is 400m. Grades range from 0.03 g/t to 61.58 g/t and widths vary from 0.05 metres to 3.04 metres. The best intersection encountered is 37.02 g/t over 1.22 metres.

Shaft

Located near the mine shaft, the vein is encountered at level 45 meters. Gold bearing mineralization appears in a broad brecciated zone consisting of alternating silicified, pyritized and sericitized diorite bands, and thin milky quartz bands. The distribution of the gold contents is erratic although gold values increase at a depth. The results of sampling of drift made by North Bordulac Mines show that there would be more than one gold bearing structure besides the shaft as North and South satellite veins to the shaft veins within that sector, these are not taken into account in the resource estimation at the moment. Grades range from 0.01 g/t to 28.01g/t and widths vary from 0.12 metres to 2.41 metres. The best intersection encountered is 18.15g/t over 1.53 metres.

Boucher
During one site visit in November 2006, core from the new Rocmec diamond drill hole RS- 06-01 was reviewed and sampling instructions were given, the mineralized zone was spectacular with presence of visible gold associated with quartz carbonate vein. The zone is located at 165m on the footwall of the McDowell zone. The zone is very impressive and differs significantly by the amount of quartz and the mineralized core width. Visible gold was observed and special sampling procedures were taken to obtain a representative assay value. Grades range from 0.01g/t to 29.94 g/t and widths vary from 0.43 metres to 2.74 metres. The best intersection encountered is 20.06 g/t over 1.45 metres (click to view core samples).

Boucher 2

The Boucher 2 zone is similar to the Boucher, but it is located 25 m behind to the north on the foot wall of the Boucher, locating it almost 190m from the McDowell, no other diamond drill holes have reached such a distance from the McDowell on the north side. It also indicates that mineralization is not limited to the actually known corridor but extent to the north of the previously known sectors. Grades range from 0.01g/t to 29.76 g/t and widths vary from 0.16 metres to 3.77 metres. The best intersection encountered is 27.91 g/t over 1.77 metres.

"We are very pleased with the results to date as they confirm structure continuity and various grade intersections. Upon reception of the of a new NI43-101 compliant resource calculation report and the scoping study, the next step will be to analyse several development scenarios that are currently on the table, such as; driving a new exploration decline from surface, exploration drift from existing underground openings, etc…Furthermore, the recent acquisition of 99 claims surrounding the Rocmec 1 property will be the focus of evaluation with an innovative approach." stated Donald Brisebois, President and CEO of Rocmec Mining Inc.

Thermal fragmentation mining method overview:
Using a burner powered by diesel fuel, the intense heat created within the vein shatters the rock containing the precious metal contents, into small fragments. The ore bearing vein is directly extracted, greatly reducing the dilution factor and the inefficiencies associated with traditional mining methods which extract large amounts of waste rock.

  • With this method, it's now possible to extract a narrow mining corridor with widths of 30 cm to 1 metre.
  • 3 to 6 inch pilot holes drilled into the vein with conventional drill
  • Thermal Fragmentation (burner operating at 1800 °C) is inserted and spalls the rock, quickly increasing the diameter of the hole to 30 - 90 cm
  • Extraction of ore in 0 - 13 mm fragments
  • Break leftover rock between fragmented holes to recover remaining ore

Until recently, the use of chemical explosives was the only effective way of breaking hard rock. An innovative approach, consisting in thermal fragmentation, is currently in operation. The technology utilizes the heat generated by a powerful burner, powered by diesel fuel and air, to create a thermal stress and break the rock. The thermal reaction allows for the enlargement of 15cm to 1metre holes by breaking the rock in a spalling effect. This technology has been used in Russia for over 40 years in large-scale open pits for the drilling of large blast holes. Use of this technology in selective ore extraction is a definitive plus for precious metal properties that would otherwise be uneconomical using existing mining methods.
The new approach to thermal fragmentation consists in the enlargement of a 15-cm hole previously drilled with a long hole drill. A strong burner, powered by diesel fuel and air, is inserted in the hole, lowered to the bottom and lighted. The heat generated raises the in-hole temperature up to 1800°C. This creates thermal stresses that spall the rock. In simple terms, spalling is considered as a form of decrepitation caused by an unequal expansion of rock crystals that overcomes molecule cohesion. The broken material produced during this process ranges in size from fine-grained to 4 cm.
Each work site is organised within two superimposed drift levels, approximately 20 meters apart. By drifting directly into the ore, we minimise mining waste and development costs. Once, the fragmentation complete, the leftover rock between the fragmented holes is then blasted and remaining ore recovered. Through the use of soft explosive charges, the hangingwall and footwall are left intact and only the mineralised corridor itself is extracted (click to view sketch of layout and burner).

Treatment plant

A 75 tpd treatment plant is installed underground on the 130 metre level, a first in the Canadian mining industry, according to Rocmec's research (click to view treatment plant). The flotation process is an ecological way of extracting precious metals as it does not employ cyanide. After a gravity circuit, soaping agents are used to recuperate the gold along with the copper and pyrite present in the mineralised ore. Left-over sterile material is used as backfill therefore no tailings pond is required. The success in controlling dilution and reducing operating costs by using the thermal fragmentation mining method will allow Rocmec to mine and treat, only the high-grade in-situ ore contained in the mineralised structures.

Environmentally friendly

There is a growing need to develop sustainable mining methods that minimise the environmental footprint left behind by mining operations. In all corners of the world, local populations have expressed their concerns about mine operations being established near their habitat as awareness about the negative affects of industrial activities has spread. While developing the Thermal Fragmentation Mining Method, important efforts were made to reduce the environmental effects mine operations have on the surrounding areas. Using the method, mine development is performed directly into ore resulting in less waste rock being extracted and displaced into large piles at the surface. By solely extracting the mineralised zone, 4 times less rock needs to be mined for the equivalent mineral content. As a result of less rock being mined, fewer tonnes need to be processed at the mill to extract the precious metals. The quantity of chemical agents needed in the process is greatly reduced. Furthermore, the quantity of energy needed to process the ore is also greatly diminished since less rock is sent to the mill. The reduced quantity of energy for hauling and processing the ore results in fewer greenhouse gases being emitted. The mining residue that remains once the precious metal contents are removed is 4 times less abundant, meaning much smaller tailing areas need to be constructed, maintained, and rehabilitated once mining operations have ceased. The space needed to host the mine site is greatly reduced, the alterations to the landscape are significantly diminished, and the result is a cleaner and more responsible approach to mine operations. By lessoning the effects that conventional mining causes to the environment, Rocmec, with its patented thermal fragmentation process prides itself in being a good "green" Corporate citizen.

Thermal fragmentation…mining ounces not TONNES!

The Thermal Fragmentation Mining Method video can be viewed on Rocmec's website or by clicking the following link:
http://www.rocmecmines.com/video_an.asp

About Rocmec Mining Inc.

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