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By J. A. Zimmer, M. S. Hillis, D. Moredock, J. A. Organiscak, A. B. Cecala

Enclosed cabs have been used on surface mining equipment for many years to protect equipment operators from health and safety hazards. The surface mining and quarrying process is a highly mechanized process that generates large quantities of respirable dust. Due to economic factors, more older mining equipment is being used today than in years past. With this older equipment, it is common to observe deterioration of many components on the enclosed cabs, which greatly reduce their protection effectiveness. NIOSH has performed a number of different field studies, as well as a comprehensive laboratory study, evaluating various factors and parameters regarding enclosed cabs. NIOSH has recently completed a cooperative research effort to evaluate the effectiveness of a newly designed unidirectional powered precleaner, filter and pressurizer that brings clean filtered air in at the roof of the cab and extracts all recirculated air near the floor. This research effort provided another example of the enhancement in air quality that can be achieved in an enclosed cab from the implementation of an improved filtration system and by establishing positive pressurization from increased intake air volume and sealing the cab. This testing showed a significant reduction in respirable dust levels in the enclosed cab when comparing baseline versus post-testing results. Since dust levels were similar near the roof and floor of the cab during post-testing, the unidirectional flow pattern did not appear to significantly improve the performance over the conventional design in this study.

Jan 1, 2009

By Donald G. Rogich

The concept of initiating a large action-oriented contract, directed toward inherently safe mining systems, was conceived by the U. S. Bureau of Mines in January 1970. At that time we were in the process of establishing research contracts and grants, about 100 of which were let in FY 71 to deal individually with fairly specific technological areas. These projects in the aggregate covered a wide spectrum of health and safety problems. What appeared to be necessary was the creation of a project or program that would provide a focal point for the demonstration of many of the results of this research and also in the action sense culminate with working hardware and systems that could be tested and demonstrated over a fairly long teen. The concept of working demonstrable systems, rather than just a conceptual study, was, felt to be necessary for two significant reasons. In the development of any new system, the translation from concept to working hardware is usually a costly and time consuming process which acts as a deterrent to implementation. Secondly, many decisions in the mining community to change equipment or systems ,are based on first hand observation of the new system, in operational practice, an attitude which is certainly understandable in view of the high capital costs of equipment. The decision was made to procure a single R&D contract which would be aimed at developing underground coal mining systems which

Jan 1, 1972

By Cody Telgheder, Mamoun Laraki

The U.S. Department of Energy (DOE) Hanford Site had a multi-decade career of supporting America’s defense system during World War II and the Cold War. A multi-reactor site, DOE Hanford produced plutonium for atomic weapons and steam for generating electricity. In addition, a network of nuclear facilities was built and used to support the research and development process, like 324 Building contained within the Hanford Site’s 300 Area. In 1989, after closing its doors to plutonium production, the DOE, Environmental Protection Agency (EPA), and Washington State Department of Ecology took on a challenging, legally binding accord to clean up the Hanford Site. As part of the final clean-up project within the 300 Area, CH2M Hill Plateau Remediation Company (CHPRC) contracted Apollo Mechanical Contractors who contracted Nicholson Construction Company (Nicholson) to design and construct an underpinning micropile system to support excavation efforts directly underneath the 324 Building “B-Cell” structure which in turn would facilitate the complete removal of the contaminated soils directly beneath the structure. The work was completed in complex and challenging conditions that required an airtight drilling system, two layers of protective clothing, a hood with a Powered Air Purifying Respirator (PAPR), the use of long reach tools, and continuous radiological monitoring. This paper will address the design, construction, and challenges encountered with underpinning a structure within a highly sensitive Category II nuclear environment.

Oct 31, 2023

By G. A. Smyres

The Bureau of Mines investigated a HCI-02 leaching procedure to recover Cu, Ni, and Co from a low-grade bulk sulfide flotation concentrate prepared from the Duluth gabbro complex. Since the Duluth gabbro complex is the largest known and unexploited Ni resource in the United States, the development of options for extracting the metal values from the flotation concentrate of this domestic resource is necessary. Conditions were determined for producing a pregnant solution low in Fe to facilitate recovery of the metal values. Leaching experiments were conducted at 15 pct solids, 1000 to 1200 C, 0.2 to 0.3 g HCI per gram concentrate in a 50-gal reactor pressurized to 50 pSig with 02. Base metal extractions from the concentrate were, in percent, 90 to 92 Cu, 99 Ni, 97 to 99 Co, and 0.1 .Fe. Precious metals extractions were erratic and unpredictable; at best their extractions were, in percent, 55 Au, 90 Ag, 40 Pt, and 45 Pd. The reaction time at 1200 C was 0.5 h. The use of compressed air instead of 02 as the oxidant was also investigated. Solvent extraction using LIX 622 was used to remove Cu from the pregnant solution. Cementation on Cu was tested for precious metals recovery, while sulfide precipitation was used to produce a Ni-Co product. A conceptual flowsheet for treating the Duluth gabbro concentrate is proposed.

Jan 1, 1985

In considering the organization of research, it is necessary to know just what research is, what objects are in mind when setting out to conduct research, and what are the functional units which are required to enable a coordinated effort in research to proceed.The dictionary defines research in the following terms: Laborious and patient search, as for truth, diligent inquiry or examination in seeking facts or principles; inquiry, scrutiny; to search or examine with continued care; to seek diligently; to search again; to examine anew.This is, of course, simply a formal definition, but the reference to "labour", "patience" and "diligence" should be noted.The following quotation from an answer to the question "What is Research?", published recently in a technical journal, puts some life into the formal definition:- Essentially, it (Research) is nothing but a state of mind a friendly, welcoming attitude toward change. Going out to look for a change instead of waiting for it to come. Research, for practical men, is an effort to do things better... The research state of mind can apply to anything: personal affairs or any kind of business, big or little. It is the problem-solving mind as contrasted with the let-well-enough-alone mind . . . It is the "to-morrow" mind instead of the "yesterday" mind. Note the statements that: Essentially, it (Research) is nothing but a state of mind, and the research state of mind can apply to anything.

Jan 1, 1950

By Y Wang

Inadequate goaf gas control may lead to gas exceedances in the ventilation return air, which will trip power in longwalls and cause production stoppage. To effectively control gas emissions, Australian mines heavily rely on drilling vertical goaf holes to capture coalmine methane before it migrates to mine openings. The wide application of goaf gas drainage may change the goaf pressure distribution, lead to more ventilation air leakage, and consequently increase gas explosion and spontaneous combustion risks. This paper focuses on analysing goaf gas drainage production data from a case study longwall mine in Australia. The correlation between suction pressure, total flow rate, gas flow rate and air leakage rate were analysed in detail as the face-to-hole distance changes. Suction pressure is found to be positively correlated with total flow rate, and their correlation also varies at different goaf locations due to various goaf compaction and flow resistance. This paper also proposed a theoretical method to calculate the goaf resistance of ventilation air leakage pathways. Based on several basic assumptions and different goaf drainage scenarios, the leakage airflow pathway resistance in the goaf at different face-to-hole distances can be calculated. The model results suggested that the resistance of air leakage pathways from the working face to individual goaf holes increased with the face-to-hole distance. The resistance results can also be used to calculate the corresponding permeability at the same position, which can be used as input data for CFD or Ventsim models.

Oct 12, 2022

By M. Pearson, W. Bristowe, A. Hanson

"There's no such thing as quality assurance; only quality control ... by inspection. "(1) A common misunderstanding in the procurement and construction of custom designed, fabricated pressure vessels and piping systems is that quality assurance can be achieved by simply referencing codes, standards, ISO 9002, QMS or other such programs in the contract documents. In the authors' experience, nothing could be further from the truth, not detrimental to the performance of the equipment than the exclusion of inspection activities and reliance upon warranties and "fit-for-purpose" clauses. Likewise, the expectation that fabricators, suppliers, or third party inspectors can provide such assurances is also unrealistic where they have limited knowledge of the process, material selection criteria, or limited technical resources. The development and successful execution of a quality assurance program is a collaborative effort by engineers, designers, material suppliers, equipment fabricators, and field inspectors with the full understanding and support of the end user.This paper presents an outline of the quality control activities undertaken by the authors for several recently completed and on-going hydrometallurgical projects. The activities include: prequalification of fabricators and sub-vendors, shop audits, material validation testing, material source control and verification, positive material identification of weld metal overlay, specialised welding inspection, contamination control for titanium and titanium-clad fabrication, eddy current and mass spectrometer (helium) leak testing of shell-and-tube heat exchangers, hot cycle testing of titanium clad equipment, tolerance verification for refractory lined equipment, final inspection and cleaning.

Jan 1, 2004

By George Piscsalko

Quality control of drilled shafts and ACIP piles is greatly dependent upon the practices of the site personnel. In many applications it is difficult to properly inspect the shaft prior to concreting, such as when the shaft is drilled under slurry. In other cases, such as ACIP piles, it is impossible to inspect the shaft in any manner prior to concreting. There are numerous methods currently available to assess the integrity of drilled shafts and ACIP piles. Each method has its advantages and limitations. This paper will compare the various available methods as well as introduce a new method for assessing integrity in drilled shafts and ACIP piles. This new method, known as Thermal Integrity Profiling, determines the integrity over 100% of the shaft both inside and outside the reinforcing cage by measuring the hydration temperature of the concrete along the length of the shaft. These temperature measurements can be made by either passing a thermal probe through a standard Cross Hole access tube typically 12 to 48 hours after concrete placement, or from embedding thermal wires within the shaft prior to concrete placement and monitoring them with unattended data collectors for 12 to 48 hours after concrete placement. This Thermal Integrity Profile method will be described in detail and several case histories will be presented. Additional testing methods which will be compared include low strain Pile Integrity Testing, and Cross Hole Sonic Logging. Advantages and limitations for each method will be discussed.

By G. B. Harris

It has long been appreciated that chloride chemistry has a number of advantages over the more traditional sulphate route for both extracting and separating metals. Modern materials of construction, coupled with the development of a more cost-effective and efficient hydrochloric acid regeneration technology mean that chloride-based processes are now more competitive and attractive. Such processing routes are able to recover more of the contained metal values in a feed, including iron in a benign and/or marketable form, and particularly the so-called rare and rare-earth elements which are increasing in demand in our electronic age. These factors, therefore, add appreciably both to the overall economics of a project, but also offer a much more sustainable approach to our dwindling natural resources. Additionally, chloride-based flowsheets can be much more environmentally-friendly, offering practical alternatives to two of the biggest headaches faced by the industry, namely cyanide usage and the generation of red muds. This paper presents a brief theoretical background, focusing on the latest developments of ferrous iron oxidation and the low-temperature, selective hydrochloric acid regeneration process, which is the key unit operation for any chloride flowsheet, and discusses in general the advantages of the chloride approach. Several recently-developed flowsheets, which have been tested at the miniplant level, are presented for gold, base metals, titaniferous magnetites and lead-silver ores wherein the advantages of considering a chloride approach are highlighted.

Jan 1, 2014

By Federick W. Miller

The Bureau of Mines has investigated the availability of columbium from 19 deposits (3 producers and 16 nonproducers) in 7 market economy countries (MEC?s). Brazil has the largest recoverable columbium resource, posessing approximately 2.39 million metric tons Wmt), or 69 pet of the MEC total (3.47 Mmt). The Western Hemisphere countries of Brazil, Canada and the United States contain 3.14 Mrnt of recoverable columbium or 90 pnt of the MEC total. Columbium recovered as a byproduct of tin mining is not included as part of MEC resources in this study. Currently producing mines are Araxa and Catalao in Brazil, and Niobec in Canada, These three mines have 2.42 Mmt of recoverable resources or approximately 69 pct of the MEC total. It is estimated that these mines, operating at full capacity, could satisfy cumulative MEC demand (based on an annual growth rate of 5.1 pct) for the next 20 yr. The United States is totally dependent upon foreign sources for its columbium supply. The majority of U.S. columbium is imported from Brazil in the form of steelmaking- grade ferrocolumbium. Canada has been the sole source of pyrochlore concentrates since Brazil discontinued exports in 1981. The United States also imports small (but important) quantities of columbium as columbite concentrates from Nigeria and Brazil, as columbite contained in tin slags from Thailand and Malaysia, and as synthetic concentrates from the Federal Republic of Germany.

Jan 1, 1986

By Rodrigo Sanchotene Silva

Currently the industries of paint have directed their efforts on cleaner production of products that provide effective performance in corrosion protection of metallic materials. This work search introduce a new alternative of organic coating, without the presence of hazardous metals and replace equipments commercials used method of anodic protection for protection of oxidized metals. From this it, was produced Smart Paint (SP), consisting of Paint Acrylic Commercial (PAC) mixed the 1 % of binder, compound by the conducting polymer, Polyaniline Emeraldine Base (PAni EB) and plasticizer 4-chloro-3-methylphenol. The SP and PAC were applied to plates of carbon steel AISI 1010, with the aid of dip coat technique and then were subjected to drying for 48 h. The SP was characterized by thermals and physicochemical analyzes in order to verify possible changes in chemical properties of the ink produced, beyond perform electrochemical tests of Open Circuit Potential and Electrochemical Impedance Spectroscopy, employing equipment Potentiostat/Galvanostat Autolab PGSTAT302 Ecochemie, and aqueous 2 mol.L-1 of H2SO4. The results obtained allow us to state that the plasticizer does not alter the electrochemical properties of PAni and application of binder PAni EB to PAC does not alter the physicochemical properties of commercial coating. The binder PAni EB adds to PAC the capacity to induce the formation or maintenance of protective oxides in oxidizable metals submitted to harsh environments, method known as anodic corrosion protection.

Aug 8, 2018

By Robert H. Ridgway

This circular outlines salient facts regarding the manganese-ore industry in the United States and the world. It is founded chiefly upon published information available in the literature of the subject. The Bureau of Mines has in its files additional, more detailed data upon many of the topics presented very briefly here, and will endeavor to assist the mineral industries and public by giving further information in response to individual inquiries. The Bureau will welcome comments, criticisms, and contributions of data that may assist in making later additions of this circular more accurate, or in developing more fully its mineral files pertaining to manganese. In reporting the production of manganese-bearing ores in the United States the following classification has been adopted by the Bureau of Mines: (1) Metallurgical-grade ores, under which have been classified manganese ores containing 35 percent or more of manganese used in the manufacture of iron and steel, ferruginous manganese ore containing 10 to 35 percent of manganese, manganiferous iron ore containing 5 to 10 percent of manganese, and manganiferous zinc residuum; (2) battery ore; (3) fluxing ores, under which are classified ores that may contain a few ounces of silver and are rich enough in manganese to make them valuable chiefly for fluxing purposes in nonferrous smelters; and (4) miscellaneous ores, under which are classified the ores shipped to brick manufacturers, glass makers, and manufacturers of manganese chemicals.

Jan 1, 1933

By S Marshall, A Fowler

The Augusta underground mine at Costerfield in Central Victoria has been in operation since mid 2006; however, AGD Operations Pty Ltd have explored and undertaken open pit operations in the area for over 20 years. The high-grade, narrow gold-antimony orebody is being mined using both mechanised and hand-held methods, to produce up to 70 000 tonnes per annum at ten grams per tonne gold and six per cent stibnite. AGD Operations Pty Ltd processes the ore on site using gravity and flotation to produce two products; a concentrate which is sold to Chinese smelters and a gravity concentrate which is refined off-site. The circuit achieves up to 30 per cent recovery of gold from gravity methods. There are many challenges in the underground mine, including an orebody with an average width of 300 mm, very poor rock mass conditions in the host rock and variable dips in the ore along strike, between 45¦ and 90¦. The upper levels of the mine have been developed ready for stoping; however, their depths range from 20 m to 70 m below surface in both oxide and transitional material. A major fault structure consisting of mud has been encountered underground and is associated with the orebody causing very poor ground conditions, water inflow and requiring additional reinforcement. The northern limit of the mine is defined by the proximity of historical workings in the South Costerfield mine, which is being continuously dewatered.

Jan 1, 2008

By Peter Ay, Vincenz Mehlstaubl, Satyanarayana Narra

"This study gives an insight into non-destructive testing methods suitable for porosity analysis at a small scale, firstly summarizing relevant state-of-the-art technology and pending patents, secondly realizing and documenting the start-up of the VHX-2000 digital microscope by the manufacturer Keyence and thirdly demonstrating practical application with the extended analysis of three fundamentally different agglomerates for which important application-related parameters are determined. Various analysis procedures on the different agglomerates the efficient and timesaving operational features of the digital microscope are outlined. Firstly an analysis of flax fibre agglomerates determines the process conditions best suited to produce agglomerates with specific properties by determining sphericity, cubicity, density and porosity as well as fibre damage and alteration. Secondly the production of iron-hydroxide - hemp-fibre agglomerates serves to obtain information on porosity values as a result of a cauterization of the fibres. The third analysis provides estimations of porosity values for acid-treated lignin agglomerates. Measurements were carried out with compact dry agglomerates and with soaked, expanded agglomerates, determining factors for total water carrying capacity. Practicability of non-destructive testing by digital microscopy is demonstrated and explained concerning the applications in this study by obtaining definite structural findings about the analysed agglomerates. Information on its operation is made available by a practice-oriented manual for the VHX-2000 digital microscope. Further suggestions for more in-detail analysis results with different instruments are given."

Jan 1, 2014

By E. Henderson, L. K. Daneshmend

Drawpoint control is critical in determining the cutoff point for load-haul-dump mucking operations to minimize dilution. It is also necessary to ensure even mucking distribution and to prevent possible hang-up of material within a stope. A prototype production monitoring and reporting system has been developed for load-haul-dump operations in under-ground mines. The system generates accurate and timely information regarding mucked tonnages and drawpoint and ore/waste pass utilization. The monitoring system integrates a PLC-based load weighing system with a radio frequency identification (RFID) system for locating the vehicle. The system records the identification and time of entry and exit of each draw-point and ore/waste pass visited during a shift, as well as the weight of each bucket load. A trial of the system was conducted at the CAN-MET Experimental Mine near Val d’Or, Quebec. The monitoring and reporting system functioned as designed, with the exception that the maximum read range of the RFID tags under dynamic conditions was found to be a limitation. RFID systems with greater range capabilities have been identified for a second generation system. The system is the first of its type in North America to demonstrate that RFID tagscan be successfully applied to locate trackless underground equipment. Because of their ability to locate equipment and personnel within underground mines, RFID systems should be considered a key technology for future mine information and process control systems.

Jan 1, 1996

By Robert B. Tippin

A number of recent studies 1-4 suggest that steelmaking expansion might be achieved more economically by a combination of the prereduction furnace and the electric steelmaking furnace rather than through new blast furnace construction. Supergrade concentrates would be the first step in an evolving technology which bypasses the blast furnace and in which the concentrates are first made into pre¬reduced pellets and then used directly in electric steelmaking, Prereduced pellets made from superconcentrates should not only be competitive with scrap, but should be a preferred feed for the electric furnace because of the absence of such residual elements as copper and nickel. Furthermore, geographic areas remote from present steelmaking centers may find the electric furnace to be an economical method of providing local steel requirements. The development of successful methods of producing superconcentrates may also be expected to find application to conventional blast furnace burdens. The need for methods of increasing grade of domestic concentrates will become increasingly urgent in the face of competition from high grade imports. Only a small percentage of domestic iron ore production can qualify as superconcentrates, (Superconcentrates for the purpose of this investigation are limi¬ted to those concentrates which contain a maximum of 2 percent S'02). During the last several years the Twin Cities Metallurgy Research Center of the Bureau of Mines has directed research efforts to develop methods of manufacturing superconcentrates from present standard grade products by cationic flotation, screening, and magnetic separation.

Jan 1, 1971

By Takashi Furuyama, Sukeyuki Mori, Tetsuo Ikejiri, Abel Bissombolo, Yoshitsugu Koga, Masamichi Hata

In Japan, the increasing number of automobiles newly put into circulation is followed by a larger amount of end-of-life vehicles from which valuable metals are being recovered in shredder and related plants. Nevertheless, the processing of these scrapped automobiles which has reach a recycling rate of about 75%, generates a huge volume of waste, locally known as .shredder dust., which is commonly dumped on landfills. The saturation and depletion of valuable disposal sites in the near future, as well as the social and environmental problems related to the accumulation of these residues disposals are a major challenge for the automobile shredding industry. To promote an alternative way for the management of these disposals, the authors have initiated and developed a system for their processing, on the basis that more than 90% of these residues are combustible materials that could be used as refuses derived fuel. The developed processing system points out the mechanical/physical separation of shredded automobiles residues into two streams by means of an ascending airflow passing through a vertical zigzag separator and, the compaction of the light-density fraction of materials (that is about 60% of auto shredder residue recovered as float products and mainly composed of cotton, sponges and light plastics) to form a refuse derived fuel (RDF), the density, calorific value and ignition loss of which are 1.19 g/cm3, 4470 kcal/kg and 60.7%, respectively.

Jan 1, 2003

By R. J. Durrheim, B. Manzunzu, V. Midzi

Selecting ground motion prediction models (GMPM) is crucial in assessing seismic hazard levels in a specific region. This study investigates the influence of ground motion model (GMM) selection on seismic hazard assessment in Johannesburg, South Africa. Most seismic events affecting Johannesburg are related to mining activities and water ingress into the underground mine voids. The most seismically active regions in South Africa include areas around Klerksdorp, Welkom, and Carletonville. These regions experience a significant number of earthquakes, with mining activities being a major factor contributing to seismic events. Ten ground motion prediction equations were selected from regions of similar tectonics setting and were assessed to see if they correspond to the available local data. Six of these were also compared to the ground motions produced by the earthquake of 14 August 2014, which occurred in the Orkney area, one of the mining areas in South Africa. Sensitivity analyses were also carried out to assess the influence of ground motion prediction equations (GMPE) on the seismic hazard of Johannesburg. The results indicate that the choice of GMPM significantly affects the estimation of seismic hazard levels in Johannesburg. Different GMM can lead to varying ground shaking intensity predictions, impacting risk assessments and engineering design considerations. The findings highlight the importance of carefully selecting appropriate GMM tailored to Johannesburg’s specific geological and tectonic characteristics. Understanding how different models perform in this region is essential for accurate seismic risk mitigation strategies.

Jan 12, 2025

By C. A. Young, J. D. Miller

Adsorption isotherms previously determined by in-situ Fourier transform infrared/internal reflection spectroscopy (FT-IR/IRS) for oleate adsorption at calcite and fluorite surfaces near pH 9 and at various temperatures are compared. Results indicate that, at both mineral surfaces, chemisorption occurs at equilibrium concentrations below approximately l x l0-5 M oleate while calcium dioleate surface precipitation occurs at higher equilibrium oleate concentrations. The extent of chemisorption at the calcite surface is 3 to 5 times less than that at the fluorite surface while the extent of calcium dioleate surface precipitation on calcite is nearly a magnitude larger than that on fluorite. However, for both minerals, surface precipitation decreases with increasing chemisorption. Contact angle measurements and flotation recoveries show the hydrophobicity of fluorite to be greater than that of calcite at each of the temperatures and oleate concentrations studied. Significant differences are noted only in the chemisorption region. Unlike calcite, the hydrophobicity of fluorite was sensitive to the presence of oxygen in the system. Multichannel Laser Raman Spectroscopy (MLRS) showed this behavior was caused by the double-bond reactivity of adjacent chemisorbed oleate molecules and subsequent formation of an epoxide/polyether complex at the fluorite surface. Such a reaction product could not be detected at the calcite surface. These differences in adsorption density, hydrophobicity, and polymerization behavior are discussed in terms of the intrinsic surface properties of the minerals.

Jan 1, 1999

By H. R. Butler, R. N. Browne

"The International Nickel Company of Canada Limited consumes some 33 ½ millions of gallons of fresh water and reuses more than 100 millions of gallons of water daily. The continuing search for suitable recycle methodology has enabled the Company to put one 25,000 TPD mill on line utilizing recycled water entirely and a second 35,000 TPD mill is under construction which will likewise employ the concept of recycled water. Future milling plans are aimed at the replacement of all fresh water with recycled water, including sewage effluent and mine waste water.WATER REUSE AT INCO’s SUDBURY MILLSAs man searches unexplored horizons for new and economic industry, he must be constantly and acutely aware of the presence or absence of that precious commodity without which Industry, indeed Man himself, could not survive -- W A T E R. The water requirements of the world today are magnanimous, considering that in 1960 the estimated consumption in the United States was over 300 billion GPD (l) or more than 1,700 GPD per person(5) The magnitude of the problem can be visualized as one considers that three times this quantity of water will be required in the United States by the year 2000, when the dependable supplies of water are estimated to be only two-thirds of that required(2). How, then can we continue to wreak such havoc on that life-sustaining substance - WATER?"

Jan 1, 1970