Browsing by Subject "Mesabi"

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Bulletin No. 10. The Iron-Bearing Rocks of the Mesabi Range in Minnesota
(Minnesota Geological Survey, 1894) Spurr, J.Edward
Study of the rocks on the Mesabi Iron Range, Minnesota. In this bulletin the writer has endeavored to add to the knowledge of one of the most perplexing and fascinating fields in American geology. At the same time, some apology must be offered for the incompleteness of the work. Both time and opportunity have been too scanty for a thorough study and analysis of all of the problems which have presented themselves. New modifications of old principles. and new principles, will be found to bave been active in other areas, apart from that especially studied; and, not improbably, in this area itself. Economic geology in these departments is as yet rudimentary, but it is hoped that the main points bere presented will prove sound, and can safely be made the basis for more advanced work.
Bulletin No. 17. The Magnetite Deposits of the Eastern Mesabi Range Minnesota
(Minnesota Geological Survey, 1919) Grout, Frank F.; Broderick, T.M.
The Mesabi range is a belt of iron-bearing formation about 100 miles long, located about 80 miles north of Duluth, which is situated at the west end of Lake Superior. The trend of the belt is east-north- east. The iron-bearing formation, commonly called taconite, is largely drift covered throughout the main range and has few of the topographic features of a "range." It is called a range because iron-bearing formations in other districts form ranges; and at the east end of the Mesabi district there are some rocky hills rising 200 to 400 feet above the general level. This report is a discussion of the eastern end of the range-that part which lies between the town of Mesaba and Birch Lake, a distance of about 20 miles. This portion of the range is commonly called the "east Mesabi." It is distinguished from the rest of the range by several features, besides the topography above mentioned. In this area, outcrops are numerous; most of the iron is in magnetic form; recrystallization has increased the size of grain and reduced the porosity; there has been very little leaching or enrichment; and in places the beds are more highly tilted. These several peculiarities make the east Mesabi a logical unit for separate study. The field work was done in the summer of 1917, by Frank F. Grout and T. M. Broderick. The Mesabi Syndicate (D. C. Jackling, and Hayden-Stone and Company) were at that time actively exploring certain parts of the area and Mr. W. G. Swart, in charge at the Duluth office, made the work much more effective by rendering many drill records accessible to the Survey. A large number of samples have been assayed in their laboratories.
Bulletin No. 19. Contributions to the Geology of the Mesabi Range with Special Reference to the Magnetites of the Iron-bearing Formation West of Mesaba
(Minnesota Geological Survey, 1924) Gruner, John W.
This paper treats the geology of that portion of the Mesabi Range that lies west of the town of Mesaba. The Mesabi Range east of Mesaba was recently surveyed by Grout and Broderick, and the Gunflint Range by Broderick. The subjects treated include (I) the stratigraphic subdivisions and structure of the iron formation, (2) the occurrence of large magnetite bodies, possibly ore reserves for the future, (3) the origin of the formation and of the ores. The geologic setting of the district as a whole is briefly reviewed.
Bulletin No. 6. Iron Ores of Minnesota
(Minnesota Geological Survey, 1891) Winchell, N.H.; Winchell, H.V.
We have attempted to give, in this bulletin, such information concerning the iron ores of Minnesota as might be wanted by the explorer, the miner, the geologist and the citizen of the state. There has been a great demand recently for such a discussion of the iron ores of the Northwest. As the discovery of new mining grounds has, year after year, extended the interest in iron mining among a greater number of individuals and corporations who naturally look to the official survey for information and guidance, so have the number and complexity of the problems involved increased. We have not essayed the settlement of all the scientific questions that have arisen through this extension of the field of observation. We have simply collected the new facts as we have learned them and have made an initial effort to group all of them, both old and new, under a classification intended to make them indicate some general principles. Our results are not wholly in accord with those of some of our predecessors-as theirs were not with theirs. We would have been glad to have taken more time for further field and laboratory work. It is evident, however, that we should never reach perfection. It was equally evident that justice to a large and expectant constituency required the preparation of a report on the iron ores, however far it might fall short of rendering justice to the subject. It is only through successive partial studies, and the publication of the incompleted results that some additions are made to our knowledge of the geology of the ores of iron. Our contribution to that fund of knowledge will go with others, both earlier and later, to enable some fortunate future geologist to prepare an exposition that will be both thorough and complete. We shall be satisfied if we may be able to add a small quantum to that end.
Compressed Air Energy Storage (CAES) in Northern Minnesota Using Underground Mine Workings and Above Ground Features
(University of Minnesota Duluth, 2015) Fosnacht, Donald R; Wilson, Elizabeth J; Marr, Jeffrey D; Carranza-Torres, Carlos; Hauck, Steven A; Teasley, Rebecca
The goal of this research project is to determine the potential viability, environmental sustainability, and societal benefits of CAES, as a vital, enabling technology for wind turbine based power generation. The intent of this research is to provide a clear roadmap for CAES development in Minnesota. This project is multifaceted and draws resources across the University System and from key industrial partners: Great River Energy and Minnesota Power. The results from the project will provide vital information to decision makers on the potential of CAES and give guidance on how the technology can be implemented using the unique assets of the Minnesota’ various Iron Ranges (Mesabi and Cuyuna) or in other areas, so that renewable mandates and greenhouse gas reduction can be effectively accomplished. The results show that the topography and water resources exist at various sites that could allow a 100 to 200 MW facility to be constructed if the overall economic, mineral rights, and environmental issues associated with a given site can be properly managed. This report delves into the possibilities and outlines selection criteria that can be used for site selection. Other information is developed to compare the potential economic impact of implementation of the project within the constraints of the factors that can be monetized using the current policy environment. Finally, potential life cycle, regulatory, environmental, and permitting issues that are associated with implementation of the concept are discussed.
Geologic Map Mesabi Iron Range, Minnesota, second edition
(Mesabi Range Geological Society (MRGS) and Minnesota Geological Survey, 1999) Meineke, David G; Buchheit, Richard L; Dahlberg, Henk E; Morey, G B; Warren, LeRoy E
Historic strip-map of a 100 mile-long, 10 mile-wide area covering portions of St. Louis and Itasca counties, and enclosing the Mesabi Iron Range and parts of the Duluth Complex. Scale 1: 62500. First compiled and released in 1993, this map has never been formally published with a cite-able reference. Data and assistance for the compilation was provided by numerous companies, individuals and organizations which are listed on the map plate. The map has been in the charge of the Mesabi Range Geological Society and they have provided the MGS permission to host a scanned version of this map under the MGS holdings on the University of Minnesota Digital Conservancy (2019). The original map of 1993 has been superseded by the 1999 edition to correct certain errors in the cartographic base. The geology portion of the map was not altered.
Investigation into Production of Iron Ore Concentrates with less than 3 percent Silica from Minnesota Taconites Report Two · Erie Concentrate
(University of Minnesota Duluth, 1991-06) Benner, Blair R; Bleifuss, Rodney L
The pellets produced by Minnesota taconite companies generally contain between 4.0 and 7.0 percent silica. These silica levels were established initially by the concentratability of the ore, that is, its response to closed circuit ball mill grinding and magnetic concentration. Those operations that had taconite that was easy to concentrate generally produced lower silica pellets. As processing technology improved and it became possible to achieve lower silica levels constraints imposed by the blast-furnace operation became limiting. These constraints related primarily to sulphur and alkali levels in the furnace which control both the volume and chemistry of the furnace slag. Because the trend in blast-furnace practice has been to move toward lower slag volumes, pellets with lower silica levels have become more desirable. Recent extensive installation of external hot metal desulphurization facilities at many steel works allows even lower slag volumes. The basic driving force to go to lower slag volumes is the cost and availability of high quality metallurgical grade coke and related environmental problems. The recent move to produce fluxed pellets has made lower pellet silica levels more attractive because of the lower palletizing costs related to both the lower flux addition and higher production rates with a lower silica content. A common target silica level in fluxed pellets is now about 4.0 percent. A 4.0 percent silica pellet requires a concentrate containing between 3.7 and 3.9 percent silica depending upon bentonite addition levels. This lower silica level has been accomplished in some plants by the use of fine screens, while other plants require the use of silica flotation. The lower silica level has been accomplished at a relatively small incremental cost, generally less than $0.50 per ton. With increasing pressure from the blast furnaces for lower-silica pellets to reduce coke consumption, concentrate silica levels on the order of 3.0 percent may be common in the future. In addition to the need to produce a lower silica blast-furnace feed, there is a potential need to produce even lower silica concentrates, below 3.0 percent, as feed stock for direct steelmaking. Worldwide the current research emphasis is on the development of a coal-based direct-steelmaking process to replace the conventional two step, blast furnace-basic oxygen furnace, process. Most of the current prototype direct steel making processes would benefit from a lower silica feed. These low silica levels will require increasingly complex and expensive secondary treatment of normal magnetic concentrates which exceed the capability of current taconite processing flowsheets. The purpose of this test program is to establish the lower silica limits that can be achieved by current technology for various Minnesota taconites and gain a preliminary indication of the cost.Because the magnetite concentrates produced by different taconite plants range significantly in terms of their size-silica relationships the program included three different concentrate sources for evaluation. Major differences will exist between concentrates produced in a fully autogenous grinding system and those produced in a conventional rod mill-ball mill circuit in which the ball mills are closed with hydrocyclones and/or a combination of hydrocyclones and fine screens. There are also differences in the nature of the siliceous gangue minerals in the various operations. The concentrates from the western Mesabi range contain quartz and low- grade metamorphic iron silicates such as minnesotaite, stilpnomelane, and talc and iron carbonates. The concentrates from the east Mesabi metamorphosed iron formation contain high grade metamorphic iron silicates such as cummingtonite, grunerite, and fayalite as well as quartz. The type of gangue mineral greatly affects the ability to upgrade the concentrates by silica flotation. The purpose of this test program is to determine the lowest silica content that it is technically possible to produce from three different concentrate sources representing the east Mesabi metamorphosed iron formation (Erie), the unmetamorphosed central range produced in a rod mill and ball mill circuit (Minntac), and the unmetamorphosed western Mesabi produced in an autogenous milling circuit (Hibtac). Sufficient data were collected to allow preliminary cost estimates to be made at several silica levels. The cost estimates will be based on reagent consumption, regrind power and metal requirements, and iron recovery. This report contains all of the information obtained on the Erie samples. This includes the results of the initial characterization studies, basic bench scale beneficiation test results, pilot plant flotation data, and the results of the secondary and tertiary treatment of bulk flotation froth to improve overall iron recovery.
Minnesota Taconite Workers Health Study: Environmental Study of Airborne Particulate Matter in Mesabi Iron Range Communities and Taconite Processing Plants - A Characterization of the Mineral Component of Particulate Matter
(University of Minnesota Duluth, 2019-12) Monson Geerts, Stephen D; Hudak, George J; Marple, Virgil; Lundgren, Dale; Zanko, Lawrence M; Olson, Bernard; Bandli, Bryan
The Minnesota Taconite Workers Health Study (MTWHS) was initiated in 2008 and included a multicomponent study to further understand taconite worker health issues on the Mesabi Iron Range (MIR) in northeastern Minnesota. Approximately $4.9 million funding was provided by the Minnesota Legislature to conduct five separate studies related to this initiative, including:  An Occupational Exposure Assessment, conducted by the University of Minnesota School of Public Health (SPH);  A Mortality (Cause of Death) study, conducted by the University of Minnesota SPH;  Incidence studies, conducted by the University of Minnesota SPH;  A Respiratory Survey of Taconite Workers and Spouses, conducted by the University of Minnesota SPH; and  An Environmental Study of Airborne Particulate Matter, conducted by the Natural Resources Research Institute (NRRI) at the University of Minnesota Duluth (UMD). Results of the four studies conducted by the University of Minnesota SPH can be found on the Taconite Workers Health Study website (http://taconiteworkers.umn.edu/news/documents/Taconite_FinalReport_120114.pdf). NRRI’s “Environmental Study of Airborne Particulate Matter” comprises a multi-faceted characterization of size-fractionated airborne particulate matter (PM) from MIR community “rooftop” locations, background sites, and all taconite processing facilities active between 2008 and 2014. Characterization includes gravimetric determinations, chemical characterization, mineralogical characterization, and morphological characterization. This report specifically discusses the mineralogy and morphology of EMPs collected from the rooftops of five communities located within the MIR, three reference or background locations, and the six taconite processing plants. The samples were collected between 2008 and 2011.
Minnesota Taconite Workers Health Study: Environmental Study of Airborne Particulate Matter in Mesabi Iron Range Communities and Taconite Processing Plants - Development of Standard Operating Procedures for Particulate Collection and Gravimetric Analysis
(University of Minnesota Duluth, 2019-12) Monson Geerts, Stephen D; Hudak, George J; Marple, Virgil; Lundgren, Dale; Olson, Bernard; Zanko, Lawrence M; Bandli, Bryan; Brecke, Devon M
The Minnesota Taconite Workers Health Study (MTWHS) was initiated in 2008 and included a multicomponent study to further understand taconite worker health issues on the Mesabi Iron Range (MIR) in northeastern Minnesota. Approximately $4.9 million funding was provided by the Minnesota Legislature to conduct five separate studies related to this initiative, including:  An Occupational Exposure Assessment, conducted by the University of Minnesota School of Public Health (SPH);  A Mortality (Cause of Death) study, conducted by the University of Minnesota SPH;  Incidence studies, conducted by the University of Minnesota SPH;  A Respiratory Survey of Taconite Workers and Spouses, conducted by the University of Minnesota SPH; and  An Environmental Study of Airborne Particulate Matter, conducted by the Natural Resources Research Institute (NRRI) at the University of Minnesota Duluth (UMD). NRRI’s “Environmental Study of Airborne Particulate Matter” comprises a multi-faceted characterization of size-fractionated airborne particulate matter (PM) from MIR community “rooftop” locations, background sites, and all taconite processing facilities active between 2008 and 2014. Characterization includes gravimetric determinations, chemical characterization, mineralogical characterization, and morphological characterization. This report discusses the standard operating procedures for particle collection and gravimetric analysis. The methodology and practices that have been developed and performed have been completed in conjunction with NRRI’s Science Advisory Board and in collaboration with aerosol scientists at the University of Minnesota Department of Mechanical Engineering and University of Florida-Gainesville. As well, this report outlines the development of the sampling methodology and the history of in-house experiments conducted throughout the project to strengthen the sampling design that ultimately resulted in the development of the standard operating procedures adopted by, and practiced in, this portion of the study. Definitions for specific terms used in this document are consistent with terminology described in Appendix G.
Minnesota Taconite Workers Health Study: Environmental Study of Airborne Particulate Matter in Mesabi Iron Range Communities and Taconite Processing Plants - Elemental Chemistry of Particulate Matter
(University of Minnesota Duluth, 2019-12) Monson Geerts, Stephen D; Hudak, George J; Marple, Virgil; Lundgren, Dale; Gordee, Sarah M; Olson, Bernard; Zanko, Lawrence M
The Minnesota Taconite Workers Health Study (MTWHS) was initiated in 2008 and included a multicomponent study to further understand taconite worker health issues on the Mesabi Iron Range (MIR) in northeastern Minnesota. Approximately $4.9 million funding was provided by the Minnesota Legislature to conduct five separate studies related to this initiative, including: ▪ An Occupational Exposure Assessment, conducted by the University of Minnesota School of Public Health (SPH); ▪ A Mortality (Cause of Death) study, conducted by the University of Minnesota SPH; ▪ Incidence studies, conducted by the University of Minnesota SPH; ▪ A Respiratory Survey of Taconite Workers and Spouses, conducted by the University of Minnesota SPH; and ▪ An Environmental Study of Airborne Particulate Matter, conducted by the Natural Resources Research Institute (NRRI) at the University of Minnesota Duluth (UMD). NRRI’s “Environmental Study of Airborne Particulate Matter” comprises a multi-faceted characterization of size-fractionated airborne particulate matter (PM) from MIR community “rooftop” locations, background sites, and all taconite processing facilities active between 2008 and 2014. Characterization includes gravimetric determinations, chemical characterization, mineralogical characterization, and morphological characterization. This report specifically discusses the elemental chemistry of particulate matter (PM) collected from the rooftops of five communities located within the Mesabi Iron Range (MIR), three reference or background locations, and the six taconite processing plants while they were active (operating) and inactive (temporarily, but completely, shut down). The samples were collected between 2008 and 2011.
Minnesota Taconite Workers Health Study: Environmental Study of Airborne Particulate Matter in Mesabi Iron Range Communities and Taconite Processing Plants - Lake Sediment Study
(University of Minnesota Duluth, 2019-12) Zanko, Lawrence M; Reavie, Euan D; Post, Sara P
Atmospheric deposition of airborne particulate matter such as fugitive dust contributes to sediment that accumulates at the bottom of a lake. Because of this phenomenon, lake sediment can provide an historic mineralogical and chemical record of what may have been in the air at the time of its atmospheric deposition. This point is important, because the NRRI’s role in the Minnesota Taconite Workers Health Study (MTWHS) was to not only help answer the question “What is in the air?” by conducting present-day in-plant and community air sampling, but – and even more challengingly – to potentially answer the question “What was in the air, when?” by collecting and analyzing historic samples. Lake sediment was the only historic sampling medium available that could allow the investigators to make an attempt to assess what might have been present in the air in the past on Minnesota’s Mesabi Iron Range (MIR). The NRRI therefore core-sampled, age-dated, and characterized intervals of sediment from two MIR lakes – Silver Lake in Virginia, on the central MIR, and “North-of-Snort” Lake on the eastern end of the MIR, near Babbitt (Fig. i). The objective was to determine if fugitive mineral dust generated by past iron ore/taconite mining activity could be discerned in mineral particulate matter (PM) deposited and preserved in the sediment of both lakes.
Minnesota Taconite Workers Health Study: Environmental Study of Airborne Particulate Matter in Mesabi Iron Range Communities and Taconite Processing Plants - Mesabi Iron Range Community Particulate Matter Collection and Gravimetric Analysis
(University of Minnesota Duluth, 2019-12) Monson Geerts, Stephen D; Hudak, George J; Marple, Virgil; Lundgren, Dale; Zanko, Lawrence M; Olson, Bernard
The Minnesota Taconite Workers Health Study (MTWHS) was initiated in 2008 and included a multicomponent study to further understand taconite worker health issues on the Mesabi Iron Range (MIR) in northeastern Minnesota. Approximately $4.9 million funding was provided by the Minnesota Legislature to conduct five separate studies related to this initiative, including:  An Occupational Exposure Assessment, conducted by the University of Minnesota School of Public Health (SPH);  A Mortality (Cause of Death) study, conducted by the University of Minnesota SPH;  Incidence studies, conducted by the University of Minnesota SPH;  A Respiratory Survey of Taconite Workers and Spouses, conducted by the University of Minnesota SPH; and  An Environmental Study of Airborne Particulate Matter, conducted by the Natural Resources Research Institute (NRRI) at the University of Minnesota Duluth (UMD). NRRI’s “Environmental Study of Airborne Particulate Matter” comprises a multi-faceted characterization of size-fractionated airborne particulate matter (PM) from MIR community “rooftop” locations, background sites, and all taconite processing facilities active between 2008 and 2014. Characterization includes gravimetric determinations, chemical characterization, mineralogical characterization, and morphological characterization. This report specifically discusses the methods and gravimetric results of multiple aerosol PM sample collections from five communities located within the MIR, as well as three background locations. The samples were collected between 2008 and 2011.
Minnesota Taconite Workers Health Study: Environmental Study of Airborne Particulate Matter in Mesabi Iron Range Communities and Taconite Processing Plants - Taconite Processing Facilities Particulate Matter Collection and Gravimetric Analysis
(University of Minnesota Duluth, 2019-12) Monson Geerts, Stephen D; Hudak, George J; Marple, Virgil; Lundgren, Dale; Zanko, Lawrence M; Olson, Bernard
The Minnesota Taconite Workers Health Study (MTWHS) was initiated in 2008 and included a multicomponent study to further understand taconite worker health issues on the Mesabi Iron Range (MIR) in northeastern Minnesota. Approximately $4.9 million funding was provided by the Minnesota Legislature to conduct five separate studies related to this initiative, including:  An Occupational Exposure Assessment, conducted by the University of Minnesota School of Public Health (SPH);  A Mortality (Cause of Death) study, conducted by the University of Minnesota SPH;  Incidence studies, conducted by the University of Minnesota SPH;  A Respiratory Survey of Taconite Workers and Spouses, conducted by the University of Minnesota SPH; and  An Environmental Study of Airborne Particulate Matter, conducted by the Natural Resources Research Institute (NRRI) at the University of Minnesota Duluth (UMD). NRRI’s “Environmental Study of Airborne Particulate Matter” comprises a multi-faceted characterization of size-fractionated airborne particulate matter (PM) from MIR community “rooftop” locations, background sites, and all taconite processing facilities active between 2008 and 2014. Characterization includes gravimetric determinations, chemical characterization, mineralogical characterization, and morphological characterization. This report specifically discusses the methods and gravimetric results of multiple aerosol PM sample collections from active (operating) and inactive (temporarily, but completely, shut down) taconite plants on the MIR. Taconite plant samples were collected in 2009 and 2010.
Summary Report: Environmental Particulate Matter Characterization
(University of Minnesota Duluth, 2019-11) Monson Geerts, Stephen D; Hudak, George J; Zanko, Lawrence M; Fosnacht, Donald R
The NRRI characterization studies provide physical (size and shape), mineralogical, chemical, geological, geographical, and historical context to the findings of the University of Minnesota’s School of Public Health (SPH) and the University of Minnesota Medical School (UMMS). The SPH and UMMS findings (Finnegan and Mandel, 2014) showed that mesothelioma is associated with working longer in the taconite industry. However, the SPH and UMMS investigators “…were not able to state with certainty that the association with EMPs and mesothelioma was related to the ore dust or to the use of commercial asbestos or both.” The NRRI findings indicate the following: 1) Low concentrations of PM10, PM2.5, and EMPs in Mesabi Iron Range community air. 2) Elemental iron concentrations in MIR communities were similar to elemental iron concentrations in background sampling locations when taconite mines/plants were inactive. When taconite mines/plants were active, the elemental iron concentrations within communities were found to be statistically higher. 3) Mineralogically and morphologically, the EMPs identified in MIR communities and taconite processing plants were dominated by particles that did not fit the “countable”/”covered” classification criteria. Of the 145 “covered” EMPs identified within the six MIR taconite processing plants, a total of 8 were “countable” (NIOSH, 2011), representing 1.1% of the total number of EMPs, out of 691 total. These EMPs were detected in two taconite plants (seven in one plant and one in another); no other “countable”/”covered” EMPs were detected in the other four plants. 4) The lake sediment study returned similar results, in which 4 of the study’s 790 identified EMPs found in the lake sediment samples met the “countable”/”covered” classification. 5) In comparison to the NIOSH standard, for countable particles, the results from this study show that the community air has significantly lower amounts than the standard. 6) Only one plant and two areas in this plant had countable EMPs above the NIOSH benchmark. 7) The highest particulate matter found was for the Minneapolis reference site in comparison for the Range communities and the other two reference sites. 8) The use of MOUDI sampling techniques is a good method for better understanding not only what is in the air, but also the size of the particles that are in the air. 9) Study of lake sediment can be used to interpret some of the impacts of past industrial activities and to gain a better understanding of the impact of local geology.

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