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By Wilbert J. Huff

This is the sixth of a series of annual reports describing the work of the Explosives Division, Bureau of Mines, United States Department of the Interior.3/ It deals particularly with the activities of the division from July 1, 1940 to June 30, 1941. The studies outlined in this and preceding reports of the series have been conducted under the direction of the author and the respective unit leaders, to whom specific credit is given.

Jan 1, 1942

By Wilbert J. Huff

This is the sixth of a series of annual reports describing the work of the? Explosives Division, Bureau of Mines, United States Department of the Interior.3/ It deals particularly with the activities of the division from July 1, 1940, to June 30, 1941. The studies outlined in this and preceding reports of the series have been conducted under the direction of the author and the respective unit leaders, to whom specific credit is given.

Jan 1, 1942

Constraints on the mineral industry are best treated as issues that have to be understood and managed in partnership rather than in conflict with communities. TheZapopan development at Mt Todd in Australia and the Martha Hill development at Waihi in New Zealand are but two of many recent successful examples at the local level.   However, at the national level, the issues are more complex and more difficult to resolve because the most influential stakeholders are now the urban electorates and governments defer to their perceptions when making decisions and policy. In the developed countries, government policies for the development of mineral resources have been progressively eroded since the early 1970s. At the same time policies for the environment and for native land rights have generally been carried out in a way that has reduced access to minerals and increased the cost and risks for prospectors and developers (Hancock, 1995). Since the end of the Cold War, the lesser developed countries (LDCs) have introduced policies to attract investment in their mineral resources that remained undeveloped under previous unstable or hostile regimes. The increased attraction of these LDCs and the decreased attraction of the developed countries has caused many Australian and North American companies to outlay increasing proportions of their budgets and capital investment in the LDCs.   Significantly, LDC policies for environment protection do not discourage exploration and mine development, Surveys of the relative appeal of the LDCs and the traditional mining countries of the developed world, rate Chile, Argentina and Indonesia ahead of Australia and Canada in terms of risk, delays and ease of doing business (Australian Mining Monthly, February 1994).

Jan 1, 1995

By Norman O. Lotter, André R. Laplante

"The pursuit of concentrator surveying for purposes of metal accounting or process optimization has not yet connected with the well-published realm of geostatistics. The reality of lognormality in time has seldom been discussed. One publication by Krige, 1962, examined such effects for a gold concentrator in South Africa, towards an information system that would provide feedback to the mining and surveying teams on grade control of ore mined.During present studies which are designing and testing a new survey model, called statistical benchmark surveying, it was found that the distributions of feed, concentrate and tailings bear significant residual signs of the parent lognormality in space. The multiple hosting of paymetals in different mineral species complicates the understanding of these distributions. These features have to be recognized and treated in order to perform appropriate quality control on the diagnostic sampling performed in the pursuit of statistical benchmark surveying.It is shown in this paper that the above two features can actually be used to advantage in the diagnosis of continuous periods of operations data ahead of such surveying, including the estimation of recoverable paymetals in flotation tailings from a graphical method.INTRODUCTIONAssessment of Concentrator PerformanceMilling and flotation, sometimes accompanied by gravity separation, are well-established unit processes, which have traditionally been used to treat ore that has been mined. This is because these processes liberate, then separate, the valuable minerals, which contain paymetals, from host gangue. This is often done by a combination of crushing and grinding processes, or autogenous grinding, to liberate the paymetal minerals, followed by gravity separation and/or flotation, to separate these valuable minerals into a concentrate, or several concentrates. These concentrate(s) have a lower bulk than the parent ore from which they are derived. Further, they contain a high percentage of the valuable minerals. Accordingly, they are more economically treated in subsequent beneficiation processes than the ore from which they were produced."

Jan 1, 2005

By T Atchison

The Vale Ferro Carajßs S11D project in northern Brazil is based on the movement of unprecedented volumes of waste and ore for mobile in-pit crushing and conveying or ætrucklessÆ systems. In peak years, the system is intended to handle a combined 160 Mt of material.The planning and implementation of the first such system for Vale, in a remote greenfield site, utilising the services of a range of international study, design and supply partners has provided a unique set of technical and project delivery challenges. The lessons from these are of value to the industry as the trend to remote and high-volume operations continues.This paper describes the key features of the mining system and documents the challenges and mitigations for important technical, cultural and project delivery issues that have arisen. It is a combined description of the journey taken by both Vale (as owner) and SKM (as delivery partner) over the course of many years.CITATION:Atchison, T, 2013. Lessons from the S11D truckless mining project, in Proceedings Iron Ore 2013 , pp 177-184 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By K. Nielsen, J. Kristiansen

A series of laboratory blasting and grinding tests on three types of hard and competent rock (coarse-grained monzonite, fine-grained granite and very fine-grained gabbro) showed that a higher level of applied explosive energy enhanced grindability and produced a larger amount of fine (-0.106 mm) material. This confirmed reported industrial experience and the results of previous investigations. However, the results did not provide any information on the quantitative relationship between the energy applied in primary blasting and that required in subsequent comminution. Only about 1% of energy consumed in conventional grinding is used to create new surfaces, while power efficencies in cone crushers have been estimated at 70-80%. In blasting, up to 20% of explosive energy may be transmitted to the surrounding rock as elastic strain energy, leading to both primary rock breakage and the generation of microcracks

Dec 1, 1995

By P. G. Pigott

This Bureau of Mines laboratory research demonstrated that building bricks meeting ASTM specification C62-66 for grades SW and MW of FBS-type bricks can be produced from waste copper mill tailings. Waste tailings from accumulations at Magna, Utah, Anaconda, Mont., and Hayden, Miami, and San Manuel, Ariz., were dry-pressed into bricks, and the products were tested in accordance with ASTM Designation C67-66 on sampling, and testing of brick. An evaluation derived from pilot-plant production of similar brick at the Coal Research Bureau of West Virginia University indicated the production cost to be about $34 per 1,000 bricks. Utilization of such mill tailings on a commercial scale would eliminate the need for digging new pits for brick raw material production, conserve natural resources, and simultaneously remove potential sources of air pollution.

Jan 1, 1971

By Mark S. Sanders

Six underground coal mine shuttle cars (three high seam and three low seam) were used to assess visibility using the concept of visual attention locations (VALs) and an improved human eye reference measurement instrument (HERMI Mark II). Each machine was assessed in the inby and outby direction of travel with no canopy and with the canopy in its highest, and lowest position. In addition, the illumination level at each VAL was determined. Results showed that the most important variable determining visibility was operator eye position. When this variable is controlled, the addition of a canopy has no effect on visibility. Further, with eye position controlled, there is no difference in visibility between high and low seam machines. The visibility and illumination assessments found blind spots in the operator's field of view located on the opposite side of the car from the operator and ahead of the machine. Suggestions for reducing the blind spots were made. The report also included a procedure manual for using HERMI and the system of VALs to assess visibility from underground shuttle cars, continuous miners, and scoops.

Jan 1, 1983

By Ryan W. Ulansky

This paper presents the conceptual design of a magnetically-levitated skip for use in an underground mine. A skip is used to move rock from an underground mine to its surface processing facility. Conventionally the skip is raised and lowered by cables, similar to an elevator. In a magnetically-levitated skip, the cable is replaced with a linear induction or synchronous motor to provide propulsion and levitation. Removal of the cables in a magnetically-levitated skip provides many advantages over a conventional system including the ability: to negotiate corners, to travel vertically in the shaft as well as horizontally to the mining face, and to move a very large volume of material using multiple skips in a small shaft. A magnetically-levitated skip is a safer, more environmentally-friendly, productive alternative to conventional skipping. It has the further advantage to decrease haulage distances for underground vehicles.

May 1, 2002

This paper investigates the effects of solids concentration and the addition of Dispersant S40 on the flowability of original and ground limestone slurries. A rotational viscometer with a concentric cylinder geometry and a controlled-stress rheometer with a cone-and-plate geometry were used to characterize the rheological behaviors of limestone slurries. The rheological behavior of original limestone slurries (<100 µm) is transformed through different types of flows with increasing solids concentration. The use of Dispersant S40 can improve the slurry flowability by decreasing viscosity and eliminating Casson yield stress. It is therefore used as a grinding aid for the wet ultrafine grinding of limestone. The rheological behaviors of ground limestone slurries vary with grinding from a starting dilatant flow-ability to a resulting pseudoplastic one with an evident Casson yield stress in combination with a thixotropic character. The appearance of pseudoplastic flowability combining thixotropy is related to the fineness of a ground product and its specific surface area, which are both correlated to solids concentration and the additive amount of Dispersant S40. In addition, the accurate rheological characterization of time-dependent fluids is dependent on the instruments used and operation conditions.

Jan 1, 2007

New Zealand depends on foreign investment for economic development. This also applies to the development of New Zealand&apos;s mineral resources. For this foreign investment to happen there must be some incentives to attract the investment. While prospectivity is the dominant parameter considered by investors it is not a variable that can be changed, only the perception of New Zealand&apos;s prospectivity. Other parameters likely to be considered are sovereign risk, red tape, green tape, land access, civil unrest, land claims, social risk, labour relations, infrastructure and natural disasters. Regulators and political will can vary some of these parameters. Where New Zealand fits internationally can be measured by investors&apos; perceptions of these parameters. Following on from these perceptions New Zealand can be seen to have advantages in some areas and be disadvantaged in others. How to deal with the disadvantages to give investors confidence is not easy in the New Zealand environment where the development of mineral resources plays a small part in an economy dominated by agriculture. Added to this is the current global state of the minerals industry which offers even more of a challenge to attract foreign investment to develop New Zealand&apos;s mineral resources.

Jan 1, 2000

By Joseph A. Sutton

This study was undertaken by the Bureau of Mines to determine whether the sulfur-oxidizing bacterium Thiobacillus thiooxidans could use sulfur compounds to produce sulfuric acid in sufficient quantities to leach valuable metals from low-grade ores. The results of extended tests indicated that the bacterium is capable of extracting appreciable amounts of copper and cobalt from ore and mineral samples when sulfur is available in a state that can be readily assimilated by the organisms. Under the conditions of these tests, this organism was not able to assimilate and oxidize the sulfur as it occurred in the ores and minerals. Ores containing copper minerals in the silicate, carbonate, and oxide forms, in the presence of elemental sulfur, were more susceptible to bacterial action than ores containing copper minerals in the sulfide form. Thiobacillus thiooxidans remained active on elemental sulfur in the presence of some of the ores which were tested, but could not tolerate others. Therefore, strains of the bacterium were progressively adjusted to increasing concentrations (0.5 to 10 grams) of the individual ores until they could remain active on 10-gram portions of all ores being tested.

Jan 1, 1961

Formation of either sodium jarosite or lead jarosite from concentrated chloride solutions containing small concentrations of sulphate has been demonstrated. Sodium jarosite is precipitated at 95-100&#176;C from FeC13-FeCI2-NaCI-PbCI2 solutions to which was added Na2SO4 or Li2SO4 in amounts greater than 0.05 M. In the absence of alkali metal ions capable of forming jarosites, lead jarosite was precipitated from either FeCI3-PbCI2 or FeCI3-FeCI2-LiCI-PbCI2 solutions to which had been added small amounts of sulphate. Many of the factors affecting jarosite precipitation from chloride solution have been elucidated, and the most critical were sulphate concentration and initial pH. Concentrations of HCI in excess of O. I M essentially suppressed the production of jarosite in chloride media. Alkali jarosite, precipitated in the presence of dissolved lead, incorporates a small amount of this metal into the alkali jarosite lattice. Small but significant amounts of copper can also be incorporated into alkali jarosite and the amount is further increased in the presence of lead. Other divalent base metals such as Zn, Cd or Ni are not significantly precipitated. Sulphate control in either FeCI3 or FeCl3-NaCI leaching systems could likely be maintained by jarosite precipitation provided that the acid concentration of the solution was low.

Jan 1, 1981

By L. Nahai

Iran&apos;s petroleum industry is nearly 50 years old and the oldest in the Near East. According to published figures, Iran ranks third in production and reserves in the Near East. These reserves (including probable reserves) are estimated at 35 billion barrels and constitute about 11 percent of the world&apos;s total. Iran is the sixth largest producer of crude petroleum in the world. The 1961 output of more than 430 million barrels was 5 percent of total world out-put for the year. In the same year, Iran ranked fourth among world petroleum exporters, providing 8.4 percent of total world exports.

Jan 1, 1963

By J. W. Thompson

ORES PROCESS OF ORE CONCENTRATION-PATENTABILITY. The patent issued to Sulman, Pickard, and Ballot, November 6, 1905, and assigned to Minerals Separation and Minerals Separation American Syndicate, for new and useful improvements in ore concen- tration, its object being to separate metalliferous matter from gangue by means of oils and fatty acids that have a preferential affinity for such metalliferous matter, the principal feature of which is "agitat- ing the mixture to cause the oil-coated mineral to form a froth," was clearly anticipated by other patents, and each step in the process described in the Sulman, Pickard, and Ballot patent is fully described in more than one of the prior patents, with the single exception of the reduced quantity of oil used; but the discovery that the small fraction of oil is sufficient to produce flotation of the metalliferous matter can not be made by itself or in combination, the subject of a patent. Hyde v. Minerals Separation, 214 Fed., 100, p. 109, May, 1914. ACTION FOR CONVERSION OF MINERALS. In an action by the grantor of a certain mine and mining property against his grantee to recover damages for the conversion of a quantity of ore that the grantor before the conveyance had mined and extracted from the mine and placed on the dump near the mine, the plaintiff is not entitled to recover where it appears that at the time the ore was placed on the dump the mine was owned and operated by a mining company and that at the time the ore was taken out of the mine the company had no intention of doing anything with it but simply deposited it on the dump as waste and to give an opportunity to develop the mine and get better ore to send to the smelter, and that

Jan 1, 1915

By A. J. Hyett

Due to the ongoing revolution in electronics and communications more cost-effective geotechnical instruments can be manufactured using digital technology. This new generation of digital instruments have embedded microcontrollers that provide highly accurate and reliable measurement of geotechnical behaviour in real world units that can be immediately interpreted. Digital measurements can be transmitted across existing mine-wide wireless communication networks, interfaced directly with infra-red enabled PDA?s or PC?s, and parsed to memory by low-cost data-loggers.

Oct 1, 2004

By James A. Finch

"I offer a personal view of what the next 30 years holds for mineral processing. Re-stating that mineral processing will remain a vibrant industry in raw material production, growth opportunities in waste management are identified. The processing sequence familiar now (mining -mineral processing -extraction) will become more interwoven. In situ processing (i.e., milling underground) will evolve from concept to demonstration. Opportunities to exploit physical properties altered in chemical (pyro-and hydro-) processing will present themselves. In primary grinding, the path to AG/SAG milling will progress with little deviation but opportunities in regrinding are wide open. Flotation will see the trend to designing bubble/particle reactors accelerate simultaneously with a vigorous response from mechanical cell suppliers. Gravity separation remains a bastion of the lone inventor but I anticipate that the new lines will come from the waste management business. I finish by examining the ""research cycle"", identifying growth in small ""high tech"" companies and university research centres.IntroductionI have been asked to offer a personal view of""where we are going in mineral processing?"". Gazing into crystal balls is quite a cottage industry as we approach the end of the millennium. Academics are often asked to assume the role of visionary, I presume because it is considered in their mandate, to reflect and philosophize (or, less charitably, because they are considered to have the time). Since this is the 30th Annual Canadian Mineral Processors Operators Conference, I am tempted to suggest the next 30 years as my frame of reference. This is about equivalent to one engineer's career or, given it takes typically 15 years to go from concept to realization in mineral process engineering (Napier-Munn, l 997a), about 2 ""invention cycles"". With this length of cycle, much that is familiar now will remain so over the 30 years.Research and development (R&D) is in response to need. The overarching need in mining is to find new ore bodies. Process developments cannot compensate for a depleting deposit or a declining commodity price. Mineral processing R&D is characterized by incremental gains, aimed at pushing the mine down the cost per tonne league table. Breakthroughs are the exception (flotation at the turn of the century was one). This must be kept in mind when trying to predict the future in our business."

Jan 1, 1998

Validation and Simulation of Optimised Compressive Crushing Ores and aggregates are used in countless applications all around in the society. The frequent and escalating usage of these natural resources requires efforts aimed at not only making do with what is available, but also undertaking actions to improve the production yield and the processes involved. This strive to improve the performance and efficiency of existing crushers and crushing processes has brought about research concerning optimisation of crushing plants as well as theoretical optimisation of crushing. Previous work shows that different applications and different materials require different compressive crushing in order to accomplish a theoretically optimal size distribution. These optimisation results, obtained by genetic evolutionary algorithms and evaluated with so called fitness functions, convey the theoretically optimal number of compressions and their corresponding compression ratios. Presented in this paper are thus some laboratory crushing tests, which are conducted in order to validate a set of previously optimised crushing sequences. More specifically, interparticle crushing sequences are carried out in a Piston-die testing equipment, where samples are sieved between each compression. The subsequent analysis of these results shows good correlation with model predictions, which combined with a comparative study between presented optimisation results and measured data from a real crusher indicate a significant potential for improvement. However, before redesigning crushers according to what is theoretically optimal, the resulting impact as well as the effects on the outcome of a crushing plant must be examined. Crushing plant simulations using the software PlantDesigner« are consequently performed. Models of existing crushers are altered, resulting in changed particle size distributions from some of the crushers in a crushing plant. Thence, it is concluded that significant gains can be made in terms of capacity, process yield and energy consumption.

Sep 13, 2010

By William M. Hinton

This report describes the approach, procedures, and results of a program to develop training materials for roof bolter operators. The objective of the program was to design and produce a training sequence which would prepare roof bolter trainees for job performance. Data was collected and analyzed using the general procedures of Instructional Systems Development (ISD). Input data came from a previous roof bolter training analysis program. This data was expanded and structured through a series of ISD steps: objectives hierarchies, media selection, syllabus, lesson specifications, and train¬ing materials development. The resulting program consisted of an ordered sequence of 15 lessons. The media mix for the 15 lessons included lectures, slide-tape lessons, and hands-on instruction using operational roof bolters. Contents of all lessons were reviewed and approved by the Bureau. The key recommendations were to (1) validate the materials and measure relative effectiveness of media formats; (2) survey mines for training resources and conditions - match materials to user capabilities, rather than selection state of the art technology/media; (3) develop job performance aids (JPAs) rather than simulators; (4) create a style/media/JPA development guide for use in future projects of this kind.

Jan 1, 1982

By David Ziegler, John Babcock, Gregory Poole

On December 9, 2003 at 3:59 PM EST an earthquake with a 4.5 magnitude occurred in central Virginia. According to a survey on the US Geological Survey website, this quake was felt as far away as Bridgeton Missouri, approximately 683 mile from the epicenter1. We recorded the vibrations from this earthquake on 14 seismographs that were set up for monitoring vibrations from blasting activities in the area. Having this data gave us an opportunity to compare earthquake and blasting vibrations. The amplitudes, frequencies and duration were much different than vibrations from mining and construction blasting. A common question we get from homeowners when discussing vibrations from blasting activities is “How does that compare to the Richter scale?” The goal of this report is to provide some simple answers for that question. The Richter and Mercalli scale are compared to the particle velocities in order to show their relationship.

Jan 1, 2005