THE DRILL SERGEANT: Impact Minerals (ASX: IPT) announced trial mining of up to one million loose cubic metres (about 1.6 million tonnes) will be undertaken at the company’s Blackridge gold project located north of Clermont in central east Queensland.
Impact Minerals has signed an agreement for tribute mining with private contractor, Queensland-based Nimble Resources, which will take responsibility for all set up, mining, processing and rehabilitation costs at the project.
In return Impact has financially de-risked the next stage of exploration and development of Blackridge.
The company will also benefit from the receipt of a sliding scale Net Smelter Royalty (NSR) of up to 15 per cent depending on the average monthly grade of gold mined.
Impact declared the trial mining phase, if successful, would be major step forward in demonstrating the potential for a larger open pit mine at Blackridge and follows the recent recognition of large volumes of free-digging oxide ore with exceptional gold recoveries of more than 95 per cent by wet gravity processing methods in recent bulk sampling programs.
The bulk sampling programs were done in conjunction with Nimble, which was so encouraged by the results, it approached Impact to initiate the trial mining.
Nimble boasts specialist skills and equipment in both wet and dry gravity gold processing technologies and is of the opinion that a large portion of the oxide material at Blackridge may potentially be dry processed.
Nimble will initially trial a proprietary dry processing technology with a throughput capacity of about 90 cubic metres per hour (about 150 tonnes per hour).
In addition, Impact will work with Nimble to determine optimal processing routes for the other two material types in the deposit which are not suitable for dry processing: wet clay-rich material and less oxidised to fresh bedrock.
“This agreement is a very positive step forward for the Blackridge project,” Impact Minerals managing director Dr Mike Jones said in the company’s announcement to the Australian Securities Exchange.
“We know that the best way to determine grade in coarse gold deposits such as Blackridge is to simply start mining.
“This is inherently very high risk and so this agreement gives Impact a very low risk entry to mining by trial mining of only a modest part of the mineralised area which extends over at least 1,500 metres along trend.
“In addition, Impact, under the royalty payment provisions will receive at least a modest cash flow from the trial.
“Having worked with Nimble Resources for the past 18 months Impact has established that the company is a very capable operator and we look forward to working with them and starting the trial as quickly as practicable.
“The use of their dry processing technology in the first instance also significantly decreases the environmental risk and the large water requirements for a wet processing plant.
“Impact will also continue to assess other processing alternatives for other material types which are key targets for the larger scale potential at Blackridge.”
The Blackridge project is an advanced conglomerate-hosted gold project that covers the historic Blackridge and Springs mining centres located about 25 kilometres of Clermont.
The gold fields produced about 185,000 ounces of gold from 1879 to the early 1900s from surface down to depths of about 70 metres in small shafts and related underground workings.
Impact Minerals has previously completed two phases of bulk sampling of the conglomerate material with very encouraging results from a wet gravity processing plant.
Gold was recovered from samples taken over 1,000m of trend with grades ranging from 0.07 grams per cubic metre to 2.17g/m3 at an average of 0.36g/m3.
All material sampled was free digging down to at least four to five metres below surface with gold present, in at least a few locations, throughout the profile.
Large volumes of such material are present at Blackridge over the 1,500m of trend.