Dalradian Resources Inc. (TSX:DNA) (AIM:DALR) ("Dalradian" or the "Company") announces results from a third test stope at its Curraghinalt Gold Project in Northern Ireland. Stope 3 is located on the V-75 vein complementing two previous test stopes in the same area. The third stope was used to validate the long-hole mining method on a relatively shallow dipping (50-55°) portion of the vein in comparison to Stopes 1 and 2, which had dips of 73° and 76° respectively. Stope 3 attained an average width of 1.80 metres, with estimated dilution to the designed stope of 64% and removal of an estimated 303 ounces of gold at a grade of 9.41 g/t from 1,001 tonnes of material.
Eric Tremblay, Chief Operating Officer of Dalradian commented,
"I am particularly pleased with the results from the third stope. This demonstrates our ability to long-hole stope veins at the shallow end of the range that we are likely to encounter at this deposit. The dilution was lower than predicted by the model and resulted in a diluted grade of 9.41 g/t of gold. With the exception of a single wedge failure in the footwall at the end of mining, Stope 3 remained open without support for several weeks. This indicates that we can easily manage dilution from the footwall by using simple low cost methods such as cable bracing."
Table 1: Comparison of contained ounces of gold between resource model and test stoping results
Table 2: Comparison of stope design vs. actual results
** Design grade is based on the 2016 resource model; actual results grade is based on extensive muck sampling
*** Design width is the minimum width necessary to recover all of the mineralized material predicted
**** Post-mining volume was corrected to reflect removal of a single 190 tonne non-dilutory slab which fell into the stope void in the absence of normal operational ground support methods and after mucking
The third test stoping area is in close proximity to the first two test stopes, approximately 60 metres below the surface on the V-75 vein at the deepest point of the current development (see figures 1-3 for location; all figures referenced in this news release can be accessed at http://www.dalradian.com/news-and-events/news-releases/news-releases-details/December-8-2016-News-Release-Figures/default.aspx). This location was selected as it contained shallower dipping veining than in Stopes 1 and 2, thereby testing long-hole mining in a more broadly representative manner.
Stope 3 was 15 metres long and 14.1 metres high (see figures 4 and 5). Orica Mining Services aided in the design of the test stoping program, while CMAC-Thyssen worked alongside Dalradian staff in drilling and blasting the test stopes. The design of the stopes was based on 100% recovery of the vein using zipper drilling to reduce the amount of drilling, the powder factor and minimize dilution. The dilution anticipated by the preliminary geotechnical model was 85% on Stope 3 with a length of 15 metres, whereas actual results were 64% dilution with a 15 metre length.
Eric Tremblay, P.Eng., Chief Operating Officer, and Greg Hope, MSc, MAIG, Chief Consulting Geologist, Dalradian Resources, are the Qualified Persons who supervised the preparation of the technical data in this news release.
Underground development along the veins was sampled by the Production Geologist via chip panel sampling, across the full width of the face for each round on advance. Distinct geological zones were sampled separately (vein separate from wall rock), with a general minimum-maximum horizontal sample width of 0.10 metre to 1 metre and chip sizes approximating 3-4 centimetres. Four to five kilograms of material was chipped with a rock hammer from two thirds the height of each face down to the sill, in volumetric proportion based on relative abundance of mineralization versus gangue. Sample locations were measured from a surveyed control point. Channel samples were saw-cut into the sills of the 170 and 150 western sublevels along the V-75 vein for comparison with face and drill hole sampling. Samples were submitted to ALS Laboratories in the Republic of Ireland.
Muck samples were taken continuously throughout the mucking process of each stope, at a frequency of 1 sample taken every two scoop buckets from the stope (each scoop bucket contains an estimate of 2.6 tonnes of muck). Sampling was done by the scoop operator, using a shovel to put muck into the individual sample bags, which allowed a representative sample of both coarse and fine rock fragments to be collected. Sampling was done by the same three individuals over the whole period of the program for consistency and the Production Geologist performed regular audits of the sampling technique. Sample bags were numbered in sequence representing the scoop bucket from which they were taken. The sample bags were tagged and secured by the Production Geologist and samples were submitted to ALS Laboratories in the Republic of Ireland. 367 muck samples were taken from Stope 3, totalling 1.8 tonnes of ore, or an average of 5 kg per sample.
Quality assurance and quality control procedures identified no material issues. Face, channel and muck samples were analyzed by a 50 gram gold fire assay with either an atomic absorption, or a gravimetric finish for samples initially reporting over 100.0 g/t gold.
ALS Laboratories is accredited by the Irish National Accreditation Board (INAB) to undertake testing, including for Ores and Minerals (INAB P9 703), as detailed in the Schedule bearing the Registration Number 173T, in compliance with the International Standard ISO/IEC 17025:2005 2nd Edition "General Requirements for the Competence of Testing and Calibration Laboratories".