Heron Confirms 10Mt (M+I) of High Grade Tailings at 6.2% ZnEq within Revised JORC 2012 Mineral Resource Estimate
ACCESSWIRE
- Incorporates additional 2008 and 2011 drilling - Mineral Resource now based on 332 holes for 2,683 metres - 4.6% increase in Measured and Indicated Mineral Resources tonnages - 6.1% lower overall tonnages than previous estimate due principally to more conservative density estimates - Metal grades similar to previous estimates and have confirmed the high grade content of this material - Mine planning for a revised Mineral Reserve has commenced and together with the underground project will form the basis of the production plan for the ongoing Woodlawn Feasibility Study
SYDNEY, AUSTRALIA / ACCESSWIRE / October 19, 2015 / Heron Resources Limited (ASX:HRR TSX:HER, "Heron" or the "Company") is pleased to provide an updated estimate of the Woodlawn Tailings Retreatment Project (WRP) Mineral Resource at its wholly owned Woodlawn Project, located 250km south-west of Sydney, New South Wales, Australia. The previous estimate which dated from 2008 has been revised to incorporate additional drilling between 2008 and 2011. The estimate methodology and reporting is based on the requirements of the JORC 2012 Code.
Woodlawn Tailings JORC 2012 Mineral Resource estimate summary:
The update to the WRP Resource is an integral part of the ongoing Woodlawn Feasibility Study with this work providing key input data for the tailings retreatment component of the project. The upgrade of the Mineral Resource to JORC 2012 required a comprehensive review of previous work and also allowed for the inclusion of drilling data that had been completed after the previous estimate. This detailed review, and the inclusion of the additional data, further improves the confidence in the reported estimates and will provide the basis for a new mining study and updated Mineral Reserve estimate.
The WRP is based around the re-processing of the tailings generated from the Woodlawn open-pit and underground mining operations that ran from 1978 to 1998. The tailings are contained in three tailings dams; Tailings Dam North (TDN), Tailings Dam South (TDS) and Tailings Dam West (TDW), see Figures 1-3. A proportion of TDN was previously re-treated with these re-treated tailings placed back into the same dam. These retreated tailings are estimated separately and designated "North_R" in the tables below.
A number of drill programs have been undertaken over the years, with the estimate utilising a total of 332 drill holes (distribution shown in Figure 3) and 1,312 samples. Drilling was mostly undertaken by Vibracore and push core drilling rigs. Samples were taken in approximately 1-2 metre intervals down the holes. Parts of the dams have been covered in water and remain undrilled and such areas account for the majority of the Inferred Mineral Resources category (Figure 3).
Drill samples were analysed at commercial Australian laboratories and industry standard methods were employed. The estimation was undertaken utilising a mining software package with grade distribution based on kriged or inverse-distance interpolations. No cut-off grades have been applied to the estimate as there is gross uniformity to the grades and no selective mining is envisaged. The available historic records of tailings placed into the dams (totalling 10.95Mt) reconciles to within approximately 1% of the total tonnages contained within the updated Mineral Resource Estimate.
Measured and Indicated Mineral Resource categories were based on drill hole spacing, while Inferred Mineral Resources occupy areas under water or where sparse drilling is present. Mining factors were taken into account when selecting the block size for the estimate; the estimate is based on 10m x 10m x 1m block sizes that have subsequently converted to 10m x 10m x 5m for mine scheduling and reserve reporting. The mining of the tailings is expected to proceed using hydraulic mining methods on 5 to 10m benches.
Further details can be found in the JORC (2012) Table 1 at the end of the report.
The following tables provide various breakdowns of the Mineral Resource estimate.
By Dam:
By Mineral Resource Category:
Figure 1: Aerial View of the Woodlawn Project area showing the Tailings Dams; the subject of this Mineral Resource estimate. To view the image, please click on the following link: https://www.accesswire.com/uploads/8476_image1.jpg
Figure 2: Oblique plan view of the tailings dams showing the Mineral Resource blocks colour coded by ZnEq% To view the image, please click on the following link: https://www.accesswire.com/uploads/8476_image2.jpg
Figure 3: Plan view of the tailings dams showing the Mineral Resource blocks colour coded by resource category and drill collars To view the image, please click on the following link: https://www.accesswire.com/uploads/8476_image3.jpg
Forward Program
The revision of the Mineral Resource estimate for the WRP is an important component of the Feasibility Study, due for completion in June 2016, for the combined development of the tailings and underground mining operations. The revised estimate incorporates a substantial amount of new drilling data and provides a more robust estimate for planning work.
The block model for the estimate is now being optimised for mining and process scheduling which will also generate the Mineral Reserve base for the Feasibility Study.
A program of further drilling is being planned on the tailings dams as part of the Feasibility Study to provide additional material for metallurgical and paste-fill testwork.
The completed Technical Report in standard form prescribed by Canadian National Instrument 43-101 Standards of Disclosure for Mineral Projects will be published on Heron's web site, the ASX (HRR.AX) and SEDAR www.sedar.com (HER.TO) within 45 days of this news release.The Mineral Resource was classified into Measured, Indicated or Inferred categories in accordance with the guidelines of the 2012 edition of the JORC Code. It should be noted that there are no material differences between the Mineral Resource categories reported herein whether using those defined by JORC (2012) or the CIM Definition Standards on Mineral Resources and Reserves (CIM Definition Standards) adopted by CIM Council on May 10, 2014. The Mineral Resource, Mineral Reserve, and Mining Study definitions as described in the CIM Definition Standards are incorporated, by reference, into National Instrument 43-101 - Standards of Disclosure for Mineral Projects (NI 43-101).
[1] Zn equivalents (ZnEq) in this release are based on the formula: Zn(%) + 0.81 x Pb(%) + 3.12 x Cu(%) + 0.86 x Au(g/t) + 0.03 x Ag(g/t). Metal prices used in the calculation are: Zn US$2,300/t, Pb US$ 2,050/t, Cu US$6,600/t, Au US$1,250/oz and Ag US$18/oz. All these metals are expected to be recoverable. Refer to p15 of the announcement of 22 April 2015 entitled "Preliminary Economic Assessment Delivers Strong Business Case for the Woodlawn Zinc-Copper Project" for further information.
About Heron Resources Limited:
Heron is engaged in the exploration and development of base and precious metal deposits in Australia. Heron's primary development project is the high grade Woodlawn Zinc-Copper Project located 250km southwest of Sydney, Australia.
The Woodlawn Tailings Mineral Resource estimate contained in this release has been completed and compiled by Mr Robin Rankin, a Competent Person who is a Member (No. 110551) of the Australasian Institute of Mining and Metallurgy (AusIMM) and accredited by the AusIMM since 2000 as a Chartered Professional (CP) in the geology discipline. Mr Rankin consults to Heron as Principal Consulting Geologist of independent geological consultancy GeoRes. He and GeoRes are professionally and financially independent of Heron, the consulting was on a fee basis and results were not contingent on payments. He has sufficient experience, which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he is undertaking to qualify as a Competent Person as defined in the JORC Code (2012 edition) and "qualified person" as this term is defined in Canadian National Instrument 43-101. Mr Rankin consents to the inclusion in this release of the matters based on his information in the form and context in which it appears.
CAUTIONARY NOTE REGARDING FORWARD-LOOKING INFORMATION
This news release contains forward-looking statements and forward-looking information within the meaning of applicable Canadian securities laws, which are based on expectations, estimates and projections as of the date of this news release. This forward-looking information includes, or may be based upon, without limitation, estimates, forecasts and statements as to management's expectations with respect to, among other things, the timing and amount of funding required to execute the Company's exploration, development and business plans, capital and exploration expenditures, the effect on the Company of any changes to existing legislation or policy, government regulation of mining operations, the length of time required to obtain permits, certifications and approvals, the success of exploration, development and mining activities, the geology of the Company's properties, environmental risks, the availability of labour, the focus of the Company in the future, demand and market outlook for precious metals and the prices thereof, progress in development of mineral properties, the Company's ability to raise funding privately or on a public market in the future, the Company's future growth, results of operations, performance, and business prospects and opportunities. Wherever possible, words such as "anticipate", "believe", "expect", "intend", "may" and similar expressions have been used to identify such forward-looking information. Forward-looking information is based on the opinions and estimates of management at the date the information is given, and on information available to management at such time. Forward-looking information involves significant risks, uncertainties, assumptions and other factors that could cause actual results, performance or achievements to differ materially from the results discussed or implied in the forward-looking information. These factors, including, but not limited to, fluctuations in currency markets, fluctuations in commodity prices, the ability of the Company to access sufficient capital on favourable terms or at all, changes in national and local government legislation, taxation, controls, regulations, political or economic developments in Canada, Australia or other countries in which the Company does business or may carry on business in the future, operational or technical difficulties in connection with exploration or development activities, employee relations, the speculative nature of mineral exploration and development, obtaining necessary licenses and permits, diminishing quantities and grades of mineral reserves, contests over title to properties, especially title to undeveloped properties, the inherent risks involved in the exploration and development of mineral properties, the uncertainties involved in interpreting drill results and other geological data, environmental hazards, industrial accidents, unusual or unexpected formations, pressures, cave-ins and flooding, limitations of insurance coverage and the possibility of project cost overruns or unanticipated costs and expenses, and should be considered carefully. Many of these uncertainties and contingencies can affect the Company's actual results and could cause actual results to differ materially from those expressed or implied in any forward-looking statements made by, or on behalf of, the Company. Prospective investors should not place undue reliance on any forward-looking information. Although the forward-looking information contained in this news release is based upon what management believes, or believed at the time, to be reasonable assumptions, the Company cannot assure prospective purchasers that actual results will be consistent with such forward-looking information, as there may be other factors that cause results not to be as anticipated, estimated or intended, and neither the Company nor any other person assumes responsibility for the accuracy and completeness of any such forward-looking information. The Company does not undertake, and assumes no obligation, to update or revise any such forward-looking statements or forward-looking information contained herein to reflect new events or circumstances, except as may be required by law. No stock exchange, regulation services provider, securities commission or other regulatory authority has approved or disapproved the information contained in this news release.
