Probably not..although Digger is.
I can report that the Glass earth website now has the annual report and MD&A locked in as pdfs. Here is part of the MD&A relating to WKP.
None of this text is entirely new, it's been around for a few weeks/months. It's just great to read and hold in view. It's the second to last sentence I'm having trouble with. What does it mean? I think that being realistic, all the test work and the drilling programme will have to be completed before the Project First Resource Estimate can be published. Clarification from head office would be helpful here. If that is the case, the drilling needs to get underway pronto, before the winter season hits. Although perhaps the lone helicoptered drilling rig doesn't have such an issue with access. WKP36 and 37 assays are needed first.Exploration on the WKP project demonstrates that it is a very large permissive low sulphidation
epithermal gold system (approximately 1.2km by 1km). Following on from historical exploration of the
Eastern Zone evaluated by various parties in the 1980’s and 1990’s the Hauraki Joint Venture work has
identified two other significant zones of mineralisation (Central and Western Zones), and recently
intersected mineralisation on the Eastern Graben structure where the current focus of drilling activity
continues.
In the Central Zone broad low grade intercepts are a feature (WKP26 151m at 1.2ppm Au, and WKP27
102.2m at 1.1 ppm Au) with the margins of a voluminous rhyolite rock type providing a focus of
hydrothermal fluid flow and high grade gold mineralisation. The interior of the competent and
homogeneous rhyolite rock has permitted regular fracturing and broad hydrothermal fluid flow with
resulting consistent large-tonnage low-grade gold mineralisation.
This contrasts with the East Graben structure within the Eastern Zone which is typically dominated by
discrete veins. Drill core from 580m down-hole in WKP35 shows episodic high level crustiform banded
veins, hydrothermal and tectonic brecciation corresponding with multiple phases of mineralisation,
hosted on the position of rhyolite and andesite lithologies. Assay results for this interval returned 7.9m
grading 5.1 ppm Au, including 3.4m grading 8.3 ppm Au. This style of mineralization on the Eastern
Graben structure was new for this project and important because there are strong similarities with major
gold mines in the vicinity, namely Martha, Favona, and Golden Cross.
The broad low grade gold mineralisation within the Central Zone and veins relating to the East Graben
structure lie on a major north-north–east trending structure marking the intersection of rhyolite (west)
and more intermediate andesite pyroclastics (to the east). This is a district scale structure, identified on
magnetic and resistivity (geophysical) data, and may represent the primary focus of significant coherent
mineralisation in the WKP area.
The HJV plans a significant exploration programme for 2013, focussing initially on the evaluation of the
Eastern Graben Structure and to include a project first resource estimate, metallurgical test work, rock
engineering study, geophysics and a 2,500m diamond drill programme. The estimated cost for this
programme is NZ$2.7 million.
What does it take to get those core samples assayed? You'd think that with geologists and lab/chemical engineers being produced by our universities every year, someone would step into any gap in the NZ mineral reporting market. In the Waikato, a big and profitable lapse in speedy agricultural soil/grass/water/crop data analysis was filled by Hills Laboratories.
AA Spectrophotometers sell new for about US$12,500 to $20,000. Guess you'd need a diamond rock sample cutter, a furnace, a small rock crusher, some crucibles and some chemicals and reagents. And a quality certification, maybe the tricky part.How are ore and waste defined?
Samples of rock from within the pit or from underground are sent to the SGS laboratory in Waihi to determine gold content.
The data generated from assaying is used to map out which areas are suitable to process as ore and which areas are waste material to be used to build the waste rock embankment or to be used as backfill underground.
In process testing - double checking
Throughout the extraction process at the Newmont Waihi Gold mill, samples of solution, solids and activated carbon are removed for analysis to determine the efficiency of the process. The solids and the carbon samples are analysed by the fire assay technique for gold and aqua regia for silver. The solutions are aspirated (turned into a fine mist) into an AA Spectrophotometer.
Fire assay
Fire assay involves adding a ground portion of the solid (or carbon) to a crucible containing a flux. Flux is used to lower the melting point of the samples to ensure the entire sample becomes liquid during firing. The flux contains borax, soda ash, silica flour, litharge (lead oxide) and silver nitrate in various quantities. In the firing stage everything turns liquid and the lead oxide forms into small globules of metallic lead. The globules fall through the liquid and form an amalgam with any other metals it comes into contact with, including gold and silver. This all collects in the bottom of the crucible. After about an hour at 1,000 degrees Celsius the contents of the crucible are poured into a conical mould to cool. Again the lead, being more dense than other material, quickly settles to the tip of the conical mould and solidifies along with the glass-like rock remains.
When cooled, the lead is separated from the glass and then cupelled. Cupellation involves placing the lead ‘button’ into a pre-heated cupel at 1,000 degrees C. A cupel is a small cup made of magnesium sulphate which is a material that is capable of absorbing the lead. At this temperature the metals liquefy and lead is absorbed into the cupel. Gold and silver having a higher surface tension than lead, are not absorbed and remain as a small ‘prill’ in the bottom of the cupel. The cupel and prill are removed from the furnace and allowed to cool. The prill is then dissolved in aqua regia. The resulting solution is aspirated into an AA Spectrophotometer to determine the gold content.
Aqua regia
Silver in the solids and carbons is determined by dissolving the sample in aqua regia, a mixture of hydrochloric and nitric acids. The sample has specific volumes of each acid added, then is placed on a heating block to digest. When completed the resulting solution is diluted and then aspirated into an AA Spectrophotometer.
References and acknowledgements
The information on this page was kindly supplied by SGS NZ Ltd.
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