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By Andrew Griffiths

The emphasis in the title of this paper should be placed on the world "Total", since the detoxification of cyanide in its free and weakly-complexed form with H202 has already found application in many areas, including the treatment of mining effluents. One of the most common forms of cyanide found in gold-mill effluents is hexacyanoferrate (usually ferrocyanide), which is included in measurements of total cyanide but is too stable to be oxidized by H202 or any other conventional oxidizing agent. This has led to the view that H202 cannot be used to detoxify effluents containing hexacyanoferrates, when a limit has been set on total cyanide. A process is described in this paper which does meet this requirement, and which has already been demonstated in two Canadian gold mills. Before describing the new process, the terms "free", "total" and "weakly-complexed" cyanide will be defined as they are used in this paper.

Jan 1, 1998

By R. L. Templin

The increasing use of aluminum and its alloys in commercial fields tias demanded a better understanding of their machining properties. This fact is exemplified by problems that have arisen in the automotive and airplane industries, but many in other fields might be cited. As pure alunlinum and its alloys in their various commercial conditions show appreciable differences in their machining properties, it is not surprising that quite divergent solutions have been offered for the machining problems encountered. However, if the fundamental requirements of the most suitable cutting tools for these metals are understood, these machining problems lend themselves more readily to satisfactory solutions. Since the machining of free cutting brass and mild steel is understood by most persons accustomed to working these metals, it may serve our purpose better to first make a general comparison of the tools more commonly used in machining these metals with the tools most suitable for machining aluminum, then proceed to a more specific discussion of the individual tools. Comparison oF Cutting Tools Cutting tools commonly used for machining free cutting brass usually have little, if any, top and side rake; they are ground on a medium to coarse abrasive wheel and used without any cutting compound or with a cutting compound that has a paraffin base. Those ordinarily used for steel have some top and side rake, are usually ground on a medium to fine abrasive wheel, and are often used with soluble-oil cutting compounds. The proper tools for aluminum and its alloys should have appreciably more side and top rake than the tools for cutting steel; should have very keen edges obtained by grinding with fine or very fine abrasive wheels supplemented in many cases by hand stoning with an oil-stone; and should be used with suitable cutting compounds whenever possible. In many cases, tools suitable for machining aluminum and its alloys are not appreciably different from tools commonly used for cutting hardwoods. The front clearance of a tool most suitable for machining aluminum and its alloys should be about 6°, the top rake from 30" to 50°, making the total angle of the cutting edge of the tool from 35' to 55". A side

By M. J. Voigt, R. A. Govender, A. Mainza, L. Bbosa

"Mineral texture is a critical factor which controls ore variability and is an important attribute in geometallurgy. In relation to downstream processes, it affects the fracture pattern during breakage, where rock strength is inherently a function of mineral texture. Because of the subjective nature of mineral texture, it has not been easy to quantify, especially in the context of a measurement suitable for use in geometallurgical programmes. The aim of this paper is to present the first steps in developing a 3D mineral texture quantification method for drill core and to assess its sensitivity to differences in rock strength using a case study. The methodology includes classifying the textural information using the 3D grey level co-occurrence matrices (GLCM) and X-ray computed tomography (XCT) coupled method. Rock strength tests were performed using the split Hopkinson pressure bar (SHPB). The case study investigates a heterogeneous polymetallic sulphide deposit and a homogeneous shale subdivided into three ’mineral textural types’. The variability is largely captured by the GLCM matrices, and preliminary trends can be observed where the shale is finer grained and has a higher yield strength in comparison with the coarser grained polymetallic sulphide ore. IntroductionModern mining requires the exploitation of lower grade and more complex, heterogeneous orebodies to address the growing industry demands. Historically, processing plants were designed and built based on average ore characteristics and therefore are relatively inflexible when facing the full spectrum of ore variability in heterogeneous orebodies (Lamberg, 2011; Lotter, 2011; Schouwstra et al., 2013). The practice of geometallurgy represents an opportunity to manage ore variability in the mining industry (Powell 2013; Baum, 2014; Yildirim et al., 2014; Nguyen, 2013). It focuses on quantifying the relationships between ore characteristics and their downstream mining and processing responses, often starting with small-scale laboratory testing. The purpose of geometallurgy is linked to maximizing the net present value (NPV) of an orebody by minimizing technical and operational risk – where ‘ore variability’ is considered one of the most significant technical risks."

Apr 1, 2019

By L Manca, P B. Hills, D Tyler, N Pollington

This paper describes a collaborative project undertaken by Newcrest Mining Limited (Newcrest) and pitt&sherry to identify, develop and then implement global best practices to manage the exposure to inrush (dry and mud) hazards in underground mining operations. An extensive literature review was undertaken to identify past experience globally and the current state of knowledge and practice in managing inrush hazard. A key requirement of the literature review was the development of a list of guiding questions which would form a framework for approaching operators to discuss the topic, capture recent learnings and understand current operating practices to allow the development of a best practice solution. An initial cohort of 14 mines across four continents chose to contribute and detailed interviews were carried out by the project team. The outcome from the literature review, interviews with participating mines and various internal discussions was a comprehensive summary document detailing Basic versus Best Practice management of the inrush hazard. This document is being used as a gap analysis tool by Newcrest to assess and guide the management of inrush hazard at their existing and future operations. The summary document has also been provided to the participating mines for their consideration. The project is iterative and will continue to evolve as new experiences, knowledge and practices come to light.

Mar 15, 2021

By Reinol Compañero, Ivy Gonzales, Herman Mendoza, Brian Buenaventura

"The extraction of gold in the Philippines has been a significant challenge for the past decades. Around 70-75% of gold mined in the country can be accounted from the small-scale mining industry which primarily use the traditional cyanidation and amalgamation; processes which have been advocated due to its adverse affects to health and environment. To address this challenge, an alternative clean and sustainable technology was developed for the small-scale miners to recover gold and other metal/mineral values efficiently from Philippine ores. An initial survey was conducted and followed through with extensive mineralogical investigations ascertain the best method applicable. It was determined that Philippine gold occur in ore as (1) very fine particles in the microns range, (2) free-milling, which is in abundance, and (3) locked particles with sulfides --- it was concluded that enhanced gravity concentration and flotation are viable alternatives. A comprehensive test regime was followed to check the response of the ores obtained from different small-scale mining districts across the country. It was shown conclusively that the gold ores respond positively, with recoveries using gravity concentration and flotation of at least 95% and 88%, respectively; exceeding the nominal recoveries using cyanidation or amalgamation. A specific process flow was designed for each type of ore with customized parameters. It was determined that while capital expenditure of implementing these alternative processes is higher than what is currently being used, the operational aspects show that it is much more economical to apply enhanced gravity and flotation. It should be noted that the process developed addresses the critical issue of environmental costs which should be more than enough to justify the shift from the current to the novel and sustainable technologies."

Jan 1, 2014

By L D. Munro, S A. Jackson

This paper provides a logical approach to developing a TSF design concept through: • Identifying key properties of tailings and containment structures; • Reviewing underlying principles for effective operation; • Showing how these apply to select an appropriate TMS; and • Demonstrating how to align the TMS to site-specific constraints and TSF design. This approach follows a path of rigorous data analysis independent of discharge parameters (whether low-density slurry, paste or cake disposal) to select the most cost-effective and sustainable approach for any given material or site.

Jul 1, 2021

By Fleming, R. C.

ONE OF THE NEWEST developments of industry rising from the commercial application of scientific knowledge is in the making of solid carbon dioxide from the gas about 1925 the first efforts were made to manufacture "dry ice" on a large scale and at a price to permit widespread use. From that beginning the industry has grown to a consumption of 40,000 tons in 1930. Carbon-dioxide ice, as the name implies, is merely the gas compressed and cooled to a solid. The ice has a temperature of 109° F. below zero and is in many ways superior to water ice. It evaporates to a gaseous form so it is not wet and leaves no trace; in fact, one suggested minor use is as coasters under water glasses on the dining table. The gas is harmless except in large concentrations and. when the ice is used as a refrigerant, the resulting gas actually becomes a preservative, keeping oxygen away from perishable products. Not only does the ice have a greater amount of cold in a small volume than water ice but cooling is effected by direct contact of the resulting gas with the materials to be refrigerated rather than by convection air currents.

Jan 1, 1932

By Brendan Demich, Brendan Macdonald, Timothy J. Orr, Jason Navoyski, Jennica L. Bellanca, William J. Helfrich

Recent advances in computing, rendering and display technologies have generated increased accessibility to virtual reality. Virtual reality allows for the creation of dynamic, high-fidelity environments to simulate dangerous situations and test conditions and to visualize concepts. Consequently, numerous products have been developed, but many of these are limited in scope. Therefore, U.S. National Institute for Occupational Safety and Health (NIOSH) researchers developed a virtual-reality framework, called VR Mine, to rapidly create an underground mine for human data collection, simulation, visualization and training. This paper describes the features of VR Mine, including mine generation, simulated networks, proximity detection systems, and the integration and visualization of real-time ventilation models.

By G. Bezuidenhout, N. C. Steenkamp

Buying centres are the first point of contact that determines whether ore will be considered as having sufficient provenance to be considered ethically sourced. The information that needs to be captured on the blockchain platform ranges from reports on in-loco inspections and audits of mining and purchase sites. This will guide passive and active monitoring of mining activities, trade-offs for identification systems, including biometrics for the registration of artisanal sellers, scrutiny on the selection of security measures and companies for buyer centres and stockpiling warehouses, evaluation of active and passive infrastructure security, and remote monitoring applications. Assistance with selection and training in geochemical testing instruments to determine the grade of ore material or concentrates and sorting, on-the-ground investigations, guidance on monitoring methods from stockpile and packing area along the transport route to the final destination are required.

Jan 1, 2023

By FHATUWANI SENGANI

The understanding of yielding pillar behavior has been well documented in terms of pillar strength using numerical simulations and empirical formulas, but the understanding of how fracture propagates in a matured yielding pillar is not well established. A new empirical summation chart of fracture distribution along the matured yielding pillar is presented in this paper. The chart was developed using ground penetrating radar (GPR) supported by borescope observations, focusing on monitoring the distribution of extension fracture.

By Tony Szwilski

Using Unity 3D as a collaborative multi-user virtual on-line environment, an interactive virtual underground mine platform (IVUMP) is being developed to provide on-line access to mine safety preparedness training with a focus on mine emergency response exercises (MEREs). Communication and information flow among MERE participants and their actions can be monitored, recorded and evaluated. A mine ventilation simulation utility VFIRE is being incorporated to enhance the realism and interactive nature of the ?in-world? exercises as well as extend its functionality to include training in real-time ventilation and fire control.

Aug 1, 2013

Production targets are the basis for almost every decision made by operations personnel in the daily operation of a concentrator. It is the production targets that determine how the plant is operated and therefore determine its efficiency. However, to achieve maximum plant efficiency production targets must be relevant to the process and achievable.In RoseberyÆs case, for many years, production targets were taken from budget data which, with the exception of mill feed tonnes and grades were carried forward from the previous budget. The zinc concentrate grade target was fixed at 57 per cent Zn, a long-term average; it was the accepted æstandardÆ for Rosebery. Historical data showed this target was never consistently achieved and plant efficiency was highly variable.Investigations into the possible causes for the variable performance ruled out plant and mechanical issues. Despite the Rosebery concentratorÆs age the plant and equipment are more than serviceable and reliable. The mineralogy of the ore and specifically the iron content of the sphalerite was found to be the most significant determinant of zinc concentrate grade. It was found with increasing frequency that the zinc grade of the sphalerite in the ore was below the zinc concentrate grade target. Consequently on these occasions attempts to meet the required concentrate target destabilised the process resulting in plant inefficiencies.Using the correlation between iron and zinc, data modelling was able to accurately predict the maximum zinc concentrate grade achievable for any ore type. By using on stream analysis instrumentation the operations personnel are now provided with constantly updated concentrate grade targets. By knowing the mineralogical limits of the ore at the time it is being treated process stability is maintained allowing plant efficiency to be optimised. This has resulted in a step change in plant performance and a significant increase in revenue.CITATION:Harris, G R, 2012. Developing and implementing ore-specific targets for the Rosebery Concentrator, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 321-324 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

The 1980's has seen a revolution in gold mine developments in Australasia. We are witnessing a near ten fold increase in all phases of gold mine development ranging from exploration through to production. Ounces produced have yet to mirror this activity but have increased from a low point of 600,000 in 1980 to 1,800,000 ounces in 1985 in Australia alone. In 1980 the region had less than 10 gold mines, yet 14 new mines started production in 1985 and as many as 28 might start up in the next 18 months. Developing gold mines in the 1980's in Australasia has not been the easiest of jobs, yet the great number of new developments suggest that we have entered a new era that will rank in history along with the 1850's, 1890's and 1930's as high points.Within- our Australasian region two very distinctive styles of gold deposits are being discovered and developed. On the Australian mainland the new mines are in geologically old rocks and are mostly the low grade haloes surrounding worked out high grade deposits. Most are limited life open pit operations depending on recent innovative carbon-in-pulp or heap leach technology. In the Pacific Islands region the style of discoveries are geologically recent, large bulk-low-grade deposits often geologically analogous to porphyry copper deposits. These deposits are typically 10 to 20 times larger than those being proved up on the Australian mainland.

Jan 1, 1986

By Sevket Acar, Tim Acton

"Zarafshan/Newmont is a 50/25/25 joint venture between Newmont Gold and the State Committee for Geology and Mineral Resources, and Navoi Mining and Metallurgical Combinat, two entities of the Republic of Uzbekistan. The Zarafshan/Newmont joint venture consists of a heap leaching operation which will process 220 million metric tonnes of existing low-grade oxide ore stockpiles (averaging 0.036 oz Au/t) from the Muruntau mine. Net recovery over the 17-year life of the project is expected to be 4.8 million ounces of gold.The plant construction started in October 1993 and operations commenced on May 25, 1995. The crushing plant consists of four stages of crushing and screening to produce a 95% passing 3.35 mm product, followed by heap leaching and gold recovery by the Merrill-Crowe process. The dore metal is refined at the Muruntau refinery. All gold produced by the joint venture is sold on the world market. IntroductionThe Muruntau mine and nearby town of Zarafshan are located in the center of the Kyzylkum desert, 250 miles west of Tashkent, capital of Uzbekistan. Following a mining conference in Moscow in 1990, a Newmont geologist was among the first team of westerners to visit the Muruntau Mine, the second largest gold producer in the former Soviet Union. At Muruntau, they found 220 million tonnes of low grade gold ore that had been stockpiled during the previous 25 years. In February, 1992, six months after Uzbekistan's independence, Newmont signed a 50/50 joint venture agreement with the Uzbek government to use heap leach technology to process the ore. The feasibility study was completed in November of 1992. Plant construction started in October, 1993 and operations commenced on May 25, 1995.Newmont Metallurgical Services performed metallurgical studies to obtain heap leach process design criteria parameters. The initial metallurgical study on 20 grab samples is the subject of this paper."

Jan 1, 1997

By Rob Farnfield, Ben Williams, Bob Woolley

This paper outlines how drilling safety standards are being driven forward in the United Kingdom’s surface mining and quarrying industry with developments in equipment, procedures and competence.

Jan 1, 2010

By G Anderson, V Lawson, P Voigt

Glencore operates zinc concentrators at both Mount Isa and McArthur River. Both orebodies have a history of complexity and required the development of new technologies to maximise the value from these long-life assets. The Mount Isa orebodies were plagued since operations started in 1931 with complex mineral textures making separation challenging and many areas uneconomic. Examples are given in Figure 1 with different grain sizes from the same orebody in different areas. The McArthur River deposit, located in the Northern Territory, was discovered by Mount Isa Mines geologists in 1955 (Logan, Murray and Williams 1990). The extremely fine-grained nature of the ore was quickly recognised and the difficult separation of the minerals was soon obvious. The geographical, metallurgical and economic factors resulted in the orebody not being developed until the technologies for the mineral separation had been developed. The development of the IsaMill allowed for an economic mineral separation flowsheet to be developed and ore treatment commenced in May 1995 (Nihill, Stewart and Bowen 1998). CITATION: Lawson, V, Anderson, G and Voigt, P, 2018. Developing technologies for a complex orebody, in Proceedings Complex Orebodies Conference 2018, pp 116–118 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By Robert Horwood, Richard Harvey

The copper stave was a development of the Blast Furnace cooling system intended to utilise the high heat transfer properties of copper within a fully covered shell cooling solution. They were originally conceived as being able to provide a permanent cooling lining for use primarily in the higher heat zones of the Blast Furnace. Despite a large number of campaign successes around the world the everlasting concept has not proven universal, with some plants having suffered issues in two particular areas: stave bending (leading to water leaks at back of the stave) and stave wear (erosion on the hot face). Primetals Technologies have in the past been approached to provide assistance to a number of Blast Furnace operators who were experiencing operational issues with the copper stave furnace cooling systems of others. Through knowledge gained resolving these issues, and with the positive experiences of their own copper stave designs, Primetals Technologies have worked towards developing a new concept in copper stave design capable of providing a more robust solution to cope with the greater productivities of modern ironmaking. This paper will provide an outline to the concepts that have driven the design of this new technology.

Oct 1, 2019

By D Kent, R Paine

"Automated mining systems are increasingly being seen as a key requirement for a productive mining operation in the future. The importance of an integrated communication network infrastructure to support such systems is growing.This paper outlines the introduction of automated mining systems in large conventional mines as well as their growing role in block cave mines currently operating or being developed. The paper will then focus on a case study of how the communication infrastructure is fundamental to the operation of such systems and explain why the resultant communication networks require much more than just increased bandwidth (data capacity) to properly support the automation system within the overall mine operation.Mining operations already embarking down this road are discovering that the required network must be based on a true enterprise level architecture to not only enable the mine’s current plans for remote and automated mining, but also provide a scalable and integrated platform for future developments and requirements. The emerging issues for the communication network to truly support automation systems include: increased complexities of operating and maintaining multiple networks integration issues with disparate systems problems with reporting particularly as demands for corporate reporting and compatibility with enterprise systems become the norm ongoing management challenges, which will only increase with the proliferation of new technologies.The paper will explore how certain mining operations are addressing this by adopting a long-term strategy for automation deployment, which includes laying the necessary foundation architecture to meet their current requirements, while supporting their future visions for the fully automated mine.CITATION:Paine, R and Kent, D, 2014. Developing the foundation communication infrastructure to support remote and automated mining initiatives in underground mines, in Proceedings 12th AusIMM Underground Operators’ Conference 2014, pp 151–158 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 24, 2014

By J. C. Beidelman

One of the oldest settled portions of Canada is that "strip of land" extending into the Gulf of St. Lawrence, known as the Gaspe peninsula, with the Bay of Chaleur on its southern boundary. This "strip of land" is still so very sparcely populated that only at a few places does settlement extend more than a few miles from the coast. ? The peninsula is 160 miles long, 75 miles wide and with the exception of the above mentioned settlements is a mountainous wildness-void of all roads or inhabitants. Developments in the interior, of all nature, out-side of the cutting of timber by limit holders, was entirely lacking until the year 1915, when mining was first commenced. In the summer of 1844 Sir William Logan made a preliminary survey across the peninsula, from Cape Chat on the Gulf of St. Lawrence to Cascapedia on the Bay of Chaleur, passing through a country ?of which very little was known at that time. After a rather rough trip to the headwaters of the Grand Cascapedia river, Logan's party descended this river to its mouth, passing ten miles west of what is now known as the Federal mines. There is no record of Logan, or of any of his party, finding zinc or lead ores of any character on their journey across the peninsula, and until 1909 no precious or base metals were discovered within reasonable distance of Logan's survey.

Jan 1, 1924

By A. Allaire, J. Torrealba-Vargas, R. Welyhorsky

Early testwork was carried out to select the plant process design criteria and flowsheet selection. Additional testwork was carried out during the feasibility study to support the optimization of the plant design criteria. The test results showed that the recovery of gold was not very sensitive to grind size in the range of 75 to 105 microns. An additional result was that the presence of lead nitrate did not improve the kinetics of gold leaching. This conclusion was supported by the low content of sulphides in the ore. It was also found that the presence of lead nitrate increased copper dissolution, producing the potential for an increase of copper reporting to electrowinning, which is detrimental to the overall gold recovery process. The use of oxygen in leaching was investigated to increase leach kinetics. The results of leaching tests to compare using oxygen instead of air indicated that, due to the improved leach time, it was possible to reduce the number of leaching tanks from twenty four (24) to twenty (20).

Jan 1, 2011