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By Q. Feng

"Efforts have been tried to apply the mixture of mine tailings and fly ash as construction materials. Through the present investigation, a protocol to make construction materials using the mixture of mine tailings and fly ash has been set up. The experiment results of the present work also help set up the working conditions such as activation temperature and time, the concentration of NaOH, the addition of Ca(OH)2, forming pressure, mine tailing to fly ash weight ratio, curing temperature and curing time. The findings of the present work provide a novel method for the geopolymerization of the mixture of mine tailings and fly ash as construction materials, such as bricks for construction and road pavement. INTRODUCTION In mining activity, after the valuable materials are extracted from ores, millions of tons of solid rejects, i.e., mine tailings, are stored in the tailings dam, which occupies a huge area of land and leads to high monetary, environmental and ecological costs. For example, the impoundment of mine tailings can bring with serious environmental problems such as mine dust and tailing dam failure. On the other hand, the making of general construction material results in a lot of greenhouse gas emission. Therefore, it is of great interest to utilize mine tailings, for which a lot of energy has been consumed during the comminution process, as construction materials using the novel geopolymerization technique. (Xu and van Deventer, 2000, 2002a, 2002b; Pacheco-Torgal et al., 2007, 2008; Zhang et al., 2011; Ahmari et al., 2012) Fly ash is another industrial waste which needs to be carefully impounded because of its potential impact on environment. Many efforts have been tried to utilize fly ash as construction materials because it is a silica/alumina rich aluminosilicate source. In addition, the facts that fly ash is quite reactive to alkali and its particle size is usually very small (< 50 microns) make the specific material an ideal source for the geopolymerization process to make construction materials. Geopolymerization is a process of obtaining a polymeric structure from aluminosilicate by dissolving aluminosilicate sources in a strong alkali (NaOH) solution at an elevated temperature. After being cured at an elevated temperature for a specific time, the geopolymerization product shows a greatly increased compressive strength. Therefore, the product can be used as construction material such as bricks and road pavement. It provides a very promising method to apply aluminosilicate sources such as mine tailings and fly ash as construction materials."

Jan 1, 2016

By A. M. Tunstall

Blasting is commonly viewed separately from mechanical handling and crushing. This view is misleading because the degree of fragmentation achieved by blasting can have a significant effect on the efficiency of these processes and, hence, on the overall cost of the mining operation. In this paper, aspects of blasting and crushing and their interaction are examined. A case study is also presented that dramatically illustrates the influence of blast fragmentation on subsequent processing and on the financial implications involved

Jan 1, 1997

By Orville D. Mussey

During, 1956 the water used in mining iron ore in the United States amounted to about 2 billion gallons and the water used in producing iron concentrates-amounted to about 166 billion gallons. By 1980 an increase of about 65 percent is anticipated in the amount of water used for mining and beneficiating iron ore. Except for boiler-feed makeup water the quality requirements for water, for mining and beneficiating iron ores are not stringent. Adequate supplies. of water for development should be available at reasonable cost with the possible exception of some in arid regions.

Jan 1, 1961

By E. Lefeuvre

Precambien in age, the phospate deposit under study which outcrops to the south forms a synclinal consisting of only one mineralized horizon. The synclinal strikes SSW/NNE, dips from 30 to 60 NNE and is about 5 km wide. The deposit has been explored by : - trenches and pits about 50 m apart in the outcropping area ; - core drill holes forming lines perpendicular to the outcrop. These lines are about 100 m apart. On each line, the drill holes are about 50 m apart The phosphate layer is clearly visible and has then been defined from the geologicia1 description of drill hole logs. The layer has been divided into two parts : a very rich, altered part at the hanging wall and a poor part displaying opposite physical characteristics, i.e. a fresh and hard rock. With open pit mining in view, the deposit has been divided into a 3-dimension network of blocks, each block measuring 50 X 50 X 100 m. The tonnages of rich and poor ore, PO25, MgO, Si02, CaO and R2O3 grades and the tonnages of barren waste at the hanging wall and the footwall have been calculated for each block. Given the dip of the phosphate layer ranging from 30 to 60° and its relative thickness (between 10 and 15 m), it was impossible or inappropriate to carry out direct calculation by 3-dimension kriging : too many neighboring blocks to obtain sufficient date and impossibility to draw up the morphology of the layer.

Jan 1, 1986

By K. A. Natarajan, M. K. Yelloji Rao

Significance of grinding media wear and its effect on chalcopyrite flotation are discussed. Laboratory marked ball wear tests were conducted grinding chalcopyrite ore and quartzite dry, wet, and with collector added during grinding. The effects of oxygen and nitrogen on ball wear were evaluated by the addition of chalcopyrite mineral while grinding quartzite. The effect of dry and wet grinding on chalcopyrite flotation was also studied. Results show abrasive wear is greater in quartzite grinding than in grinding chalcopyrite. Oxygen increases the corrosive wear of high carbon low alloy steel balls in the presence of chalcopyrite ore. Chalcopyrite flotation was retarded due to wet grinding in the presence of oxygen. Though collector reagent increased the media wear, it improved the flotation of chalcopyrite. Probable electrochemical reactions encountered in a grinding mill are outlined.

Jan 1, 1991

By C. Haycocks

The evolution of longwall mining is briefly traced from its inception in England in the 1620&apos;s. In the beginning this method recovered 90% of coal with roof closure controlled by packs and walls. Mechanization began with kerf cutting, crude face conveyors, and improved face support. Full face mining was accompanied by the introduction of self-advancing hydraulic supports. U.S. longwalls evolved a retreating system to recover blocks of coal outlined by room and pillar panels. Computer control combined with the most modern technology has greatly increased productivity. Past trends are used to predict future technological directions.

Jan 1, 1997

By T. L. Carstensen

The Miami In-situ mine of BHP Copper is located in Globe-Miami, Arizona. The mine leaches mineralized leach capping over a supergene enriched sulfide deposit, and has produced over 500 million lbs of copper during the last 50 years. The Miami unit has identified several opportunities to enhance and expand in-situ production. A computer block model consisting of strict geologic controls, mineralogy, and metallurgical data was developed to assist in the determination of the leachable copper resource. An understanding of the accessibility and solubility of the resource to leaching solutions and the integration of hydrogeologic and hydrometallurgical information was necessary for completion of this project.

Jan 1, 1997

By J. C. C. C. Menezes, R. A. S. Silva, A. V. Colling, I. A. H. Scheneider

"Coagulants rich in ferric sulfate can be obtained from pyrite-containing coal tailings using a biohydrometallurgical process. The aim of this study is to evaluate the relationship between quantity of pyrite and rate of oxidation, with regard to the consequent production of ferric sulfate for potential use as a coagulant for water and wastewater treatment. Leaching experiments were carried out on the laboratory scale on four coal tailings with different concentrations of pyrite. Characterization of the coal tailings was conducted for the following parameters: total sulfur, pyritic sulfur, sulfate sulfur, organic sulfur, and elemental analysis of CHN (carbon, hydrogen, nitrogen). The samples were also subjected to X-ray diffraction analysis to assess their mineral compositions. The leaching experiments were accomplished using a laboratory column constructed as a packed bed reactor with a sprinkling system in a closed circuit. After four weeks of leaching, the liquor was filtered and evaporated to an iron concentration of about 12 percent w/w, which is typical of the ferric sulfate coagulants commercialized in Brazil. IntroductionCoagulants used for the treatment of water and wastewater are predominantly inorganic salts of ferric iron and aluminum. Aluminum salts, including aluminum sulfate and aluminum chloride, and prehydrolyzed metal-ion reagents, such as polyaluminum sulfate (PAS) and polyaluminum chloride (PAC), are the coagulants most widely used for water treatment (Bratby, 1980; Tchobanoglous et al., 2003; Buzin et al., 2014).However, the presence of residual amounts of aluminum in drinking water has been controversially implicated in neurological diseases (Association of California Water Agencies, 2000; Becaria et al., 2006; Campbell, Hamai and Bondy, 2001; Rondeau et al., 2000; Walton, 2006). A possible alternative is to use iron-based coagulants, such as ferric chloride, ferric sulfate or polyferric sulfate, instead of the aluminum salts (Jiang, Graham and Harward, 1996; Jiang and Graham, 1998). Iron-based coagulants are commonly produced by the acid dissolution of iron scraps or iron ore (Tchobanoglous et al., 2003).Recent studies have shown that it is possible to produce ferric sulfate coagulants from the pyrite present in coal tailings through a biohydrometallurgical process (Colling et al., 2011). The main advantage of this process is that it does not require acid addition, which can be favorable in terms of production costs. Acidophilic bacteria, such as Acidithiobacillus ferrooxidans, can increase the rate of pyrite oxidation and dissolution by several times (Kontopoulos, 1998; Brett and Jillian, 2003; Johnson and Hallberg 2003). They can be highly significant in the bioprocessing of coal tailings for the production of ferric coagulants, as their action favors the acidification of the medium and iron leach (Colling et al., 2011)"

Jan 1, 2016

By M. T. Ityokumbul

Flotation columns and their variations are increasingly replacing conventional cells in mineral processing circuitry. While the operational characteristics of columns differ from those of conventional cells, the same scale-up methodologies are being employed in design. This practice may be attributed to poor understanding of the factors controlling throughput. The use of tall flotation columns is frequently justified on the requirement for increased particle residence time. It is shown that longer particle residence times in the column cell alone do not translate into increased recoveries. Throughput data from several industrial flotation column installations is presented. An attempt at using dimensional analysis to provide scale-up methodology for the factors controlling column throughput is made.

Jan 1, 1995

By PAITIP THIRAVETYAN, KANJANA KUDPENG

The aim of this study was to investigate the influence of amino acids (glycine, aspartic acid, glutamic acid, lysine and tryptophan) and organic acids (citric, malic, tartaric, fumaric, oxalic, succinic and ascorbic acid) on gold extraction from silicate ore. Use of amino acids to extract gold was preferred compared with organic acids due to the presence of carboxylic group and amine groups in amino acids. Among the assessed amino acids, aspartic acid and glutamic acid had higher capacities to extract gold due to their structures, which lacked aromatic rings and long side chains. Organic acids could also extract gold. In particular, oxalic and succinic acids had the greatest capacity to extract gold versus the other tested organic acids. Moreover, aspartic acid had a greater capacity to extract gold from ores than the same concentration of succinic acid. We confirmed the aspartic acid and succinic acid functional groups by Fourier transform infrared spectroscopy. The findings revealed that aspartic acid had a greater capacity to extract gold than succinic acid due to the presence of both amine and carboxylic groups (succinic acid contained only a carboxylic group). The optimal gold:aspartic acid molar ratio was 1:6 and low concentrations of aspartic acid extracted 35–42%of gold from silicate ore within 15 days. This can be used as an alternative to traditional methods for extracting gold from ore; it is non-toxic to human health and environmentally friendly.

Aug 10, 2021

By S. Hodgson

Introduction The Red Dog zinc/lead deposit in northwest Alaska is the second largest zinc deposit ever discovered. Being developed by Cominco Alaska, with startup scheduled for early 1990, it will ultimately be the largest zinc mine in the Western World. Table 1 shows the reserves of the deposit. Bob Baker, a local bush pilot, discovered Red Dog in 1968. The US Geological Survey assessed the find. But the Red Dog site had been withdrawn from staking by provisions in the Alaska Native Claims Settlement Act of 1971 (ANCSA). Under the terms of ANCSA, the deposit was selected by the NANA Regional Corporation, one of 13 native corporations established by the Act. Then, in 1980, the US Congress confirmed this selection, in the Alaska National Interest Lands Conservation Act. In 1982, Cominco and NANA reached an agreement that has led to the development of the mine. Under the agreement, Cominco leases the property from NANA, develops and operates the mine, and markets the concentrate produced. In return, NANA receives royalties and, after capital recovery, participates in the net proceeds from the operation. The Alaska State Government is also playing a role in the development of the mine. Under the auspices of the Alaska Industrial Development Authority (AIDA), the state will construct, own, and operate the DeLong Mountains Regional Transportation System. This consists of a 84-km (52¬mile) road from the minesite to the Chukchi Sea. Located here are the port facilities necessary to store and ship the annual concentrate production and receive the mine fuel and supplies. For using this transportation system, Cominco will pay an annual toll fee. Over the anticipated 50 year life of the operation, the fee will provide a 6.5% return to the State of Alaska. In late 1986, Cominco&apos;s Board of Directors approved the Red Dog project. And, during the summer of 1987, road construction began. In February 1988, initial stripping began at the ore body and construction started at the millsite. Project setting The project site is approximately 1000 km (600 miles) northwest of Anchorage, 84 km (52 miles) east of tidewater on the Chukchi Sea, and 192 km (120 miles) north of the Arctic Circle (Fig. 1). The countryside consists of low, rolling hills that lead into mountains north and east of the deposit. The vegetation is typical tundra mat. And the site is in an area of permafrost. However, the permafrost is relatively warm and some areas have been found to be thawed. Examples would be creek bottoms and the site of the main waste dump.

Jan 12, 1988

By L. E. Garner

Aggregate resources should be considered primary factors in urban development. Resource planning is essential because land values, previous construction, or zoning restrictions often preempt exploitation of aggregate deposits within an urban area. Sequential land use practices allow development of areas prior to urban development. Population and aggregate consumption trends in Austin, Texas, indicate that substantial quantities of reserves will be lost to future development. Aggregate materials are present in nearby seas. However, a comparison of transportation and reclamation costs indicates that reclaiming land after mineral extraction can be significantly cheaper than transporting materials longer distances.

Jan 1, 1979

By R. Kramer, A. Habibi

"Diesel Particulate Matter (DPM) measurements were taken at Tronox’s Westvaco Trona mine in Wyoming. Both shift-average and real-time monitoring using Elf pumps and Airtec analyzers, were used. The mine’s underground transportation fleet consists of more than 250 diesel-powered vehicles. A vehicle monitoring log tracked fleet usage during the test; logged data consisted of vehicle type, direction of travel, and time. The log was used in analysis to determine the DPM spread rate, of normally operating equipment, in the different entries with respect to vehicle location. Airflow velocity measurements at the stations were taken during the survey. The survey results also identified vehicles with higher emission rates. An ECOM gas and a MAHA DPM analyzer, both located in the mine’s underground emission shop, were used to obtain various vehicle emission rates. The correlation of the workshop and field measurements was investigated with regard to the machine activity, fuel usage and atmospheric conditions. The results were used to identify and execute a ventilation project to reroute 45% of diesel shop air back to intake entries, by interlocking an automated door and a regulator. The result is reduced DPM downstream. INTRODUCTION DPM has been classified as a potential occupational carcinogen by the National Institute for Occupational Safety and Health (NIOSH).The Mine Safety and Health Administration (MSHA) rule governing DPM exposures in metal and nonmetal mines cites total carbon (TC), a summation of elemental carbon (EC) and organic carbon (OC) obtained by NIOSH Method 5040, as a surrogate for determining DPM exposures (Noll, 2006). MSHA personnel use the 1973 sampling criteria outlined by the American Conference of Government Industrial Hygienists (ACGIH) for collecting compliance-based respirable and inhalation samples in metal/nonmetal mines. Instrumentation developments are allowing improved real time monitoring of ventilation parameters. DPM is within the aerodynamic particle size range of the samplers used for respirable and inhalable dust measurements. If a sampler used by MSHA to collect inhalable or respirable dust samples in underground metal/nonmetal mines was used to collect DPM, both the DPM and mine ore dust would accumulate on the sample filter (Noll, 2006). To comply with the requirement and lower the DPM exposure, mines are implementing a variety of control technologies such as emission based maintenance programs where adjustments or repairs are performed on the vehicles (McGinn, 2000)."

Jan 1, 2016

By James L. Withiam, P. C. Kelsall

The manuscript of this paper was not available for publication when the Proceedings went to press. Should the authors elect, they may distribute copies at the time of the Symposium.

Jan 1, 1986

By D. R. Bomberger

An automatic microscope has been developed to .measure the size and populations of macerals and minerals in fine coal particles. Differentiations are made on the basis of reflectance. This study is concerned with the size distribution of pyrite inclusions. Most fine coal cleaning processes do not remove pyrite as completely as a straight density separation. Consideration of the pyrite size distribution is suggested as a more accurate method of predicting sulfur reduction by a cleaning process. Analyses of float-sink results and Deister Table operation in terms of pyrite particle sizes are made. Other potential applications of automatic microscopy are also discussed.

Jan 1, 1963

By Scott W. Harrison, Richard E. Aaseng

In 1993 Ispat Inland Mining Company began mining its Laurentian ore reserve, which has six distinct ore types that are extremely variable. Initially batch processing was necessary to optimize mining equipment utilization. The variability as found in the ground was compensated for in plant operation, which proved ineffective. When the last of the six ore types was introduced in 1997, production, quality, and cost were seriously impacted. In-pit blending was the solution developed by the process management team to provide the plant feed required to economically process all six ore types in the Laurentian reserve.

Jan 1, 2000

By H. Sevim

Belt network simulators developed in the last two decades are reviewed. Critical parameters in belt network design are identified, and the capabilities of belt simulators in providing values of these parameters are investigated. An alternative design model that optimizes values of the critical parameters is introduced. To illustrate the capabilities of the alternative model, a real life case is treated and the outcomes are discussed.

Jan 1, 1990

By C. C. Harvey

As we move towards the 21st Century there are several factors that will influence the markets and processing requirements for industrial minerals. Traditional markets for many industrial minerals in the developed world are frequently stagnant or decreasing because of their maturity or due to environmental factors such as reclamation, recovery of byproducts, and recycling. Some industrial minerals are greatly affected by these factors, while others are either immune to or have adapted successfully to meet these challenges. In the developing countries of the world, there is rapid market growth and resource exploitation. The future of specific mineral commodities in several markets will be discussed.

Jan 1, 1997

By Frank E. Chase

Retreat mining is one of the most hazardous operations conducted underground. One of the keys to miner safety and an efficient recovery of the reserves is to design adequately sized production pillars to prevent pillar squeezes, excessive pillar spalling, severe floor heave, roof falls, and pillar bumps. Currently, few pillar design approaches are available which consider the abutment pressures generated by the gob. The Bureau of Mines is developing a method called Analysis of Retreat Mining Pillar Stability (ARMPS) to aid in the design of retreating sections. Back analysis of 42 case studies indicates that ARMPS can be helpful in predicting stability during retreat mining operations.

Jan 1, 1993

By M. Scherzinger, M. Dr. Mazurkiewicz

Additional progress in comminution can be achieved if the compressive crushing principle commonly used at present is changed to one where particles are fragmented by the tensile growth of preexisting internal flaws or cracks, under internal waterjet pressure. This idea was studied in a number of tests and generated results and conclusions are the subject of this paper. It covers tests with different jets imposed on rock samples during compressive load as well as without any loading.

Jan 1, 1992