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By Thomas Barkley

Recent developments in hardware and software have made accurate measurement of Underground Face (Development) Drilling a reality. New and compact laser profiling equipment makes it possible to measure drilled material left on the face as well as the actual tracks of the holes drilled in the rounds. Utilization of these available technologies makes it possible to correctly define the drilling accuracy and the blasting pull. Through the use of actual face round measurements, I will show the level of definition and amount of information that can be collected.

Jan 1, 2003

By Kyle Wagner, William Joa, Colter Angell, Catherine Johnson, Marty Langenderfer, David Doucet

The goal of any business is to seek the maximum profitability for the organization through optimization the use of resources, processes and the application of new technologies. An analysis of various case studies demonstrate that blasting can have positive impacts on the crushing and milling processes resulting in increased profitability for the mining industry (Grundstrom, Kanchibotla, Jankovich & Thornton, 2001). This paper describes the case study of two copper mines in Peru producing Cu-Mo and Cu-Au concentrates, which together with their strategic partner, have implemented a project focused on the improvement of rock fragmentation. The project was based on techniques of pattern size reduction, the use of high energy explosives and the technology of electronic initiation. Combined, these techniques were shown to have significantly impacted the efficiency of downstream processes.

Jan 1, 2019

By John H. Johnson

This report covers the third and final year of work conducted under U. S. Bureau of Mines Grant G0166027, "Monitoring of Mine Air Pollutants". The report discusses work performed in three areas. These are the White Pine Mine (WPM) Experimental Unit, diesel mine-vehicle tailpipe emissions monitoring, and mine ambient air concentration data analysis. The WPM experimental unit was used to study diesel exhaust stratification in an 80 foot long dead-end heading while loading ore with a Wagner ST-5D scoop train LHD. The MTU Mine Air Monitoring Laboratory (MAML) was used to gather temperature and CO2 concentration data at 10 locations. Three different ventilation conditions were compared. The data substantiate the presence of strong buoyant forces of the hot exhaust gases which result in temperature stratification in dead-end headings. The diesel mine-vehicle tailpipe emissions monitoring study involved laboratory measurements of diesel undiluted exhaust pollutant concentrations by the portable tailpipe emissions measurement apparatus (EMA) assembled for in-mine use. The results were compared with simultaneous measurements by standard laboratory exhaust monitoring instruments. These results indicate that accurate field source quality control measurements can be obtained for CO2, CO and NO but NO2 results were low for all engine conditions. The mine ambient air concentration data analysis study included analysis of diesel pollutant concentration data in the Orchard Valley Mine air and comparison of the results with data collected earlier in the White Pine and Brushy Creek mines. The analysis included preparation of lognormal frequency distributions and calculations of C02-based concentration ratios and correlations. In the three mines compared, pollutant concentrations are distributed quite similarly, and the concentrations appear to be controlled to present standards.

Jan 1, 1979

By Derek Ellis

Volume II of this two-part series on Submarine Tailings Disposal (STD) as a tailings management option for coastal and island mines contains descriptions of lesser known case histories. The Misima gold mine (Papua New Guinea) and the Black Angel lead-zinc mine (Greenland) are described in some detail as the best documented cases. Atlas copper mine (The Philippines) is less fully described due to relative lack of documentation. The Misima and Atlas STD systems are working to their design criteria. At Black Angel the system adopted did not prevent contamination for a number of reasons, which are now understood. Two cases are described where STD is being developed. They are the Cayeli Bakir copper mine Turkey), and the Toquepala and Cuajone mines (Peru). There is excellent documentation available for both cases. Three case histories are described where tailings have reached the sea either through beach or river discharge. In one case the STD option has been explored (Marcopper Mine, The Philippines). In the others we explore in hindsight whether STD might have been a viable alternative using the Screening Criteria that this Volume develops - see below. The mines are Bougainville Copper Mine in Papua New Guinea, and Jordan River Mine (Canada). There is potential for STD at all three sites. Finally, the Volume presents Screening Criteria for appraising STD, based on the experience in design, operation and environmental impact reviewed in the case histories.

Jan 1, 1994

By Susan M. Moore

Many challenges are faced by workers in lower-seam (42 inches or less) mines. The lower-seam heights confine mine workers to their knees as they perform their daily tasks such as installing roof bolts, delivering supplies, repairing belt, or cutting coal. Miners working in these lower seams often consider kneepads to be their only line of defense against knee injuries. However, healthy knees do not start and stop with kneepads. Other interventions such as changing postures, proper hygiene, and work station design may also be used to reduce mine workers? risks for developing knee injuries. Incorporating these and many other interventions into a mine worker?s ?way of life? is an important step to ensuring a long, healthy career and retirement. Keeping knees healthy is also a key aspect to reducing costs in low-seam mines as the industry battles rising health care costs, and training/recruitment of replacement workers is time-consuming and costly. Educating the workforce about the possible interventions to reduce knee injury risk is a primary objective for the National Institute for Occupational Safety and Health?s (NIOSH) Pittsburgh Research Laboratory (PRL). Therefore, NIOSH researchers, along with industry and academia, developed a training package to educate the mining com­munity about some possible interventions beyond kneepads that may be used to help decrease knee injury rates. Increased awareness and simple changes are the first steps to reducing knee injuries.

Jan 1, 2008

By Frank B. Fulkerson

A study was made of scrap iron and steel in the South Central States in order to determine trends in processing, shipment, and consumption if this important commodity. These data were derived in part from statistical sources and in part by visits to scrap yards and steel mills. Trends in the industry were reviewed. Dealers in 1963 supplied 1.8 million tons of iron and steel scrap to steel mills and foundries in the south-central area, compared with 2.1 mill ion tons in 1955. Most of the scrap was processed and shipped within 200 to 300 miles of consuming centers. Exports provide a principal outlet for dealers along the gulf coast. Most of the scrap that fills these orders is loaded onto freight cars at yards in Texas and Louisiana and is shipped to ports for direct transfer from railroad car to ship. The tonnage exported varies greatly from year to year. The largest scrap operations are in or near large cities which are heavy scrap generating areas, steel mill sites, or port cities for export of scrap. A tentative analysis indicates that the short-run supply of prepared scrap is inelastic to price changes; therefore, buyers probably are in a strong bargaining position at times of declining demand. One technological development in the iron and steel scrap industry is the use of large presses which can take complete automobiles with frames, wheels, springs, and other heavy parts still intact and reduce them to bundles. At Houston, Tex., and Kansas City, Mo., shredding plants are in operation that reduce car bodies and other light scrap into flat pieces 4 to 6 inches in size.

Jan 1, 1966

By Roger Storry, Arnaud Hochart, David Harris, Olivier Martin

"INTRODUCTIONThe Port of Miami Tunnel (POMT), designed and constructed by Bouygues Civil Works Florida between 2009 and 2014, was a Public Private Partnership between the Miami Access Tunnel Concessionaire, Florida Department of Transport, Miami-Dade County and the City of Miami. The project comprises dual 11.3m internal diameter, 1.27km long, twin lane road tunnels running between Watson and Dodge islands under the main shipping channel in Biscayne Bay. Five cross passages (CPs), spaced at 200m centre to centre, provide emergency access between the two tunnels, as shown in Figure 1.The CPs were constructed by open-face excavation methods but the particular geological conditions at the project site (loose and variable carbonate sedimentary strata with very high permeability) required specific ground treatment solutions to provide safe excavation conditions and to ensure the long term serviceability of the permanent works construction. Where access allowed, ground treatment was performed from the ground surface using deep-mixing techniques; however, at two locations (CP2 and CP3) surface access was restricted and ground treatment by freezing, performed from the tunnels, was required. The CPs are 12.3m long with an excavation diameter of 5.8m and are located up to 30m below the water table partly or wholly within the Key Largo limestone (termed Layer S7 in the ground model). Layer S7 is a coralline limestone having a metastable honeycomb structure and high variable porosity. At CP2 the upper portion of the excavation was within the overlying Anastasia Formation limestone (Layer S6), comprising a highly permeable coquina. The geological profile along the project is shown in Figure 2.This paper presents aspects of the freeze design and the risk mitigation necessary to successfully achieve the construction of the CPs in the unique geological conditions."

Jan 1, 2016

IN dealing with this subject the intention is not to write a detailed description of the various methods in vogue on the Kalgoorlie field, but rather to give a brief outline of three of the methods which are most universally in force, and from which, ultimately, a few comparisons may be drawn. The three methods which the writer proposes embodying in this article are known as "The Rill," "The Flatback," and "The Shrinkage." For comparative purposes each method will be applied to a block of ore 500 feet in length, and opened up by levels 200 feet apart."The Rin" System. It is necessary in this system, for facilitating mullocking, to make connections between levels by rising and winzing at about every 100 feet or 150 feet along the orebody. After the leading stope is beaten off for the full length ofthe drive, the level is timbered. Single stulls are put in up to a width of fourteen feet. If the span is too great for stulls, set timbers or saddleback stuUs are used. Stulls are lagged over with 4-in gimlet poles, and wooden chutes are built at intervals of 50-feet. Ore passes are cribbed up through the filling directly above each chute, and are constructed of 7-in. round timber or 9 in x 3 in square timber, the passes measuring 4 ft x 4 ft in the clear.Occasionally a double pass may be carried up, one side serving as a travelling way. Stoping is commenced off the winzes, and rills are gradually formed, one on either end of each winze. The rills are generally at an angle of 37° off the horizontal, this allowing for the boring...

Jan 1, 1909

By M. Abdellatif

Keywords: Magnesium, pyrometallurgy, Mintek Extensive testwork on atmospheric thermal magnesium production has highlighted certain important fundamental and operational factors that have a major influence on magnesium extraction and its extraction rate, the condensation efficiency of magnesium, as well as on the quality of the condensed metal. The possible impact of these factors on the selection and preparation of raw materials, recipe choice, furnace electrical energy consumption, and on the refining requirements of the crude magnesium is discussed. Selected pilot plant operational and metallurgical data are also presented.

Jan 1, 2006

By W. W. Mason

The United States began exporting coal in the late 1800'5, at first in very small quantities to Canada and beginning in 1897 and 1896, to the east coast of South America. Shipments to European countries began on a very limited basis in 1902 and these shipments increased gradually until World War One when shipments overseas increased from the 8 million tons per year level to 22 million tons. After the war exports dropped as fast as they had increased and, with the exception of exports to Canada, remained at very low levels until just after World War 11 when the United States again emerged as a major coal exporter. World War II left the coal industries of Europe in ruin. As the United States was the only country able to supply the large quantities of coal at reasonable prices needed for reconstruction of the European economy, the U. S. coal exports overseas expanded rapidly to 42.5 million tons in 1947. Additionally, we shipped 25 -2 million tons of coal to Canada In that year for a total export of 68.7 million tons. Unfortunately, that level was not reached again until 1957 when exports reached an all-time high of 76 .4 million tons- -a high I might add that has not been reached since.

Jan 1, 1980

By Eldon Keith Stanek

This annual report deals with four distinct tasks related to research on the safety and reliability of mine electrical power systems. Task one is to develop tests and the associated instrumentation to detect incipient faults on a mine or any low-voltage power system. Task two is a dual effort related to the digital prediction of electrical transients on mine power systems and laboratory testing of transient suppression devices. Task three is also a dual effort. This task consists of both theoretical and laboratory work to assess both the reliability and the fail-safe characteristics of several items of protective equipment used in mine power systems. Task four consists of an effort to use programmable calculators and/or computer terminals to check overcurrent protective device coordination.

Jan 1, 1976

By I. Haskett

ABSTRACT The Redwater pool, in north-central Alberta, was discovered in October, 1948, and at the end of 1950 was about 85 per cent developed. Production is from a Devonian coral limestone reef and is found at an average depth of 3,150 feet. The pool has an estimated .productive area of 37,000 acres, and a maximum oil zone thickness of slightly over 200 feet. Wide variations exist in both type and values of porosity, with the average value determined for the reservoir being 6.16 per cent. The total stock tank oil in place is about 1.24 billion barrels. The crude has a saturation pressure of 485 psig, com-pared to the original value of 1,050 psig for the reservoir, and the principal recovery mechanism so far has been the natural water drive. Cumulative production to January 1st, 1951, has been about 15.5 million barrels. These withdrawals resulted in a reservoir pressure decline of slightly over 100 psi. Predictions of future behaviour indicate that the water drive will not be of sufficient magnitude to maintain the reservoir above saturation pressure past 1953, and that, with natural depletion, the pool will be produced largely by a solution gas drive. Pressure maintenance by water injection has been considered and the possibility of raising the pressure to the original value of 1,050 psig is also discussed. INTRODUCTION WITH the discovery of the Lewduc pool, early in 1947, the Devonian limestone became the major geological formation contributing to Western Canada's rapidly growing petroleum reserves. Redwater, discovered in October, 1948, is now the largest known Devonian pool in Canada, with a recoverable reserve estimated at approximately 500 million barrels. Until recent years, the knowledge of the nature and characteristics of this type of limestone reservoir has been comparatively limited.

Jan 1, 1951

By J. R. Thoenen

This circular is part 6 of the third paper (entitled "Excavation") of a series summarizing the technical problems involved in the production and preparation of sand and gravel. Part 1 discussed the use of power shovels, draglines, and excavator cranes; part 2, power scrapers, slackline cableway excavators, and hydraulic monitors; part 3, hydraulic, clamshall, ladder, and diaper dredges; part 4, haulage equipment, particularly industrial cars with locomotive or hoist as the motive power; part 5, conveyor belt, motor truck, pump and pipe line, towboat and barges, and aerial-trams haulage. This circular discusses the application of these various types of equipment to the different types of sand and gravel deposits and contains a reference bibliography. It completes the discussion of excavating problems.

Jan 1, 1936

By C. Wade, A. Swart, M. Dworzanowski

AngloGold Ashanti operate a pyrite flotation plant at their East Gold Plant, Acid Plant and Flotation Plant (EGAF) metallurgical complex within their Vaal River operations in the North West province in South Africa. The flotation plant feed is reclaimed pyrite rich tailings and the concentrate produced is used as the source of sulphur for the EGAF acid plant. The sulphuric acid produced is in turn used for the recovery of uranium at the Vaal River South uranium plant. The original flotation plant built in 1960 was based on the use of many small volume flotation cells and was becoming very expensive to operate and its age severely limited further operation. A decision was taken in 2005 to replace this plant with a new one based on fewer, larger volume flotation cells. This paper describes the benefits of using larger volume flotation cells in this new flotation plant when compared to the smaller volume flotation cells in the old plant. The benefits of the new plant include a smaller plant footprint, fewer flotation cells, fewer pumps, no distribution boxes, simpler piping, a greater flotation volume and a reduction in installed power. The saving in capital cost could not be quantified because of the age of the old plant. The savings in operating cost will arise from fewer operators, less maintenance and reduced power consumption. The new plant has not been in operation long enough to quantify the benefits in operating cost and metallurgical performance. However, recovery improvements can be expected given the greater flotation volume (increased residence time) and the installation of larger, more efficient flotation cells.

Jan 1, 2007

By I. Yelkin, Erico Tabosa, Alex Jankovic, R. Hayashida, R. Faveere

"The mining industry faces growing challenges from more complex and lower grade deposits, rising costs, limited energy and water availability, and increasing societal pressure to operate more sustainably. Mining operations need to be more efficient, not just to reduce environmental impact, but also to remain economically viable.To maximize profitability and sustainability, existing operations and new projects must consider integration and optimization of all stages of production. A mining operation is essentially a series of inter-connected processes, with the performance and outputs of each stage affecting the subsequent ones. Optimizing stages in isolation can result in sub-optimal overall performance.The industry has long recognized the benefits of holistic optimization using the Mine-to-Mill concept, and there are many well documented successes. However, it is increasingly common to observe operations simply increasing explosive consumption in the mine and expecting optimization of the entire value chain (mining and processing). For true holistic optimization, blast intensity is not necessarily increased, but rather adjusted to best suit the requirements of the different types of ores treated, the circuit configuration and equipment, installed comminution power and the downstream beneficiation processes. It is a fully integrated effort with optimization of many aspects in the mine, comminution and separation processes.To be successful, optimization of the production chain from mine to process requires a site-specific, structured methodology supported by extensive ore characterization, auditing, surveys, data analysis, mathematical modelling simulations and a cost / benefit analysis. Following this methodology, optimization strategies are rapidly identified and implemented considering mine and plant constraints. Management needs to set up appropriate KPIs and site personnel need to be trained for the new operating strategies to be successfully incorporated into site practices and procedures in the production environment. This will ensure the benefits are achieved and maintained. This paper describes the methodology employed by Hatch to improve overall efficiency and profitability from mine to process. Two case study examples at Russian gold operations and benefits achieved are presented."

Jan 1, 2018

By C A. Locke, J Cassidy, J L. Mauk

The Waihi-Waitekauri region hosts numerous low-sulfidation epithermal deposits that both outcrop and occur at depth. Zones of intense hydrothermal alteration enclose the Au-Ag bearing quartz vein deposits. Hydrothermal alteration includes the destruction of magnetite by hydrothermal fluids, pervasive silicification adjacent to quartz lodes and potassium enrichment due to adularia and illite deposition. High-resolution airborne magnetic and radiometric, and new gravity data delineate distinct geophysical anomalies associated with hydrothermal alteration and mineralisation. Five magnetically quiet zones occur in the region varying in size from 3 to 34 km2 and in geometry from circular to irregular zones. These zones represent the near-surface extent of strong to intense hydrothermal alteration associated with fossil geothermal systems. All epithermal deposits in the region occur in magnetically quiet zones. Over 120 new gravity stations together with existing data across the Waihi district have defined a positive Bouguer gravity anomaly coincident with the magnetically quiet zone. Eastern and western gradients of 50 gu/km bound the anomaly that contains two flat gravity highs west and east of the Waihi deposit. Strong potassium signatures in airborne radiometric data correlate with outcropping zones of alteration and are consistent with the presence of adularia and illite minerals. Hydrothermally altered zones are represented by areas of low Th/K ratios as a result of low thorium concentrations in andesite and elevated potassium levels in altered zones.

Jan 1, 2003

By J Siliézar

The Ernest Henry Mine (EHM) is situated 38 km north-east of Cloncurry in the Mount Isa – Cloncurry mineral district of northwest Queensland. The EHM orebody is an iron oxide copper gold deposit with an average grade of one per cent copper, 0.5 g/t gold and 23 per cent magnetite, with current reserves of approximately 88 Mt.The copper concentrator is a single line plant with a nominal throughput rate of 1300 tonnes per hour. An average of 350 000 tonnes of concentrate is produced each year containing around 100 000 tonnes of copper metal and 120 000 troy ounces of gold.In December 2009, Xstrata Copper announced approval of a $589 M investment to extend the life of EHM to at least 2024, through the transformation of open pit mining operations to a major underground mine together with the construction of an associated magnetite extraction plant.The EHM magnetite plant extracts the magnetite from the copper concentrator’s tailings stream. It will produce approximately 1.2 Mt of magnetite concentrate per annum at full capacity for export to Asia, making EHM Queensland’s first iron ore concentrate exporter. Construction of the magnetite extraction plant commenced in July 2010 and was completed in January 2011.This paper gives an overview of the development of the EHM magnetite extraction plant flow sheet from the early mineralogy and laboratory test work through to the plant commissioning and early operation of the base plant. It has a major focus on the commissioning learnings from the plant start-up and includes a review of the operational performance of the plant versus original design and expectations.

Jul 11, 2011

By Vladko Panayotov, Marinela Panayotova

"Recently, in order to extract metals, the industry is trying to process old metallurgical slag. The material requires very fine grinding that results in enhanced slime-formation. This in turn leads to problems in the course of the flotation process and to a loss of metal. In addition, it causes difficulties in the wastewater treatment aimed at water reuse. The aggregation and separation of the fine particles and their further subjecting to mineral processing would result in more efficient use of raw materials. Closing the water cycle also would be facilitated. The paper presents results from studying sixteen flocculation reagents, commercially available for treating municipal wastewater, including products based on nanotechnology, for their ability to rend the production wastewater in suitable for reuse in the flotation. It turned out that, from all studied reagents, the cationic C-587 is suitable for the purpose. Some of reagents were studied for their ability to flocculate selectively, in presence of coke fines, rich in copper fines which are produced at grinding of a slag from lead-zinc metallurgy. Most promising reagents are chosen, based on the chemical analysis of the flocculated materials. Open-cycle rough copper flotation experiments with the flocculated fines and recycled wastewater gave encouraging results."

Jan 1, 2014

By J Salaya, J Kwak, L Keeney, S Dehkhoda

In addition to volatile commodity prices influencing decision making, in recent years, social and environmental performance have become important decision drivers within the mining industry. There are increased demands from stakeholders, communities, and governments to ensure that raw materials are mined, processed and refined responsibly. The industry also faces the challenge of better managing its waste, which has led to severe consequences when not done properly. The high commodity prices of the late 90s and early 2000s encouraged larger economies of scale and drove mining companies to extract large volumes of rock for separation and concentration at the downstream processes. Over time, as ore grades dropped, the cost of mining escalated and tailings volumes grew. This arduous process also caused strains on recovery cost and performance. Scarcity of water and energy resources coupled with increased production demands and higher operating costs are putting pressure on companies to find innovative ways to increase mining intensities. Hatch’s value chain optimisation methodologies, specifically Grade Engineering® and early waste rejection of the mine, have been of interest to intensify operational performance and minimise waste generation. Enabling preconcentration of the plant throughput, the methodology has significant potential to improve overall metal production and reduce water and energy intensities, whilst minimising wet tailings. Using representative data from real world mines, this paper reports on a case study that evaluates the impact of preconcentration using sensor-based ore sorting on downstream process improvements as well as energy, water and tailings reduction. Financial and economic viability of this technique is presented for both brownfield and greenfield implementation cases. The results show that business case for preconcentration is best when: the distribution of metal in the run of mine ore is negatively skewed and left tailed; mining costs are low; energy, water and tailings management costs are high; and low cost methods of recovering pay metal from low grade material are available.

Nov 10, 2020

By G. G. Barbante

The oxidation behaviour of selenide matte with a substantial Cu content and low Ag differs significantly from that of high-Ag matte. Low-Ag selenide mattes display a large oxygen solubility and the upper boundary of the miscibility gap in the Ag-Cu-Se-O system is depressed to quite low Se contents. As a result, the formation of Ag metal is considerably delayed. The oxidised selenide matte, low in Se and with a relatively high oxygen content, has previously been termed oxymelt. With further oxidation, its composition enters the misciblity gap and crude Ag is formed. The sodium silicate slag captures very little of the SeO2 and the dissolved Ag2O(s) content of the slag is relatively small, with a Raoultian activity coefficient of 0.57. This value was found to be independent of the slag's Cu2O content

Jun 19, 1905