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By Tina Maniatis

Applied Biosciences has developed a biological technology for removal of arsenic, nitrate, selenium, and other metals from mining and industrial waste waters.The ABMet® technology was implemented at a closed gold mine site in Canada for removing arsenic from tailings pond water. The system included six bioreactors that began treating water in the spring of 2004. Design criteria incorporated a maximum flow of 567 L/min (150 gallons per minute) and water temperatures ranging from 10°C to 15°C. Influent arsenic concentrations range from 0.5 mg/L to 1.5 mg/L. The ABMet® technology consistently removes arsenic to below detection limits (0.02 mg/L). Data from the full scale system will be presented, as well as regulatory requirements and site specific challenges. Keywords: Arsenic, Sulfate Reduction, Metal Sulfide Precipitate, Biological Water Treatment

Jan 1, 2005

By S. C. Termes

The Bureau of Mines conducted research on the flocculation of various minerals with insoluble cross-linked starch xanthate (ISX) to determine its potential as a beneficiation technique for low-grade, highly dissem-inated ores and for selective desliming. Covellite, chalcocite, pyrite, pyrrhotite, chalcopyrite, bornite, sphalerite, galena, and molybdenite fines flocculate with ISX. Floc formation, floc size, and settling rate are dependent on pH, with the pH dependence differing for each mineral. Quartz is not flocculated by ISX. Experiments to obtain selective flocculation of sulfides from quartz were attempted. Good selectivity was only obtained for the bornite-quartz system. postflocculation separations resulted in flocculated bornite in grades as high as 92 pet. Evidence is presented that the flocculation of many of the sulfide minerals with ISX may involve covalent bonding of the xanthate group to lattice metal site(s).

Jan 1, 1983

By M. O. Magnuson

As part of an experiment in the restoration of lands strip-mined for coal, revegetation studies were conducted at three backfilled strip-mine sites in north-central Pennsylvania. The sites were subdivided into plots that were given varying amounts of lime and fertilizer. In tests conducted cooperatively with State and Federal agronomy experts, the plots were then planted with a variety of trees, shrubs, and grass-legume mixtures. Initial tree and shrub survival was not appreciably affected by lime and fertilizer applications where the spoil pH was above 4.5. Of 14 species of trees and shrubs tested, Norway spruce, black locust, Japanese larch, pitch pine, and white pine were the hardiest. The ground-cover percentage of grass-legume mixtures in the second growing season was substantially increased by using lime and fertilizer. Mixtures comprised partly of fescue were the most satisfactory.

Jan 1, 1968

By Mark E. Gershon

Conventional methods of drillhole site selection are reviewed briefly. Two approaches using geostatistics are then discussed, both of which have been shown to yield improved results. Finally, a branch and bound algorithm is described which will select the best locations for drilling from a user specified number of possible drill sites. Two options are discussed. First, the user can specify a maximum drilling investment or a maximum number of drillholes and the program will select the locations yielding the minimum estimation variance. This amounts to getting the most for a given investment. Alternatively, a maximum tolerable estimation variance can be specified and the program will select the number and location of the drillholes to obtain the desired information at a minimum cost. Another benefit of the approach is the quantification of the tradeoffs between investment and information obtained.

Jan 1, 1983

The Pilbara iron ore industry has seen rapid growth over the last five years and is now bracing itself for another expansion which will take its seaborne trade to beyond 500 Mt/a. To effectively utilise port capacities, port stockpile turnover will become extremely rapid and each stockpile built will have to be of a quality which is precise and unbiased.Sampling systems at the older Pilbara mine sites were generally designed during the 1980s and reflect the practices which were considered adequate at the time. Hence, the precision of measurement at production sites is generally unknown and quality assurance (QA) of sampling facilities falls short of what current best practice suggests. This paper suggests practical improvements in sampling practices and quality assurance, which will assist the industry in achieving quality objectives in times of rapid mining expansion.

Jan 1, 2008

The solution mining review did not arrive in time for publication in the May issue. The term solution mining is commonly used to refer to heap leaching, dump leaching, in situ mining and bore hole slurry mining technologies. The US Bureau of Mines is continuing with research in these areas. Commercial application of these technologies is progressing. There is an ongoing cooperative research project between the Bureau of Mines and the Santa Cruz Joint Venture to evaluate in situ copper mining at a field site near Casa Grande, AZ. The project is currently in the environmental permitting stage. The Bureau is preparing an environmental assessment for the project as part of the National Environmental Policy Act. The Bureau is also continuing with laboratory experiments to study the leaching characteristics of atacamite ore from the field test site, as

Jan 1, 1993

By S. Suda

Hydrogen storage materials have been investigated for more than 30 years, particularly on metal hydrides. These materials are, however, considered today impractical because of their poor hydrogen capacity measured by mass density and their poor surface properties and characteristics against impurities. Recent R&D activities have been located in new categories of materials such as complex hydrides and chemical hydrides. Among these materials, NaAlH4 (one of alanates), Li-based complex hydride, and NaBH4 (SBH: sodium borohydride) are 3 major candidates as hydrogen storage materials. In the presentation, SBH as a non-reversible on-site but recyclable off-site is described in view of its practical availability as the source of H- (protide) applied for a new type of fuel cell named Direct Borohydride Fuel Cell (DBFC) and H2 (hydrogen) for Proton Exchange Membrane Fuel Cell (PEMFC).

Jan 1, 2006

By Rudy Rogers

When Gas hydrate formation rates have two steps: a nucleation induction step and an agglomeration step. Hydrate induction in distilled water is extremely slow because of lack of nucleating particles. Our laboratory found that synthetic anionic surfactants greatly improve both hydrate induction and agglomeration because the surfactant?s hydrophilic head absorbs water molecules and the hydrophobic tail absorbs hydrocarbon gas molecules, creating necessary nucleation sites. Vast hydrate deposits inhabit seafloors. What is the seafloor hydrate nucleating mechanism? We find that nano-particles of smectite clays (bentonite and nontronite) are hydrate-nucleating sites in sea-water-saturated, packed porous media, especially when trace quantities of anionic biosurfactants adsorb on the clay particles. Microbes and their bioproducts proliferate around seafloor gas hydrate accumulations. The seafloor microbe-mineral-hydrate synergy is explored in this paper. Keywords: gas hydrates, biosurfactants, crystal nucleation, smectites

Jan 1, 2008

By John L. Floyd

One of the key factors that controls the overall profitability of surface operations is the required volume of excavated material. If the overall angle of final walls can be maximized the amount of material excavated will be reduced. However, as the slope angle becomes steeper the wall's factor of safety decreases. As a result, the development and implementation of efficient wall control blast designs becomes critical to achieving stable walls. Many site specific conditions should be taken into account when defining the methods that will be used to lessen blast induced wall damage. This paper will discuss the steps needed to properly evaluate the site and develop efficient designs. Four variations of wall control blast designs will be evaluated in terms of cost and performance. In addition, the paper will include the quality controls needed to successfully implement and refine the blast design.

Jan 1, 1998

By T. Motzer

Sustainability management and reporting plays an important role in controlling and communicating a company's efforts in sustainable development. A variety of standards comprising a multitude of indicators often require similar information but with different data quality, level of detail and coverage. This may lead to inconsistencies in external communication because of the difficulties in collection and aggregation of data from different company sites and organisational levels. Using a central database system accessible via internet makes the process of data management more efficient: All relevant information can be collected on-site, with a defined data quality, credibility and consistency. Any type of sustainability indicator can be calculated automatically, once the data is collected. Individual analyses and predefined reports, e.g. GRI G3, can be easily generated and immediately published, making your sustainability communication transparent and reliable.

Jan 1, 2007

By Steven W. Hunt, Ronald E. Heuer, Safdar A. Gill

A 3.3 m (11 feet) diameter, 51 m (168 feet) deep temporary steel casing which had been sunk within glacial soils buckled and collapsed on July 29, 1985. The collapse occurred at the CT-8 Dropshaft site in Milwaukee while two workmen were contact grouting outside the casing in an attempt to stop groundwater inflows through a bottom plug. This paper describes the soil and groundwater conditions at the site, the casing design, the method of shaft construction, and probable causes of the buckling failure. Specific aspects of the paper include: slurry method of shaft excavation and casing installation, soil creep, earth pressure due to three dimensional arching, and buckling strength of a casing surrounded by slurry rather than grout and firm soil. The paper should be of interest to designers and constructors of temporary ground support systems for deep shafts.

Jan 1, 1995

Ocean environmental factors are an intriguing new set of parameters to be dealt with in the prospecting and exploration phases of resource development for both the continental margins and the deep ocean. While information and data gathering programs for ocean minerals would parallel onshore procedures, their costs generally run higher. Commercial Prospecting-Identification of Mining Sites Two modes of prospecting can be identified-commercia1 prospecting (in which the ultimate objective is to define potential mining sites), and scientific prospecting, which is conducted with different objectives in mind. For ocean exploration, both types of prospecting are carried out prior to the obtaining of any exclusive rights to explore and exploit a specific deposit. Deepsea's John Flipse adds: "Any commercial prospecting program should by its very nature require the freedom to search wherever minerals might occur with maximum flexibility."

Jan 4, 1975

By M. E. Gershon

Conventional methods of drill hole site selection are reviewed briefly. Two approaches using geostatistics are then discussed, both of which have been shown to yield improved results. Finally, a branch and bound algorithm is described which will select the best locations for drilling from a user specified number of possible drill sites. Two options are discussed. First, the user can specify a maximum drilling investment or a maximum number of drill holes and the program will select the locations yielding the minimum estimation variance. This amounts to getting the most for a given investment. Alternatively, a maximum tolerable estimation variance can be specified and the program will select the number and location of the drill holes to obtain the desired information at a minimum cost. Another benefit of the approach is the quantification of the tradeoffs between investment and information obtained.

Jan 1, 1985

By E. M. Frizzell

In an effort to economically and efficiently enhance the erosion control aspects of present surface coal mine reclamation practices, the US Bureau of Mines has recently completed a two-phase research program wherein irrigation strategies and equipment developed under the first phase were field tested on three surface coal mine sites. The fundamental basis for the use of irrigation as a reclamation tool is to provide the plant moisture requirements as a supplement to prevailing natural precipitation, and thereby support the natural growth of drought-hardy native vegetation. Portable solid-set irrigation equipment and several irrigation strategies were tested on large 6-ha (15-acre) sites in Montana, Wyoming, and New Mexico. Results of these tests will be presented which include daily irrigations, precipitation levels, soil moistures, climatic data, and density cover and biomass of the native plants.

Jan 1, 1987

The Canada Centre for Mineral and Energy Technology (CANMET) /Calgary Coal Research Laboratory and the National Research Council in Ottawa established a joint working research group with industry to develop and test various computer models for application in surface coal mining operations in western Canada.The first part of the paper deals with the problems the group experienced during the past two years especially having model specification and requirements defined and understand site management practices.The second part of the paper deals with site specific development of general mine model for TransAlta Utilities' Highvale Mine in Alberta. Described here are the development of an interactive truck/shovel model for their three pit operation, selection and application of dragline model for tandem operation with the extended bench method, criteria for operational model of the five seams operation with selec-tive mining approach.

Jan 1, 1985

By David Brown, Glen Hall, Ken DeVos, Frank Barone

Dredging and Flooding was completed on the Falconbridge Limited "New Tailings Area" in the period from 1996 through 1998, as part of their site closure measures. Part of the decision making process and closure planning was water quality prediction, including oxidation and diffusion modelling. The purpose of this modeling was to define the potential water quality that would result during and after dredging. A significant body of research on the geochemistry and oxidation kinetics of this site had been compiled. The results of the modeling provide practical insight on the potential water quality that may be expected. Water quality in the pond has steadily improved since flooding was completed with the exception of short term peaks during spring runoff. Aquatic vegetation is appearing through natural recovery and transplanting of local species, and colonies of minnows are now observed in the ponds.

Jan 1, 2000

By R E. Langston, S M. Gazioglu

A preconstruction inventory program was conducted to determine the existing conditions of residential, non-residential and all other structures within 2,000 feet of the blasting limits for a highway excavation site in Asheville, North Carolina. Prior to major production blasting, eleven test blasts were detonated to establish site specific propagation parameters in order to develop contours of maximum allowable explosive charge weights per delay. The method of scaling distance by the square root of charge weight per delay was utilized in developing the contours of allowable charge weights. The charge weight contours were revised during blasting operations as additional vibration data became available. The effects of blast induced vibrations on a nearby water storage reservoir, a nearby vehicular tunnel and other adjacent residential and non-residential structures were observed and monitored over a period of two years of blasting operations.

Jan 1, 1980

Hamersley Iron Pty. Limited mines and pro cesses iron ore from two orebodies at Tom Price and Paraburdoo, situated in the North West of Western Australia. Conventional open pit mining methods are used at both sites in that material is drilled and blasted in benches, loaded by shovels and hauled to the Primary Crushers or dumped on waste or low grade material stockpiles. The present drilling fleet, consisting of eight high capacity Bucyrus Erie Rotary drills has evolved from an initial fleet of a large number of small percussion rigs. There are significant physical differences between the ore types encountered at both mines which nec- essitate the drilling of smaller diameter blast holes at Paraburdoo than those at Tom Price. The drilling practice at each site is dis- cussed, with examples of performance achieve- ments under varying drilling conditions.

Jan 1, 1978

By Ruschitzka C

The productivity and economic success of a German hard coal mine is attributed to the high productivity of a small number of operation points; however high rates of production are associated with increased gas emission at the working sites. Therefore modem high technology is required in order to reach the planned production rate, since high methane concentrations often cause unplanned breakdowns in operation. The optimised simulation of gas emission is a fundamental planning tool for mine design as well as for determining the potential of a coal deposit and has increased in significance over the last years. Methane-INFO enables the three-dimensional, graphical simulation of a working site taking account of different aspects such as the mine design, ventilation, production rate, geology, seam quality, gas exhaustion, etc. The following paper gives a short overview over the benefits of the discussed system.

Jan 1, 1995

By G Showers, R Triglavcanin

The complexity of understanding the whole thickening process to achieve real performance improvements cannot be underestimated. The last significant change in feedwell design was more than 15 years ago with the introduction of self-dilution systems û firstly with OutotecÆs Autodil, followed by FLSmidthÆs E-Duc. Now, following many years of extensive in-house research, including close collaboration with AMIRA and the CSIRO, Outotec has launched the next generation Vane Feedwell. The Vane Feedwell has been globally patented and installed at various sites. This paper briefly outlines the feedwellÆs development using CFD modelling and its subsequent performance in a æreal lifeÆ site installation. Plant results of the first commercial Vane Feedwell, in a mineral sands application, are discussed. The Vane Feedwell was retrofitted so comparative data of pre- and post-installation is shown.

Jan 1, 2009