Dalradian Resources Inc. (DNA-T)
Ore Sorting Increases Grade of a Bulk Sample by 55% at Dalradian's Curraghinalt Project
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TORONTO, ONTARIO--(Marketwired - Sept. 18, 2017) - Dalradian Resources Inc. (TSX:DNA)(AIM:DALR) ("Dalradian" or the "Company") announces positive ore sorting test results based on a bulk sample of mineralized development material from several of the veins at the Curraghinalt Gold Projectin Northern Ireland. Testing was carried out by Outotec at their TOMRA sorting test facility in Wedel, Germany on approximately 5 tonnes of material grading 9.52 g/t Au. Using x-ray and laser technology, plus additional screening prior to processing, the amount of non-mineralized (waste) material that would be sent to the mill in an operating mine was reduced by 35.8% and the grade increased by 54.6% to 14.72 g/t Au with a gold recovery of 99.3% (see Figure 1 available at dalradian.com. Similar results would be expected if implemented into a mine scale situation.
Ore sorting technology has been used in diamond processing operations for many years and is now used with a variety of other commodities including tungsten and gold. The ore sorting process has become increasingly efficient with advancements in x-ray, laser and computer technology. It was anticipated that ore sorting would be a good fit at Curraghinalt because of the large contrast in density and colour between the high-grade quartz-sulphide veins and the surrounding country rock.
Throughout the testing, the ability to effectively sort the ore from Curraghinalt was clearly demonstrated. Using only x-ray technology with rougher stage material, waste removal of 50.5% with a gold recovery of 97.8% was achieved. When the laser scavenger step was added, which is used to recover additional mineralized material from the x-ray waste material, total gold recovery increased to 99.3% at the expense of a decrease in total waste removal to 35.8%. Optimisation of the proposed process, including a cost benefit analysis of the secondary scavenger circuit, will be needed prior to implementation of the technology.
Eric Tremblay, Dalradian's Chief Operating Officer commented: "These are very good results. Independent testing proves our high-grade gold is easily sorted from waste. We can now show that a modest capital investment in this technology will improve Curraghinalt's already robust grades and project economics. We plan to investigate it further by visiting operations using the technology prior to designing our own ore sorting infrastructure for inclusion in an updated feasibility study."
Ore sorting has the potential to considerably reduce costs at the mill by decreasing the amount of ore processed to produce the same number of ounces. Applying the results of the testing to the Curraghinalt deposit Mineral Reserve Estimate, would potentially eliminate approximately 1.87 million tonnes of non-mineralized material prior to processing (see Figure 2 available at dalradian.com. Using the base case feasibility cost estimate of US$27.8/tonne for milling, this could result in savings of US$52 million against a revenue loss of approximately US$12.6 million (at 1,250 US$/oz) due to recovery being reduced by 0.7%. Further cost savings are expected from the replacement of cut and fill mining previously adopted for dilution control with mechanized long hole mining. Application of ore sorting also has the potential to decrease the cut-off grade, which would result in more mineable ounces and increase the throughput of the mine.
Table 1: Curraghinalt Mineral Reserve Estimate
| Category | Diluted tonnes
(' 000 t) | Au Grade
(g/t) | Au Ounces
(' 000 oz) | | Proven | 28 | 18.93 | 17 | | Probable | 5,211 | 8.48 | 1,421 | | TOTAL | 5,239 | 8.54 | 1,438 |
Note: All figures have been rounded to reflect the relative accuracy of the estimates. Discrepancies in sums may be due to rounding.
Details of the Mineral Reserve Estimate can be found in the Company's technical report titled "NI 43-101 Feasibility Study Technical Report on the Curraghinalt Gold Project Northern Ireland" (the "Technical Report"), dated January 25, 2017 and prepared by Garett Macdonald, P.Eng., Michael Makarenko, P.Eng., Indi Gopinathan, P.Eng. and Stacy Freudigmann, P.Eng., all of JDS Energy & Mining Inc., and Jean-François Couture, P.Geo., Bruce Murphy, P.Eng., Cam Scott, P.Eng., all of SRK Consulting (Canada) Inc., and William Harding, C.Geol., of SRK Consulting (UK) Ltd., all of whom are independent Qualified Persons as defined by NI 43-101. The Technical Report is available on the Company's website and on SEDAR at www.sedar.com.
Qualified Person and QA/QC
Eric Tremblay, P.Eng., Dalradian Chief Operating Officer, is the Qualified Person who supervised the preparation of the technical data in this news release.
Sample preparation was performed by SGS Minerals England. Assays were carried out by Wheal Jane Laboratory of Cornwall, England under supervision of SGS Minerals England. The analysis methods are ISO17025 accredited and the laboratory is ISO 14001 and ISO 9001 certified. Gold assays were performed in triplicates, and the average of these three results were used for each sample.
About Dalradian Resources Inc.
Dalradian Resources Inc. is a mineral exploration and development company that is focused on advancing its high-grade Curraghinalt Gold Projectlocated in Northern Ireland, United Kingdom.
About Outotec
Outotec is a minerals and metals processing technology company providing services to the mining industry. Their head office is located in Helsinki.
www.outotec.com
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