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By G. E. Frantti

UNDER the auspices of the Geophysical Committee of Michigan College of Mining and Technology, an investigation was made in Michigan's Upper Peninsula to obtain geophysical data" related to the regional subsurface geology in the area covered by Paleozoic sediments. The area surveyed includes that portion of the Upper Peninsula which lies between R18W to R26W and T41N and T49N, covering approximately 1300 square miles. On the index map, Fig. 1, it is represented by the cross-hatched zone west of Munising. Four of the five sites of detailed investigation are indicated by the letters A, B, C, and D. A detailed gravity and magnetic survey had previously been conducted by J. G. Wilsonz near Perkins, 8 miles north of Rapid River, on a local anomalous area. Results of his work, which showed a large positive magnetic anomaly associated with a gravity anomaly, aroused interest in the possible economic significance of the formations underlying the Paleozoic sediments in this part of the Upper Peninsula. Early in the 1900's the Michigan Geological Survey, as well as many private companies, had done a considerable amount of dip needle work near the southwest corner of the area discussed in this paper. Most of the information available to the writer was obtained from indicated magnetic anomalies on the geological map of the northern peninsula of Michigan. Results of the geophysical activities of mining companies in the vicinity of the Marquette range and Gwinn district were unavailable to the author. Physiography and Geography: The region under consideration has low to moderate relief. About half the area is comprised of swampy lowlands, and because of the swamps and forests much of the land is almost inaccessible. The major drainage system is dendritic, with streams flowing into Lake Michigan on the south and Lake Superior on the north. The general geology, shown in Fig. 2, indicates an overlay of Paleozoic sediments on pre-Cambrian formations along a line running approximately south from Marquette (not shown on the geological map). Actual contact between pre-Cambrian and Paleozoic sediments is not known because most of the area is covered with glacial till, and outcrops are very scarce. Exposures of the Paleozoic sediments show that these beds in the northern areas dip gently under Lake Superior and that in the southern areas they 'dip gently to the southeast. Outcroppings of the pre-Cambrian formations occur primarily to the west of the surveyed area except in the northwest corner where the Laurentian series outcrop as far east as the Gwinn district and also in T46N, R24W. Instrumentation: Gravity measurements were made with the Worden portable gravity meter. Since this was chiefly a reconnaissance regional survey, both the large and small dials were used. The instrument used had a constant of 0.0035 milligals per scale division, a working range of about 25 milligals.

Jan 1, 1957

By Mahiyar Nasarwanji, Jonathan K. Hrica, Jonisha P. Pollard, Lydia M. Kocher, Brianna M. Eiter

Within the metal/nonmetal mining sector, fall-related incidents account for a large proportion of fatal and nonfatal injuries that occur in mining in the United States. However, the events and contributing factors leading up to these incidents have not been fully investigated. To help provide a clearer picture of these factors, an analysis of imminent danger orders issued by the U.S. Mine Safety and Health Administration (MSHA) from 2010 through 2017 at both surface and underground metal/nonmetal mine sites revealed that most orders are associated with fall risks. Of these cases, 84 percent involved the workers not using fall protection, fall protection not being provided or the improper use of fall protection. Fall risks for workers most frequently occurred when standing on mobile equipment, performing maintenance and repairs on plant equipment or working near highwalls. In most cases, a single, basic, corrective action — such as using fall protection — would have allowed workers to perform the task safely. Overall, these findings suggest that a systematic approach is needed to identify, eliminate and prevent imminent danger situations. Furthermore, to protect mineworkers from falls from height, frequently performed tasks requiring fall protection should be redesigned to eliminate the reliance on personal fall protection.

By L. Xinguang

Shandong MinMetals Corporation, a state-owned import and export organization located in the city of Qingdao, Shandong Province, China, was opened in 1954, with the mission of marketing metal products and industrial raw material in oversea areas for hard currency to support the modernization project of the country as well as the province. The management officers are appointed by the provincial government, and report to the Foreign Trade Department of Shandong Province. Meanwhile, the company also receives guidance from MinMetals head office in Beijing, the capital city of China. The head office does not own and control any provincial MinMetals organizations, but merely coordinate business among provinces.

Jan 1, 1990

By George H. Popper

The Bureau of Mines has evaluated the extent of phosphate resources available for recovery by the experimental borehole mining method in the Southeastern Coastal Plain of the United States- Phosphate re- sources at overburden depths greater than 30 m are as a rule currently unsuitable for recovery through conventional mining methods because of economic, environmental, or technical considerations. In the identified deposit areas, borehole mining operations are projected to yield a more favorable rate of return and to be environmentally more desirable than conventional surface mining. Borehole mining resource estimates presented in this study are preliminary and designed to serve as a basis for future resource evaluations, as the current data base is relatively sparse and incomplete. The resulting resources have, therefore, been classified as hypothetical and speculative and are subject to up- dating as additional exploratory data become available. Hypothetical and speculative resources amenable to borehole mining are estimated to total about 385 billion metric tons (rat) of phosphate matrix with a minimum in situ grade of 5 pct P205. With projected borehole mining capabilities and current conventional beneficiation procedures, this resource would make available approximately 64 billion mt of phosphate rock product at an estimated grade of 30 pct P205.

Jan 1, 1985

By Donivan L. Gordon, Fred H. Dorheim

Often, as viewed by the public and many in the mining industry, abandoned limestone and gypsum quarries offer a simple, economic solution to the twofold problem of solid-waste disposal and land reclamation. In a state where about 75% of the existing quarries are in hydrologic connection with carbonate aquifiers the rationale for considering the storage of solid waste in them must be critically examined. Consistent with the requirements of water resources protection, criteria are suggested to evaluate the potentiality of using abandoned limestone and gypsum quarries as sanitary landfill sites.

Jan 1, 1975

By A. D. Ajak

A complete mining cycle involves digging, loading, hauling and dumping of the materials. Moving the ore from the pit to the crusher or to the waste dump requires access routes, which are termed haul roads. These roads have to be designed, constructed and maintained. A review of the literature indicates a common consensus among researchers that there should be a balance between haul road economics and safety of the road users. However, there is no universally accepted theory on the design of haul road geometry and, in particular, road dimensions. The current industry practice is based on empirical data and rules of thumb developed by engineers. Therefore, this paper will use the overlooked and less valued branch of mathematics, arithmetic progression, to derive a road width equation. It is beyond the scope of this paper to discuss all road design components. The focus will be on the geometric aspects, which more often have a direct impact on road safety. In this paper, the current design practices and techniques for haul road geometrics design will be explored, using arithmetic progression to formulate road width equations, case examples to apply the equation and then validating the results with conventional techniques that have confirmed the reliability of road width equations, thus eliminating use of tables during design.

Jan 1, 2012

By M. Riddell

This paper describes the incipient heatings that occurred below ground in the High Main and Main seams at the mine between the years 1963 and 1966. The possible causes, effects and activities associated with such heatings are discussed in an attempt to establish the precautions necessary to minimize such occurrences. The assessment of as many "norms" as possible is made to enable the earliest detection and level of activity to be determined.

May 23, 1905

By John Gross

Studies in grinding efficiencies carried out at the Midvale plant of the U. S. Smelting, Refining & Mining Co. and at the Tooele plant of the International Smelting Co. Were made possible by the cooperation of these two companies with the U. S. Bureau of Mines. Mr. Alan Probert of the U. S. Smelting, Refining & Mining Co. and Mr. E. C. Peterson of the International Smelting Co., devoted their entire time to the work during the respective tests, and their services are hereby gratefully acknowledged. It is a pleasure to acknowledge also the assistance and kindness of the staffs of both companies in making it possible, at considerable trouble and expense, to sample the entire mill circuits and in furnishing the necessary supplies and special apparatus required in the work.

Jan 1, 1929

By John R. McDonnell

The Valle Vidal Unit comprises 100,000 acres In Taos and Colfax: Counties, New Mexico. The unit was donated to the American public In 1982 by the Pennzoll Co. and is administered by the U.S. Department of Agriculture Forest Service as an addition to the Carson National Forest. During 1990-1991, the Bureau of Mines conducted a mineral Investigation of the unit as authorized by an Interagency Agreement (1987) Intended to assist the Forest Service to incorporate mineral resource data In forest plans. The Bureau reviewed literature and records concerning mineral resources and mining activity, and performed a field examination of mines, prospects, and mineral occurrences in and near the Valle Vidal Unit. The La Belle mining district encompasses most of the western part of the Valle Vidal Unit. The district was most active between 1893 and 1902, after the land grant was opened to prospecting and gold discoveries were reported. The discoveries were low grade, and eventually were abandoned. The Bureau's appraisal of the district determined that lode gold occurs primarily in fissure veins in volcanic rocks, and placer gold occurs In weakly cemented sedimentary rocks and alluvial sediments; but at a grade that is currently considered subeconomic. If the price of gold increases in the future, prospecting and exploration in the area may be renewed, but the activity would likely be limited due to "acquired land status" restrictions, which require mineral leasing and prohibit claim location in the Valle Vidal Unit.

Jan 1, 1992

By M. Boodman, E. Gertner

"At first glance, the activities related to mining and mineral exploration appear to be local or domestic, rather than international, in nature. Minerals, as corporeal or tangible property, form an integral part of the land in which they are found until extracted and exploited commercially. Even in the latter phase, the tangible nature of minerals gives the impression that the law governing the commercialization of minerals is the law of their situs at any given time. The nature of minerals appears to negate the international aspect of mineral enterprises.The fundamental flaw in the above analysis is its focus upon the nature of minerals, rather than the role of persons in mineral enterprises. The high costs of mineral exploration and commercialization invariably require the involvement of international consortiums or joint ventures. Governments may not have access to the funds necessary to exploit the mineral resources that they control. Local or domestic enterprises may not have sufficient expertise for mineral exploration. Further, markets for various types of minerals are far from localized or static. For these and other reasons, the tangible and localized nature of minerals belies the fundamentally international nature of mineral exploration and commercialization."

Jan 1, 2004

By Mustafa Kumral, Yu Cheng Yang, Zhixuan Shao, Young Bin Moon

Since the discoveries of favorable deposits are becoming increasingly difficult, mining operations shift to lower grade and deeper deposits. The viability of these operations is sensitive to many factors, such as commodity prices and operating costs. Given that a mining corporation has no power to set prices, the focus is directed on minimizing the operating costs. Underground mining operations require a network infrastructure, including shaft, ramps, declines, levels, cross-cuts, raises, winzes, and adit. The design of this network is a costly process. As such, it has a significant potential to reduce development and haulage costs. Furthermore, network design is a continuous process along with development, production, and maintenance throughout mine life. Under the constraints of the turning radius, the gradient, and the obstacle avoidance for haulage network of underground mines, this paper first demonstrates network design and optimization approaches using Dubins path combined with the Hierarchical Density-Based Spatial Clustering of Applications with Noise (HDBSCAN) algorithm. A threshold-based model is developed, providing viable solutions to the network design when the number of declines is high. Furthermore, a three-dimensional Rapid-exploring Random Tree (RRT) algorithm combined with Dubins path is employed as a heuristic solver for obstacle avoidance purposes in the network. Various case studies are conducted to show the applicability of the proposed methods.

May 24, 2023

By K Thorpe

Amorphous silica deposits have been identified at Tikitere and Taheke near Rotorua. Two areas at Tikitere have been surface sampled and drilled to establish a resource of amorphous silica in excess of one million tonnes. A pilot plant was established to develop a process to manufacture a high quality super pozzolanic material. This development process took two years before a commercial product was introduced to the construction industry in 1996. The amorphous silica product, marketed as Microsilica 600, is used as a pozzolanic material to produce high quality strong and durable concrete, sprayed tunnel linings, mortars and grouts. Microsilica 600 has been used locally and exported to 11 countries.

Jan 1, 1999

By Y. L. Ding, N. A. Warner

Cylindrical pellets made from graphite and chromite mixtures were reduced in high-carbon ferrochromium melts at 1 600-1 695 degrees C, under an atmosphere of almost pure CO. The reduction rate, as measured by gas evolution, increased with increasing melt temperature and graphite addition and with decreasing pellet diameter or height, although reductant particle size had a very limited effect on kinetics. At a pellet size, heat and mass transfer were significant in controlling the early stages of reduction of large pellets while at chromite grain size, gas diffusion was probably a rate-controlling step. The time required for dissolution of unfluxed pellets into the melts was significantly longer than that for reduction. This indicates that pellet dissolution may be the limiting factor in determining the operating parameters for a proposed new process to produce high-carbon ferrochromium using melt circulation

Jun 19, 1905

By Shakuntala Tudu, Indrajit Paul, Surajit Sinha, Pulibandla Basaveswara Rao, Shaik Mahaboob Basha, Srinivas Dwarapudi

The iron and steel manufacturing sector directly accounts for 7–9% of global CO2 emissions. Raw material preparation, such as iron ore sintering, pelletizing, and cock making, is the major CO2 emitter. As climate change becomes a bigger concern, steel manufacturers need to lower CO2 emissions without hindering efficiency or increasing costs. In recent years, the percentage of iron ore pellets in blast furnaces has increased due to its uniform size, good reducibility, and high tumbler index. Pelletizing is energy-intensive and emits considerable CO2. Around 20% of CO2 emissions during pellet making come from fluxes. In the present work, the authors established a novel CO2- free flux called wollastonite (CaO.SiO2) for sustainable palletization. Pellets with varying percentages of wollastonite (0–6%) are prepared and tested for chemical, physical, and metallurgical properties. Image analysis through an optical microscope is carried out to quantify the phases of fired pellets. SEM–EDS is performed to evaluate the chemical composition of the melt and slag phases. The results showed that the reducibility index (RI) and swelling index (SI) of pellets decreased with an increase in wollastonite dosage. Pellet strength increases with an increase in wollastonite addition up to 1.2% CaO (2.27% wollastonite), and a decrease in strength is observed thereafter. The increase in strength is attributed to the increase in slag bonds. The decrease in strength beyond 1.2% CaO is mainly because of an increase in low melting eutectics and more magnetite content. Pellets with 2.27% wollastonite to get 1.2% CaO showed good physical and metallurgical properties.

Mar 4, 2024

By J. C. Holtz

Since 1937 the Bureau of Mines has conducted investigations to provide the technical information necessary to guide the safe use of diesel engines underground in the United States. Coincident with the beginning of the technical study, a survey was made of State regulations pertaining to the use of internal-combustion engines underground.3/ At that time it was found that owing to the known hazards of gasoline locomotives, many States had enacted legislation or regulations limiting or prohibiting their use underground. Some of this legislation prohibited, or could be interpreted as prohibiting, the use of any type of internal-combustion engines in underground workings. After World War II diesel-powered equipment was introduced underground in many States, and pertinent questions are received frequently by the Bureau of Mines about the regulations that permit such applications. Because it was known that new and revised regulations had been made effective in some States in the nearly 20 years that have elapsed since the previous survey,3/ the Bureau decided that a review of the latest regulations in the leading mineral-producing States would be a valuable source of information for those engaged in the production of minerals as well as others. Accordingly, where feasible, this report includes abstracts of State laws and regulations as they affect the use of internal-combustion engines underground, particularly diesel engines. The substance of comments from State officials also are included when these appear to be helpful to interpretation of the regulations.

Jan 1, 1957

By K. N. Santini, J. M. Barker

The perlite industry in the United States continued to undergo rapid change and increased competition last year as it did in 2002. U.S. production in 2004 was 510 kt (562,000 st),an increase following five consecutive years of decline (Table 1). Perlite is exported to Canada and to the Pacific Rim. These partially offset imports. Perlite imports from Greece to the eastern and Gulf Coasts of the United States declined by about 22 percent after reaching a record 240 kt (264,000 st) in 2003.But their market remains protected by high rail rates from western U.S. plants. Minor imports of perlite persist by Termolita from Mexico.

Jan 1, 2005

By W. W. Adams

Three hundred and twenty-eight mines and quarries, representing 36 States, took part in the twelfth yearly accident-prevention contest conducted by the United States Bureau of Mines and known as the National Safety Competition. Four underground mines and one open-cut mine (which represents the quarry and open-cut mine group), each the leader in its group, were awarded the ?Sentinels of Safety? trophy. Relative standing in the contest" was determined by the number of days lost from accidents in proportion to the total number of man-hours worked. Since 1925, when the National Safety Competition was inaugurated, an increasing interest has been taken in it by mining and quarrying companies as a means of stimulating mine and quarry safety by competition among similar plants. Each participating plant can, on a basis of its standing and record in the contest, determine to what extent its safety program is succeeding or to what extent it needs strengthening. With this information, each company that has a low standing in the contest can intensify its safety-promotion efforts the following year to obtain a? lower rate and possibly win the trophy or achieve honorable mention in the competition. Except for 1929, the National Safety Competition of 1936 represented more man-hours of employment than any other year since the yearly contests began.

Jan 1, 1937

By A. Güngör, Ü. Atalay

Thermal treatment can significantly improve industrial comminution operations by reducing energy requirements and increasing mineral liberation. The assistance of thermal pretreatment prior to grinding by microwave heating is scrutinized in this study. For this purpose three copper ore samples with different chemical composition were used. To see the effect of microwave heating on ore; work index, breakage rate and breakage distribution functions of original and heat treated samples were examined. The results obtained in this study did not show significant improvement in the grindability characteristics of the studied ores with microwave heat treatment. The inadequate amount of microwave transparent matrix was the main reason for the absence of cracks and micro-fractures in the microwave heated copper samples.

Jan 1, 1999

By V Mutton, L Potts, D Joyce

This paper describes the method of extracting sill pillars within the underground operation from under unconsolidated mullock fill at the Cracow Gold Mine. This pillar recovery method was initially successfully used to recover sill pillars at Crusader Mine, Western Australia in 2001. Globally significant resources have been sterilised due to the placement of loose rock fill above crown pillars and within adjacent stopes. The method described here offers significant opportunities to increase recovery of sill pillar recoveries.The royal orebody sill pillars at Cracow Gold Mine form a significant resource. Extraction of these pillars needed to be undertaken with minimal ore dilution and maximum ore recovery. The application that was selected to consolidate the loose mullock fill above each pillar used an injection grouting process (Minova FB200).Cracow Gold Mine mining method is bottom up bench mining. The pillars were left within the orebody to allow for stoping to commence whilst the decline was being developed. Due to the remainder of the orebody being extracted the only access to consolidate the backfill was from the sill pillar extraction level. Numerous problems were encountered and overcome from product selection and trial, system of injection to extraction.This pillar recovery process achieved a 95 per cent recovery of the sill pillar compared with an estimated 60 per cent typical for other mining options.CITATION:Potts, L, Mutton, V and Joyce, D, 2012. Pillar recovery at Cracow gold mine using grouted consolidated mullock, in Proceedings Narrow Vein Mining 2012 , pp 179-184 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

By F. Crundwell, A. J. Lathwood

A number of base-metal operations would like to increase production to take advantage of the higher metals prices. In general, this higher production should not be achieved with major operating changes. In hydrometallurgical facilities, leaching and pressure leaching represents one area where upfront limitations may be a bottleneck to the capacity of the entire plant. An assessment of the capacity of the leaching tanks and autoclaves was performed using a predictive model within the AweSym flowsheet simulator. The model is described, and the results of the application of the model to a number of different leaching reactors are presented. It is argued that the leaching number, which relates the residence time, particle size and the leaching rate, is of prime importance. Finally it is shown that there are some unexpected catastrophic events in increasing production capacity without a thorough understanding of the leaching operation.

Jan 1, 2007