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By David Morrison

"The history of the mining industry is littered with in-pit crushing and conveying (IPCC), which should not be confused with the International Protocol for Carbon Capture, projects that failed. The failure is not the technical one of “did it achieve the desired tonnage rate for a longish test period” but, rather, the far more important one of “did it provide return on the investment in the manner that was promised?” While quite a few can claim the former, very few system installations can claim the latter.The reasons for the many failures are numerous, but they are all characterized by a combination of an element of engineering optimism in any, or all of the production rates, the productivity, or the operating and maintenance costs and in predicting the continuity of operating conditions. In these days of big data, propagating such a situation is rapidly becoming unforgivable.In this article, the three most common scenarios put to the corporate board for approval, and the logic as to why they were selected, are examined (with the irony included intentionally).• Fully mobile crusher, fed by a shovel and conveyed out of the pit to a waste dump / process plant.• Semimobile crusher (much more expensive than a fixed crushing station but which apparently allows trucks to short haul inside the pit and improve productivity), which moves when the face moves.• Relocatable crusher (more expensive than a fixed crushing station but which gets relocated at great expense after all the fixed infrastructure impeding relocation is demolished) fed by trucks that don’t leave the pit mostly.This paper will also consider the truth about their operational performance and associate costs."

Dec 1, 2016

By W. S. Hegler

Introduction The San Antonio mine is on the north shore of Rice lake, thirty miles east of lake Winnipeg and 120 miles northeast of the city of Winnipeg. Since production was started in 1932, about 2,000,000 tons of ore have been mined. Currently in progress is an extensive development programme which involves 11,500 feet of crosscuts, 3,800 feet of raises, 1,753 feet of shaft sinking, and 160,000 cubic feet of slashing, all in footwall waste rock. It is the purpose of this .paper to indicate the necessity for this work and to describe the methods employed to carry it out. Where unknown factors are as prevalent as they are in the average Canadian gold mine, a definite answer cannot be given as to what is the most economical and efficient system for mining dipping deposits. At San Antonio, the host rock for the orebodies, locally termed basalt, occurs as a sill some hundreds of feet in width and dipping at approximately 45 degrees from surface to an unknown depth. It may be assumed that it continues well below the lowest depth established to date by diamond drilling. At present, a vertical winze (No. 3 winze) hoists the ore from the 2,360-foot level to the 1,600-foot level, on which it is hauled about 900 feet to No. 3 shaft, also vertical, and there hoisted to the mill bins on surface. To maintain ore reserves at a five-year figure, at full production, additional deep exploration was required immediately. It was decided to sink No. 4 winze, a vertical opening of the same size as the other operating shafts, to provide ten additional levels (17 to 26) at 150-foot intervals, with additional depth to allow for an underground crusher installation and usual loading-pocket facilities for three-ton skip-hoisting. The winze was bottomed at 1,753 feet below the collar, at a depth of 4,117 feet below surface, and is the deepest man-sized opening in Manitoba.

Jan 1, 1949

By John F. Haberer

DURING the twentieth century Canadians have been steadily improving their standard of living. Originally, this improvement depended almost entirely upon the export of basic raw materials and a triangular system of trade with Great Britain and the United States. However, since the Second World War, Canadian living standards have improved still further because of the very rapid d0evelopment of secondary industries. As a result of this development, the present demand for scientists and engineers exceeds the supply, and interest in scientific research has never been greater. It is the purpose of this paper to discuss the professional and economic status of Canadian scientists and engineers over the past half century. GROWTH OF RESEARCH It is difficult to determine accurately the amount of scientific research conducted in Canada since 1900. However, ?prior to World War I, it was limited and was connected mainly with primary industries and health. Government departments did some; university science faculties, overloaded with teaching responsibilities, did a little; and industry, which consisted mainly of subsidiaries of American and British firms, depended chiefy upon foreign sources for new information.

Jan 1, 1956

By A. Demirag, F. Burat

"The most important metals in the jewelry sector are undoubtedly gold and silver. As a result of workmanship work done in the jewelry industry, the tiny metal and jewel fragments and metallic powders are scattered. Given the prices of gold and silver on the market, the dust that emanates from these workshops is of great importance. Gold recycling has become as important as raw material production within the mass market and gold production industry. In 2016, 29% of the world gold supply has been obtained through recycled gold production. Waste derived from jewelry activity is included in this category, and represents an essential component of this percentage. In the scope of this study, the recovery possibilities of Au and Ag from jewelry sweeps floor sample was investigated using flotation method. In the experiments, optimum pH value, particle size, the effect of dispersant, type and amount of reagent were investigated. As a result of these studies, it was determined that the optimum pH value was 6.5 and the particle size was -212 microns. It was observed that the most suitable reactive combination was Aero 242 and Aerophine 3418A and Na2SiO3 has no positive effect on recovery of Au and Ag as a dispersant agent. As a result of tests, a final concentrate containing 268 ppm Au and 2122 ppm Ag was obtained with 81.4% and 74.5% recovery respectively. INTRODUCTION Because of the softness of pure gold, it is usually alloyed with base metals for use in jewelry, altering its hardness and ductility, melting point, color and other properties. On the other hand, gold has some special chemical properties which in normal conditions, don’t react with water, dry or humid air, oxygen, ozone, nitrogen, hydrogen, fluorine, iodine, sulfur and hydrogen. In these days, gold is used in different sectors like jewelry, electronics, finances and investing, dentistry, medicine, aerospace, awards & status symbols. According to Deutsche Bank Research, the primary usage of gold is jewelry. It has been used to make ornament and jewelry for thousands of years. In this sector craftsmen learned that alloying gold with other metals like copper, platinum and silver to increase gold’s durability. Alloying gold with other metals changes the color of the products. Another significant sector of gold is electronics. Modern electronics want the use of noble metals, like gold, especially in the areas of information processing, telecommunications, and military and space electronics (Habashi, 1997). Electronic devices use very low voltages and currents which are easily interrupted by corrosion or tarnish at the contact points. Gold is the highly efficient conductor that can carry these tiny currents and remain free of corrosion. Electronic components made with gold are highly reliable. Gold is used in connectors, switch and relay contacts, soldered joints and connecting wires. Every sophisticated electronic device have a considerable amount of gold. This includes cell phones, calculators, personal digital assistants, GPS units, and other small electronic devices. Most large electronic appliances such as television sets also contain gold. Humankind has known silver since prehistoric times like gold because silver occurs in native form. The metal is found in the Earth's crust in the pure, free elemental form native, as an alloy with gold and other metals, and in mineral such as argentite. Most silver is produced as a byproduct of copper, gold, lead, and zinc refining. Silver is very soft metal like gold also, it is the highest electrical conductivity, thermal conductivity, and the lowest electrical contact resistance of all metals (Habashi, 1997). Silver is used in different sectors like industry, jewelry, electronics, photography silver good, and coins. The main usage of silver is supplied by electronics. Silver's unsurpassed thermal and electrical conductivity among metals means it cannot easily be replaced by cheaper materials. In addition to silver is using in ener"

Jan 1, 2018

By D. G. Hattingh, A Els-Botes

"Considerable information is available on the factors influencing the iron-zinc reaction rate at 450° C of low carbon steels, in comparison there is a scarcity _of similar fundamental information of spheroidal graphite irons. This can be attributed to the more complex microstructure and ferrous alloy chemical analysis of spheroidal graphite irons. Hot-dip galvanizers have identified the complexity in controlling and predicting the thickness of the galvanized coating formed on commercial cast irons, which has serious financial implications for both the galvanizer and customer.Commercial hot-dip galvanizing has been in use for over 160 years and yet an elementary understanding of the dynamics associated with the hot-dip galvanizing of spheroidal graphite cast iron is still insufficient. To allow the. process to become a modem surface engineering technology, the fundamental aspects of the process must be thoroughly understood.When a clean iron or steel article is dipped into the molten zinc, zinc initially solidifies around the steel or iron. As heat is transferred to the article form the bath, this initial solidified zinc layer remelts and a series of iron-zinc alloy is formed by the reaction of the zinc with the surface of the article; on removal from the bath, some of the molten zinc is taken out on top of the alloy layers. At normal galvanizing temperature (450 °C), the reaction between iron and zinc is usually parabolic with time. The rate of reaction is rapid at first but then slows down and the coating thickness does not increase greatly if the article is immersed in the bath for longer times(1)."

Jan 1, 2000

By W. C. McBee

Over the past several years the Bureau of Mines has developed a sulfur concrete (SC) technology in which chemically modified sulfur is mixed with suitable mineral aggregates to produce construction materials that are resistant to corrosion by acids and salts. Modified SC materials have been tested in actual operating conditions in 50 corrosive process environments at 40 commercial plants. SC components ranging from small test coupons to 4-ton acid sump tanks were fabricated and installed at plant locations where chemical corrosion was destroying conventional concrete materials. Through cooperative agreements with several companies, floors, retaining walls, and foundations were cast in place us-ing SC materials, then monitored for resistance to corrosion and retention of strength properties.

Jan 1, 1983

By I. du Plessis

The metallurgical response of a difficult to treat coal and an easy to treat coal orebody were investigated in terms of the coal yield and the coal quality in a basic coal recovery flowsheet. The purpose of this paper is to show trends and derive principles for the treatment of different coal types. This investigation entailed using the LIMN simulator to simulate the metallurgical response by varying the plant operational parameters. The controllable plant variables investigated were: ?Cyclone size ?Screen and hydro-cyclone cut points ?Medium cut density ?Feed particle size distribution.

Jan 1, 2010

By Jing Zhou

In view of the state of the long time use of sodium cyanide in lead-zinc-sulfur-silver multimetallic ore production, we propose alternative reagents system through experimental research. The experiment first used TJ, sodium sulfide to adjust the flotation pulp, after that, zinc sulfate, sodium sulfite was added to low alkaline pulp to inhibiting zinc sulfur mineral and adapted MB, 25# aerofloat and diethyl dithiocarbamate combination collectors to float lead minerals. The obtained test index is as follows: lead concentrate recovery rate of small scale test was increased by 5 to 10%, the recovery rates of gold and silver in lead concentrate were increased by 7% and 11% respectively; the industrial test is conducted under the condition that the total grade of lead and zinc content in raw ore decreased by 4.81%, the total recovery rate of lead and zinc increased by 7%, recovery rates of gold and silver in lead concentrate were increased by 7.62% and 9.65% respectively. So it successfully realizes the target to replace the sodium cyanide, using low-alkaline non-toxic reagents system in mineral processing practice of three kinds of complex lead-zinc-sulfur ore of this mine. Keywords: refractory lead-zinc-sulfur ore, depressant, non-cyanide flotation

Sep 1, 2012

By Anna Sieminska-Lewandowska, Monika Mitew-Czajewska

"The construction of 6.3 km long central part of 2nd metro line in Warsaw was completed in September 2014 (7 stations - out of which three 25m deep stations - built using cut and cover method; two single-track tunnels constructed using four EPB TBMs as well as a short NATM section with soil freezing below the existing road tunnel). Central section of the 2nd metro line was opened to public after verification and testing in March 2015. Design and build tender for the extension of this line in East (three stations) and West direction (three stations) was announced with total length of running tunnels – approx. 5 km. Detailed description of a very complex geotechnical context, different construction methods, challenges encountered and solved during construction and finally lessons learnt on this interesting project are presented in the paper. DESCRITPTION OF THE PROJECT Introduction The very first concept plan of the metro system in Warsaw was designed several years after regaining independence by Poland in 1918. In 1929, following the geotechnical survey, design works begun, but the economic crisis of the 1930s stopped it. After a few years of break, in 1938 a coherent concept of the metro network was proposed to be implemented in phases over the next 35 years. In total, construction of 46 kilometers of metro, including 31 km of tunnels and 15 km on surface, was planned. Unfortunately, World War 2 made the implementation of those plans impossible. In the post-war period several metro designs were elaborated, but none except one was scheduled for implementation. Construction of the 1st, 23.1 km long, North-South line commenced in 1983 and finished in 2008 (Sieminska-Lewandowska et all. 2009). Nowadays, Warsaw covers the area of 517 km2 and, according to year 2014 statistical data, the city has much more than 1.7 million inhabitants. Only one operating metro line is not sufficient for such a populated city. Up-to-date metro plan, shown on Figure 1, includes also 30.5 km long 2nd metro line. It’s route is divided into four sections: Western Section with the length of approx. 9.2 km and 9 stations, Central Section with the length of 6.3 km and 7 stations, North-East Section with the length of 7.7 km and 6 stations, South-East Section with the length of 7.1 km and 6 stations. The construction of the central part of the 2nd metro line in Warsaw was completed in September 2014 and its operation started in March 2015. The paper focuses on challenges encountered and solved and lessons learnt during construction of the central part of the 2nd metro line in Warsaw."

Jan 1, 2016

By Miguel Ángel González Olivares

La mina Álamo Dorado es una mina de plata y oro a cielo abierto, cuyo circuito consta de las etapas de trituración, molienda, lixiviación en tanques, filtración, electrodepositación, refinería y el “proceso AVR” , donde se realiza la recuperación de cianuro. Sin embargo, desde sus inicios la operación de electrodepositación tuvo inconvenientes como la baja recuperación de plata (comparada a la obtenida de diseño: 98%), y un tiempo corto de vida de los ánodos de acero inoxidable, debido a la fuerte corrosión por la alta concentración de cloruros presentes en la solución rica, motivando esto un cambio diario de ánodos y desde luego un gran costo en refinería. En ese sentido, el presente texto describe las mejoras para resolver dichas dificultades a través de encontrar un material de ánodo capaz de resistir la fuerte corrosión dada por los cloruros, ofreciendo éste un mayor tiempo de vida comparada con la del ánodo de acero inoxidable, así como el aumento de la recuperación de la electrodepositación de la plata.

Sep 14, 2009

The Broken Hill Proprietary Company Limited (BHP) started as a silver-lead-zinc mining company in Broken Hill, New South Wales, Australia in the 1880s. Since then it has diversified into the resource industries of steel, iron ore, coal, petroleum and copper. BHP World Minerals is a Business Group of BHP which is one of the worldÆs largest and most diverse mineral resource enterprises. BHP supplies raw materials for steelmaking, copper concentrate and other mineral commodities to customers in more than 45 countries. BHP World Minerals has operations spread throughout the world û in Australia, the United States, Brazil, Zimbabwe and Canada. Commodities produced by BHP World Minerals currently include silver, lead, zinc, titanium minerals, platinum group metals and coal. The BHP World Minerals Cannington silver-lead-zinc mine in Queensland, Australia is a return to the cradle of BHPÆs early silver-lead-zinc years. This paper compares the success factors and challenges at Broken Hill and Cannington.

Jan 1, 1998

By D. H. Baker

These investigations were conducted to determine the feasibility of molten salt electrorefining of zirconium scrap, offgrade sponge, and alloys under contract number AT(11-1)-475 between the Atomic Energy Commission and the Federal Bureau of Mines. Offgrade zirconium sponge having a Brinell hardness of 169 can be refined by this technique to produce metal having, consistently, a Brinell hardness of less than 90. Also, zirconium alloy scrap, approximating zircaloy-2 in composition, can be refined to recover zirconium metal with a Brinell hardness of less than 100 that is essentially free of the major alloying elements. Analysis showed that the quantities of these elements were decreased as follows: iron from 0.27 to 0.002, tin from 1.36 to 0.001, nickel from 0.02 to 0.001, and chromium from 0.12 to 0.002 percent.

Jan 1, 1961

By T. Bui

The shut-off value for a panel cave mine determines when a draw point will be shut-off and mining will cease from that draw point. Using a shut-off value strategy for a panel cave mine is similar to using a cut-off value strategy for an open-pit mine. This paper will discuss how to choose an appropriate shut-off value strategy that an engineer can use when planning a panel cave mine to increase the net present value (NPV) of the project. Using a shut-off value equal to the mining and processing cost will provide the total mining reserves for a panel cave mine given a specified footprint. When the net present value analysis method is used to compare one design to another then using a shut-off value greater than the mining and processing cost will generate a higher NPV. This strategy will replace the marginal ore at the top of a draw column with higher grade ore at the bottom of newly opened draw points. A draw column is broken material which sits above a draw point and it is mined to a specified height above the draw point. This height is called the height of draw (HOD). Varying the shut-off value over the life of the mine can increase the NPV even further. This strategy would have a high shut-off value during the early stages of a mine and low shut-off value during the later stages. If the shut-off value is too high then too many tonnes would be left behind the draw point and the overall value of the mine will be decreased. Also with a high shut-off value then the production target may not be maintained due to too many draw points closing too soon.

Feb 23, 2014

By John Campbell, Miller. W. E., G. W. Jones

"INTRODUCTION Because of its interest in accident prevention, the Federal Bureau of Mines has cooperated with city officials and utilities in investigating the causes of explosions in sewers, manholes, and other underground spaces and has aided in the development of means to prevent such explosions. For several years this Bureau has cooperated with the Boston Edison Co. and the Boston Consolidated Gas Co. of Boston, Mass.,for the purpose of detecting and eliminating combustible and physiologically harmful gases in manholes in Boston and vicinity.These investigations 5/ have shown that combustible gases from the usual sources — leakage from gas—distributing systems and underground tanks and gasoline wastes — can be located and the dangerous conditions remedied by a well—planned, adequately supervised, systematic, and continuous manhole survey. However, other types of gas contamination, termed ""soil"" gases, are present in manholes at times and are more difficult to eliminate because they have no fixed origin and because seasonal and barometric chances affect their production and passage into the manhole. Soil gases usually are abnormally high in carbon dioxide and low in oxygen and contain varying amounts of methane. They are especially dangerous to men entering manholes because they lack sufficient oxygen to support life."

Feb 1, 1940

An EAF dust generated in a Swedish steel mill has been leached in hydrochloric acid at The solution obtained has been subjected to purification by cementation followed by precipitation of zinc with sodium carbonate. The thermal decomposition of the precipitate was studied using thermal analysis and X-ray diffraction. The results show that during the calcination of the precipitate three different reactions occur. The decomposition of the solid phases Zn5(CO3) (OH)6, CaZn(CO3)2 and CaCO3 occur completely at 370°C, 560°C and 940°C respectively, yielding a final product containing 61.9% ZnO and 38.1% CaO. Methods to minimize calcium and manganese in the final product are discussed.

Jan 1, 2003

By W. D. Eddy

Topaz is a fluorine-bearing aluminosilicate mineral of the kyanite-sillimanite group. The formula has been given as Al2SiO4(F,OH)2, [Al(F, OH)]2SiO4, or 2Al2O3?2Al(F, OH)3SiO2. Topaz is generally considered a semiprecious-to-precious gem mineral, but it is a fairly common minor constituent of granites. In 1937 the U.s. Geological Survey reported an occurrence of massive topaz in the 3 Brewer gold mine, Chesterfield County, S.C. Over the next 8 years considerable research was done on topaz to establish its properties and to determine possible end uses The first reported shipment of ore was in 1939 Peak production was reached in 194412, and output then began declining until the mine closed in 194913? During World War II topaz was used in refractories, as a flux in steel mills, and in the manufacture of borosilicate glass 14. The main advantage of using topaz over kyanite and sillimanite in refractory use was that calcined topaz converted to over 95 percent mullite (3A1203 .2Si02) while calcined kyanite or sillimanite contained only 88 percent mullite15. However, a major draw-back to utilization of topaz is the evolution of fluorides during calcination. In 1973 the Geological Survey reported that topaz occurred in probable commercial quantities in at least two domestic locationsl6: the Brewer area of South Carolina and a location in Colorado. The literature also indicated that progress had been made in controlling fluorine-bearing fumes. This research has progressed to the state where valuable fluorine compounds are being recovered on a commercial scale 17. Thus, a major obstacle to utilization of topaz appears to have been resolved. The Bureau of Mines under its program of advancing minerals technology initiated a project to study techniques for the concentration of topaz from disseminated materials. The objective of the study was to determine those techniques that would be used to produce topaz concentrates that could be utilized as a source of fluorine and mullite.

Jan 1, 1977

By Audrey Boissier, Marie-Anne Camon, Cecile Cathalot, Yves Fouquet, Laurent Bignon, Arnaud Agranier, Ewan Pelleter, Sylvain Bermell, Florian Besson

INTRODUCTION In October 2014, on behalf of the French government, Ifremer, along with the International Seabed Authority (ISA), signed a contract to start a detailed exploration program for seafloor massive sulfide (SMS) deposits in the work plan located on the slow spreading Mid-Atlantic ridge (MAR). The contract has a fifteen-year lifetime and the related exploration program must include the outline of SMS deposits and a resource assessment, as well as detailed environmental base line studies in the contract area. The exploration for SMS deposits generally includes detection of hydrothermal plume anomalies, acquisition of surface and near-bottom geophysical data, sampling operations from the research vessel (e.g. dredges, cores), and dive operations. The environmental studies include, among others, short and long-term oceanographic measurements, water column studies, biodiversity evaluation close and far from SMS deposits, characterization of natural hydrothermal plumes and related sedimentation. The HERMINE research cruise held from March 13th to April 28th 2018 (R/V Pourquoi Pas?) was the first cruise dedicated to exploration of active and inactive SMS and to the quantification of natural chemical input to the water column. The HERMINE cruise strategy was built up around three main objectives: (i) regional exploration including the detection of plume anomalies and the research of SMS deposits, (ii) local exploration of a SMS district and (iii) integrated study of a natural hydrothermal plume. This 3-in-1 cruise required us to optimize the switch between dives and surface operations. Day-time was devoted to dive operations whereas night-time was mostly dedicated to CTD/Rosette operations. The Nautile HOV (Human Occupied Vehicle) was well suited to the working time schedule of the cruise because it was time efficient in shorter (i.e. < 10h) dives due to fast descent and ascent speed, fast submerged forward speed, high maneuverability and the ability to carry heavy science payload as well as large volume of samples. Regional Exploration The first seventeen days of the HERMINE cruise were devoted to regional exploration, i.e. the detection of new plume anomalies and the research of new sulfide mineralization in the French work plan (10 000 km2; 6 clusters).

Jan 1, 2018

By R. S. Jones

"Fording Coal Ltd. is now in its fifth year of a 15-year contract to supply 3 million long tons of clean coal per annum to its Japanese steel-making customers. The mine employs both conventional truck-shovel and unconventional ""walking"" dragline coal mining techniques in multiple-seam pits. This paper describes the present and future application of the 60-cu.-yd dragline and truck-shovel pre-stripping fleet in 1•ecovering 5- to 40-footthick coal seams in mountainous terrain. Deep blastholes, coal flow demands, spring ""run-off"", seam and inter-seam thrust faulting, limited seam outcrop data and regional faulting are a few of the problems encountered in this application. The author discusses these problems and their solutions as applied at Fording Coal Ltd."

Jan 1, 1976

By Alfredo Plenge Thorne

El presente texto señala diversas alternativas y usos para un modelo dirigido a la optimización de una operación minera en el corto plazo, incidiendo en los aspectos mineros, metalúrgicos y comerciales. El modelo se basa en la función de utilidad financiera, cuando ésta es optimizada respecto de las variables que la conforman. Se prescinde de la variable tiempo, al considerarse este modelo como de corto plazo. Se presentan cuatro ejemplos, dos simulados con data real y dos prácticos basados en el resultado actual de la operación. Asimismo, se provee al usuario una visión integral que incluye las actividades principales de la cadena de valor en la minería; unificando criterios y evaluando los efectos de cada una de las decisiones del operador minero en la rentabilidad global de la operación, al variar los principales parámetros en el proceso productivo.

Sep 14, 2009

By Donald M. Ulbrich

Any of you who served in the military remember the admoniton to "get the lead out," In the military environment, where cost wasn&apos;t always a factor, "get the lead out" was more often a call for activity of any sort than activity of a particularly productive nature. As a result, when the top sergeant yelled "get the lead out," lots of people started moving.. . usually to get out of his way. Now there&apos;s a new cry, ..one that comes not only from the military but from an entire nation threatened with dependence on foreign sources for its energy needs. That cry ...get the coal out, Like the earlier order, it&apos;s a call to activity. A signal that the coal reserves of the United States must be tapped so that Project Independence can succeed by 1985, But it&apos;s more than a mere call to activity; it&apos;s also a call to achieve productivity. ,a call to produce coal both efficiently and acceptably. And that leads us to the key questions of where the coal is going to come from to meet that 1985 goal, and how can it best be mined. Where will the coal come from? There&apos;s no doubt much of it must come from surface mining in the West. How can this coal be mined? There are several options available but there is an excellent case to be made for using mining shovels and haul trucks due to their versatility in stripping, loading and reclamation, We&apos;ll explore this approach in this talk today.

Jan 1, 1976