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By C. H. Bucknam

Acid neutralization titrations were applied to the characterization of soil and overburden for the control and prediction of acid rock drainage in the coal fields of the eastern United States in the 1970?s (1). These became known as the Sobek methods as a result of the early United States Environmental Protection Agency publication and the methods have been modified (2) to be adapted to many applications in the metal mining sector (3,4,5,6,), and, as a result, there are a large number of acid neutralization potential methods being used that are referred to as Modified Sobek methods. Standardization of neutralization potential methods for metal bearing ores and related materials based on carbonate carbon, rather than titration, commenced in the 1990?s through the American Society of Methods and Materials (ASTM) Committee E01 on Analytical Chemistry for Metal Ores and Related Materials Subcommittee E01.02 on Ores, Concentrates and Related Metallurgical Materials (7). A subcommittee section, E01.02.05 on Environmental Methods, was organized to coordinate the method and material standardization efforts of ASTM and the Acid Drainage Technology Initiative Metal Mining Sector (ADTI-MMS) Prediction Committee (8), which took on the project of standardization of the acid neutralization potential acidity titration method (ANPA) to supplement the carbonate carbon method in E1915 (9) for application to samples which have metal carbonates (10), in particular, which result in overestimation of the neutralization potential using the carbonate carbon methods (11).

Jan 1, 2010

By Alexander N. Winchell

The construction and erection of the Coleraine concentrating plant was commenced in April, 1909, and was completed (with the machinery installed) ready for use in 1910. Attached to the main building is 'a table house large enough to accommodate con¬centrating tables for five units and space for a small machine shop and supply store. For the handling of the' railroad cars in the upper portion of the mill there is provided on the north side of the main structure a trestle approach 650 feet long, and on the south or opposite side a tail track 300 feet long. The latter is so constructed as to permit its being incorporated directly in a possible future extension of the plant. The building, viaduct approach and tail, trestle, as well as the table house, are con¬structed of steel, the total amount used being 6,100 tons. The building is covered by corrugated' steel sheeting over 2 x 6-inch wood sheathing fastened directly to the structural steel. The north end of the trestle approach is connected with the main road-beds forming the track system for delivery of the crude ore to the plant over an embankment of a maximum height of 110 feet containing over 2,000,000 cubic yards of dirt.

Jan 1, 1920

By H. J. Sohn, S. G. Doo

A systematic study was carried out to investigate the reduction reaction mechanism of oxygen on pyrite surface using electrochemical techniques. The polarization curves showed two distinct regions, the Tafel region for superoxide formation and limiting current region for diffusion of dissolved oxygen to form hydrogen peroxide. These results were confirmed with a-c impedance measurements.

Jan 1, 1990

By T. Fernandez, V. Juchen, C. Petter, F. Cantini, V. Lenz, V. I. Araújo, R. Petter, R. Darrigo, A. Young, I. G. da Costa, J. Oppermann

There are many methods to estimate costs quickly. One of these is the Parametric Method, where costs are estimated from general algorithms (or curves). Derived from an original tool based on the O’Hara model, a software called MAFMINE was developed. MAFMINE is based on parametric models to estimate investment and operational costs in mining. The software itself is based on the use of a computer model known as client-server. However, the model needs new inputs from advances made by the mining industry, mainly in terms of electrification, automation, digital transformation and preconcentration to face Environmental, Social and Governance (ESG) concerns. Thus, this work was to prepare a new core module ready to incorporate the new technologies aiming to deliver operation and capital costs associated with environmental impact mitigation. The tool generates an order of magnitude estimate for CAPEX and OPEX to establish a very first Discounted Cash Flow (DCF) in a mining venture. For quick evaluations, at a preliminary level, the results are very promising.

Mar 2, 2022

By O. F. Brown

The use of quality materials (aggregates and asphalt binder) in optimal proportions is the key to producing optimally performing hot mix asphalt (HMA). The Superpave mix design standard in the US introduced specific volumetric and binder property requirements in HMA design. Different methods for HMA constituent proportioning have been proposed in various guidelines. The design process to determine the HMA blend is currently iterative and engineers rely almost exclusively on experience. This approach is time consuming and often does not result in cost-optimal HMA mixtures. This paper introduces a mixed integer linear programming (MILP) optimization model for hot-mix asphalt constituent proportioning. The MILP model minimizes the total mix cost while satisfying all the volumetric, binder and mix property specification requirements. The model has been successfully validated with real-life example. The aggregates and binder ratios from the model were in close agreement with those from the contractor. The Bailey ratios and the gradation constraints were also satisfied. The cost of the optimal mix was $0.804/Mg less than that of the contractors?. This marginal reduction might make all the difference in an industry that is highly competitive. The MILP model also demonstrated that adding RAP to the contractor?s design would reduce the cost of the blend by $5.74/Mg. The virgin binder content was reduced by 1% because of the recycled asphalt contained in the RAP. This work represents the first successful attempt in incorporating both aggregate and asphalt performance requirements into the optimization formulation. Applying these models will ensure the minimum cost mix that meets all constraints and will increase profit margins for plant operators.

Jan 1, 2012

By Shawn McWilliams, Aini Sun, Mike Lichte, Greg Colzani

The Allegheny County Sanitary Authority (ALCOSAN) adopted its Clean Water Plan (CWP) in May 2020, as part of a federal consent decree to comply with the USEPA’s Combined Sewer Overflow (CSO) Control Policy. Planned improvements include constructing a new regional storage/conveyance tunnel system, promoting green infrastructure/ source control, and expanding the treatment plant. Preliminary planning for the tunnel system was completed in October 2020. The Ohio River Tunnel (ORT) project is the first of three tunnel projects that make up the regional tunnel system. The ORT project began final design in 2021. This paper discusses the advancements made to the ORT preliminary planning concepts considering property availability, alignment optimization, tunnel boring machine evaluation, contract packaging and delivery schedules.

Jun 13, 2023

By S. Que

Local community acceptance is a key aspect of planning and managing mining projects, whether through sustainability assessment and reporting or corporate social responsibility programs. However, there has been very little research to understand the determinants of community acceptance. This paper seeks to identify key mine characteristics and demographic factors that influence individual acceptance of mining projects. Six demographic factors and 16 mine characteristics were selected based on literature review. Four of the six demographics factors were confirmed to be significantly (p < 0.05) correlated with people?s attitude of the importance of the mine characteristics. All sixteen mine characteristics are identified as important factors. The most important mining factors are Job opportunities, water shortage or pollution, air pollution and land pollution. Both the mining and control groups have same opinion of 12 mining characteristics and differ on four (infrastructure improvement, labor shortage for other businesses, noise pollution, and mine life). During design and management of mines, this data can be used as a reference. This result will facilitate better choice experiment (survey) design for discrete choice modeling. Such discrete choice models can provide a viable framework for data-driven community engagement and sustainable mine management.

Feb 23, 2014

By Sahendra Ram, Ashok Kumar, Rakesh Kumar, AMIT KUMAR SINGH, Dheeraj Kumar, Arun Kumar Singh, Rajendra Singh

This article offers an examination of a retreat mining method conducted at the Pinoura Mine in India from 2010 to 2017. The method is atypical for coal mines of India’s coalfields. The method executes depillaring in a single pass and does not require the formation of galleries and support installation in splits, thus, reducing the cycle time. A variety of observations are discussed throughout this work and emphasis is placed on field measurements and depillaring under weak roof (RMR = 40–45). This paper discusses design techniques, specifically the estimation of the snook (remnant pillar) size, and important practical observations after the fact. The execution of this method was eventually conducted in eleven panels.

Aug 4, 2020

By J. S. Ross

The significance and role of industrial minerals in Canada differ from those in the United States, The smaller Canadian industry has recently become well diversified and self-sufficient in most commodities, However, it depends on exports, principally to the United States, for much of its market, Imports are small, but imports of several basic products manufactured from industrial minerals are large. This nation is a leading world producer of asbestos, gypsum, sulphur, nepheline syenite, titania slag, potash and barite. It has reserves in asbestos for at least 30 years enough potash to supply the current world&apos;s needs for 2,000 years and sulphur reserves for 40 years of current world demand, One of the ilmenite deposits contains enough titania to supply the current world demand for at least, 25 years.

Jan 1, 1964

By W. J. Schlitt

The development of forced aeration as an approach to enhancing copper sulfide leaching is traced from its earliest development up to present day operations using this technology. Both large-scale field tests and commercial operations are covered. The historical portion is preceded by an introductory discussion of the role of air (oxygen) in sulfide leaching. Sufficient aeration may be achieved via naturally induced convective airflow. However, cases are identified where this is insufficient, leading to retardation of the sulfide leach rate. For these situations, forced aeration may be beneficial. The historical portion of the paper focuses on the major field tests that have been conducted in Montana, Nevada and Utah, along with commercial operations in the United States, Australia, Chile and Peru. The paper concludes with some general comments about the applicability of forced aeration, which are based on the information developed to-date.

Jan 1, 2006

Scattered north and south along a 161-km (100-mile) stretch of Interstate 80, Newmont Min¬ing Corp. owns four active mining properties in Nevada?s northern high desert ? Carlin Trend Operations, Midas, Twin Creeks and Phoenix. Among the four, there are nine openpits, five underground mines and 14 processing facilities. While gold is the predominant ore, silver and copper are also produced. And in a move to hold down energy costs, Newmont built and owns the 200-MW (net), coal-fired TS power plant. This plant provides about 65 percent of the power used for Newmont?s own operations, while the rest is sold to NV Energy, which services Nevada and northeastern California. Bringing the Phoenix Mine ? Newmont?s newest in Nevada ? on-line presented many developmental and operational challenges. Located about 19 km (12 miles) southwest of the town of Battle Mountain, the general area had been home to prospectors and other mining companies since the 1860s. But any profitability in developing the lower grade gold, copper and silver deposit at Phoenix proved elusive, with Battle Mountain Gold being the last company to make an attempt. When Newmont acquired Battle Mountain Gold and its Phoenix reserves in 2001, the lower grade of ore was not a deterrent. Newmont found Nevada-wide cost savings synergies for maximizing profit during the depressed gold market of the late 1990s. The new property was aptly renamed the Phoenix Mine, a nod to its rising from the ashes of the dreams and efforts of previous mine owners.

Jan 2, 2010

By J. S. Hu

FTIR spectroscopy has been used for the characterization of adsorbed oleate at the fluorite surface. It has been found that modest changes in the adsorption density at high temperature and high oxygen potential do not provide a satisfactory explanation for the significant increase in the hydrophobic character of the system under similar conditions. Rather, FTIR spectroscopic measurements suggest that chemical interaction between adsorbed oleyl groups occurs at high temperature and/or oxygen potential and accounts for the increased hydrophobicity. Specifically, the intensity of the =CH bond of the adsorbed oleate diminishes at high temperature and/or high oxygen potential. Such a phenomenon was not observed in control tests with the calcium oleate soap. For extensive reaction at the fluorite surface, the presence of a new surface species has been identified. These results indicate that the fluorite surface catalyzes an oxidation and/or polymerization reaction between adsorbed oleyl groups which results in a more hydrophobic structure at the fluorite surface.

Jan 1, 1986

By William W. Kephart

Brockway Glass Company, Inc., manufactures glass containers at fourteen plants located in nine states. The relatively high place value of the major glass batch components dictates that raw material supplies be obtained from numerous sources in the United States and Canada. One objective of our central composition control program is to arrive at a glass composition with similar physical properties at each of our plant locations. This requires that adjustments be made in the batch compositions to compensate for chemical variations from one raw material source to another. Minor chemical variations will occur in sand, limestone, and dolomite from one source to another. Major variations are present in the alumina sources because of the diverse rock types utilized.

Jan 1, 1973

By Kevin Beirne

Most people involved in the mining industry are familiar with student-industry co-op work-study programs. Many colleges and universities have used them for years. Northern College’s Haileybury School of Mines student co-op program adds a new dimension of productivity to the college and the mining industry. The college is located in Hailey-bury, Ontario, Canada. An example of the program’s success is the school’s relationship with Sabin Metal’s SMC (Canada) Ltd.’s McAlpine Mill in Cobalt, Ontario. Students gain practical knowledge and experience while industry gains an eager-to-learn worker. And many of the college’s advanced research services are made available to industry to supplement their own capabilities. The McAlpine Mill was established to provide custom milling of slags and ores. It also recovers metal values from other products of the primary and secondary precious metal industries.

Jan 1, 1999

By Richmond Bennett

Airborne geochemistry became a reality with the advent of a high-sensitivity airborne gamma ray spectrometer with large volume NaI (TI) crystal detectors. Small variations in the concentration of potassium (as K40), thorium (as T1208) and uranium (as B1214) along the flight lines can be determined by measuring the gamma radiation with a sensitive airborne spectrometer. Small volume crystal spectrometers are useful only for detection of major surface uranium (Bi214) variations, but the large crystal volume system is an airborne geochemical exploration method capable of locating hydrothermal mineral deposits. Radioactivity as a guide to ore has been discussed in the literature by Damon (1950), Gross (1952) and others. The theoretical basis is that potassium, thorium, and uranium are concentrated in late stage solutions during magmatic crystallization. Thorium and uranium are concentrated in late stage liquids because their large atomic radius and high ionic charge prevent them from entering into the crystal lattice of common rock-forming minerals (Rankama and Sahama, 1950). Potassium, which has a large ionic radius and small charge, also can be concentrated in the high water content late stage fluids (Heier and Adams, 1964). A large proportion of uranium and thorium in rocks occurs around grain boundaries of the essential rock-forming minerals (Hurley, 1950). Uranium and thorium substitute for zirconium in zircon, a comparatively early forming mineral. However, most of the thorium and uranium is concentrated in residuals where they can be fractionated and incorporated into allanite, monazite, xenotime, and other minerals.

Jan 1, 1970

By Joseph B. Gillenwater

Miss Gertrude Carey lived next to us in Martinsburg, West Virginia for several years. She was a retired school teacher. She was also a cousin to Messers Dan and Joe Baker who owned and operated Standard Lime and Stone Company, a predecessor of Martin Marietta Corporation. She-was well acquainted with the Baker family and their history. Here is one of the legends she told my wife, Jean, and me. The Bakers were originally Tanners. They had a tannery near Frederick, Maryland. There were several boys in the family and when they were grown each man had specified responsibilities. Will Baker was assigned the duty of locating, buying, and transporting tanbark and lime. As he traveled through Maryland, Virginia, Pennsylvania, and West Virginia to locate and buy tanbark, he also talked the farmers out of some pieces of lime, which the farmers had produced in holes dug and filled with layers of limestone and wood. Will Baker took the lime and soaked a piece of hide in the milk of lime. If the lime did not spot the hide, Will Baker would get the farmer to burn some lime for him, and further tests would be made. If these tests were good - the Bakers bought the land. They eventually discovered that the limestone that would make lime that wouldn&apos;t spot the hide would also be suitable for producing steel. They began producing lime just outside Harpers Ferry, West Virginia in pots and upright kilns. That stone too small for the kilns was just perfect for railroad ballast. Now you know how "Baltimore Blue Bloods" got together!!

Jan 1, 1979

By B. Birol, M. N. Saridede

"Slag density is a significant factor in determining the process efficiency of the electroslag remelting (ESR) process, where calcium fluoride (CaF2)-based slag is formed synthetically to refine metal ingots. Although there are some former studies investigating the density of CaF2-containing slags, the prediction models focusing on them are applicable only to some specific systems. The present study aims to build a model to predict density for a wide range of CaF2-containing ESR slags. To investigate density for various slag compositions, CaF2-Al2O3-based and CaF2-Al2O3-CaO-based slag compositions were prepared. Additionally, some minor constituents like FeO, MgO and MnO were added to a 5:3:2 CaF2-Al2O3-CaO slag in order to investigate the effects of these constituents on the slag. The volumes of the prepared slags were measured in a tube furnace at 1450-1550 °C using the sessile drop technique, and their densities were calculated. The results showed that for the slags, density is related to optical basicity, and therefore a prediction model based on an Arrhenius equation was built. The model was tested with data from literature, and its limitations and validity are discussed.IntroductionThe electroslag remelting (ESR) process is a refining method in which a metal ingot is remelted under a synthetic slag. These synthetic ESR slags are mainly composed of calcium fluoride (CaF2), calcium oxide (CaO) and aluminum oxide (Al2O3). Other constituents like iron oxide (FeO), magnesium oxide (MgO), manganese oxide (MnO) and chromium oxide (Cr2O3) are added to this system in relatively low amounts, according to the type of steel ingot to be refined. The prediction of slag properties, such as electrical conductivity, viscosity and density, is crucial for the selection of the synthetic slag in order to obtain the required process parameters, like temperature, the passing time of the molten metal droplet through the slag, and metal-slag separation (Akbari, Reitz and Friedrich, 2009; Hara and Ogino, 1981; Mattar, El-Faramawy and Fathy, 2002; Mehrabi, Rahimipour and Shokuhfar, 2005; Presoly, Korp and Schneider, 2008).As slag density affects metal-slag separation in the ESR process, predicting the density of an ESR slag is important for appropriate refining and improved product quality. Although there are many studies investigating the density of slags (Akbari, Reitz and Friedrich, 2009; Aune, Hayashi and Sridhar, 2005; Hara and Ogino, 1981; Matsushita, 2011; Mills and Keene, 1987, 1981; Seetharaman et al., 2013; Shu, 2007; Shu and Chou, 2013; Sikora and Zielinski, 1974; Xu et al., 2012; Zhang and Chou, 2010), the prediction models built are generally valid for oxide-containing slags (Aune, Hayashi and Sridhar, 2005; Bottinga and Weill, 1970; Mills and Keene, 1987; Seetharaman et al., 2013; Shu, 2007; Xu et al., 2012; Zhang and Chou, 2010). These models were built on either the molar volumes of the constituents (Bottinga and Weill, 1970; Mills and Keene, 1987) or the thermodynamically calculated enthalpy or free energy of mixing, which can be applied to a system containing constituents sharing an ion, such as an O- ion for oxide systems (Aune, Hayashi and Sridhar, 2005; Hillert, 1980; Persson et al., 2007). Some recent studies modeled the density of some oxide slags on their optical basicity (Shu, 2007; Shu and Chou, 2013; Xu et al., 2012; Zhang and Chou, 2010)."

Jan 1, 2016

By J. J. Pavlica

Grinding in steel mills adversely affects the flotation removal of pyrrhotite from magnetite ores. To elucidate the effect of grinding media on the floatability of pyrrhotite, rest potential and short-circuit current measurements were made on electrode combinations of pyrrhotite-mild steel and pyrrhotite-stainless steel. Galvanic contact of pyrrhotite with mild steel increased the rate of surface reactions on pyrrhotite in air-exposed and oxygenated solutions. It was postulated that the formation of &apos; an iron hydroxide coating on the pyrrhotite adversely affected its floatability. Its formation was minimal when pyrrhotite was contacted with stainless steel. Fine magnetite particles caused slime coating on pyrrhotite surfaces by magnetic interaction and impaired the flotation of pyrrhotite.

Jan 1, 1982

By Sylvain J. Pirson

A fluid mining process has been developed by the writer whereby phosphate deposits are leached in place through the injection of a weak and recoverable acid solution much in the same manner as in the recovery of oil by water-flooding. The phosphate mineralization is dissolved In place, selectively treated in a surface plant and a high grade diacalcium phosphate substatially free of fluorine (hence of feed grade quality) is recovered. Because of its finely divided and powdery state, the plant product is highly desirable as stock material for the manufacture of triple-superphosphate and of high grade phosphatic chemicals. Details of well completion, fluid injection, areal sweep and solution efficiency, plant design and economics are presented The rate of return on investment is particularly attractive under conditions of shallow occurrence of the phosphate mineralization such as in the Bone Valley formation of Florida. The process may also be applied economically to the Phosphoria formation of wide- spread occurrence in the Northwest United States through the application of selective formation fracturing (or Hydrofrac) previous to fluid mining operations.

Jan 1, 1959

By Alexander N. Winchell

The cities of St. Paul and Minneapolis are located side by side on a double loop in the Mississippi River near the eastern boundary of Minnesota. Both cities lie on both sides &apos;of the Mississippi River, which in this region describes an S-shaped curve. The two cities together have a population of over 600,000 people, gathered in an area which has grown to be a single urban district inasmuch as the two cities have expanded until they occupy all the territory formerly between them, though the business centers are ten miles apart. St. Paul is located at the head of navigation on the Mississippi River and Minneapolis, farther upstream, at the Falls of St. Anthony. A recent water¬power development below the Falls of St. Anthony, constructed by the Federal Government, has at the same time made possible navigation to the foot of St. Anthony Falls through a lock around the dam which replaces the former rapids. Minneapolis, in 1920, had a population of 380,000 people, and St. Paul, 235,000. The two cities occupy land at an elevation of 700 to 900 feet above sea level. The average elevation is slightly less at St. Paul. Minneapolis has nearly 4,000 acres of parks and park¬ways, while St. Paul has nearly 2,000.

Jan 1, 1920