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By Bauer, Alan

In considering blasting it is necessary to consider the drilling and explosives since one is generally concerned with the total cost of muck of a certain size in the pit or through the crusher. To get a current idea of the drilling situation in open pit mines plotted in Fig. 1 are the drilling costs per ton of material vs. hole diameter for rotary drill holes in large limestone, iron ore and taconite operations. The exception is the 2-in. diam hole which was drilled with a percussion drill in limestone.

Jan 1, 1968

By S. W. Swerson

25.1-THE PURCHASING FUNCTION The word "purchase" means "to obtain by paying money or its equivalent; to buy for a price." This definition is all too simple to properly describe the word "purchase." One should consider the basic objectives of purchasing-to procure the right material, of the right quality, in the right quantity, at the right time, from the right source at the right price. Here it should be noted that in purchasing it is recognized that the best quality or grade of materials may be the only grade to purchase for a specific job. However. there are other jobs where the medium, standard or poor grade of materials is the right quality, as the lesser grade will perform adequately. In some companies the purchasing department makes the decision as to the right quality, while in others this function is shared with other departments. Years ago in business the owners controlled the purchase of required materials and services by performing the task themselves. The owners obtained the type materials and services they needed and paid the price demanded. This function was performed along with all the other duties requisite to the owner of a business, namely, clerical, hiring and firing of personnel, financial management, etc. As companies grew in size, clerical duties were assigned to other personnel and the owner usually retained the purchasing authority. This same division exists today in many small companies. However, in the larger companies, the purchasing function has been assigned to a separate department. Importance of the Purchasing Function-The larger the company the greater the need for a separate department to perform the purchasing function. Today the purchasing agent for most larger progressive companies has policy-making authority. Therefore, it is reasonable for him to report to the president or vice president of his company. Studies of several hundred companies show the purchasing department head reporting to top management 87.5% of the time. This fact in itself is indicative of the importance of recognizing that effective purchasing requires a department staffed with specialists in the field of procurement with knowledge and experience sufficient to perform in today's complicated business atmosphere. In the manufacturing field it is a common axiom that usually half of the company's dollar expenditures are for materials. If a purchasing department functions properly and the right product or service is purchased and a savings accomplished, the contribution to the net profit of the company is much greater, as opposed to sale dollars, where only a small portion is carried forward to net profit. Thus, the importance of the purchasing department and the contribution it can make to the success of the company are obvious. 25.1.1-THE PURCHASING FUNCTION 1. Responsibilities of the Purchasing Function-The purchasing agent in performing his function is acting as an agent for the company and others in the company requiring materials and services. Accordingly, he is committing the company for materials and services subject to certain limitations which the board of directors may stipulate. In view of this, the purchasing agent,'^ position must of necessity he

Jan 1, 1973

By B Patterson, Y Lanwin

Over the last decade the adoption of autonomous technology has proven its potential to fundamentally alter the mining industry, offering significant improvements in safety and productivity. Automation levels are now increasing exponentially across all parts of the supply chain from drilling, haulage, processing, rail and shipping to the maintenance of the above. However, the management of human error risk is also becoming increasingly complex as the disconnect between the people who operate and interact with mining equipment and those that design the autonomous systems grows in terms of skill and expertise. Furthermore, as comfort levels with automation increases amongst operators, complacency is increasing as the initial functional safety benefits have been realised. This paper introduces an innovative concept that unites two distinct fields, functional safety and behavioural economics, to address the complex issue of human error risk in autonomous mining operations. Functional safety, a well-established field in engineering involves identifying potential hazards, assessing risks and designing systems in a way that minimises the chances of accidents and limits their consequences. Meanwhile, behavioural economics takes a data centric approach to analysing the psychological aspects of human decision-making, acknowledging and seeking to understand the errors that can originate from cognitive biases and heuristics. This paper seeks to bridge these domains by emphasising that human error in autonomous mining is not solely a technical issue but is deeply influenced by human behaviour and decision-making processes. By incorporating insights from behavioural economics, we can better predict, prevent and manage human errors in the mining sector. By applying principles from both disciplines to a recent incident example we will explore how cognitive biases can impact peoples’ interactions with autonomous mining equipment. This interdisciplinary approach will not only enhance the design and implementation of functional safety measures in mining but also lead to the development of people centric solutions that consider the inherent fallibility of people. We will explore how human centred design can help bridge the gap between these two domains and apply systems thinking for a universal approach. Through an indepth case study analysis and empirical data, our research aims to provide actionable insights and practical recommendations for mining industry professionals, regulators and stakeholders involved in the safe integration of autonomous systems.

Apr 16, 2024

By E. Demir

Transportation cost is the dominant cost and accounts for almost half of the total mining cost in surface mining. Therefore, determining transportation cost is critically important for the economic feasibility of mining projects. Turkey produces around 85 million tons of lignite per annum. The biggest state-owned company, Turkish Coal Enterprises (TKI), accounts for 43 per cent of the country?s total lignite production. Around 85 per cent of the produced lignite is used in power plants for electricity generation and 15 per cent is used for domestic heating in cities and urban areas. On behalf of the Turkish government, TKI distributes around 2 Mt of lignite annually, at no cost to poor needy families countrywide in accordance with Social Assistance and Solidarity Funding aid. Subcontractors are utilized for lignite transportation, and conflicts arise due to the different transportation cost calculations at different mines. A robust model that provides unbiased cost estimations is therefore of paramount importance. This paper presents the transportation cost estimation software, NAKMAL, that has been developed for estimating the transportation cost of lignite from the mine face, including excavation and loading, to various final destination points through five different transportation scenarios. NAKMAL was designed using VisualStudio.NET, validated using field data and some case studies, and it is currently being used by TKI for calculation of transportation cost country-wide.

Jan 1, 2012

By A. Krishnan

Keywords: Tantalum extraction, SOM Technology, inert anode, membrane stability The Solid Oxide Oxygen Ion conducting Membrane (SOM) technology offers great potential for environment friendly and energy efficient extraction of high-energy content metals. This work was performed to demonstrate the technical and commercial viability of the technology to produce tantalum metal directly from tantalum oxide and ore concentrates using a solid-oxide, oxygen-ion-conducting membrane (SOM). The process can be used to efficiently produce tantalum metal without expensive pre-processing of raw materials and without harmful by products. The work reported in this paper is: the proof that high purity tantalum metal can be produced, study of the electrochemical behavior of the cell and the method to increase membrane stability.

Jan 1, 2005

By R. J. Armstrong, J. J. McKay

The Montana Phosphate Products Co. is currently operating three underground phosphate mines in Powell County, MOnt. † In this area the Phosphoria formation is from 35 to 50 ft thick and contains a bed of phosphate rock varying in thickness from 2 1/2 to 5 ft, overlain by 12 to 30 ft of cherty quartzite, and underlain by about the same thickness of quartzite and shaly to cherty beds. In general, the phosphate bed has a reasonably hard quartzite footwall, as well as a hard cherty hanging wall, both of which greatly facilitate the mining operation. Folding has deformed the phosphate bed to a considerable degree in the area. It is carried to surface by several of the anticlines and lowered to considerable depths in some of the syn-clines. The main structural features affecting the mining operations of the company are the Garrison anticline and the adjoining syncline and succeeding limb of a second anticline on the east (Fig I). The axis of the folding strikes roughly northwest-southeast. The three mines, namely, the Anderson, Graveley, and Luke are on different limbs of the above folds. Accordingly, the dip of the bed, and consequently the mining method, in each mine differs to a considerable degree from that of the others. For this reason, each operation will be dealt with separately. Anderson Mine LOCATION AND DEVELOPMENT Topographically this mine is in a narrow valley, the bottom of which has an altitude of 5200 ft. The phosphate bed outcrops near the ridge on the east and dips towards the valley floor at an angle of from 25 to 30°,

Jan 1, 1950

By Nadya Michel, Daniel Gros-Jean

This is a true story. Names have been changed to illustrate the importance and impact of carbon monoxide risk management in explosive blast projects and the community « Honey I’m not feeling good…” “What is going on Michael?” – – Michael was not answering so Julia, who was on the third level of the magnificent house, hurried down the stairs to check up on him in the basement. Today was day 2 of the construction work of the bathroom, yesterday they had excavated all the space for the shower. She started to breathe heavily as she was approaching the bathroom and saw Michael unconscious on the floor. “Michael!” – Julia immediately dialed 911. She opened a window since the air was heavy and went by Michael to hear him breathe and take his pulse. The paramedics took Michael on a stretcher and rushed him to the hospital. “I’m feeling dizzy” she thought to herself a couple of hours after the incident, and heard Matthew say: “Mom, I’m feeling sick”. Suddenly, she felt like she would pass out and felt in danger but couldn’t move. She desperately searched for her cellphone and dialed 911 but couldn’t speak. The dispatcher sent the firefighters and paramedics to the GPS location that was appearing on the screen and the emergency team was alerted that it was a second call in hours at the same address. When the firefighters arrived, they had to force the door to enter and found Julia in her bedroom on the third floor and Anette and Matthew also unconscious in their bedroom, lying on their respective bed. There was no smoke but on their multigas meter, carbon monoxide (CO) peaked at 1500 ppm on every level of the house, which is abnormally high.

Feb 6, 2023

By Nathan C. Rockwood

WHILE mining engineers have been searching in far corners of the country and of the world for hidden wealth there has grown up around us in nearly every city great wealth-producing mines calling for the investment of hundreds of millions of dollars and yielding products now sold for over half a billion dollars yearly-largely unknown and almost wholly neglected by mining engineers. But this neglect is explainable and excusable. They are industries of very recent origin-practically the growth of the last 25 years. They are in a very large measure the result of tremendous developments in engineering construction and the rapidly expanding use of portland cement concrete for structures of every description. Concrete as a material of construction is going through an evolution very much as did cast iron and other metals used in engineering; and this phase of the industry should appeal to the imagination of metallurgical engineers. At first iron was iron-a material of uncertain properties, owing both to small differences in chemical composition and in methods of manufacture. By successive steps iron was studied and knowledge of its properties developed-the striking effects of very small percentages of other minerals and of various heat-treatments.

Jan 1, 1924

By A. Jain

During sheet forming, metal experiences not only multi-axial load, it also undergoes strain path changes. For example, metal in the flange region may be drawn, may bend and unbend through a bead, before bending around a die radius, etc. Compression data were obtained from AZ31 sheet after pre-straining in compression along an orthogonal direction. The compression directions correspond to the sheet product (rolling-RD, transverse-TD, and normal-ND) directions. Three cases are examined: slip dominated deformation (ND) followed by twin dominated (RD or TD) deformation, twin dominated (RD or TD) followed by de-twinning (ND), and twin dominated (e.g. RD) followed by cross-twinning or secondary twinning (e.g. TD). Slip induced pre-straining simply hardens the material, while twin dominated pre-straining alters the texture allowing the material to either de-twin or re-twin upon changing the strain path. Polycrystal plasticity modeling has been used to predict qualitative features of the flow curves during strain path changes.

Jan 1, 2006

Real economic growth for 1988 may fall short of the 3.3% projected by the Department of Commerce in August 1988 because the summer drought and intense heat in many areas curtailed output more severely than expected. The economy grew at an average annual rate of 3.0% for the first three quarters of the year, slowing in the second and third quarters. Export growth, which occurred even as the dollar edged up compared with other industrial country currencies, was an important factor in the expansion. Notable gains were posted in sales of machinery, computers, aircraft, chemicals, and telecommunications equipment. Imports increased, but not as much as exports, and the U.S. trade position was still much improved from that of 1987. Personal consumption expenditures grew slightly faster than the economy as a whole. Purchases of consumer durables showed notable strength in the first half of 1988, but slowed down in the third quarter. Despite the moderate rise in interest rates, business spending for new plant and equipment also rose and contributed to 1988 gross national product (GNP) growth. Both new business investment and export demand spurred orders for U.S.-made machine tools. Orders for machine tools for the first 8 months of 1988 were almost triple those in the corresponding period in 1987.

Jan 1, 1989

By V. Galla

Waste rock facilities (WRF) generally have a large footprint depending on the strip ratio the mine plan provides. Considerable planning is involved during the initial phase of the mine plan regarding the location of the WRF. As the mining operations are commenced the locations of the WRF change accordingly with the variations in the mine plan involving feedback and support from local communities and stakeholders. Waste rock facilities management becomes challenging when the area available for placement is limited due to terrain topography, environmental and permitting constraints. Risks associated in the design of waste rock facilities constitute particle size of rock, chemistry associated with the rock for reactivity and stability of the over all facility. This paper will provide some insights on designing, scheduling and managing a WRF. Emphasis on geotechnical, geophysics and geochemistry aspects of waste rock with reference to design, construction process and scheduling of WRF are also presented. Design improvements in the reclamation slope of WRF for erosion control will be discussed. Continuous improvement (CI) methodology will be introduced in the process of WRF operations. Current practices and future recommendations towards sustainability and consistency in operating WRF will be discussed in conclusion.

Jan 1, 2011

This paper has been prepared to challenge the thinking of new leaders entering the mining industry in two areas. First, what is the worldÆs perception of mining and what does this mean to those entering the industry? Second, what is the future of learning in the mining industry and how can the industry attract and retain the best people?Then in closing, how can mining companies turn these challenges into opportunities and specifically how is BHP Billiton meeting these challenges.

Jan 1, 2004

By John E. Bailey

The advent of Nuclear Energy has caused a phenomenal growth in the uranium mining industry. To keep abreast of this surge the mining industry has located many ore bodies, determined the best types of mining adaptable to this particular type of ore and developed a highly specialized type of operation. But, has the mining industry gone far enough in the planning? Has ?built-in? safety been included in the efficient methods of operation? Preplanning safety in the mining industry, as in all industries, takes engineering and ingenuity combined with the experience and cooperation of all concerned. A system of mining can be planned on a map and it will look good. However, when the actual mining takes place, conditions may be such that deviations from the original plans may be required because of excessive water faults or other conditions encountered. With safety we may also be required to change, to conform to the characteristics of a particular operation. People in the mining industry are well aware that loose back has killed miners each year. This condition occurred in practically all types of mines. The condition is not new to us. It is also known that explosives, haulage, machinery and conditions common to all types of mining have taken a heavy toll of human life in mining. In addition to these hazards in the uranium mines, the hazard of radon is also present, Radon is a radioactive gas liberated from ores containing radium. This gas is released into the active workings by the blasting or breaking up of the ore. Sometimes it is caused by radium contaminated water seepage from abandoned workings or from the ore body itself. Until the action of this gas on the human was known, many miners were affected. Un- less adequate precuations are taken to protect the people in these mines,, they may be exposed to this hazard, Health researchers made a study of this substance to determine how it would affect the health of the men, They also studied men who had worked in previous years, in mines known to have contained radioactive materials. All of this research contributed to the present knowledge of radon and its daughter products. It is not flammable nor explosive, but, if allowed to enter the body through the respiratory organs it can cause serious damage. Mines have been operated in the past and are still being operated, which were known to contain explosive and noxious gases, indicating that this problem can be controlled. Several states have instituted laws that make it mandatory to provide adequate ventilation and use of monitoring devices to limit radon and its daughter products to a maximum of 300 micro-microcuries per liter of air. This is considered a safe limit for sustained periods of human exposure. While the findings of research do not prove conclusively that the inhalation of excessive radon or its daugher products cause lung cancer, indications point to this as a possibility, particularly radium A and radium C1 of the daughter products. The threshold limits set by law in most uranium producing states are believed to be safe. In a few years, when tests and data now in the process of collection by interested state officials and laboratories is complete, these limits may be found to be ready for revision. Studies such as these take time. At present, the limits that are used are based upon estimates. The permissible limits of exposure to radon and daughter products include a large safety factor. It is considered that a good supply of fresh air delivered to the working places, adequate dust control, the sealing of unused or abandoned workings, the removal of mine water which is generally contaminated and a safe waiting period after blasting, will hold to a minimum the dangers from this source. There are, of course, problems accompanying each of these procedures. For example, the ventilating of untimbered raises and bringing fresh, uncontaminated air to the working places may be a problem. However, a good mining man can solve these problems as they apply in each particular operation. From the information available at the present time, the daughter products containing polonium and emitting alpha radiation, may be a health hazard. Fortunately, the half life of most of the daughter products is short, however, radium D has a half life of 22 years and presents a problem of contamination in the storage of old tailings. So we can see that failure to comply with the accepted good mining practices may have harmful effects on the health of miners. It is gratifying to note the interest in this potential hazard by the officials in the uranium ore producing states, who are making extensive studies and keeping records of the men who work in this type of mining. This all provide information necessary for preplanning safety. By contrast, little has been accomplished to control the injuries and deaths from some other factors connected with most underground mining operations. I would like to discuss briefly one of the hazards which take an annual toll in our underground mines, this is falls of back and walls. This problem or hazard is present, and will be

Jan 1, 1958

By A. González

Arsenic is one of the main contaminants present in Chilean copper concentrates and its abatement represents a challenge for the process metallurgy, particularly under the strong environmental requirements in the global community. The possibility to form ferric arsenate directly from a gas phase by means of a heterogeneous reaction between an arsenic gas bearing and iron oxide was studied at laboratory scale. A thermodynamical analysis for the system Fe-As-O-S has been initially made, in order to obtain the stability conditions for the ferric arsenate or other FeAsyO2 type compounds. Experiments were made using an hematite sample suspended in a thermogravimetric device. AS4O6 gas generated from solid AS2O3 that was passed through the iron oxide sample and its instantaneous weight change was recorded directly. A kinetic study for the AS4O6 volatilization was made to control the gas composition. A chemical control between 300 and 600°C with an apparent activation energy of around 14 Kcal/mol As2O3 was determined. The samples after the reactions were chemically and XRD analysed. Arsenates detected corresponds to complex compounds. Results shows a dependence on temperature and oxygen content in the gas phase. The kinetics for iron arsenates formation is slow, reaching an arsenic capture of 6% after 80 minutes of reaction when an oxygen content of 50% is fed continuously at 800°C and 3,56% As in the gas. Experiences made at the same temperature but under higher oxygen content in a closed reactor, allowed arsenic capture close to 60%. For higher temperatures the capture is considerably lower.

Jan 1, 2003

By J. E. Dutrizac, J. B. Sunstrum

Until relatively recent times, virtually all gold was recovered by gravity and/ or amalgamation methods. Although such techniques are very effective on coarse gold, they become increasingly less useful for finer grains especially when the gold is partly enclosed in rock matrix. Throughout the nineteenth century a number of bonanza gold fields were found in the United States, South Africa, Australia and Canada. In every case the abundant supply of gold nuggets and coarse alluvial gold soon gave way to hard rock mining with its inevitable losses of fine gold in the stamp mill tailings. Continuing efforts to develop new technologies capable of dissolving gold from finely ground ore were eventually successful first with chlorination (the Plattner process) and subsequently with cyanidation. Even before the nineteenth century, however, European chemists such as Scheele and Berthollet were aware that gold could be readily dissolved in an excess of free cyanide(1). As early as 1840, a patent was issued to the Elkington brothers for the dissolution of pure gold in cyanide solution and its subsequent plating onto various metals, with or without an applied electrical current. In 1846, Elsner showed that oxygen was also required to solubilize gold or silver in cyanide media(1). Despite the fact that much work was done on the reaction of cyanide solutions with gold, a viable leaching process for gold ores did not quickly emerge although cyanide solutions were used to enhance amalgamation from the 1860s onward. Major problems were associated with the use of concentrated cyanide solutions; the costs of cyanide were excessive and it was difficult to recover gold from the concentrated media.

Jan 1, 1999

By Gordon Chen

The Block 37 Chicago Transit Authority (CTA) Tunnel Construction Project was originally designed by STV to connect Blue Line subway in North Dearborn Street and Red Line subway in State Street in the downtown Chicago Area. The project was proposed using tunnel mining techniques combined with steel pipe jacking and fiber glass rebar soil reinforcement. Weidlinger Associates, Inc. (WAI) and Kiewit Construction Company proposed an alternate design using open cut construction technology. WAI designed a complex temporary excavation support system using Soldier Pile Tremie Concrete (SPTC) walls and Soldier Pile Lagging walls supported by cross lot/corner bracing elements. Below the top of the existing tunnel, a top-down construction technique was utilized. A steel temporary traffic decking system at top of the excavation site served as the daily street traffic function as well as the first level of bracing for the support of excavation. The project encountered great challenges of soft clay conditions in downtown Chicago, numerous existing utilities in the excavation site and the requirements of protection for a number of historical buildings nearby as well as the protection of the city streets. The construction was successfully completed at both State Street/Washington Street and Dearborn Street/Randolph Street. The monitoring system showed that ground movement and adjacent building settlement was kept to a minimum during construction.

Jan 1, 2009

By Markku Virtanen, Pertti Koivistoinen

From the perspective of a large mining company the comminution circuit design is worth keeping within the boundaries of the organisation. The correct circuit design begins from the understanding of the role of grinding. Grinding is a link only in the long "comminution chain," starting from solid rock and ending at the concentrating stage. The final target in comminution is to take a part in the maximization of Net Smelter Return, which goal provides the simultaneous considering of capital costs, operating costs and the economic effect of process results. As a general rule there will be a single crushing stage only, ahead of the grinding process. Grinding does not use any metallic grinding media at all, and there will be fine crushing for critical material in the grinding circuit. Grinding has a minimum two stages, besides, at many concentrators middling products and quite often also tailings are reground.

Jan 1, 1997

By Frank Hirthammer

The paper explains the procedure of implementing Track & Trace solutions for manufacturers of explosives based on customer experiences. By using concrete examples, the process from project start to implementation is described. Lessons learned from the experiences of European explosives manufacturers are presented.

Feb 1, 2020

By THOMAS SOULE, R. I. C. Manning

The Phelps Dodge Corporation considers safety a major operating problem , both from the humanitarian standpoint , for this company has a real interest in the welfare of its employees , and from the economic standpoint , for it has found the safe way to be the most economical . In turn , a feeling among employees that the company really has their interests at heart has a wonderful psychological effect . It is bound to bring forth more and better work and to attract and keep workmen of the better class . There is keen competition between the various branches of this corporation for a trophy that is awarded each year to the one having the best accident record . This trophy was won by the Nacożari branch of the Moctezuma Copper Co. in Mexico in 1926 and 1927 , and the Morenci branch won the trophy in 1928 and 1929 .

Oct 1, 1930

Though many mining and mineral processing companies have embraced the principles of sustainable development (SD), there is still a significant challenge of applying these in a practical sense, either in plant design or as part of day-to-day operations. The high-level nature of sustainability concepts often do not translate easily into workable activities or business case evaluations. This makes it difficult for engineers and company decision makers to understand whether their actions are making a contribution to sustainable development and a long-term business case. While several organisations have their own SD tools that can, to a degree, help identify these opportunities, they are largely ad-hoc and lack the necessary thoroughness to defensibly value these opportunities. Recognising these serious shortcomings, the Cooperative Research Centre for Sustainable Resource Processing (CSRP) has undertaken the development and trial applications of SUSOP« (SUStainable OPerations), a new concept that is somewhat analogous to HAZOP and the wider risk and safety frameworks used in projects today. The key goal of the SUSOP« research project is to produce a holistic, systematic and rigorous framework for project development, capturing, recording and evaluating SD opportunities and constraints against a chosen sustainability structure (eg Five Capitals). SUSOP« is being developed through an iterative process with input from research institutions and engineering companies. This integrated approach ensures that SUSOP«, in its final form, will have the academic rigour and industry realism required to assist the resource sector contribute to societal sustainability by embedding the concepts and processes into the design and operation of their assets in a meaningful and practical manner. SUSOP« has created much traction with both engineering companies and mining and minerals operators. This conference paper presents an overview of the SUSOP« framework and its current suite of processes as well as highlighting, through practical case studies, its capability to incorporate SD considerations at different phases of an engineering project's development.

Jun 1, 2010