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By W. K. Cunningham, Edwin A. Gee

"INTRODUCTION This paper is one of many reporting on various aspects of the Bureau of Mines program during World War II directed toward alleviation of shortages in certain critical minerals some of these papers are published as technical papers information circulars, and reports of investigations, of the Bureau of Mines or in technical journals.The investigation described in this report was begun as part of the Bureau, of Mines program to develop acid processes for the extraction of alumina from low-grade bauxites and clays. A domestic shortage of high-grade bauxite suitable for treatment by the Bayer process became acute as a result of World War II; and intensive search for a practical acid process using lower-grade alumina-bearing raw materials was therefore warranted.A survey of the various methods for extraction of alumina from clay has been presented in an early Bureau of Mines publication. 4/ The principal barrier to the successful operation of an acid process has been the difficulty experienced in developing a suitable commercial method for purifying the crude aluminum salts after the clay extraction is complete. Iron salts are the foremost contamination influence. A review of the more prominent procedures that have been proposed for separating iron and aluminum salts can be found in the well-known text on aluminum by Edwards, Frary, and Jeffries. 5/The majority of acid processes to extract alumina from clay employ sulfuric acid as the leaching agent, and the purification is thus reduced to the separation of iron and aluminum, sulfates."

Feb 1, 1948

By A. B. Campbell

The mines in the eastern part of the now active region of the Tri-State zinc district of Missouri, Kansas, and Oklahoma have unusually acid water, which during periods of moderate or no rainfall is used in the mills to replace losses from evaporation, seepage-, and tailings disposal. Its use has caused difficulties by corrosion of equipment and by interference with flotation. The growing importance of flotation, which requires good water, and the increasing troubles caused by the corrosion of the milling equipment have prompted the Mississippi Valley Experiment Station of the United States Bureau of Mines, in cooperation With the Missouri School of Mines and Metallurgy, Rolla, Mo., to investigate the action of the waters on flotation and to undertake to develop means of obviating their harmful effects. The work was under the immediate direction of W. T. Schrenk, consulting chemist, United States Bureau of Mines, and professor of chemistry Missouri School of Mines and Metallurgy, and. Will H. Coghill., supervising engineer of the ore dressing section of the United States Bureau of Mines.

Jan 1, 1932

By Sadettin Bagdatli, Ali Kahriman, Umit Ozer, Alper Celtikci, Yucel Karakus

Due to population growth and rapid urbanization in Turkey, the need for the construction of residential units, transportation and infrastructure facilities has become increasingly more pressing. Since rock units encountered in the surface and underground in the construction of the subway, infrastructure and housing facilities, it is a necessity to use blast excavation methods. In recent years, large housing construction projects have been carried out especially in Turkish metropolitan areas, involving foundation excavations giving rise to great amounts of earthmoving. Since rock units encountered during foundation excavations are usually hard and solid, excavation with conventional machinery proves to be inadequate and unproductive, hence the necessity for the application of blasting technology.

Jan 1, 2014

By Kasimcan Koruk, Julian M. Ortiz

A geological model accounting for uncertainties possesses important advantages for resource estimation. Machine learning algorithms (MLAs) employed on multivariate geochemical datasets open up ways to new methodologies for such geological models with ease in comparison to traditional geostatistical methods. This article proposes a two-step MLA with an ensemble implementation to define geological domains and their uncertainties based on geochemical data. The proposed workflow is applied hierarchically on a dataset from a porphyry copper deposit to perform binary classification that can be attributed to alteration domains.

Mar 1, 2024

By Alex Olivas

El presente trabajo señala la tecnología de control e información aplicada a las zonas donde se han instalado diversos equipos de medición y control de una planta de almacenamiento, los cuales están interconectados con un PLC central mediante una red LAN y de bus de campo. Asímismo, se definen dichas zonas y se detalla donde sea pertinente las soluciones en las que se empleó la tecnología de control e información.

Aug 25, 2002

By A. T. Visser

"SynopsisAlmost 20 years have passed since the cutting-edge research by Thompson and Visser on the design and management of opencast mine haul roads was conducted in South Africa. This system is based on three principles, namely the structural ability to support the ultra-heavy truck loads, the selection of vehicle and environmentally friendly riding surface, and an appropriate level of maintenance to counteract wear and tear. Obviously, proper layout and geometry are essential.These principles have been implemented worldwide, and it is useful to review the lessons learned. The objectives of this paper are to present a critical review of the status of mine haul road design and management, and the impact that these principles have made on operations, particularly the cost-effectiveness. The paper briefly reviews the principles of the haul road design and management and the extent to which they are applicable. Case studies of a number of implementations are presented to demonstrate that the principles are sound and have been applied effectively. For example, at an international operation the transport cost of coal was 40% more expensive than anticipated in the feasibility stage, and this made the mining operation uneconomic. Correction of this problem resulted in a viable enterprise. Although designed for opencast operations, the principles are equally valid for underground operations, and initial development work will be discussed.The main conclusions are that the research approach is valid and its effectiveness has been demonstrated in a number of applications. The anticipated financial benefit has been derived, and has made the mining operations that used the principles more effective. Of major importance is the application of opencast haul road design principles to the future thrust of using driverless vehicles in opencast and underground mining, where the road quality is not negotiable as there is no driver that can avoid obstacles or severe road deterioration.IntroductionAlmost 20 years have passed since the cutting-edge research by Thompson and Visser on the design and management of opencast mine haul roads in South Africa (Thompson and Visser, 1996a, 1996b, 1998, 1999, 2000a). This system is based on three principles, namely the structural ability to support the ultra-heavy truck loads, the selection of vehicle and environmentally friendly riding surface, and an appropriate level of maintenance to counteract wear and tear. Obviously, proper layout and geometry are essential."

Jan 1, 2015

By William C. B. Gates

Demolition blasting next to an active railroad can be very challenging because of track safety, blasting vibrations, potential track fouling by blast debris, and short work windows on a live track. Recently, in eastern Washington, one of the major railroad companies has been aggressively constructing a second main track to accommodate the expected increase in rail traffic of natural resource products. To accommodate construction of the second line, the railroad company used blasting demolition techniques to remove an old railroad trestle pier on the Milwaukee Road that was in the footprint of the new track bed. The trestle bridged the present rail line and flanked the track with two massive 550-ton (499 tonne) twin-columned steel reinforced concrete piers. The railroad contracted with a specialized contractor to remove the south pier using blasting demolition techniques. The blasting design presented the following challenges: blasting during live track conditions and short work windows; designing a V-notch blast pattern to ensure the pier fell away from the live track; drilling, loading, and timing of the shot; maintaining blasting vibrations at the track below 4 in./sec (102 mm/sec); maintaining ambient overpressure noise below 133 dB; control of fly rock and debris; and track protection and emergency debris removal plan.

Jan 1, 2016

Perhaps the most significant development in China's base metal sector is the discovery of major copper porphyries in northern Jiangxi Province and the adjacent southern Anhui Province. At the center of the new exciting district is the proposed Dexing copper complex, located some 350 km east of Nanchang, the provincial capital of Jiangxi. This project represents China's first attempt to put together a major large-scale open-pit operation, comparable in magnitude to Arizona porphyry operations. With the aid of Fluor Mining and Metals, the Chinese plan to develop a 135-175 kt/d open-pit mine, a matching large-scale mill, and the infrastructure needed to accommodate the big operations. An operation of this magnitude would significantly reduce China's import requirements by some 75%. China imports of the red metal are running around 200 kt/a. Under the direction of the Ministry of Metallurgical Industry, the Chinese are currently operating a 10-kt/d mine and mill with equipment primarily of Chinese origin. Dexing engineers told ME that they are considering a possible scale-up to 20 kt/d. How this effort will ultimately jell with the major expansion program is largely a matter of conjecture. Fluor Mining and Metals received a $10-million contract in December 1978 to develop a preliminary engineering and design program. While the original plans called for a 175-kt/d capacity complex, the Chinese subsequently decided to scale it down somewhat. The current proposal is around a 135 kt/d, which would in- elude the existing operation, according to Dexing engineers. Completion of the engineering and design phase is expected by March 1980 and a go-ahead decision will likely be made at that time. The value of the engineering and construction contract is estimated between $800 million and $1 billion. At right, mined ore is dumped 150 m down the mountain to a holding pocket below for rail haulage to the processing plant. Below, a Chinese miner tackles the universal problem of hard toes in the pit with a jack leg. Reserves and Early History The Dexing mineralization consists of three principal ore bodies, including the Chushahung on the north mountain, and the Tungchang and Fuchiawu on the south mountain. Combined ore reserves are estimated by mine geologists at 1.7 Gt of 0.4-0.5% copper. As is characteristic of porphyries, the ore contains important associated values of molybdenum, rhenium, pyrite, gold, and silver. There is also some secondary calcocite and bornite with an oxidized capping. Historically, copper was recovered with iron from the pregnant solutions emanating from the Tungchang deposit as early as the Tang Dynasty (700 AD). Modern day exploration was conducted by the Bureau of Geology in 1956 and reserve figures were es-

Jan 3, 1980

A201 aluminium alloy is a high strength casting alloy with a nominal composition of Al-4.6Cu-0.3Mg-0.6Ag. It is strengthened by the O(Al2Cu) phase and the ??(Al2Cu) phase during heat treatment. Further strengthening of this alloy system can be obtained through the addition of transition elements, but care must be taken as other elements might have adverse effects on the mechanical properties. The objective of this study is to determine the influence of Mn on the tensile properties of rheo-processed Al-Cu-Mg-Ag alloy A201. ThermoCalc software was used to predict the different phases that can be expected in the alloys, and scanning electron microscopy(SEM) with energy dispersive spectroscopy (EDS) was used to investigate the actual phases that formed. The influence of these phases on tensile properties is quantified. SEM and ThermoCalc revealed that there is an increased amount of the Al20Cu2Mn3 with increasing Mn. The tensile properties showed that high amounts of Mn do have adverse effects on the tensile properties of alloy A201, especially the ductility. Keywords Semi-solid metal (SSM) forming, alloy A201, intermetallics, Al20Cu2Mn3

Jan 1, 2011

By A. J. Petrina

"At Craigmont Mines Limited, Merritt, B.C., tests were begun in March, 1965 to evaluate the use of shotcrete as a method of ground support m development headings; previously, ail drifts had. required support, which was accomplished mainly by timber and occasionally by the use of rockbolts. The tests demonstrated conclusively the effectiveness of shotcrete for supporting Craigmont's ground. Gradually, the use of timber for ground support was virtually eliminated in favour of shotcrete. This paper describes the equipment used, the operation of the equipment, pertinent cast data and opera ting details. Also discussed are other uses developed for the shot-creting equipment, the use of reinforcing bar rockbolts, and a method used at Craigmont for lining long vertical ore passes with steel plate and concrete as part of the raising cycle."

Jan 1, 1968

By A. Landsberg

Kaolinitic clays are potentially a vast domestic resource for aluminum. Utilization of this resource could decrease or eliminate the nearly complete dependence of the United States on foreign raw materials for this important metal. Furthermore, processing of clay to aluminum through anhydrous chloride metallurgy could reduce the high electrical energy requirements of the conventional Hall-Heroult aluminum reduction process. Several anhydrous chloride processes have been proposed; however, unresolved technical problems have prevented their commercialization. In particular, an acceptable chemical means has not been found to extract aluminum from clay as a highly pure anhydrous aluminum chloride. This Bureau of Mines report identifies and discusses the important chemical problems involved in achieving an acceptably rapid, self-heating, selective chlorination reaction and the subsequent separation of iron chloride byproduct from the anhydrous aluminum chloride.

Jan 1, 1983

By Axel Preusse

Due to a political decision, German hard coal mining will come to an end in the year 2018. By then, there will have been more than 150 years of industrial grade mining activities. Located in the western part of Germany is one of the most densely populated areas of Europe. Multiple coal seams have embossed the earth?s surface up to 20 meters (21.87 yards), as mining has subsided. The aftercare of hard coal mining will consist of three tasks: groundwater management, polder management, and groundwater treatment. The Ewigkeitslasten (cost in perpetuity) at the current groundwater level has been determined in the past. The actual cash value is calculated to be about 12.4 billion euros (approximately 16.5 billion dollars). The cost of groundwater management is directly related to the groundwater level. Rising groundwater levels will reduce the cost of pumping water. Known effects of rising groundwater are uplift of the surface, emission of methane gas at the surface, higher risk of cave-ins, and contamination of drinking water horizons. Each of those processes produces cost in order to prevent negative consequences (e.g., uncontrolled methane emissions) or to handle reparations (e.g., damages caused by surface uplifts). In the long run, it is the goal to minimize the Ewigkeitslast. As a first step, all cost-generating processes are specified, and a cost type based characterization is performed. The objective of this case study is to identify key parameters to determine the quality of a cost-generating process (proportional cost, fixed amount cost). Afterwards, it is intended to specify the quantitative impacts of each parameter and to set up an optimization model to minimize the overall cost. The quantitatively specified parameters will form the base out of which the optimization model is created.

Jan 1, 2013

By Lee W. Saperstien

At the heart of the mining process are a number of basic and fundamental tasks whose regular and repeated performance constitute the mining cycle. As will be discussed presently, these tasks are the basic components of the mining system. Section 9, Production Operations, provides the mine designer and engineer with an understanding of these tasks and with sufficient design principles to allow this person to create an efficient mine system. This section is meant to be an introduction and adjunct to subsequent sections that describe specific mining systems. However, sufficient design information is included here for the independent design of mine systems that may not be described elsewhere or for subsequent verification of existing designs. For the purposes of this section, mining subsumes excavation; thus this material applies to any excavation process. Accordingly, this section is written in general enough terms to include both surface and underground mining. It may be used also for civil engineering excavations that often involve the same steps. Obviously, the actual procedures undertaken in any specific mining system will appear to be very different from those taken in any other system. This is certainly true when comparing surface with underground methods. Yet the fundamental principles are often the same. This segment is written to explicate the basics. Wherever appropriate, the section will suggest the differences between the application process to surface or to underground mining.

Jan 1, 2008

By Frederic M. Langevin

?? Introduction ?? LaRonde ?? History of Seismicity and Rockbursting ?? November 27th 2002 Rockburst ?? April 1st 2006 Rockburst ?? December 11th 2006 & January 11th 2007 Rockbursts ?? Seismic Risk Management Plan ?? Conclusions ?? Located in Northwestern Quebec (Can.) ?? In operation since 1988 ?? Reserves at Shafts #1 and #2 depleted ?? Production now comes entirely from Penna Shaft ?? Deepest single-lift shaft in the western hemisphere (2240 metres) ?? 7300+ tonnes per day ?? 2007 Reserves (proven & probable): ?? By-products: Ag, Cu, Zn ?? Sinking #4 Shaft (LaRonde II winze)

Feb 1, 2008

By C. A. Ozturk

The compressive strength of rock (sc) has an important effect on design of structures in rock engineering. Compressive strength can be determined in the laboratory using the uniaxial compressive strength (UCS) test. Some other index tests, such as the point load test, are also used, particularly when suitable samples for UCS are not available. The quantification of rock texture has introduced a new method in rock engineering for estimating the mechanical and physical properties of rock materials from microscopic investigations. The aim of this study is to quantify rock texture to estimate rock strength from the texture coefficient (TC), which is determined from a statistical assessment of thin section images. Rock texture is quantified by twelve different images from a single thin section to increase the reliability of texture analysis. A data-set is prepared to investigate correlations between TC and sc. The statistical correlations are computed after classifying of the rock samples based on their lithology as well as grain features. Equations derived based on the results of this study are used to predict the approximate value of compressive strength from the texture coefficient. This method is particularly useful for preliminary studies in rock engineering projects prior to detailed site investigation.

Jan 1, 2014

This paper provides an update to a paper by the author on an overseas explorer's perception of New Zealand, presented at the 1997 New Zealand Minerals & Mining Conference. New Zealand has one of the most open and internationally competitive economies in the world. The petroleum exploration industry in New Zealand is booming with a record number of wells planned for 2000. New Zealand is keen to encourage investment in mineral exploration to develop its natural resources. A study of the geological potential of New Zealand estimated the value of known and potential resources of metals at $86 billion. Gold has the greatest potential, with a total resource estimated at $33.5 billion. The price of gold has averaged NZ$554 since the beginning of 1998, and NZ$593 in the last year, which is very competitive with other countries. An assessment of country risk compared New Zealand with twenty other countries in ten risk categories: sovereign risk, land access, environmental issues, land claims, mining legislation, social risk, infrastructure, civil unrest, natural disasters and workforce. New Zealand ranked fifth, showing it has low country risk. This provides a high degree of certainty for investment, which is important for the perception of New Zealand as an exploration destination. Corruption was considered separately, and New Zealand ranked third out of ninety countries, showing it is one of the least corrupt countries in the world. New Zealand has a favourable business environment, good geological potential, low country risk and no corruption. Despite this, New Zealand has not registered on the radar screens of overseas mineral explorers, and the positive factors appear to have been overlooked. New Zealand has considerable undeveloped mineral potential, and with the current rise in commodity prices, it is hoped New Zealand can participate in a resurgence in mineral exploration.

Jan 1, 2000

Jan 1, 1959

By Donald D. Murphy

My first contact with underground, bolt conveyors came when I was hired as a draftsman by the La-Del Conveyor & Manufacturing Company in 1935. At that tine relatively few nines were using haulage belt conveyors. Wore they were in use, they were usually loaded by chain or shaker type room conveyors which in turn were hand loaded at the working face. Duo to the low room tonnage, a gathering belt might receive who output of from six to eight rooms. For several years belts 26 and 30" in width were the favorites for coal mine use. Belt speeds very seldom exceeded 200 ft. per mm. at that time. Conveyor lengths for the majority of units lay between 1.000 and 2000 ft. For a number of years 25 H.P. drives were adequate for those conveyors. From 1940 until about 1950 loads and speeds went up slightly and 40 H.P. drives became the standard. Since the majority of mines were then using direct current power systems, we were able to use controllers with 3 or more steps of starting resistance. The slow belt speeds coupled with relatively long starting cycles kept the rate of acceleration low and gave us smooth, easy starts.

Jan 1, 1963

By L Semenyna, W Douglas

Gold is often present in solid solution with pyrite in the Carlin Trend. The presence of organic carbon along with gold hosted in sulfide, referred to as double refractory ore, requires that ore with high carbon-in-leach (CIL) preg-robbing potential and poor leach recovery is routed to a roaster. During roasting, the pyrite is oxidised to (ideally) form hematite (Fe2O3), and the gold that was present as solid solution in the pyrite forms colloids within the hematite. The ideal texture of the produced hematite is porous to allow for the penetration of cyanide for gold dissolution. Temperature and other conditions of roasting, as well as ore characteristics (pyrite mineral associations, arsenic) can affect the texture and the type of iron oxide formed. Many of these alternate iron oxide minerals result in incomplete leaching. Comprehensive gold deportment studies have proven that the majority of the gold losses in Barrick GoldstrikeÆs roaster leach tailings occur within the iron oxides created through the roasting process.The iron oxide phase that hosts the majority of the gold in tailings is in the form of by-product maghemite (?Fe2O3), which is highly magnetic. Barrick Goldstrike has designed a magnetic recovery circuit to capture these iron oxides, and with subsequent reprocessing, recover the lost gold. Pilot plant results and analysis using scanning electron microscope mineral liberation analyser (SEM MLA) shows that up to 30 per cent of the gold in tailings can be recovered with a three per cent overall mass pull to magnetic concentrate. This magnetic concentrate can be economically reprocessed, resulting in a three per cent improvement in roaster recovery.CITATION:Douglas, W and Semenyna, L, 2013. Magnetic recovery of gold-bearing iron oxides at Barrick GoldstrikeÆs roaster, in Proceedings World Gold 2013 , pp 79-86 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By Arpit Parikh

"Ground Water or Pore water pressure development in Sandy Soil formation is Critical situation in foundation analysis and design.Moreover it become severe while associated with higher liquefaction probability in river bank areas. It is difficult to find cost optimized solution for liquefaction mitigation under limited budget allocated for the project. Here in these research paper the attempt has been made to have clear picture of liquefaction by using various techniques and field tests. And its mitigation by suitable foundation type. In Bangladesh, On Bank of River Meghana, Power plant structures are proposed. The particular site is full of fine sand having partial silt throughout from EGL to 55 m depth. Hence in addition to Conventional Boring / Drilling operations, CPLT, SCPT, SCHT and PMT had been performed to arrive deterministic effect of liquefaction. By use of Geologismiki software and some excel based programs developed which indicates that Certainly liquefaction occurs under the event of earthquake. By Checking past records of Bangladesh we found, there are small magnitude earthquakes are inevitable and frequent. Hence fourth to overcome the bad effect of liquefaction, the deep pile foundation -Driven Pre Cast Solid Square Pile of 400 mm dia. had been suggested for various types of power plant structures. Which densify the soil and ground will improve in resisting liquefaction.1. INTRODUCTIONA Detailed Geotechnical/Foundation design Analysis had been done to arrive at optimum foundation design solution in highly probable liquefaction zone of Silty Fine Sand near Dhaka City of Bangladesh for proposed 750 MW Cyclic Power Plant. Hence about 24 no. of (Borehole) Boring and Drilling up to depth of 55 m from existing ground level has been carried out. Additionally, 09 nos. of Static Cone Penetration Test (SCPT), 02 Nos. of Dynamic Cone Penetration Test (DCPT), 02 Nos. of Pressure meter test (PMT), 02 nos. of Cyclic Plate load test (CPLT) of suitable capacity with 06 nos. of Seismic Cross Hole Test (SCHT) in boreholes had been carried out. The purpose of PMT and SCHT was to have clear idea about the Seismic behavior - knowhow of site. According to Basic principles of Soil Mechanics and foundation design, it is proved that PMT & SCHT are dynamic test. These tests stimulate field condition of occurrences of earthquake. In later stages of analysis, it is found that site have high probability of liquefaction through use of Geologismiki – Liquefaction Analysis Software. Author of these research paper also felt earthquake vibrations – strong aftershocks during site study where Epicenter of the earthquake was in Myanmar during month of august 2016."

Jan 1, 2017