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By Eduardo Velasco, Paz Navarro, Alfonso Navarro, Claudio Cimiotti, Alejandro Sanz, Nick Karlin

The LA Effluent Outfall tunnel is a 7-mile long, 18' internal diameter, secondary treated effluent discharge tunnel currently under construction by Dragados USA for the Los Angeles County Sanitation District No. 2 (LACSD). The purpose of this tunnel is to add redundancy and increased capacity for discharge of secondary treated effluent from the LACSD’s Joint Water Pollution Control Plant, located in Wilmington, California within Southern Los Angeles County. Current discharge from this facility flows through two existing tunnels of 8' and 12' horseshoe profile, constructed in 1937 and 1958, respectively. When the new tunnel is complete, it will add an additional capacity of 670MGD in peak wet weather flow conditions. Geology of the roughly 7 mile long tunnel was divided into six reaches by the contract documents. Tunnel Reaches (TR) 1 to 3, comprising 19,550' will be excavated in alluvial sands of the San Pedro and Lakewood formations, with cover ranging from 45 to 90 feet. In this reach the tunnel intersects the seismically active Palos Verdes fault Zone. TR 4 is a 1,600' transitional zone between alluvium and the rock formations of the Palos Verdes (PV) Hills, comprised mostly of Malaga Mudstone. TR’s 5 and 6 total 15,591', and are within the rock formations of the PV Hills with overburden ranging from 315' to 475'. The primary constituent of the PV Hills is Altamira

Jun 13, 2021

The introduction of nitro-carbo-nitrate (NCN) blasting agents has been one of the most significant innovations in the explosive industry in the last twenty years. The most commonly used blasting agent is a rather narrowly proportioned mixture by weight of 94% ammonium nitrate (AN) and 6% No. 2 diesel fuel oil (FO) that is generally designated as ANFO. Other formulations have been developed but none of these have been as extensively used as ANFO. The relative safety of the nitro-carbo-nitrate (NCN) blasting agents almost immediately suggested bulk loading techniques to obtain economies in materials handling. The first attempt at bulk handling was to pneumatically load boreholes with ANFO. When the initial experiments were made in 1957, it was apparent that there were three problem areas which needed study to minimize potential hazards. These were: 1. Static Electricity 2. Fumes 3. Safe Handling Procedures Since those early days, considerable work has been performed in evaluating these problem areas and in arriving at procedures and recommendations that would provide the required safety. Despite the relative insensitivity of ANFO type products, all normal practices for the safe handling of explosives should be obselved. Smoking should not be tolerated in the vicinity of blasting agents and misfires should be handled in the same manner as a misfire with a dynamite charge. The purpose of this Technical Report is to discuss the problems of static electricity and fumes and the solutions that have been developed. Safe handling procedures have been discussed by the Bureau of Mines and are specified by various state and local regulations. Since regulations vary from state to state, the local, applicable regulations must be followed within the area of their jurisdiction. General information is contained in a U. S. Bureau of Mines report, IC 8179, "Safety Recommendations for Sensitized Ammonium Nitrate Blasting Agents" (1963).

Jan 1, 1973

By Adrian C. Dorenfeld

Concentradora "Dana Aida" (100 t/d capacity) was built in 1971-1972 to treat dumps and ores containing mixed oxide-sulfide copper-gold-silver minerals from two veins. The veins, Don Felipe and aria are about 150 m apart, but are distinctly different mineralogically. The deposit is near San Juan de Guadalupe, Durango. Mexico. All new process equipment was manufactured locally, in or near Torreon, Coahuila. Sampling, ore testing, flowsheet design, plant design, drawings purchasing, financing, etc. was planned and directed by two engineers. Construction was executed by local miners and common labor (largely agricultural). The paper presents detailed costs for equipment and construction. The subsequent breaking-in operation is discussed.

Jan 1, 1979

By Max Friedemann, Franziska Günther, Helmut Mischo

Ensuring adequate ventilation is a critical aspect of safety in underground mining operations. In small-scale mines in particular, key ventilation parameters such as temperature, humidity, and air velocity are often measured manually and only at infrequent intervals, typically using analog instruments. As a result, real-time monitoring of environmental changes, timely detection of hazardous situations, and demand-driven ventilation control are not feasible. This presentation discusses the selection and evaluation of modern digital ventilation measurement devices, including handheld instruments with digital data logging capabilities and continuously operating sensors with potential for real-time data transmission. The investigations focus on the challenges posed by underground environments with extremely high humidity levels, which can adversely affect sensor performance and electronic components. The results are based on testing conducted at the Research and Teaching Mine of TU Bergakademie Freiberg—an underground ore mine characterized by humidity levels exceeding 95%. Findings include assessments of measurement accuracy, reliability, and practical applicability under these demanding conditions.

Feb 22, 2026

By L. Yuan, J. H. Rowland, R. A. Thomas

"Hydrogen (H2) gas released during battery charging can result in cross-interference for carbon monoxide (CO) sensors used for early fire detection and compromise the integrity of the mine atmospheric monitoring system (AMS). In this study, a series of laboratory-scale and full-scale experiments were conducted to evaluate the responses of different CO sensors to H2 gas. In the laboratory-scale experiments, constant H2 concentrations in the airflow, from 100 to 500 ppm, pass through sensors. While in the full-scale experiments, increasing H2 concentrations generated as a byproduct from charging the batteries at the battery charging station rise to the sensors under different ventilation scenarios. The H2 concentrations at the CO sensor location were measured using H2 sensors and were correlated with the CO sensor response. The effects of ventilation and sensor location on the CO sensors responses were also analyzed. The results of this study can help mining companies to select appropriate CO sensors and improve the deployment of these sensors to ensure the safeguard of underground miners. INTRODUCTION As many types of battery-powered mining equipment such as scoops and shield haulers are used in underground mining operations, charging stations are required to charge the equipment batteries. These batteries are of lead acid chemistry. A safety issue exists with the battery charging stations as all lead acid batteries produce flammable H2 gas during the normal charging process. Overcharging or excessive heat can quickly cause batteries to produce even more H2. If H2 is not appropriately diluted or dispersed, it builds up, and the risk of fire and explosion increases. Mine Safety and Health Administration (MSHA) regulation (30 CFR Part 75.340) requires that battery charging stations should be housed in noncombustible structures or be equipped with a fire suppression system. When a fire suppression system is used, the battery charging stations must be ventilated with intake air that is directed into a return air course or ventilated with intake air that is monitored for CO or smoke using an AMS. The monitoring of intake air ventilating battery charging stations should be done with sensors that are not affected by H2."

Jan 1, 2018

By J. P. Gliddon

Since 1980 a number of significant changes have been introduced at Palabora in an effort to off-set the effects of reduced product price and increased unit cost of inputs. These changes and improvements include major equipment rationalization programs, the introduction of trolley assisted truck haulage, adoption of a sophisticated computerized truck control system, pit design enhancements, improved drilling practices, use of emulsion explosives and the installation of an in-pit crushing and conveying system. The various changes, their effect on the operation and their contribution to cost reduction and improved productivity at Palabora are considered.

Jan 1, 1987

By H. Ehnes

"“Industry 4.0” – “Mining 4.0” - perhaps you have already heard of these terms? These keywords signify the next stage of industrial production. The internet and production technologies are growing closer together. Machines can communicate with one another, wherever they may happen to be located. The “Internet of Things” is the appropriate term. But what does SAFETY 7.0 mean? It is both brand new and traditional at the same time. It also has to do with the success of companies, with efficient production. And yet there is a great deal more at stake. It has to do with our lives and our safety – the supreme commodity in this world. What exactly SAFETY 7.0 means, what the number 0 stands for and the meaning of the number 7, and what this all has to do with mining will be explained in the following article. Mining is a fascinating undertaking. Mining is indispensable for a country’s economic development, whatever that may concern: infrastructure, energy supplies or raw materials for industrial production. Mining has brought forth many technological developments and innovations that can currently be found in our daily lives. Mining is impressive, grandiose and repeatedly fascinates mankind with its immense dimensions. Miners throughout the world still work hard and, for this reason, are bound to one another in a special way. In mining, every man looks out for the other; you have to be able to rely on each other. That creates a strong bond. The other side of the coin is that mining and disasters belong to normality in the media and thus also in our perception. Accidents at work and even catastrophes occur in mining, quarries, or raw material operations almost on a daily basis somewhere in the world. They are often associated with extremely serious injuries, or even a fatal outcome, for the miners affected and, in turn, dramatic consequences for the families of those involved. It could be in China, India, Russia, or somewhere in Africa, Asia or America – it mostly does not happen in front of our door or in our neighbour- hood. Perhaps because of this in the daily concert of negative headlines, we do not register these catastrophes any more in our minds. We write them off under the heading “Nothing special”, since there are, day in day out, more terrible news items about wars, civil wars, famines, or ecological disasters. Things only really change if there is a dramatic number of deaths or when we are personally affected, close by in the vicinity, or can witness the rescue action live. In Europe, these three mining disasters in particular have recently generated media resonance:"

Jan 1, 2016

By B. W. Lawrence

Shaft alignment requirements are consistently met using conventional shaft sinking methods. Little attention has been given to achieving similar alignment accuracies using rotary drilled shaft methods. Alignment of these shafts is difficult to control and guarantee. Bare shafts and shafts that use drum hoisting systems can accept some deviation. However, combining drilled shafts with Koepe hoist installations presents new accuracy requirements for drilled shafts. This paper describes the importance of verticality with practical examples, and discusses various methods of measuring verticality and their respective limitations.

Jan 1, 1989

By James N. White

Completion of the Hall Street Coal Transfer Terminal in St. Louis marks the beginning of a major shift in the movement of coal to the power generating stations of the Midwest and South Central regions of the United States. The location of the terminal is significant. The 10 million ton- per-year facility is the first high capacity rail-to-barge transfer terminal to be built on the western shore of the Mississippi. This terminal and others to follow will link the massive coal fields of the West with the high coal consuming markets adjacent to the 25,000-mile Inland Waterway System.

Jan 1, 1979

By J. R. Cobble

The Bureau of Mines has developed a process to improve the leaching kinetics of diffusion controlled systems. The system features the Bureau-developed turbomill, an attrition grinder which scrubs the reaction product coating away from the unreacted mineral grains during leaching. The system can be continuously operated at any temperature up to the boiling point of the leaching agent. This paper describes the research on the dissolution of chalcopyrite with acidified ferric sulfate which forms a sulfur product on the unreacted chalcopyrite surface. This method is a hydrometallurgical alternative to chalcopyrite smelter technology which eliminates S)2 emission problems with its associated costs. Batch testing at 90? C with the chalcopyrite/ferric sulfate system resulted in better than 99-pct extraction of copper. At an optimal energy consumption of 1,520 kW h/st, 95 pct of the copper was extracted. Recent work has been directed to development of a continuous system and SX/EW treatment of the resulting pregnant liquor from the chalcopyrite/ferric sulfate leach.

Jan 1, 1991

By Serdar Aktaş, Burcu Nilgün Çetiner

According to critical statistical studies, antimony is one of the rarest elements in the world, and global resources could be exhausted by 2050. In light of these observations, its extraction will be costly due to poor-quality ore, deep mining, remote locations, and high energy consumption. In the present study, an alkaline leaching process was carried out on stibnite concentrate to evaluate the effect of reaction parameters on the percentage of antimony extraction. The leaching efficiencies of different sulfur and hydroxide sources were studied and compared to one another to create a better understanding of the reaction process. Kinetic models were investigated to identify the reaction pathway and calculate the activation energy. The activation energy of the stibnite dissolution was assessed as 19.13 kJ/mol using a two-dimensional diffusion-reaction model. The value of activation energy indicates the quantity of energy necessary for a reaction to proceed. As expected, potassium hydroxide leaching was significantly more successful than was sodium hydroxide; however, in terms of economics, the use of sodium hydroxide was found to be more cost-efficient. Interestingly, this finding indicated that caustic leaching is still the most effective method for stibnite extraction.

Jul 23, 2020

By Fred Morelko, Michael Connelly, Brad L. Ricks

INTRODUCTION The $1.1 billion Bajo la Alumbrera Project, started up in 1997 by Minera Alumbrera Limited in the Catamarca Province of Northwestern Argentina, is the first large scale modern mining project to be developed in Argentina. Like many modern Andean mining projects, existing infrastructure was not available to economically transport the 875,000 tonnes of product per year. A variety of alternatives were investigated, including upgrading of existing roads and railroads, slurry pipelines, and combinations of these systems. The final system selected was to combine a 312 km slurry pipeline with an 820 km rail haul to a ship loading facility near Rosario. The concentrate pipeline crosses divergent terrain between the minesite at 2400 m elevation and the filter plant at 400 m elevation. The system selected represented the lowest net present cost alternative by a significant margin. BACKGROUND The Bajo Alumbrera deposit was discovered in 1947 by Professor Cetioni from the University of Tucuman. It is a large (>750 million tonnes) medium-grade (0.6%) copper deposit with high gold values (0.5 g/t*). The deposit outcrops, making it very suitable to modern, large scale, open pit mining techniques using 218 t trucks and 43 m3 shovels. Advances in gravity concentration of the gold helped to demonstrate the feasibility of the project in a study prepared by Fluor Daniel for Minera Alumbrera in 1994. The initial concentrator is the largest green-field concentrator ever constructed, rated at 85,000 t/d. Production will peak at 190,000 tonnes of copper metal and 710,000 troy ounces of gold per year, one of the top 10 copper and top 15 gold producers in the world. * Throughout this paper, the word tonne and abbreviation refer to the metric ton of 1000 kg.

Jan 1, 1998

By A. K. Bakshi

An on-line rheometer, suitable for use with slurries, has been developed at Michigan Technological University. This rheometer can be used with both Newtonian and non-Newtonian slurries, and produces complete shear-rate/shear stress curves which characterize the time-independent rheology of the slurry. The sensor utilizes the Hagen-Poiseuille equation and Boyle's Law to calculate the shear rate, slurry flowrate, and shear stress from a series of pressure measurements. The design of the unit allows the measurement sample to be continuously collected from operating process streams in the often-hostile on-line environment. The shear rate/shear stress curves can be used to conveniently calculate the apparent viscosity at any given shear rate, and also to measure any yield stress or other deviations from Newtonian behavior.

Jan 1, 1999

By John F. Martonik

When OSHA came into existence in 1970, it adopted national consensus standards to improve safety and health conditions in work places. Coke oven emissions, which are proven to cause cancer and respiratory diseases, were regulated by the coal tar pitch volatile standard, adopted from the 1969 edition of the Threshold Limit Values for Airborne Contaminants by the American Conference of Governmental Industrial Hygienists. The coal tar pitch standard, based upon the benzene soluble fraction of total particulates, limits the personal exposure to 200 micrograms of the benzene soluble fractions of total particulate per cubic meter of air. This standard can be classified as a performance standard because only general limits are set which allows the employer to choose for themselves the means to comply. Both the United Steelworkers of America and the American Iron and Steel Institute petitioned the Secretary of Labor to write a new standard for coke oven missions, each thinking the coal tar pitch standard unsatisfactory.

Jan 1, 1980

By Devin Burns, Saima Ghazal, Michael Owusu-Tweneboah, Kwame Awuah-Offei

Trust in AI systems and the nature and amount of information about the system can influence decision-making. It is, therefore, crucial to understand how AI-powered monitoring systems (e.g., gas monitoring systems) influence miners’ trust and decision-making in emergency evacuation. This work focused on measuring the differences between how participants respond to a simulated underground mine emergency evacuation situation when warnings are represented as coming from a human or AI-based monitoring system. We also manipulated the amount of information participants received about the system, yielding a 2×2 between-participants survey design. The participants received an alert message about rising gas levels in a mine and provided a response on how they would react and reported their perceived safety. We also asked questions to assess their trust in, preference for AI over human-based gas monitoring systems, and whether they are willing to delegate the duties of underground gas monitoring to AI systems. The experiment results show the amount of information had a significant influence on miners’ trust and decision-making. The safety perception of participants based on age, number of children and ethnicity was significantly different from one category to another. This work provides valuable insights as the mining industry deploys AI systems to aid mine safety.

Feb 1, 2025

By A. Tew

The Ernest Henry copper-gold project is located in North West Queensland, Australia and commenced production in late August 1997. Utilising a philosophy of selecting the biggest proven equipment available Ernest Henry at full production will treat 9 Mtpa through a single grinding line over a 15 year mine life. 350.000 tonnes of concentrate a year will be produced, containing 95,000 tonnes of copper and 120,000ounces of gold. The two mills recently commissioned at the Ernest Henry Copper/Gold Mine are a 10.4m x 5.1m (34 ft x 16.75 ft) SAG Mill and a 6.1m x 8.4m (20 ft x 27.5 ft) ball mill. The mills have a power draw of 11 MW (14745 hp) and 5.5 MW (7373hp) respectively. While the SAG Mill is not the largest SAG Mill in the world, it is the largest shell-supported SAG Mill in the world. The Ernest Henry mills epitomise the new standard design of large grinding mills. The design was introduced more than 20years ago and has been further developed from extensive experience with grinding mills and the need to produce a design, which overcomes the recognised problems of large mills. The result is a design with the potential to be used for mills up to the largest for which machine tools can be found to fabricate and machine them. currently approximately 15m (48')overall diameter.

Jan 1, 1999

By S. Borner Schweizer

An overview over SAM’s approach to assess corporate sustainability performance illustrates how sustainability challenges are linked to trends, assessment criteria and finally company performance. This process is exemplified with some general and industry specific criteria. Lastly, results of the Dow Jones Sustainability Assessment 2004 show a considerable gap between leading and average companies. Best practice examples demonstrate how lagging companies could improve their sustainability performance.

Jan 1, 2005

By H. C. Morehead

The United States Cement, along with other industries, is being devastated by an unprecedented penetration of domestic markets by imported products. The overriding questions are: 1. Have foreign manufacturers improved their processes to an extent they can outperform U.S. producers in their home markets? 2. Is it gross inefficiency on the part of the U.S. producers that is allowing foreign producers to be capable of replacing a local U.S. producer in his normal home market? 3. Is there a combination of the first two questions that economically justifies this type of market overrun? The answer is a simple NO!. In a fair trade market atmosphere, U.S. producers are definitely competitive.

Jan 1, 1985

By Todd Minoski, Matthew McElhinney, Morgan Sears, Craig Compton

In an effort to advance the science underlying ground control engineering, researchers with the National Institute for Occupational Safety and Health (NIOSH) are frequently involved in field studies at collaborating mines. Often, these field studies involve visiting the mine site, instrumentation installation, and data acquisition. Each of these aspects involve potential risks to NIOSH employees. As an organization whose mission it is to promote the health and safety of mine workers, the health and safety of our workforce is paramount. This paper provides documentation of the best practices followed by NIOSH employees who are tasked with visiting and conducting work at underground and surface mines. This includes Mine Safety and Health Administration (MSHA) approved training, mine site specific training, and hazards associated with all aspects of mining that could be encountered by the employee. Additionally, this paper details best practices associated specifically with instrumentation installation including the mitigation of hazards associated with the proper equipment handling, drilling, and the mine environment. The information showcased in this paper can be used as considerations for industry practitioners such as mine operators, consultants, and academic researchers engaged in the installation of instrumentation in the field. Furthermore, the best practices detailed in this paper can be used as a foundation for agreements made between mine operators and researchers to ensure safety procedures will be followed while on mine property. This will result in enhanced safety of both researchers involved in field studies as well as mine employees tasked with assisting and accompanying those researchers.

Feb 1, 2024

By Onur Golbası, Berk Gokce

Investment decisions in the mining industry are complicated by sector-specific uncertainties. This study presents a multi-submodule system dynamics model to capture the dynamic complexities of decision-making across mineral property development stages. The model includes five interconnected subsystems: valuation, production, growth strategy, demand, and finance. Developed through system decomposition, expert input, and literature, the model is tested on a hypothetical copper mine with 850 ktpa capacity and 1% cu grade. Simulated over five years with quarterly steps, it estimates an enterprise value of $78.9 million and a target growth rate of 11.2%. Results highlight the significant effects of operating costs, capital policies, and inflation on free cash flow, and the critical role of mineral reserves in sustaining growth. This model supports strategic investment analysis across different minerals and development phases, offering mining investors a robust tool for optimizing decisions.

Feb 22, 2026