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By Thomas V. Falkie

Of the various critics of federal energy and minerals policy we are hearing these days--and they are legion--few make their points more vividly than our fellow SME member and eloquent spokesman for the mineral industry. Mr. Eugene Guccione. In a moment of comparative mellowness. Mr. Guccione recently characterized Washington's time-honored legislative and bureaucratic machinery as a case of "...scientific illiterates asking the incompetents to do the unnecessary." I hope the prevailing industry view of government is not quite that harsh, and yet one cannot deny that government intervention is indeed pressing in on the mineral industry with increasing force. What is happening today in Washington and in state capitols will have enormous impact--both short and long term--on the future of coal and mineral production in the United States. Symptoms of this trend are everywhere. In the first place, there is a sentiment, widely held and still spreading, that the government must become involved-- that no matter what the problem, the solution lies in more government intervention. Free enterprise versus statist, reflex reaction organizations. When it cones to regulation in the resource field, there is too often a tendency to start out by assuming guilt on the part of the mineral industry. This can lead to laws governing mineral recovery that are more punitive than constructive...laws drawn up with little research into the scientific or economic considerations involved.

Jan 1, 1975

By R. J. Sweigard

Three case studies were undertaken to investigate the role of land use potential evaluation in reclamation planning and to determine the impact of regional differences on the evaluation process. The three surface mines studied were representative of operations in the Appalachian, Interior, and Northern Great Plains provinces. The scope of the investigations included a survey of regional characteristics, a detailed investigation of the mining operations and site conditions, and an assessment of local land use planning activities in the area of the mine. Special attention was given to key factors that presently determine the use of reclaimed land. Also, for each case study, the postmining land use potential was evaluated using site planning principles. Specifically, the environmental, economic, and social impacts of several potential postmining land use plans were considered.

Jan 1, 1983

This one day field trip is sponsored by the Denver Region Exploration Geologists? Society, May 14th 2009. The trip highlights major geologic features and some notable uranium occurrences along the north-south mountain-basin boundary southwest of Denver and continuing north to Fort Collins, Colorado. Uranium deposits visited include sandstone?hosted roll front type and polymetallic veins hosted in metamorphic rocks. A replacement ?episyenite? type occurrence is considered via description and hand samples but is not visited owing to logistical constraints. Recovery methods addressed include underground mining and in-situ leach recovery. Samples of Precambrian basement rocks, deposit host rocks, uranium ore samples, and ore polished sections viewed by reflected light microscopy will be available. A road map showing the locations of the stops serves as the front cover of this field guide. The Robinson episyenite-hosted occurrence (not visited) is labeled as Stop 6. A stratigraphic column is provided which shows the position of the host rocks at each stop (Figure 1-1).

Jan 1, 2009

By R. Venkataramani

Even though the mining industry in 1966 produced more ore than ever before, current extraction rates are only a fraction of what is expected in the later years of the twentieth century. Nearly 90% of all metals and-mineral products consumed last year was recovered by open-pit mining. This has placed great pressure on this segment of the industry which has, consequently, resulted in some spectacular developments. With increasing size of projects, the need for increased sophistication of engineering, planning, management and administration of modern mining installations has never become more apparent. The design of complete systems for the mine and plant that fit the mould of today's business and social environments is undergoing an evolutionary process. Traditional concepts in mine development and operations are being sidestepped in favor of new ideas and principles. As the overburden thickness increases, materials handling presents a major problem to mining companies, especially those concerned with the mass production of ore and waste from low-grade deposits. The profit margin here is likely to be significantly less as to take chances with capital investment. 1 Constant efforts are needed to improve upon productivity if the ore is to be economically mined.

Jan 1, 1970

By R. E. Mason

Shotcrete has been used for approximately 20 years to facilitate tunnel excavation through poor ground. Early examples of such usage in North America include the recuperation of the Granduc Mines access tunnel in Northern British Columbia, and similar work performed in the Carley V. Porter and Big Walker Tunnels in the United States. Mining companies such as Craigmont Mines in B.C. and Hecla Mines have used shotcrete in their workings for the past ten years. Shotcrete is now a widely utilized fool in the mining and tunnel construction industries in North America, but the accumulated experience is too limited for many to fully appreciate the capability of shotcrete to control ground movements and to understand the limitations of this tool. It is common, for instance, to use shotcrete to "bridge the gap" between rock bolt-supported and steel-rib supported ground and to avoid the use of shotcrete in water-bearing ground. Shotcrete can, and has been, used economically and practically under most severe ground conditions.

Jan 1, 1976

By John B. Squyres

The purpose of this paper is to describe certain features of the uranium deposits of the South San Juan Basin, and to suggest a mode of origin for the deposits which is consistent with the data. A series of photographs is included at the end of the paper to illustrate the nature of the ore bodies. Since the general geology of the Grants Region is well described in the literature, it will be only briefly reviewed, and the time will be spent instead on the morphology, spatial relations, and geochemistry of the ore deposits. Part of this material is original, but data and ideas have been taken from a variety of sources, including the literature and the personnel of the USGS, the AEC, and many of the operating companies of the South San Juan Basin. I gratefully acknowledge these sources. The accuracy of the data and the conclusions presented here are my own responsibility, however.

Jan 1, 1974

By Sam H. Patterson

Australia has led the world in bauxite production since 1976, and only the Republic of Guinea has larger bauxite resources. India has a small integrated aluminum industry, and deposits containing more than 1 Gt (billion metric tons) of bauxite were discovered in the 1970's. The Peoples Republic of China has large bauxite resources scattered in several regions, but it is a monohydrate type that is difficult to process for aluminum. Indonesia and Malaysia both have long histories of bauxite mining, and both have limited resources of high-grade bauxite. Districts containing bauxite resources in the 10 Mt to 150 Mt (million metric tons) range are scattered in countries along the eastern rim of the Pacific Ocean, on islands in this ocean, and on the western and northern rims of the Indian Ocean.

Jan 1, 1982

By Debra Switzer, Swapnil Urankar, Douglas Watson, Steven Hunter, Chandranth Banerjee, Shashank Pathak

A hydrocyclone is a piece of equipment commonly used as a classifier in mill circuit operations. Traditionally, hydrocyclone performance is characterized by the classification efficiency parameter, such as cut size (d50c), sharpness of separation () and bypass (Rf ). A plethora of endeavors have already been made to develop parametric models to determine hydrocyclone performance that correlate design and process variables. In contrast to those studies, we made an attempt to develop an approach to derive required design parameters purely from hydrodynamic principles that provides a platform to optimize the operation of a hydrocyclone for a given application. In this selection methodology, we calculated the differential pressure at the air core, as well as the tangential velocity at the boundary of the air core from the vortex principle in a confined geometry at different operating regimes. A series of experiments were conducted using Weir’s Cavex® hydrocylone where process variables—such as solids concentration and feed flowrates—were experimentally studied to determine the key classification parameters. For the validation of the current approach we used the same process variables to derive design parameters and compared them with the existing design. The current approach can provide insights towards the selection of design parameters and can be useful for mining industry professionals to optimize different operating parameters of hydrocyclones to achieve the best performance.

Feb 1, 2024

By David De Lemos Pires

Mining is essentially a materials management process where materials are classified, excavated, moved to a desired location, processed at a cost and sold for a price hopefully to generate a profit. ?How much is that cost and can it be reduced?? is the age-old question. The requirement for a paradigm shift with regard to materials movement in search of low-cost production has not just happened by chance but, rather, has been driven by agents of change that include mining companies, consultants, governments and equipment suppliers. During the past 100 years of mining, surface mining technology has involved humans with hand tools, humans with machinery and unmanned automated equipment. In the past 50 years, surface mining technology has evolved and now takes the form of trucks and loaders (TL), in-pit-crushing conveying (IPCC) and autonomous haulage equipment (AHS).

Dec 1, 2013

By Mustafa Fener, Masoud Rostami, Sair Kahraman, Behnaz Dibavar

The paper introduces a new rock mass cuttability classification (RMCC) system for roadheaders used in coal mines. It includes performance prediction models for both axial and transverse roadheaders, based on six parameters: uniaxial compressive strength, Cerchar abrasivity index, volumetric joint count, strike and dip of joints, joint aperture, and groundwater condition. The study validates the RMCC system through field and laboratory measurements, showing high correlation coefficients between net cutting rates and RMCC indices.

Nov 1, 2023

By Ping Zhang, Xu Ma

Perturbations from mining operations significantly affect the stability of rock masses, especially with the increase in mining depths. This study uses the discrete element method (DEM) to investigate shear slip failure along discontinuities in an underground mine, aiming to quantify seismic moment and seismic energy to better understand seismic hazards.

May 1, 2023

By W. T. Reid

Analysis of the energy resources available in the United States confirms that coal will be needed to satisfy the future energy needs. The trends in the market place, particularly economic and political, suggest that the bulk of the coal will be consumed for generation of electricity. The utilization of coal to produce electricity will require technical solutions to the variable characteristics of coal and ash, development of methods to improve coal quality, and public acceptance of the cost of compliance with environmental standards.

Jan 1, 1983

By M. Sengupta

Surface mining in arctic regions is characterized by many unique problems. Continuous and discontinuous permafrost (perennially frozen ground) occurs in most of the arctic and subarctic areas. Permafrost presents special problems of slope stability. Stability of permafrost depends on its temperature, moisture content and material type. Permafrost slope fails due to solifluction, disturbance of ice rich slopes, and liquefaction. Drilling and blasting of frozen ground present special problems. Depending on their degree of saturation with water, freezing soils and rocks have a number of important characteristics that affect blasting efficiency. Metals used in mining equipment and mining structures require special selection. At low temperatures many steels lose most of their normal ductility and toughness (resistance to brittle fracture). The paper discusses engineering solutions to unique problems of arctic mining.

Jan 1, 1986

By Turan Uysal, Thierno Saidou Barry, MURAT ERDEMOGLU, Mustafa Birinci

Nonbauxite ores such as aluminum silicate clays and coal fly ashes have been widely considered as potential resources of alumina (Al2O3). The interest focused on these ores is due to their high alumina content. Over the years, in countries where there are little or no bauxite reserves or where the recovery of existing bauxite ores to produce alumina with the Bayer process is not economical, alternative processes have been explored. Among these processes, acid leaching is seen as the most attractive process. In the acid leaching process, heat treatment for thermal activation to destruct the refractory structure of the minerals in the ores is generally recommended as a pretreatment method. Recently, the applicability of high energy ball mills, which are useful for mechanical activation as a pretreatment method before leaching, has attracted much attention. This is a short summary of our previous review [1], giving the details of alumina manufacturing from thermally and mechanically activated clays and coal fly ashes by acid leaching.

By H. Cetin

The availability of coal resources of selected 7.5-minute quadrangles of southwest Indiana was examined in this study. Resources were defined as original coal in place, remaining after mining, and currently available considering land-use and technological restrictions. The amount of coal mined from each study area varies depending on the mining practices of the companies operating within the area. Of the three quadrangle investigations, the available resources range from 50 percent to 79 percent of the original resources. Most of the coal resources under deep-minable category were not available because of technologic restrictions, such as insufficient coal thickness.

Jan 1, 1996

By C. E. Jordan, B. J. Scheiner

The Bureau of Mines has developed a continuous ultrasonic flotation cell for the recovery of Florida phosphate ore. Within a small mixing chamber near the bottom of the flotation cell, an ultrasonic probe agitates an injected mixture of air, water, and phosphate ore and breaks the air into fine bubbles. Phosphate particles are preferentially attached to these fine bubbles and floated in the main chamber of the flotation cell. Over 94 pct of the phosphate was recovered, resulting in a 30 pct P205 concentrate. The ultrasonic energy consumption was less than 7 kW.h/mt of phosphate ore.

Jan 1, 1989

By K. N. Han, Y. Guan

The dissolution behavior of silver and copper from silver/copper alloys in ammoniacal solutions was investigated using a rotating disc. Oxygen was used as an oxidant. The effects of the alloy composition, concentration of lixiviants, stirring speed and temperature on the overall dissolution kinetics were studied. Three silver/copper alloys (containing 76.7, 46.9 and 24.1% silver) were used in this study. The rates of dissolution for these alloys were compared to that of pure silver and copper under the same testing conditions. Emphasis was given to the galvanic effect on the overall dissolution rates.

Jan 1, 1995

By D. R. Gladwell

This study examined the-feasibility of clay mineral identification and quantification by reflectance radiometry and subsequently developed a computer algorithm for deconvolution of the component spectra. Clay mineral analysis of 53 rocks and soils from Alberta, Saskatchewan, Ontario and Nevada by X-ray diffraction (XRD) compare favourably with the radiometric determinations. The application of the technique to precious metal exploration was examined at the Horse Canyon epithermal gold deposit, Cortez Mine, Nevada where low levels of illite and kaolinite are present alongside local silicification. Consequent on the success of the laboratory and field work a field portable clay mineral analysis system was designed and constructed.

Jan 1, 1985

By S. K. Kawatra

Outokumpu Electronics has designed a new on-line coal slurry ash analyzer, based on an instrument developed at Michigan Technological University. The primary goal was to build an accurate instrument at the lowest possible cost. The instrument determines ash content from measurements of X-ray backscatter, iron K, fluorescence, and low-energy y-ray absorption. It is capable of measuring the ash content with a standard error of 1.1% ash over an analysis range of 9-21% ash and 7-22% solids. The analyzer was tested on coals from United States, Poland, Great Britain and the USSR.

Jan 1, 1993

By J. A. Frew, G. I. Orrock, R. M. Glen

The zinc flotation circuit was sampled to provide sized information on its metallurgical performance. A good balance was obtained and the roughing, scavenging, cleaning and regrind sections were assessed. Substantial losses of sphalerite occurred in all sizes. The limitations were poor recovery in the cleaning section which resulted in substantial recycling of 15-30µm sphalerite and iron sulphides, and inability to float +38µm sphalerite in the roughers. Regrinding increased sphalerite recovery by 7% with no loss in grade. Liberation measurements enabled balances for six size fractions to be calculated and the role of liberation on the metallurgical performance was assessed.

Jan 1, 1993