Search Documents

By T. J. DeMull

AMAX's Sleeper Mine uses conventional cyanidation milling and heap leaching techniques to produce gold. Since milling operations commenced in March 1986, average ore processing rates have improved from the design rate of 455 tonnes per day to more than 720 tonnes per day. Heap leaching was added to the process facilities in September 1986 at a design rate of 1,500 tonnes per day, and current heap leaching rates exceed 2,680 tonnes per day. Presented are descriptions of the Sleeper processing facilities with emphasis on the crushing and grinding circuits, a review of the selection of crushing and grinding equipment, and a summary of operating performance during the first 16 months of operations.

Jan 1, 1988

By Dieter Wanner

Off-gas cleaning from metallurgical? plants, requires in many cases very low dust contents which are, difficult to achieve with conventional scrubbers, even with high energy input. Lurgi has developed a scrubber which improves the separation of the fine dust by electrical charge prior to the scrubbing zone,, An Electrostatic Scrubber has been successfully installed for the off-gas cleaning from slag granulation after a waelz kiln achieving less than l mg/m3 in the clean gas.

Jan 1, 1992

By Tatsuki Uzawa, Takashi Nagai

The consumption of Nd and Dy is increasing dramatically because of an exceptionally high demand for Nd-Fe-B-(Dy) magnets and a significant amount of the magnets are wasted. It is important to develop a recycle process the elements from the wasted magnets. In this study, Nd and Dy were extracted from the magnets by silver at high temperature. Nd can be extracted more than 70 % by silver. However, Dy is extracted only 25 % in the same experimental condition.

Jan 1, 2014

By Hassan El-Shall

Treatment of plant effluent including waste water and associated soluble and insoluble substances, is of a primary concern of many process industries including mineral processing operations. The major objective of such treatment is the removal of such impurities which can interfere with the process through the use of recycled water, and/or to comply with environmental ordinances. For example, Ramirez and Clements (1978) state that molybdenum contents in the range of 19 mg/1 eventually poison ion exchange resigns used for the extraction of uranium. In addition, recent restrictions by the EPA on molybdenum discharge values for mining waste water necessitate removal of this metal to (0.5-1.0 mg/1).

Jan 1, 1984

By Daniel Saramak, Agnieszka Saramak

A big issue in crushing and grinding operations in raw materials handling is high energy consumption and low breakage effectiveness. According to the Legendre [7], only 10% of energy input is directly consumed on the feed material breakage, while the remaining portion is dissipated in the form of heat and noise [8]. In the industry of limestone powder production, the grinding operations constitute integral part of technological circuits, and the energy consumption in operations of industrial comminution consume as high as 2% of world energy [14]. High-pressure grinding is the technology with proved energy benefits both in ore processing circuits and in limestone grinding. The promising results concerned mostly the achieved energy savings and good results of material breakage were achieved and demonstrated in numerous investigations [1,3,12]. However, it appears that a proper selection of operational parameters of the press devise, determination the feed material characteristics and adjustment of process course san be of a key-significance in improving an effectiveness the HPGR operation. Operational parameters of devices and process course should be verified towards the characteristics of the feed material, which mainly applies to the particle size and shape of the feed material and its moisture, and also mineralization in case of ores [2,4,9]. There are various investigations concerning an impact of the operational pressing force on comminution results which mostly refer to the determination of energy consumption and crushing ratio [5,6,10,13]. Investigations on the moisture content are less common, however their results suggest that, in general, the HPGR feed with higher moisture shows the tendency to higher comminution intensity, while the energy consumption increases together with increasing of feed material moisture. Investigations on olivine sand feed [11] showed that crushing ratio decreases for higher moisture, especially when the material is crushed at higher pressing force. HPGR devices, however, shouldn’t be regarded as a unique and perfect solution for comminution of each type of material. But they indeed may bring technological and economic benefits, comparing to conventional crushing and grinding machines, resulting in more favourable breakage of material particles and lower consumption of energy per unit mass of processed feed material.

Feb 1, 2025

By A. Griffiths

The? use of hydrogen peroxide to detoxify gold mill waste waters containing cyanide and other toxic substances is already an established technology. Recent advances have extended the range of application of hydrogen peroxide treatment to include the removal of complex iron cyanides, the simultaneous removal of cyanide and toxic metals down to very low levels and treatment of barren bleeds, CIP' pulps and tailings pond discharges. Three treatment plants are described here. Each was installed at a gold mine in North America in 1987 and each illustrates a different application of hydrogen peroxide. The need for individual design of the detoxification plant to fit particular requirements is shown by the examples chosen.

Jan 1, 1988

By Carlos Lam, Joram M. Amir, Erez I. Amir

"Abstract The modulus of elasticity of pile material (E) is an important parameter for the interpretation of both static and dynamic loading tests on piles. This value is commonly assumed to be constant with depth though it may not be true for deep bored piles due to the chosen casting method and/or selfweight consolidation. To provide evidence to support this proposition, the results of compressive strength tests on core samples taken from four different studies have been presented. The results show a marked increase in the strength and stiffness values with depth. The results of crosshole ultrasonic tests conducted at another site also confirm the same pattern. It is therefore recommended that before load testing a pile the distribution of the E values along the pile axis should be investigated. This will ensure the use of a realistic elastic modulus value and hence the correct interpretation of thedistribution between the shaft and end resistances.IntroductionThe modulus of elasticity of pile material (E) is an important parameter for the interpretation of both static and dynamic load tests on piles. Multiplying E by the strain measured by either strain gauges (e.g. ASTM D4945) or tell-tales (e.g. Geffen and Amir, 1971) gives the stresses acting at a given pile section. Typically, in the absence of better information, the value of E is derived from laboratory tests on concrete cubes or cylinder specimens taken on site and is assumed to be constant along the pile. While this may be correct for pre-fabricated concrete piles that are cast in horizontal molds, it may not be true for cast-in-place piles that are produced in the vertical position.There are at least two factors that may contribute to the change in concrete properties with depth in a bored pile. First, the casting methods may be by free fall in dry holes (e.g. Kiefer and Baker, 1994) or by using a tremie tube if support fluids are used. In the former case, the earlier batches reach the bottom of the pile bore at a higher velocity and are thus compacted under higher energy. Second, regardless of the casting method, the fresh concrete in the pile bore will always consolidate at least partially under its own self weight. The materials in the lower parts of the pile will therefore experience a higher consolidating pressure. This can reduce the pore volume and the water content in the wet concrete, thus changing the properties of the hardened concrete. Recent research by Justs et al. (2011) has shown that even a relatively small pressure can have a significant positive effect on concrete properties such as compressive strength and stiffness. However, the possible change of concrete properties with depth is commonly ignored by foundation engineers in the current design practice."

Jan 1, 2014

By Yijia Dong, Mingjun Rao, Pengxu Cao, Jun Luo, Guanghui Li, Zhiwei Peng

Coal fly ash (CFA), as a by-product generated from coal fired power stations, is widely used for autoclaved concrete block production. It has been found that the generation of tobermorite is great benefit to the block strength during autoclaving. In this study, the tobermorite fibers synthesized from CFA and lime via the hydrothermal process are used as the revulsive to promote the mechanic strength of the concrete blocks. The results show that tobermorite fibers with 0.01–0.5 lm in diameter and 1–3 lm in length are obtained at 200 °C for 0.2 h. As the addition of prepared tobermorite fibers increases from 0 wt% to 2.0 wt%, the compression strength of concrete block increases from 24.6 to 40.5 MPa, and the compression strength of aerated concrete block produced under the optimized conditions can reach above 7.5 MPa.

Mar 1, 2018

By H. I. Meyer

The mine is a large open-pit copper mine located near Tucson, AZ. Mining operations involve shovels digging at relatively fixed locations and haul trucks moving the muck to a primary ore crusher, a primary waste crusher, and directly to waste dumps. The total investment in shovels and trucks is some $100 million. Fig. l is a schematic drawing of the operation. A static method of truck assignment is used; i.e., each driver is given one particular shovel to serve until reassigned by the dispatcher. A dynamic system is one where trucks are reassigned after each trip. The problem is to compute a near optimum assignment of trucks for efficient operation.

Jan 1, 1979

By M Hassall

There is a plethora of activities that have been, and continue to be, performed to improve the health, safety and well-being of workers involved in resource industry activities. These activities include implementation of risk management systems, performing risk assessments, constructing bow-ties, implementing critical control management systems, undertaking personal, process and functional safety initiatives, implementing psychological and physical health as well as industrial hygiene programs. Despite the significant work that has occurred over the last several decades, unacceptable levels of fatalities, injuries and illnesses continue to persist as evidenced by Safe Work Australia statistics.

Apr 16, 2024

By Chris Breeds, Ken Johnston, Omar Fulton

This paper describes the process typically involved with obtaining permits for quarry blasting in urban, suburban, and rural areas, including: content of SEPA (State Environmental Policy Act) driven documentation; regulatory review and comment; public interaction; public hearing(s); periodic regulatory review(s); negotiated solutions; monitoring; and the role of public interaction, demonstration(s), and education in the process. Case studies will be presented of projects undertaken in the State of Washington that illustrate the approach and regulatory interaction as well as the importance of public interaction throughout the process. Reference will be made to the role of national and state regulations and local codes and ordinances that provide additional limitations on blasting practice. The paper will also present regional blast monitoring data that are used in the permitting process and the layout and design of blast monitoring systems typically required as conditions of the quarrying permit. Our presentation will include tools, which we have developed to assist with explaining blast related phenomenon to both regulators and the public.

Jan 1, 2003

By G. T. Daware, M. J. Chaddha, S. P. Masurkar, P. G. Bhukte, A. Agnihotri

JNARDDC has evaluated bauxite deposits of India from the geo-technological point of view. During the evaluation studies, it was observed that bauxite deposits are associated with saprolite resources. During bauxite mining, various low-grade materials such as saprolite, laterite and low-grade bauxite are generated. These materials typically have low-alumina, high-iron oxide and high-silica content. Owing to their inferior quality, these materials cannot be used for alumina production and hence remain unutilized at the mine site. For the present study, the saprolite samples were collected from the Western Ghats bauxite deposits in India. The sintering studies were conducted on saprolite granules using a variety of parameters. The sintered granules were characterized, and their properties determined. The test results showed that bulk density, apparent density, porosity and refractoriness (PCE 1645–1659 °C) of the aggregates were within the range of refractory specifications. The feasibility tests carried out at the refractory industry indicated that the developed aggregates are suitable as refractory material and can substitute for calcined clay. Currently, high-purity clay resources used in the refractory industry are limited and fast exhausting; therefore, the industry is likely to face an acute shortage of raw materials, which will become more critical in the future. Therefore the sintered granules (aggregates) developed from saprolite, which is a mining waste, provide a low-cost, eco-friendly solution for the fast-exhausting resources of the high-purity clays. The developed process may change the Indian bauxite mining scenario because saprolite may substitute as a potential raw material for the refractory industry.

Apr 12, 2021

By M. Harrison, C. H. Stockwell

"Metals vah1ed at more than $200,000,000 have been obtained, mainly since 1930, from the mines of northern Manitoba. The greater part of this production has been copper, zinc, and gold from the Flin Flon, Sherritt Gordon, and Mandy mines. The chief mines from which gold alone has been produced are God's Lake, Laguna, and Gurney. At present (May 1947) Flin Flon and Sherritt Gordon are the only producing mines, but the Nor-Acme property is being developed for large-scale production of gold. Large deposits of nickel and copper are being diamond drilled at Lynn Lake, and the Thompson, Ferro, and other properties are being developed. The mineral deposits lie within irregular or elongated areas of Precambrian sedimentary and volcanic rocks, surrounded by granite ( Fig. 1).The common rock types include basic and acidic flows, agglomerate, ruff, greywacke, arkose, argilli te, conglomerate, and their gneissoid and schistose derivatives. They are invaded by sills, dykes, and irregular bodies of gabbro and diorite, and all are cut by granite. Some of the sediments are interstratified with volcanics, and others are deposited unconformably on them.STRUCTURAL GEOLOGYLittle is known of the structures of the rocks in the area as a whole, because by far the greater part is unexplored or has been covered only by reconnaissance surveys. Available information indicates a general east structural trend in the southeast part, whereas in the west part the folding is mote complex with no definite overall trend. However, in a few small areas in the western part where detailed work has been done, as around the Flin Flon, Sherritt-Gordon, Nor-Acme, and other properties, the structure is fairly well known. The following descriptions apply chiefly to these areas ."

Jan 1, 1954

By G. Avramovic-Cingara, H. J. McQueen

The microstructure of commercially pure aluminum was investigated by using polarized optical microscopy (POM), orientation imaging microscopy (OIM), and transmission electron microscopy (TEM) techniques. Specimens were deformed in torsion at 400°C and equivalent strain rate of 0.1 s-1, to various strains of 0.2, 0.5, 1, 4, and 6. The results indicate that POM can usefully reveal grain and subgrain structures over a large field in aluminum. TEM is most suitable to study dislocation substructure and evolution of subgrains. While TEM microscopy and OIM are capable of resolving individual subgrains, OIM can not reliably distinguish subgrains with small misorientations, particularly in samples with low strain. On the other hand, the OIM technique is very useful in the analysis of many regions surrounded by high, medium, and low angle boundaries (HAB, MAB, LAB). Various misorientation maps were studied using different data processing methods. The analysis revealed that the subgrain size is relatively insensitive to strain. The fraction of low LAB ( < 5°) decreased and HAB (>15°) increased conversely with increasing strain, whereas MAB (5-15°) remained stable. The development of an increasingly bimodal grain boundary misorientation distribution is consistent with the predominance of dynamic recovery (DRV) in the evolution of microstructure, combined with geometrical dynamic recrystallization (gDRX), now called grain-refining DRV.

Jan 1, 2006

By William Gleason

The mining industry is under immense pressure to not only meet increasing demand for minerals, but to do so in an environmentally safe and sustainable manner. Growth in electric vehicles, battery storage, renewable energy infrastructure and data centers to power artificial intelligence (AI) has led to an unprecedented demand for minerals such as copper, lithium, rare earth elements and others. The need for these minerals for national defense has only increased the pressure on the mining industry. Increased geopolitical tensions between the United States, China and Russia has added a sense of urgency as supply chains have become a focal point for the U.S. Department of Energy (DOE) and Defense (DOD) and other government agencies. The International Energy Agency (IEA) predicts that copper demand is expected to grow by 50 percent by 2040 while demand for lithium could increase eight-fold by 2040 and demand for nickel and cobalt could double. The challenges to meet the increased demand include technological, workforce, exploration and environmental issues. From Feb. 22-26, the global mining industry will converge on Salt Lake City, UT for the MINEXCHANGE 2026 SME Annual Conference & Expo where these challenges and others will be addressed by some of the leading minds in the industry. Included in this year’s conference is the Resilient Energy in Mining Symposium, a symposium with input from across SME that looks to address some of the most significant challenges the industry is facing. “Adopting environmental, social and governance (ESG) best practices has become a necessity for the mining industry, not an option. The Resilient Energy in Mining Symposium is crucial for MINEXCHANGE 2026 because it addresses the complex challenges of transforming traditional mining operations to support a sustainable and secure energy future,” Lisa Gonzales, principal engineering at Arcadias and MINEXCHANGE 2026 SME Annual Conference Chair and chair of the Resilient Energy in Mining Symposium said. “Mining is inherently energy-intensive, yet it is also foundational to the global energy transition, supplying the critical minerals needed for renewable technologies. By bringing together industry leaders, the symposium fosters collaboration and actionable change, showcasing advancements and real-world solutions that demonstrate the tangible benefits of resilient energy strategies. This unique forum enables knowledge sharing, inspires innovative thinking, and helps set the standard for sustainable practices across the sector.” The symposium was created in direct response to a SME member survey in 2023 conducted by the Responsible Mining and Underground Construction (RMUC) Strategic Committee. “The survey highlighted a strong demand for technical resources on energy transition, carbon reduction, renewable power, climate change, and ESG reporting,” Gonzales said. “To address this, I collaborated with RMUC to engage committee members from all SME Divisions, ensuring a diverse and comprehensive platform that reflects every aspect of mining. We intentionally structured the symposium to centralize key content and minimize duplication across divisions.”

Jan 1, 2026

By S. F. Kaplan, A. S. Dolotov, V. N. Kovalev

"The proportion of refractory sulphide ores and concentrates in world gold mining industry is growing every year. Pressure oxidation of these materials (in autoclave) allows to oxidize gold hosting minerals. Traces of halides and pseudohalides present in the slurry liquids contribute to formation of complex gold compounds. Sorption-active carbon present in ores leads to irreversible adsorption of complex gold compounds and their loss. The objective of the research is to study gold extraction dependence on the concentration of chloride-, cyanide- and thiocyanate-ions in the slurry liquids during pressure oxidation. Double refractory flotation concentrate of the Bakyrchik deposit was used for the testwork. The research was planned on the basis of a full factorial experimental design with additional refining experiments. Ligand concentrations (0 – 1000 mg/l Cl-, 0 – 600 mg/l CN-, 0 – 1200 mg/l of SCN-), temperature (200 – 240 °?) and retention time (1 – 6 h) were used as variables of pressure oxidation process. It was determined that sulfide minerals oxidize much faster than ""organic"" carbon. Under the conditions of T = 240 ?C, t = 2 h, sulphide sulfur oxidation was 95.6%, while ""organic"" carbon oxidation was 46.1 %. Each of the examined ligands has a significant adverse impact on gold extraction. Analysis of the experimental data demonstrated that with a high degree of confidence (R2 = 0.883) gold extraction does not depend on the ligand type, but only on its concentration and the ""organic"" carbon oxidation degree. In case of complete oxidation of ""organic"" carbon, the presence of the ligand (L = Cl-, CNS-, CN-) in the liquids at a concentration of up to 20 millimole/L does not significantly affect gold extraction. The assumption that the main factor of preg-robbing in ???-CIL treatment of double refractory concentrates is the natural ""organic"" carbon sorption-active to gold has been confirmed. INTRODUCTION In recent decades, placer gold mining has been gradually declining and hardrock gold mining, including ""refractory"" gold mining, has been growing all over the world, as well as in the Russian Federation (http://www.miningworld.ru, 2015). One of the main reasons why gold ores are refractory is gold adsorption on natural carbonaceous materials (""organic carbon""). Only a few technologies are suitable for processing such ore concentrates (a significant amount of gold is contained in refractory hardrock ore both in Russia and worldwide) (Vorob'yev-Desyatovskiy N.V., Yepifanov A.V., 2014)."

Jan 1, 2018

By Mahmut Yavuz

to in Old Uighur Turkish as Tolay kopugu, in Ottoman Turkish as Derya kopugu, and in modern Turkish as Luletasi. Scientifically known as sepiolite, it is represented by the formula Si12Mg8O30(OH)4(H2O)4(8H2O). Sepiolite is a natural clay mineral composed of hydrous magnesium silicate, characterized by a structure of alternating blocks and tunnels that develop in the direction of the fiber. Each structural block contains two silica tetrahedral sheets surrounding a central layer of magnesium oxide- hydroxide. Sepiolite exists in two distinct forms in nature: alpha-sepiolite and beta-sepiolite. Alpha- sepiolite is amorphous, compact, and resembles pellets that look like sea froth, hence its Turkish name Luletasi. In contrast, beta-sepiolite appears as amorphous aggregates or small, flat, round particles. These two forms exhibit different physical properties. Meerschaum was also studied by Brauner and Preisinger in 1958, who agreed that it primarily consists of sepiolite (2MgO·3SiO2·nH2O). According to these researchers, water is present in its mineral, zeolitic, crystal, and structural forms. Meerschaum is commonly used for adsorbing various liquids, as an ion exchanger, and for dispersing and insulating paraffin in the chemical industry (Gokdemir and Dogan, 2011). Sepiolite deposits of the meerschaum type are primarily found in Turkey, Somalia, Tanzania, Kenya, and Mexico. Alongside high-quality, low-density, and highly porous meerschaum, Somalia also has sedimentary sepiolite formations. The total reserves of these deposits are estimated at around 50–100 million tons (Sariiz and Isik, 1995). Meerschaum, also known as “white gold” or “sepiolite,” is a unique mineral highly prized for its lightness, heat- resistant properties, and ability to be carved into intricate designs. Found predominantly in Eskisehir, Turkiye, meerschaum mining and processing have become significant contributors to the local economy and cultural heritage. This paper explores the history, economic importance, mining practices, and environmental impacts of meerschaum mining in Eskisehir and discusses the challenges and opportunities faced by the industry.

Feb 1, 2025

By J. Paul

Mining engineers in charge of open pit mine planning very often face decision making situations dealing with the selection of the most economical method for the removal of overburden. Ripping versus conventional drilling and blasting are the options considered. The choice of a particular overburden removal method depends upon the physic-mechanical properties of the overburden material as well as the various cost factors involved in the process. The analysis of techno-economical factors involved in different methods of overburden removal needs detailed study and investigation by a technical expert. But the expert system "Fragmentation System Design" has been created in a way such that it will help and expedite the decision making process relating to overburden removal in surface mines. Furthermore, this expert system can be used for detailed design aspects of overburden removal in open pit mines.

Jan 1, 1988

By M Fritz, B Ziegelaar

"For moisture samples, the International Standard for iron ore sampling states the following: Moisture samples shall be processed as soon as possible and test portions weighed immediately. If this is not possible, samples shall be stored in non-absorbent airtight containers with a minimum of free air space to minimise any change in moisture content, but should be prepared without delay. ISO 3082 (2009)Prescribing what to do is of course easy. Putting it in practice is, however, a little more problematic.The iron ore industry has seen quite some changes in the last ten to 15 years, such as: a large increase in the volume of seaborne trade new ore types and blends coming onto the market new mines, processing plants and port facilities producing more and loading faster an increase in wet processed ore products a dramatic rise and then equally dramatic fall in the iron ore price followed by a recent recovery.All of the above have had an effect on sampling facilities. The large increase in volume coupled with ambitions such as labour efficiency, safer operations and higher precision has driven the installation and retrofitting of automated sampling and robotic sampling preparation plants in order to keep up with increased quality control.Designers of sampling facilities are invariably instructed to build plants that comply with ISO 3082. In general this means that the plants are compliant in respect of the number of primary increments, gross sample masses and sample division rules. The clause at the beginning of this abstract is mostly overlooked as it only appears in a section (4.1) describing the basic requirements of a sampling system.An error of 0.1 per cent in moisture changes the value of 1 Mt of iron ore at US$50/t by US$50 000. At 700 Mt/a of Australian iron ore exports, this is US$35 M. Frequently, errors from 0.5 to 1 per cent in moisture measurements are encountered.In comparison an error of 0.1 per cent Fe is US$0.081 (US$50/t and 62 per cent Fe base) per tonne, that is US$81 000 per Mt or about US$51 M for the same Australian annual iron ore exports.It is somewhat mystifying that we in the ISO Technical committees spend extraordinary energy (= money and time) on improving measurement techniques, whilst the big costs are in sampling errors. This is particularly true for moisture measurement. Our paper quantifies some of the sources of moisture measurements errors and suggests mitigating actions.CITATION:Ziegelaar, B and Fritz, M, 2017. Sampling for the percentage moisture in the iron ore industry, in Proceedings Eighth World Conference on Sampling and Blending, pp 271–274 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

May 9, 2017

By N. Chow

The recovery of manganese from lower grade resources has been studied for a number of years. Of key importance of prior work, was the discovery that higher valent manganese resource can be readily leached with sulfurous acid. This eliminates the need for high temperature reduction roasting that is conventionally used in processing high grade material. High temperature roasting is energy intensive, emits a large amount of carbon dioxide, and would not be economical for processing lower grade material. While the prior work provides important information to extract manganese from lower grade resources, the production of unwanted by-products, and high water and energy usage has limited its commercial use. This paper describes the results from laboratory work that demonstrate solutions to problems, which to this point preclude commercial development. Preliminary mass and energy balances show that a significant opportunity exists in producing manganese with this hydrometallurgical scheme in a low cost, environmentally friendly manner. Emphasis of the work is on low water use, low overall energy use and economic destruction of unwanted by-products.

Jan 1, 2011