Rucker D.F.,HydroGEOPHYSICS Inc. |
Zaebst R.J.,Carlota Copper Company |
Gillis J.,Metallurgical Consultant |
Cain J.C.,HydroGEOPHYSICS Inc. |
Teague B.,Carlota Copper Company
Hydrometallurgy | Year: 2017
A significant amount of metal inventory can reside in a leach pad due to unfavorable metallurgical and hydraulic conditions. Continued leaching using surface irrigation will likely be unsuccessful at recovery in any reasonable time frame. In this work, we investigate how subsurface leaching (SSL), using wells to facilitate the delivery of barren solution, could potentially increase recovery and drawdown the inventory in a shorter period of time. An initial characterization campaign of the leach pad using drilling and assaying along with geophysical methods showed that inventory was high because the ore remained dry from compaction. Other areas were also shown to have preferential flow paths as a means to drain solution out of the leach pad. Assaying results taken from sonic coring and auger cuttings, and extrapolated across the leach pad, revealed a potential of 37 × 106 kg of acid soluble copper. Our investigation covers the first 1000 days of SSL, with 110 PVC wells distributed across five main areas. During this time, we estimate production at 2.26 × 106 kg of copper based on the amount of solution introduced through the wells multiplied by the average copper grade from a number of sources, including monitoring wells and newly formed side slope seeps. Some areas performed better than others, especially where assays revealed that acid soluble copper was greater than 50% of total copper. The SSL program is expected to continue for at least another 1000 days, and we expect an additional 7 × 106 to 15 × 106 kg will be withdrawn from inventory. © 2017 Elsevier B.V.
News Article | May 23, 2017
VANCOUVER, BRITISH COLUMBIA--(Marketwired - May 23, 2017) - Anfield Gold Corp. ("Anfield" or "Company") (TSX VENTURE:ANF) is pleased to announce the results from its last round of metallurgical testing for the Coringa Project ("Coringa" or "Project"). The results were positive, demonstrating recoveries of 98% gold and 61% silver. These results were achieved by testing a master composite representing mineralized material from the Meio and Serra zones of the Project using gravity concentration followed by carbon-in-leach ("CIL") cyanidation of the gravity tails. The master composite was a 50/50 blend of mineralized material from each zone that utilized core from 19 out of the 229 drill holes that have been completed across both zones. The master composite also responded very well to whole ore cyanidation with gold extraction rates similar to those obtained by gravity concentration followed by CIL cyanidation; however, whole ore cyanidation was shown to have 9% lower silver recoveries. Anfield anticipates using gravity concentration followed by CIL cyanidation of gravity tails in the final flow sheet for the Project's feasibility study, expected in July 2017. The metallurgical testing was undertaken by C.H. Plenge & CIA S.A. ("C.H. Plenge") at its laboratory in Lima, Peru. C.H. Plenge is not related to Anfield. On May 10, 2017, Anfield received formal consent for the Project from the Instituto Nacional de Colonização e Reforma Agrária ("INCRA"). INCRA's consent was required by the Secretaria de Estado de Meio Ambiente e Sustentabilidade ("SEMAS") as a pre-requirement to issuance of permits for the commencement of construction and operations at Coringa. Anfield continues to engage with SEMAS as the agency works to finalize and issue the required permits. Pre-construction activities at Coringa continue to advance, with the latest developments listed below: All Anfield sample assay results have been monitored through a quality control / quality assurance ("QA/QC") program including the insertion of blind standards, blanks and the reanalysis of duplicate samples. The results of the QA/QC program and the resampling program indicate that the sample database is of sufficient accuracy and precision. Nelson King, SME Registered Member and Metallurgical Consultant to Anfield, is a Qualified Person as defined by National Instrument 43-101 Standards of Disclosure for Mineral Projects. Mr. King has assisted Anfield in the development and direction of the metallurgical testing program for the Project, has visited C.H. Plenge's laboratory in Lima to observe the testing program, and has reviewed and approved the content of this press release relating to the metallurgical testing. Mr. King also verified the results of the metallurgical testing. Anfield Gold Corp. (TSX VENTURE:ANF) is a Vancouver, Canada based precious metal exploration and development company focused on the development of the Coringa Project located in Para State, Brazil. Anfield's strategic plan also includes the acquisition of other gold projects with the goal of becoming a mid-tier gold mining company. Further details are available on the Company's website at https://anfieldgold.com Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this news release. Certain statements and information herein, including all statements that are not historical facts, contain forward-looking statements and forward-looking information within the meaning of applicable securities laws. Often, but not always, forward-looking statements can be identified by the use of words such as "plans," "intends," "will" "are expected" or variations of such words and phrases. Forward looking statements or information in this press release include, but are not limited to, the rate of ore recovery at the Project, the preparation of, and timing to completion of, a feasibility study for the Project; Anfield's strategic plan to acquire other gold projects with the goal of becoming a mid-tier gold mining company, timing to completion of pre-construction activities and plan to use gravity concentration followed by CIL cyanidation of gravity tails. In making the forward-looking statements in this release, Anfield has applied certain factors and assumptions that are based on information currently available to Anfield as well as Anfield's current beliefs and assumptions (including Anfield's belief in the accuracy of the mineral resource estimate). Although Anfield considers these beliefs and assumptions to be reasonable based on information currently available to it, they may prove to be incorrect, and the forward-looking statements in this release are subject to numerous risks, uncertainties and other factors that may cause future results to differ materially from those expressed or implied in such forward-looking statements. Such risk factors include, among others, additional drilling and exploration may determine that there is no potentially viable mine plan for the Project, risks associated with the business of Anfield, risks related to reliance on technical information provided by Magellan Minerals Ltd. as related to the Project; risks relating to exploration and potential development of the Company's projects; risks related to obtaining the permits and approvals necessary to develop and commission the Project on terms that are acceptable to Anfield; risks related to Anfield identifying suitable acquisition targets; business and economic conditions in the mining industry generally; the supply and demand for labour and other project inputs; prices for commodities to be produced and changes in commodity prices; changes in interest and currency exchange rates; risks relating to unanticipated operational difficulties (including failure of plant, equipment or processes to operate in accordance with specifications or expectations, cost escalation, unavailability of materials and equipment, government action or delays in the receipt of government approvals, industrial disturbances or other job action, and unanticipated events related to health, safety and environmental matters); risks relating to adverse weather conditions; political risk and social unrest; changes in general economic conditions or conditions in the financial markets; and changes to business and economic conditions in the mining industry generally. Although Anfield has attempted to identify important factors that could cause actual results to differ materially from those contained in forward-looking information, there may be other factors that cause results not to be as anticipated, estimated or intended. There can be no assurance that such information will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking information. Anfield does not undertake to update any forward-looking information, except in accordance with applicable securities laws.
Washnock R.,Freeport McMoRan Inc. |
Zarate G.,Anglo American |
Scheffel R.,Metallurgical Consultant
2016 SME Annual Conference and Expo: The Future for Mining in a Data-Driven World | Year: 2016
The second survey of global copper leaching operations has been completed, the data published in 1998 has been updated. A survey questionnaire was sent to 40 identified copper leach operations around the world including those leach properties still in operation that responded to the 1998 survey. This paper lists the results of 26 operations that responded to the survey. Selected information from the survey is represented in graphical form.
MacKey P.J.,P.J. Mackey Technology Inc. |
Wraith A.E.,Metallurgical Consultant
Transactions of the Institutions of Mining and Metallurgy, Section C: Mineral Processing and Extractive Metallurgy | Year: 2012
The world's first copper electrorefinery started production in 1869 at Pembrey in South Wales and was closed in March 1912. Refining principles pioneered there form the foundation of modern electrorefining practice. A cathode recovered at closure and now in the collection of the Swansea Museum, Wales, is the earliest authenticated British example of electrorefined copper as cathode. This unique artefact was sampled and assayed to establish its composition and market quality and to help elucidate refining capability at that time. The sampling method was based upon drilling into the edge of the cathode plate in order to protect its display integrity; assaying was by inductively coupled plasma mass spectrometry, the present received method for refined copper. Comparison with contemporaneous cathode and wire bar assays indicates that the Pembrey cathode would have been competitive in the copper market of its day, but with questions about its relatively high levels of silver and, to a lesser extent, arsenic. © 2012 Institute of Materials, Minerals and Mining and The AusIMM.
Cobb H.,Metallurgical Consultant
Advanced Materials and Processes | Year: 2010
Walter Percy Chrysler, the vice president and General Manager of General Motors, contacted William Van Alen to build the tallest building in the world. Construction began in December 1928, and the steel skeleton was soon rising at the rate of four stories a week. Meanwhile, George Orhstrom, president of the Bank of Manhattan, announced that he would be erecting a building at 40 Wall Street that would top out at 840 feet, 32 feet taller than Chrysler's goal. Van Alen then announced his plans to build to 842 feet, which was a scant 24 inches higher than that announced for the 40 Wall Street building. The building had an area of one million square feet, and had thirty-two elevators. When fully occupied, it would house 10,000 tenants and employees, not to mention thousands of visitors. The custodial staff would number 350, and the building would be cleaned daily with a modern central vacuum cleaning system.
Wheatcroft M.,Metallurgical Consultant |
Miller D.,ABS Pacific
Proc. of the Int. Conf. on Advances in Welding Science and Technology for Construction, Energy and Transportation, AWST 2010, held in Conj. with the 63rd Annual Assembly of IIW 2010 | Year: 2010
A key element in the quality of a ship is the quality of its weldments. This paper will show how some of the current rules and regulations governing the quality of welded ship and offshore structures were conceived and grew, discuss a variety of structures and speculate on future directions concerning the fabrication of ships and other marine vehicles and structures. Merchant ships and buoyant and fixed offshore structures have distinctly different requirements as regards materials and welding. These differences are not only the result of different operating environments. Legal climate, regulatory philosophy, service history, life cycle economics, technological innovation, and political expediency have all played roles in shaping requirements in the marine and offshore industries. Changes in operating environments (for example deeper, rougher and colder waters), the internationalization of litigation, demands for faster ships, the transportation of hydrocarbons in different forms as well as the continuing drive for greater productivity and more efficient designs place challenges on maintaining structures fit for the purpose of safely going to sea.
Gaylard P.G.,Metallurgical Consultant |
Randolph N.G.,United Investments |
Wortley C.M.G.,Metallurgical Consultant
Journal of the Southern African Institute of Mining and Metallurgy | Year: 2014
In the wake of the financial crisis that affected world markets in 2002, there has been an increasing international focus on corporate governance. Various corporate governance codes of practice have been introduced, such as the Sarbanes-Oxley legislation in the USA, the Combined Code in the UK, and King III in South Africa. This focus on corporate governance has increased since the most recent financial crisis in 2008, the effects of which are still being felt world-wide. In the mining and minerals industry, reliable metal accounting is essential to sound corporate governance and is also becoming a focus of increased attention and concern, particularly as the figures generated by the metal accounting system feed directly into the financial accounts of mining companies. Mass measurement, sampling, and analysis provide the input data for the metal accounting system and sound corporate governance requires that the procedures used are based on best practice and that the data generated is accurate and handled correctly, transparently, and consistently to produce the accounting reports. The AMIRA Code of Practice for Metal Accounting has been widely adopted in the industry as a means to achieve this, and the compilers of the Code have conducted numerous metal accounting audits at operations, both in South Africa and abroad. These audits have shown that there is a real need for such a code of practice. © The Southern African Institute of Mining and Metallurgy, 2014.
Song H.Y.,Ohio State University |
Evans G.M.,Metallurgical consultant |
Babu S.S.,University of Tennessee at Knoxville
Science and Technology of Welding and Joining | Year: 2014
Often, scatter in mechanical properties of multi-pass steel weldments is qualitatively attributed to the underlying heterogeneous microstructure brought about by spatial variations of multiple thermal cycles. In this research, a method for quantitative heterogeneity calculation based on measured variations of microstructure and hardness throughout the multi-pass weld metals including various reheated regions was explored. Published data from multi-pass welds with controlled titanium additions (7-32 wt ppm) were correlated to comprehensive microstructure characterization. The scatter in 7 wt ppm Ti steel welds was larger than that of 32 wt ppm Ti steel welds. This change in scatter is correlated to spatial distributions of microstructural heterogeneity parameter, rather than the average value of heterogeneity parameter for the whole weldment. © 2014 Institute of Materials, Minerals and Mining.
Birol F.,Metallurgical Consultant |
Birol Y.,TUBITAK - Marmara Research Center
Corrosion Engineering Science and Technology | Year: 2014
Corrosion of twin belt and twin roll cast AlMg3Mn sheet samples was investigated. The AlMg3Mn sheet samples submitted to immersion tests undergo alkaline pitting around Al-Fe and ac-Al(Fe,Mn)Si intermetallic particles in the twin roll and twin belt cast samples respectively. The weight loss is higher in the latter and increases with increasing homogenisation temperature for both groups. The twin roll cast AlMg3Mn samples reveal very few and small alkaline corrosion pits and hence much less weight loss in the immersion tests. The pitting activity is governed in the immersion tests by themicrogalvanic corrosion activities between the intermetallic particles and the matrix while the anodic particles were inactive. © 2014 Institute of Materials, Minerals and Mining.