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By P. G. Hallof

Only recently has the term Induced Polarization found its way into geophysical literature. Schlumberger first mentioned the possible use of the induced polarization effect in one of his early papers. Later, induced polarization was the subject of several university theses, such as Seigel's at the University of Toronto and Bliel's at the Michigan School of Technology. In addition, a group at the New Mexico School of Mining and Technobgy has done work on induced polarization. There is very little to be found in print on the subject of induced polarization. Several papers have been presented at meetings, the 1958 AIME and SEG* conventions, for instance, on laboratory measurements of the effect and theoretical considerations useful in the interpretation of field results. This paper is the first attempt to present actual field results which show the usefulness of induced polarization as a prospecting technique. There are several phenomena that can cause polarization when electrical current is passed through the ground. In a paper presented at the 1958 SEG* meetings Professor T. R. Madden of M. I. T. demonstrated that only two of these gave rise to appreciable effects. The first is a result of the membrane and diffusion effects in a sandstone that contains appre- ciable amounts of clay minerals. The unbonded charges associated with the clay mineral forma material that passes positive and negative ions with different mobilities. When current is passed through such a system for some period of time, polarization results. The second phenomenon, which gives rise to very much larger polarization effects, is the one used in the new prospecting technique. These effects are a result of the blocking action or polarization of metallic or electronic conductors in a medium of ionic solution conduction. This electrochemical polarization, called "the over-voltage effect" by electro-chemists, occurs whenever electrical current is passed through a volume of rock which contains metallic minerals such as base metal sulphides. This polarization at metallic interfaces in ionic solutions depends upon the chemical energies necessary to allow the ions to continue the flow of current by giving up or receiving an electron from the metallic surfaces. The energy stored in this reaction isanalogous to that stored when a condenser is charged. If a d. c. current flowing through such a system is interrupted, the polarization can be detected as a small, decaying current that flows after the applied current is discontinued. The decaying potential measured is a result of the current flow caused by charges returning to their equilibrium positions from the positions they assumed under the applied potential field. Because of the polarization, there is an excess of change at each metallic interface. There is an alternate method of measurement of the induced polarization effect. The electrical

Jan 1, 1961

By Donggen Fang, Liu Xuan, Jilai Xue

SiO2 and Al2O3 in the metallurgical slag of nickel laterite ore have great recycling values. In this work, Si and Al were extracted from the slag in NaOH based molten salts through alkali roasting and water leaching process for preparing zeolite materials. The extraction ratio of SiO2 increases with increased temperature and appropriately prolonged time, and more than 80% SiO2 can be recycled from the slag after roasting at 550°C. Si and Al from the slag are in the filtered liquor for producing zeolite materials, while Mg, Ca, Fe and other impurities remain in the leached residues. Adding Na2CO3 into the alkalin-slag roasting process can reduce the amount of pure NaOH used with minor decrease in extraction ratio of SiO2, while make better separation of Ca to avoid it getting into the filtered liquor. Adding Al2O3 into the alkalin roasting process can replace part of more expensive NaAlO2 addition that is required for preparing zeotite material, which may bring out a minor decrease in extraction ratio of SiO2 due to formation of NaAlSiO 4 in the filtered residues. Quality X zeolite and 4A zeolite materials can be made from the starting liquor containing Si and Al recycled from the laterite nickel slag through alkali roasting and water leaching process.

Mar 1, 2018

By Ian Selby

Recent offshore diamond exploration has been concentrated in the SW Joseph Bonaparte Gulf. I`IW Australia. Extensive high resolution seismic and sampling surveys have been carried out in Cambridge Gulf, offshore of the mouth of the OR River and other rivers of the region. Surface-tow boomer surveys have been correlated with sampling data from vibracores and a wide diameter (1m) airlift system, providing a geological framework for the area. Although large-scale bulk sampling has not been undertaken, there has been no reported recovery of diamonds since 1993. The geology and prospectivity of a range of potential diamond traps in high energy, fluvial and transgressive depositional settings has been assessed. Potentially diamondiferous targets include (i) a shoreline apron. (ii) fluvial/estuarine channel infills and terraces and (iii) ravinement surfaces.. Although there is evidence for a long history of fluvial development and sea level changes, the majority of the investigated traps represent the result of erosion and sedimentation during and following the last interglacial. Significant volumes of unconsolidated gravels and coarse-grained sands with occasional indurated layers are present, and are locally exposed at sea beet In place s thick successions (>5m) of fine-grained overburden overlie the coarse-grained sediments.

Jan 1, 1998

By M. McClintock

"High Pressure Grinding Rolls (HPGR) is increasingly being chosen for comminution circuits for its energy-efficiency for hard rock mining operations. Despite HPGR’s growing popularity, geo-metallurgy programs are still prohibitively expensive because of large sample requirements. Traditionally, sizing HPGR application requires a significant amount of sample, in the order of 1 to 10 tonnes, depending on the level of study and complexity of the resource. Therefore, engineering and design of HPGR circuits typically are reliant on few composites that are required to be representative of the resource and mine plan. Three bench scale HPGR test methodologies were developed in 2015 at NBK Institute of Mining Engineering at the University of British Columbia (UBC) capable of defining the energy size breakage relationship of pilot HPGR. These methodologies were developed to allow bench scale testing for different levels of study from PEA (Preliminary Economic Assessment) to detailed design and operations. The Piston Press test defines the energy size reduction relationship by measuring specific energy consumption and corresponding feed and product size distributions. The advantage of Piston Press testing is the small sample requirement of 5 to 10 kg. Small sample requirements allow multiple samples to be tested across a deposit. Piston Press testing allows extensive geo-metallurgy programs that can determine ore variability and inform in optimization and production planning. To date, the Piston Press methodologies have been validated on a pilot-scale HPGR unit located at UBC. Recently, testing was conducted to calibrate and validate the Piston Press test against full-scale HPGR on a gold sulphide ore deposit. The program included the collection of operational data with the respective HPGR feed and recycle sample. Sample collected was used both for Piston Press testing and HPGR piloting. This paper discusses the test-work and results as carried out during this program, using the aforementioned methodologies."

Jan 1, 2018

By Eric P. Bregman

As part of an on-going effort to improve water quality and reduce discharge into Boston Harbor, the Massachusetts Water Resources Authority (MWRA) East Boston Branch Sewer Relief Project was designed under a Federal mandate from the United States Environmental Protection Agency (EPA) to upgrade the aging sewer system, increase system storage and greatly reduce the volume of combined sewer overflows into the Harbor. The project scope of work includes the installation of over 2 miles (11,800 linear feet) of 36-inch and 66-inch diameter sewer relief piping, twenty (20) temporary shafts and an approximate 100 foot open cut section, located within the densely populated neighborhood of East Boston, Massachusetts. This area is a former marshland backfilled in the early to mid 1800?s where busy commercial streets co-mingle with thickly settled residential houses. The subsurface conditions present within Boston?s complex geology include the presence of subsurface contamination as well as complex networks of underground utilities. Additional site limitations included low headroom, noise, and traffic restrictions. Together these limitations required the design of individual earth support systems, tailored for each shaft location. Moreover, challenging subsurface conditions identified during construction required design modifications to minimize cost and schedule impacts related to construction dewatering, treatment of contaminated groundwater, internal bracing, and utility relocations. This paper provides a case history of the Geo-structural design and performance of various earth support techniques utilized to construct jacking and receiving shafts designed to launch and receive two (2) micro-tunnel boring machines (MTBM) and to support the construction of new deep shaft structures in an urban coastal area.

By Eric P. Bregman, Franklin M. Grynkewicz, John E. Regan

"As part of an on-going effort to improve water quality and reduce discharge into Boston Harbor, the Massachusetts Water Resources Authority (MWRA) East Boston Branch Sewer Relief Project was designed under a Federal mandate from the United States Environmental Protection Agency (EPA) to upgrade the aging sewer system, increase system storage and greatly reduce the volume of combined sewer overflows into the Harbor. The project scope of work includes the installation of over 2 miles (11,800 linear feet) of 36-inch and 66-inch diameter sewer relief piping, twenty (20) temporary shafts and an approximate 100 foot open cut section, located within the densely populated neighborhood of East Boston, Massachusetts. This area is a former marshland backfilled in the early to mid 1800’s where busy commercial streets co-mingle with thickly settled residential houses.The subsurface conditions present within Boston’s complex geology include the presence of subsurface contamination as well as complex networks of underground utilities. Additional site limitations included low headroom, noise, and traffic restrictions. Together these limitations required the design of individual earth support systems, tailored for each shaft location. Moreover, challenging subsurface conditions identified during construction required design modifications to minimize cost and schedule impacts related to construction dewatering, treatment of contaminated groundwater, internal bracing, and utility relocations.This paper provides a case history of the Geo-structural design and performance of various earth support techniques utilized to construct jacking and receiving shafts designed to launch and receive two (2) micro-tunnel boring machines (MTBM) and to support the construction of new deep shaft structures in an urban coastal area."

Jan 1, 2017

One of the most important factors leading to the success of a cement plant is its location. A multicriteria decision-making method is used to rank alternative plant locations. The set of criteria is established and corresponding criteria should be established for each case study, although this multicriteria decision-making approach has broader applicability. In this paper, the analytic hierarchy process (AHP) with 5 criteria is used to develop a location evaluation hierarchy for an alumina?cement plant in East Azerbaijan province of Iran. Five alternatives for the plant location are evaluated. The main criteria are transportation, water supply, power supply, fuel supply and land. Other criteria have the same importance as these five alternatives. The alternatives are ranked by a multicriteria method and the best site is proposed. Keywords: plant location; multicriteria decision-making

Jan 1, 2005

By Barton J. Suchomel

Introduction Despite perennial economic turbulence, Argentina continues to push ahead with efforts to develop its fledgling hardrock mining industry. The country lacks the infrastructure and mining history of neighboring Chile, but contains vast areas of great resource potential. The eastern slope of the Andean Cordillera in west-northwest Argentina is a relatively little-explored region offering geology highly conducive to the occurrence of base and precious metals deposits. Past exploration has concentrated on locating and evaluating porphyry copper-molybdenum (Cu-Mo) type occurrences. Comparatively little attention has been given to precious metals potential. An interesting and important group of base and precious metals prospects in northwestern Argentina occurs within and adjacent to the Upper Miocene Farallon Negro volcanic complex in Catamarca province. The volcanic complex contains numerous base and precious metals vein occurrences, high gold porphyry copper prospects, and possible disseminated gold targets that have attracted relatively minor attention in the past. Various geologic aspects of the region have been reported by several workers (Llambias, 1970, 1972; Caelles et al, 1971; and Sillitoe, 1973). Regional geology The Farallon Negro volcanic complex is located within the Sierras Pampeanas morphostructural province about 200 km (125 miles) east of the main Andean Cordillera (Fig. 1). The Sierras Pampeanas is characterized by north-south-trending basin and range topography that developed during the Miocene and Pliocene. Uplifted blocks are composed mainly of lower Paleozoic metasediments and granitoid plutonic rocks unconformably overlain by Tertiary redbeds and minor carbonates. A consistent landward migration of volcanic and intrusive ac¬tivity occurred in this region of the Andes from the early Mesozoic through the mid-Tertiary. An eastward extension of magmatism during the Miocene and Pliocene resulted in the formation of the Farallon Negro volcanic center. Volcanism at Farallon Negro ini-

Jan 8, 1988

By A. J. Lynch, L. Ergun, M. Oner

"A research program on modelling cement grinding circuits has been in operation at Hacettepe University, Ankara, for four years. It has concentrated so far on tube mill and air separator grinding circuits for cement clinker, with emphasis on plant sampling surveys, including axial sampling inside the tube mills. The methodology is to use plant data to build the models and to supplement this by laboratory data where necessary, for example the determination of breakage functions. The plant data come from comprehensive sampling surveys and so far 33 surveys of clinker grinding circuits have been carried out in 9 plants. The operating conditions have been• mill sizes – 3.2 to 4.8 metres diameter and 8.5 to 15 metres long,• mill feed rates – 46 to 158 tonnes per hour,• air flow through mills – 25000 to 125000 cubic metres per hour,• cement clinker work indexes – 10.3 to 18,• separator sizes – 2. to 3.1 metres diameter,• separator feed rates – 132 to 689 tonnes per hour,• separator speeds – 12.3 to 21 metres per second.The ball mill model is Whiten’s perfect mixing model and the separator model is the Tromp curve with a fish-hook. This paper emphasises on the importance of calculating the breakage rates and the discharge functions with three case studies at five different circuits which were selected for discussion because they show how particular features of circuit operation can be included in the general models. Size distributiongraphs are used to illustrate every aspect of the discussion.In case I the special emphasis on calculating the breakage rates and discharge rates separately is given in a high pressure grinding roll-ball mill-separator circuit. The tonnes of each size fraction in the mill and the calculated values of R/D, D and R are determined. The values of R per mw are also given to allow comparison with mills of other sizes. The circuit allows the comparison of the static type (V Sep) and dynamic type separators (SKS). Comparing the reduced efficiencies shows that the dynamic separator is slightly more efficient than the static one.In case 2 data are given from two compartment tube mills having the same diameter and the motor power but different ball size gradation. The breakage rate particle size variation of the second chamber of two mills indicate that having finer ball size distribution causes higher breakage rate values."

Jan 1, 2003

By J. Bouchard, A. Desbiens, M. Maldonado, R. del Villar

ABSTRACT: Despite many years of practical applications in mineral processing plants, the potential of column flotation has still not been fully exploited. The challenge in measuring some key variables is certainly an important contributing factor to this situation. Reliable online measurement of varibles, such as the froth depth, bias, gas hold-up, frother concentration, bubble surface area flux, and bubble size distribution, provides opportunities for the application of various advanced control strategies and real-time optimization based on an economic criterion. For several years, Université Laval’sLaboratoire d’observation et d’optimisation des procédés researchers have been working on these opportunities. This paper describes the most recent advances and current research trends.

Jan 1, 2011

By Andre L. De Vegt

For the past eight years Paques has been engaged in the development and installation of treatment systems based on biotechnological processes to remove sulfur compounds from water, air and gaseous streams. Metal and sulfate can be removed from mine waters using two biological steps: 1. Sulfate reducing bacteria convert sulfate to hydrogen sulfide (HzS). The HzS reacts with the dissolved metals to form insoluble metal sulfide precipitates. 2. Sulfide oxidizing bacteria convert excess H2S to elemental sulfur. Paques has designed and installed a groundwater treatment system for the Budelco zinc refinery in the Netherlands to remove metals and sulfate as described above. The system has been operating since May 1992 treating a flow of 5000 m3/d. A test program, utilizing a large scale pilot plant, will commence in November 1995 at a copper mine in the U.S.A. to remediate groundwater contaminated with sulfate and heavy metals. Biological reactor performance and selective metal recovery will be studied. Sulfur dioxide (S00 can be removed from fluegas using a combination of scrubber technology and the two biological steps. The end product is elemental sulfur. A commercial size biological desulfurization plant has been in operation since July 1994 treating 50,000 Nm3/h of fluegas. Sulfide can be removed from mining waters or anaerobic wetlands using a THIOPAQ® Sulfide Oxidizing reactor.

Jan 1, 1996

The Department of Mineral Resources has a statutory responsibility for mine site environmental management and control in New South Wales. The Department is focusing on an environmental management systems (EMS) approach, as a management tool to achieve æbest practiceÆ outcomes both within our own organisation and on mine sites. One of the DepartmentÆs tools is environmental risk assessment and management which incorporates the Mining, Rehabilitation and Environmental Management Process (MREMP). The MREMP was introduced many years ago in order to integrate the activities of key stakeholders who may have a material interest in the mine. The MREMP provides an ideal mechanism by which ædue diligenceÆ requirements and environmental management programs can be integrated into mining operations and lead to a sustainable post-mining land use.

Jan 1, 2002

By E. A. Adey, C. Baciu, P. Whitbread-Abrutat, M. Varul, T. Ejdemo, R. K. Shail, F. Wall

Responsible mining requires stakeholder engagement throughout all operational stages and after mine closure. By assessing the current and anticipated future socio-economic and environmental impacts, a company can maximise the positive impacts they can have on a community, whilst minimising any negative impacts. Despite the current emphasis on companies maintaining effective stakeholder relations to gain their ‘social license’ to operate, findings of the present study reveal a wide variation in community expectations, with different degrees of ‘acceptability’ evident across seven sites in Romania (Rosia Montana), Sweden (Kristineberg), the United Kingdom (Cornwall), Bosnia Herzegovina (Vihovici) and Russia (Karabash, Gay and Mednogorsk). These variations reflect the current status of mining within a community, as well as its socio-economic background and the nature of existing engagement with mining companies already operating in the region.

Jan 1, 2011

By M. Pope

By 1950, packaged oil and gas fired boilers were on the market for capacities up to 30,000 lbs./hr. By 1962, capacities were up to 100,000 lbs./hr. and even higher when separate heat traps (economizers and air preheaters) were attached to the boiler packages. During this period, complete packaged coal fired boilers were developed into the 10-15,000 lbs./hr. range. Oil and gas fired plant designs became very compact, "basementless", and far: less costly than the coal fired plants of any capacity. Coal fired plants remained large and expensive, required field erection of boilers and required basements. With the spectacular strides made in automation, oil and gas plants became far less costly to operate, requiring only the part-time attendance of a single operator. Some advances were made in coal fired plants, but not to the degree attained by the fluid fuel competition.

Jan 1, 1965

By M. G. Hester

The ore reserve modeling of stratiform uranium deposits to be mined by selective underground mining methods must be done with consideration of the erratic nature of the ore forming processes that produced the mineralization. Estimation methods that model the uranium grade as a smooth transition between high grade and low grade drillhole intercepts tend to greatly overestimate the ore tonnage. Care must be taken to first establish realistic ore pod geometries and then estimate the grade of the reserve units within the pods.

Jan 1, 1985

By D R. Seaman, Y Peng, F Burns, D J. Bradshaw

Telfer Gold Mine is a gold-copper mine in the eastern Pilbara of Western Australia, owned and operated by Newcrest Mining Limited. TelferÆs ores are processed by a dual train, 21 Mt/a, concentrator where gold is primarily recovered by gravity concentration and the flotation of a gold-bearing copper concentrate. A minor portion of TelferÆs gold is also recovered to a pyrite concentrate that undergoes treatment via carbon-in-leach (CIL) cyanidation. The gold recovery of the CIL circuit is below the industry standard and operates with a high reagent consumption rate.With a new fine-grinding facility, the Telfer process plant will have the ability to liberate copper and gold from the pyrite concentrate and recover these by flotation prior to the existing leaching circuit. This process will improve overall gold and copper extraction, while reducing reagent consumption in the CIL circuit.This article is an overview of the development of this methodology. Size-by-size analysis and mineralogical studies of monthly composites identified factors limiting the CIL gold recovery and the causes of high reagent consumption. Laboratory studies confirmed a relationship between the regrind product size and gold leach recovery. The addition of an intermediate flotation stage ensured that the regrind circuit will improve overall recovery while at the same time reducing operating costs. Without the addition of a flotation stage, the additional reagent consumption from regrinding alone would be prohibitive towards increasing recovery. Pilot scale studies confirmed the conditions required to selectively recover gold and copper from the pyrite concentrate as well as establishing the full scale regrinding energy requirements. Construction of this facility at Telfer is currently underway.CITATION:Burns, F, Seaman, D R, Peng, Y and Bradshaw, D J, 2012. Development of a pyrite regrind circuit at Telfer Gold Mine, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 45-52 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By T. C. Maswanganyi, G. L. Smith, R. C. A. Minnitt

This paper identifies the strategic gaps and opportunities for the South African mining industry’s contribution towards advancing sustainable development. Mineral resources companies are confronted by a range of complex social performance challenges, which largely manifest in sporadic community and labour unrest, undermining the sustainability and profitability of these companies. Integrating supply chain management, strategic long-term planning and sustainability planning is identified as a strategic gap that can contribute towards the sustainability of mining companies, if effectively implemented. Contributing towards sustainable development by the South African mining industry is not merely a voluntary requirement on the industry but a legal requirement in terms of the Minerals and Petroleum Resources Development Act No. 28 of 2002. This Act is legislation aimed at advancing socioeconomic development in communities that host mining operations and in areas that provide labour to the South African mining industry. In contributing towards the advancement of sustainable development in mining host communities, not only will mining companies fulfil a legal requirement in terms of the Minerals and Petroleum Resources Development Act, but they will also prevent negative social and economic impacts in those communities. This paper identifies innovative and cost-effective ways of advancing sustainable development by integrating strategic supply chain management, strategic long-term planning, and sustainability planning.

Dec 15, 2025

By Y. X. Zhao

This paper briefly describes the characteristics and induced factors of coal mining bumps based on the investigation of recent bumps accidents occurred in China. According to the theory of non-equilibrium thermodynamic and dissipate structure, the process of strain energy accumulation and dissipation in the ?Coal-Surrounding Rock? system (CSRS) is discussed during the preparation of coal bumps. In addition, a series of experiments are conducted to analyze the relationship between bump-prone property and micro-structural characteristics of coal. The process of coal bumps induced by propagation of fractures and deterioration of coal mass properties are also analyzed systematically.

May 1, 2009

By G Williams

Discussing equipment, systems of work, the need for updated programmes of local seismic exploration, and developments within the South Wales coalfield.

Jan 1, 1993

By P. Oliver

Rockburst conditions were first encountered at Inco's Sudbury area operations in the mid 1930's when mining advanced to below the 610 m (2000 ft.) horizon. Now, mining is being carried out at depths down to 2130 m (7000 ft.) at Inco'a Creighton Mine. While rockburst potentials have increased with depth. improvements in mine planning, methods, support systems and developments in destressing have alleviated the condition to where it is less of a problem now than it was in the early years. Hang of the improvements were developed, of necessity. through observation and reasoning because these were the only tools available at the time. Now, we are making use of stress - measurements, numerical modelling and microseismic source location technology to - help further reduce rockburat hazards.

Jan 1, 1987