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By Gerald M. Rich

Magma Copper Company, a subsidiary of Newmont Mining Corporation, has initiated many changes in the continuous casting of 5/16 inch diameter copper rod since startup of the San Manuel rod plant in early 1972. With rod production at forty percent over design capacity, many production records have been established including a record cast of 761 tons of salable rod in a twenty-four hour period. The most challenging and rewarding introduction was the continued utilization of an alloyed copper casting wheel in lieu of the conventional steel wheel. With proper cooling and careful control of the mold release agents. as much as 58.000 tons of copper were cast on a single copper wheel. Other advantages are: 1) Fifteen percent increase in available casting time 2) Reject rod from steel inclusions was reduced by nearly one-hundred percent 3) Wheel cost was decreased by ninety-one percent 4) Natural gas consumption dropped approximately fifteen percent 5) Large increase in refractory component life 6) Reduction of manhours/ton. Many other modifications have contributed to excellent rod quality and high operating efficiency. A two-piece launder was replaced with a single castable launder which reduced oxygen pickup and provided better slag removal. Modifications to the bar preparation unit, pickling system, and coiler resulted in considerably higher milling efficiency.

Jan 1, 1976

By P. C. Tully

The vapor pressure-temperature relationships for saturated pure liquid nitrogen are calculated by the Strobridge equation using a digital computer. This information is presented in two tables: first) in pressure increments of 0.1 psi from 1.8 to 492.9 psia) and second) in temperature increments of 0.1° from 63.15° to 126.26° K. These tables should facilitate the calibration of temperature-measuring devices over this temperature range.

Jan 1, 1967

By Roy G. Stott, John A. Johnson, Floyd G. Anderson

"This information circular discusses drilling and blasting in open-cut iron-ore mines and is one of a series of papers describing iron-ore mining practices in the Lake Superior district to aid in preventing accidents in that industry.The Lake Superior district consists of the Marquette and Menominee ranges of Michigan, the Gogebic range of Michigan and Wisconsin, and the Vermilion, Mesabi, and Cuyuna range of Minnesota. Open-cut mines produce 8o percent of the iron ore mined in the district; 98 percent of the total Lake Superior district open-cut ore is produced in Minnesota and 2 percent in Michigan. The entire Wisconsin iron-ore production is from underground nines. The Mesabi range in Minnesota produced 93 percent of the open-cut iron ore and 76 percent of the total iron ore in the district in 1947.During the 8-year period 1940-47, 619,000,000 gross tons of iron ore were shipped from mines of the district, or 85 percent of the United States output. Approximately 78,000,000 gross tons of iron ore were shipped from the mines of Minnesota, Michigan, and Wisconsin in 1947.This paper is based primarily on observations daring the period July 1947 to March 1948. Thirty-two open-cut mines were visited; 28 on the Mesabi range, 3 on the Cuyuna range, and 1 on the Marquette range. In 1947, 36,100,000 tons of iron ore was shipped from these 32 mines, or 59 percent of the open-cut ore and 46 percent of the total iron ore shipped from the district. During 1947 about 90 open-cut iron-ore mines were operating in the district, and the annual production of each ranged from 25,000 to 10,000,000 tons.Many recommendations included in this paper for improving safety and preventing injuries to employees were taken from Bureau of Mines Information Circular 7387.Data were collected under the direction of Frank E. Cash, former supervising engineer, Health and Safety Division, Bureau of Nines, Duluth, Minnesota. E. W. Felegy, mining engineer, Safety Branch, gave valuable assistance in reviewing and editing the manuscript.The authors gratefully acknowledge the information and assistance given and the numerous courtesies extended to them by officials of the following mining companies:All the Lake Superior iron ores occur in bedded formations that range from less than 100 feet to over 2,000 feet in thickness. These formations are designated by one commonly applied name, ""iron formations.""4/The Mesabi range in northern Minnesota, about 70 miles northwest of Duluth, was opened to mining in 1892; it is the largest single source of iron ore in the United States. It is 75 miles long and, because of the gentle dip of the ore formation, it ranges in width from 1-1/2 to 3 miles.5/ The ore formation, which is nearly horizontal, has a maximum thickness of about 450 feet and is covered by a glacial drift that ranges from 10 to over 100 feet in thickness. Most of the ore is near the surface and adaptable to open-cut mining."

Mar 1, 1950

By CHONG WEI, TATYANA KATSAGA, DEREK APEL

This study provides an effective determination process of the interface microstructural parameters in the numerical modeling of the mechanical interaction between two different geomaterials involved with frictional-bonded interfaces, such as the interaction between backfill columns and the surrounding rocks, or the soil-structure interaction, by using the coupled finite-difference and discrete-element (FD-DE) method. The test results validated the feasibility and rationality of the coupled FD-DE method for modeling the combined specimens with frictional-bonded interfaces or joints. Furthermore, this study provides valuable numerical modeling experience for investigating the shear behavior at the interface between cemented backfill columns and surrounding walls by using the coupled FD-DE method.

By J. F. Barry

Newmont Mining Corporation and Barrick Goldstrike Mines, Inc. concluded an exchange of land and reserves in an agreement signed May 3, 1999.This exchange of assets allowed Newmont to develop the Deep Post underground mine from within Barrick’s Betze-Post open pit, thus reducing capital expenditures, lowering operating costs, and advancing the production schedule by nearly three years. Based on previous experience, Newmont is confident that the Deep Post underground mine can be successfully developed and operated within a large, active, open pit mine. The project also faces difficult geotechnical conditions including weak ground, scattered pockets of groundwater, and elevated rock temperatures.

Jan 1, 2000

Several common ratios used for determining spontaneous combustion activity rely on comparing the amount of various products of oxidation with the amount of oxygen consumed to produce these products. As coal gets hotter, oxidation reactions become more efficient meaning more products produced for less oxygen consumed. There are many problems associated with accurately determining the true amount of oxygen used. These problems relate to the monitoring technique (and its associated uncertainties) used to generate the results, deficiencies in the established equations utilized in calculations, dilution with other gases and other sources of oxygen depletion. Typically the oxygen deficiency is over estimated, resulting in the under estimation of the indicating ratio. For this reason the use of ?one off? calculations to determine the status of the underground environment is not recommended. Instead trends of these ratios should be used to identify increases which indicate an increase in oxidation intensity. This paper outlines problems associated with the monitoring techniques and equations used to determine the oxygen deficiency.

Jan 1, 2009

By Diogo Barcellos Moraes

O presente trabalho tem como premissa abordar estudos baseados na metodologia Troca Rápida de Ferramentas (TRF ou em inglês, SMED – Single-Minute Exchange of Die), e realizar um estudo de caso na empresa Votorantim Siderurgia. O objetivo principal é a redução do tempo de setup da máquina de Tela de Coluna, a fim de minimizar o desperdício de tempo e maximizar a produtividade. Além disso, obteve ganhos efetivos no layout de ferramentas, programa 5S, tempo de atividades, entre outros.

Oct 30, 2017

By Forrest T. Moyer

The safety record of the metal mining and milling industries in 1965 is reviewed by the Bureau of Mines. The overall injury-frequency rate of 23.77 per million man-hours was 5 percent lower than in 1964 and was the lowest annual rate in a statistical history beginning with 1931. The injury-severity rate of 3,521 days lost per million man-hours in 1965 represented a 5-percent improvement over 1964. However, the total of 3,825 disabling work injuries comprised 61 fatal and 3,764 nonfatal injuries, one and 92 more, respectively, than in 1964. At primary nonferrous smelters, refineries, and reduction plants, the injury-frequency rate of 8.97 per million man-hours in 1965 was 13 percent lower, but the severity rate percent higher than in 1964. these plants in 1965, 4 more of 1,173 days lost per million man-hours was 17 There were 12 fatal and 971 nonfatal injuries at and 28 fewer, respectively, than in 1964.

Jan 1, 1969

By R Hargreaves, C Morley

The authors often see problems on mine sites that are due to insufficient feedback between technical discipline silos as the realities on the ground fail to inform the models and plans used to drive resource exploitation. Resource modelling, reserve definition, life-of-mine planning, short-term mine planning and scheduling, mine operations and beneficiation operations are all processes that inform each other, but in many instances feedback between these processes occurs in an ad hoc way and only after problems have come to light.Universal reconciliation uses a multidisciplinary approach across the entire mining value chain to identify both opportunity and loss of value and to maximise operational performance. This paper will look at the operational effectiveness of universal reconciliation and will outline the important elements that make it successful, including how to map out the detail underpinning modelling, planning and execution processes. We do this by documenting the physical processes, logical work practices, organisational roles and responsibilities, data origin and quality, working assumptions and information management practices at an operation. The results quickly show how misinformation and assumption causes suboptimal decisions to be taken, where inefficiencies exist and what the opportunity is to remedy these issues.A universal reconciliation study opens up an opportunity for stakeholders to reassess how the operation should be run and how operational effectiveness should be measured. Clear envelopes for reconciliation become obvious and questions about the practicality and data quality can be addressed.A reconciliation code of practice is a key element of a successful universal reconciliation project and the authors outline the important aspects that will provide an operating model, showing the effectiveness of the resource and reserve modelling, the practicality of the mine planning and scheduling practices, how well the mine operations team are executing these schedules and how effective the processing area is given what it is fed. Most importantly, a system that allows operations time to react before the losses become systemic and that is based on identifying early warnings from hard data when these processes start to wobble is outlined. Finally as a case study, the revenue and cost benefits resulting from universal reconciliation diagnostic projects for nine mine sites is documented.CITATION:Hargreaves, R and Morley, C, 2014. Universal reconciliation – a multidisciplinary approach across the entire mining value chain to identify loss of value and maximise operational performance, in Proceedings Ninth International Mining Geology Conference 2014 , pp 411–420 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By K. Mondal

A macroscopic approach integrated with microscopic analyses for wettability characterization is presented. Wetting depends on 1) Contact between the dust and the fluid droplets, 2) Wettability of the particles by the wetting fluid, and 3) Wettability rate (due to low contact times). The goal of this paper is to show that the wetting rate is a significant factor in dust control. Samples from the roof, three different horizons of the coal seam and the floor were pulverized to less than 25 µm. Experiments were conducted with known wetting fluids to correlate surface tension and equilibrium wettability. Further analyses were performed in terms of surface charge (zeta potential), particle size, mineral composition, elemental composition, and quartz content. The surface tension reduction was also achieved by the use of chemicals and/or altering the temperature of the water. Two methods were used to evaluate wettability rates: a) near real-time comparison of wettability rates, and b) comprehensive evaluation of the intrinsic wettability rates. The data obtained provides meaningful insights towards the design of engineering controls for an economical solution to dust control in coal mines.

Jan 1, 2012

By Randy R. Williams, Roberto R. Olivera, Brian W. Wilson, Marina S. W. Li

"An extensive, deep mixing (DM) ground improvement program using the Cutter Soil Mixing (CSM) technique was designed and constructed in 2013 to support up to 20 m (66 ft) high Mechanically Stabilized Earth (MSE) walls and bulk earthworks for the development of the Kitimat Liquefied Natural Gas (LNG) facility at Bish Cove, British Columbia. The deep mixing program consisted of overlapping rectangular panels of in situ cement treated soils, constructed using the CSM technique, to form barrettes covering an area of approximately 12,900 m2 (15,428 yd2) and providing suitable static and seismic stability of foundation soils for support of the proposed MSE walls, which would in turn support LNG facilities. The deep mixing program comprised of 1645 CSM panels that were constructed through varying thicknesses and discontinuous layers of very soft fine-grained marine deposits and/or loose sandy silt to silty sand deposits, embedding typically 2 m ( 6.6 ft) into dense silty sand to sand and gravel. CSM panel depths ranged from 5 m (16 ft) to 30 m (98 ft) and were constructed by treating approximately 73,900 m3 (96,658 yd3) of soil yielding average unconfined compressive strengths exceeding 2.5MPa (363 psi).This paper outlines the approach adopted for the design of the CSM ground improvement program in the highly variable subsurface conditions present at the site. A phased sitespecific investigation consisting of boreholes, test pits, Cone Penetration Tests, piston tube sampling, advanced laboratory testing and groundwater monitoring was implemented. In addition, soil-cement bench scale testing was completed, followed by installation of 8 CSM panels for field trial purposes. Extensive geotechnical static and seismic analyses including Limit Equilibrium stability analyses, liquefaction assessments, and advanced numerical modeling were undertaken to optimize the design and meet the project-specific design performance criteria. The Design-Build team worked closely to develop and implement Quality Assurance and Quality Control plans and managed significant construction challenges while achieving suitable panel termination depths."

Jan 1, 2017

By Henry Mackay

THE interesting paper recently submitted by Messrs. Tobelmann and Potter' shows that chemical problems have developed which are of great interest in this new and important branch of metallurgy. Those who realize what a process of this kind really involves will agree that it deserves a better name than "leaching process." The word leaching conveys the idea that the copper is simply leached out of the ore with acid and then precipitated on iron; the chemistry of such a process would be of little interest. As, however, during the first year's operation of this plant 24,400,532 lb. (11,067,837 kg.) or about two-thirds of the produce, was electrolytic copper, while 7,992,033 lb., or about one-third, was cement copper, it would seem more appropriate to term the process electrochemical. It further appears, from the particulars given, that efforts have been made to have the entire production in the form of electrolytic copper. -This could be done if the chemistry of the problem were kept in balance, so that it would not be necessary to discard any solutions that carried copper and acid of commercial value. A process, such as that under consideration, in which the copper is precipitated from solution by electrolysis, the solvent being at the same time regenerated, is one that requires special chemical and electrochemical knowledge and experience if all the -copper in solution that has been extracted from the ore is to be successfully and economically produced as electrolytic copper. The object of this paper is to discuss, from the practical and theoretical standpoints, the chemical and electrochemical problems involved in the working of a process of this kind, and' which must be solved to keep it in chemical and electrochemical equilibrium. In such a process, if the chemical balance is maintained, a solution can be used alternately as a

Jan 9, 1919

By W. C. McBee

A family of modified-sulfur cements has been developed by the Bureau of Mines for the preparation of construction materials with improved properties. Various types of sulfur cements were prepared by reacting sulfur with mixtures of dicyclopentadiene (DCPD) and oligomers of cyclopentadiene (CPD). Durable cements were prepared with structural characteristics ranging from rigid to flexible. These cements were used to prepare corrosion-resistant materials for use in a wide variety of industrial applications where resistance to acidic and salt conditions is needed. These materials were prepared as rigid concretes, flexible pavings, spray coatings, and grouts. Production of modified-sulfur cements in a commercial-size plant was demonstrated.

Jan 1, 1981

By M L. van Kampen

The recent (2005) amendments to the Resource Management Act 1991 have made it clear that there is no obligation on an applicant to consult. However the importance and value in consulting with the community, particularly before commencing a major project, cannot be understated.   This paper looks at the provisions of the Resource Management Act as they relate to consultation and public participation in the process, and will discuss the benefits of consultation both before an application is filed and following the filing of the application. Engaging with the local community can help shape a project to better fit the community, engender support and address opposition. In short, taking the extra step to what is legally required, can help smooth what is potentially a bumpy road. Examples in practice of the value of consultation are given.

Jan 1, 2006

By E. Farrokh

Estimation of the cutter life and cost is a part of evaluating performance for a hard rock TBM in any project. Various approaches has been proposed for calculation of disc cutter life in various rock types based on machine specifications and rock strength and abrasivity. Cutter change time is a parameter that is used in some of the estimates and is defined as the average time required for changing a cutter on the cutter head and cutter life is the number of cubic meters of excavated rock per each disc cutter. Analysis of cutter life information of several tunnel projects from around the world has revealed that the published models for estimation of cutter consumption require some revisions to offer a more accurate prediction. The preliminary analysis of data shows that the average cutter change time is approximately 66 minutes for different cutter sizes and there is a minimal difference between corresponding cutter change times of the large (e.g. 19 or 20 in) versus smaller cutters (e.g. 15.5 to 17 in). This paper reviews the available and published cutter life data from various projects. It also introduces new models for estimation of cutter life and cutter change time as part of TBM down time and utilization analysis.

Feb 27, 2013

By Dan Brown

A method is outlined for computing the contribution of a micropile group to global stability of a sliding mass. The forces in the micropile are computed in a way which accounts for the effect of soil mass movement on the mobilization of axial and shear forces and which maintains compatibility between shear and axial force as a function of displacement. The method provides a rigorous model to incorporate the pile forces into the stability calculations, including the effect of pile forces on the resultant shear and normal forces at the sliding surface. This paper demonstrates the proposed solution using a simple example slope.

Jan 1, 2007

By AIME AIME

A SIDE from the technical sessions held as noted elsewhere, the chairman of the various sub-committees of the Mining Methods Committee, together with a few other specialists, were invited to a conference with President Bradley, which was held on Wednesday afternoon, Feb. 20. The general plan of a comprehensive series of comparable papers descriptive of mining practice in various parts of the country, launched by this committee some seven years ago having been adopted by the U. S. Bureau of Mines, the feeling was general that the Committee could safely 1eave.that part of its work in these capable hands and turn its attention to other matters. The plans of the Bureau were presented as below by Charles William Wright of the Bureau.

Jan 1, 1929

The creation of an accurate and precise enough database requires the collection of many representative samples, subsampling and assaying them without destroying their integrity. The selection and implementation of sampling protocols often lead to severe difficulties, making the unaware practitioner vulnerable to massive exploration, feasibility and operating failures. Therefore, there is no substitute for a good understanding of the Theory of Sampling (TOS). Either because of ignorance, or because of short-term economic reasons, failure to comply with many stringent conditions can be devastating for the validity of a feasibility study, leading to false evaluations, to the abandonment of a viable property, or to the exploitation of one that is not profitable. All these failures have something in common: insufficient duplicate sampling, subsampling and assaying were performed; very important, preliminary heterogeneity tests were never performed; for short-term economic reasons, poor sampling and subsampling protocols were selected, second-class sampling systems and weightometers were installed and poor preventive maintenance and cleaning were implemented;and sampling experts were called only when the project was obviously in trouble. The conclusion is clear: in due time, iterative auditing of sampling practices is an insurance policy against massive financial losses for the company involved. A complete, comprehensive 100 point checklist of sampling Quality Assurance and Quality Control is provided, so critically important details to ensure success are not forgotten.

Mar 1, 2010

The New Zealand Minerals Industry is small but growing. Over the next 10 years it will be facing stiff international competition for skills to support this growth, particularly from Australia who are forecasting that a further 70 000 people will be employed by 2015.   The value of commodities mined and quarried in NZ continues to increase; and the value of coal, metals and industrial minerals production reached $1.505 billion in 2006, an increase of 15 per cent on 2005. Production increases will continue à. Latest Crown Minerals statistics show that national prospecting and exploration expenditure rose to $29.9 million in the year ended March 31 2006 û an increase of 46 per cent from the $20.4 million spent in the March 2005 year. The equivalent 2001 year expenditure was only $2.48 million.   The industry already experiences difficulty in recruiting the people it needs with ongoing demand for skilled underground miners, trades people, and mining professionals. This discussion paper will outline the national context with regard to labour, skills and training. It will suggest options and provide an opportunity for conference participants to discuss the way forward.

Jan 1, 2007

By Biplop Das, E. Herrera, A. Burrows, P. J. Mackey, G. R. F. Alvear Flores

Since the first commercial plant was built at Mount Isa, another twenty ISASMELT™ furnaces have come into commercial operation, and construction of new plants continues. The primary copper ISASMELT™ top submerged lance (TSL) technology continues to attract interest from potential users who seek to smelt productively. In addition to the known benefits of productivity and flexibility, ISASMELT™ operators have also achieved improvements to energy efficiency when switching from their previous technologies. The recent production statistics for operation at Tuticorin, India show that ISASMELT™ has taken the first steps into territory beyond 400,000 t/y (copper cathode basis) and this will likely be the scale chosen by future new copper smelters operating purely on a toll smelting basis. Highly energy-efficient technologies will be expected at these smelters

Jan 1, 2015