The global iron industry and the Anthropocene

2020 ◽  
pp. 205301962098233
Author(s):  
Kevin Mallinger ◽  
Martin Mergili
Keyword(s):  
Iron Ore ◽  
Magnetic Particles ◽  
Steel Corrosion ◽  
Global Changes ◽  
Iron Industry ◽  
Iron And Steel ◽  
Physical Chemical ◽  
Organic Particles ◽  
Rock Overburden

Iron ore is the most mined metal and the second most mined mineral in the world. The mining of iron ore and the processing of iron and steel increased sharply during the 20th century and peaked at the beginning of the 21st century. Associated processes along the iron ore cycle (mining, processing, recycling, weathering) such as the massive displacement of rock, the emission of waste and pollutants, or the weathering of products resulted in long-term environmental and stratigraphic changes. Key findings link the iron ore industry to 170 gigatons of rock overburden, a global share of CO2 with 7.6%, mercury with 7.4%, and a variety of other metals, pollutants, and residues. These global changes led to physical, chemical, biological, magnetic, and sequential markers, which are used for the justification of the Anthropocene. The potential markers vary significantly regarding their persistence and measurability, but key findings are summarised as TMPs (Technogenic Magnetic Particles), SCPs (Spheroidal Carbonaceous fly ash Particles), POPs (Persistent Organic Particles), heavy metals (vanadium, mercury, etc.), as well as steel input and steel corrosion residues.

Some Aspects on the Use of Iron Canisters for HLW

1985 ◽  
Vol 50 ◽  
Author(s):  
Ivars Neretnieks
Keyword(s):  
Bentonite Clay ◽  
Potential Effect ◽  
Hydrogen Gas ◽  
Lithostatic Pressure ◽  
Equilibrium Pressure ◽  
Capillary Suction ◽  
Compacted Bentonite ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Rock Overburden

AbstractIron canisters for high level nuclear waste embedded in compacted bentonite in deep geologic repositories will corrode forming hydrogen gas. The equilibrium pressure (when corrosion would stop) has been estimated to be between 500 and 1000 atm. under repository conditions. As this is much higher than the lithostatic pressure (weight of rock overburden) the gas must be allowed to escape before it disrupts the repository. Escape by diffusion alone is not sufficient but recent experiments have demonstrated that the larger pores in the bentonite are blown free of water and let the gas escape before excessive pressures build up.The potential effect of a capillary breaking layer (CBL) has been explored. A fine layer nearest the canister (e.q. quartz sand) would have much lower capillary suction pressures than the bentonite clay and would keep the water out as long as there is sufficient overpressure. As long as the CBL is void of liquid water no radionuclides can escape, even if the canister is penetrated.

Sensitivity Studies of the Effect of Cladding Degradation on TSPA Results

2002 ◽  
Vol 713 ◽  
Author(s):  
Eric Siegmann ◽  
Eve Devonec
Keyword(s):  
Failure Rate ◽  
Localized Corrosion ◽  
Base Case ◽  
Driving Mechanism ◽  
Total System ◽  
Degradation Model ◽  
Large Computer ◽  
Peak Dose ◽  
Sensitivity Studies ◽  
Rock Overburden

ABSTRACTThe Commercial Spent Nuclear Fuel (CSNF) cladding directly influences the dose by reducing the release rate of radionuclides compared to bare fuel. A cladding degradation model was introduced in the Total System Performance Assessment – Viability Assessment (TSPA-VA) and has evolved into the TSPA-SR (Sight Recommendation), Rev 00 and most recently the Supplemental Science and Performance Analyses (SSPA) models. TSPAs are large computer models that predict how the radionuclides might escape through the various barriers and migrate through the different geological regions and predict the dose to the critical population. The major components in the cladding degradation model are initial cladding failure, creep, stress corrosion cracking (SCC), localized corrosion, mechanical failures (due to seismic events and rock overburden) and cladding unzipping. In the bare fuel case, the dose is controlled by the failure rate of the waste packages (WPs), the solubility limits for certain radionuclides, and the rate of diffusion of the radionuclides through the cracks in the WPs. The cladding degradation model involves two steps, perforation followed by unzipping. Sensitivity studies have shown that cladding limits dose primarily by preventing dissolution of the UO2 fuel (when the cladding is not perforated). If all the cladding is assumed to be perforated and cladding unzipping occurs, the peak dose would be within 4% of that of bare fuel. The UO2 dissolution rate (the driving mechanism for cladding unzipping) is sufficiently rapid that assuming instant dissolution increases the dose by only 12% from the base case. In the current cladding degradation model, cladding accounts for a reduction in dose for the first 100,000 years of a factor of 16 when compared with bare fuel. This is because of the low initial cladding failure rate (2.1% including SCC and creep) and few failures from localized corrosion (late WP breach and limited water entering the WPs). Failure of the cladding by rock overburden accounts for an increasing trend in dose at times greater than 100,500 years. This mechanism increases the peak dose and delays the peak from approximately 200,000 to 300,000 years. In conclusion, the cladding degradation model, mostly through preventing water from contacting the UO2, reduces the dose predicted in the TSPA analysis.

UNDERGROUND MUON ENERGY SPECTRA WITH THE MACRO TRD

2005 ◽  
Vol 20 (29) ◽  
pp. 6968-6970
Author(s):  
M. N. MAZZIOTTA ◽  
M. BRIGIDA ◽  
C. FAVUZZI ◽  
P. FUSCO ◽  
F. GARGANO ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
Residual Energy ◽  
Energy Spectra ◽  
Muon Energy ◽  
Depth Range ◽  
Cosmic Ray Interactions ◽  
Single Muon ◽  
Rock Depth ◽  
Rock Overburden ◽  
Underground Muon

The MACRO detector was located in the Hall B of the Gran Sasso underground Laboratories under an average rock overburden of 3700 hg/cm2. A TRD composed by three identical modules, covering an horizontal area of 36 m2, was added to the MACRO detector in order to measure the residual energy of muons entering MACRO. This kind of measurement provides a useful tool to study the primary cosmic ray energy spectra and composition, their interactions with the Earth's atmosphere and the propagation of muons inside the rock. The results of the measurement of the energy of single and double muons crossing MACRO will be presented. Our data show that double muons are more energetic than single ones in the rock depth range from 3000 to 6500 hg/cm2. Single muon data confirm the reliability of the models adopted to describe the cosmic ray interactions with the atmosphere and the muon propagation inside the rock.

Comparing seepage and selenium desorption in blasted-rock fills using two reclamation techniques

2019 ◽  
Vol 53 (3) ◽  
pp. 443-451
Author(s):  
Nathan DePriest ◽  
Leslie Hopkinson ◽  
John Quaranta
Keyword(s):  
Three Dimensional ◽  
Lower Surface ◽  
Infiltration Capacity ◽  
Groundwater Movement ◽  
Valley Fill ◽  
Dimensional Finite Element ◽  
Valley Fills ◽  
Water Volumes ◽  
Three Dimensional Finite Element ◽  
Rock Overburden

Geomorphic reclaimed landforms aim to improve groundwater movement and diminish contaminant transport through increased runoff and reduced groundwater infiltration. The objective of this research was to determine if geomorphic reclamation techniques result in improved selenium concentrations of discharge water as compared to conventional reclamation for valley-fills constructed of blasted rock. Comparisons investigated if groundwater and contaminant desorption could be improved by altering valley-fill construction. Three-dimensional finite-element groundwater modelling was performed on two valley-fill geometries and was coupled with laboratory testing of selenium leaching from blasted-rock overburden. Selenium desorption characteristics and distributions were compared. Lower water volumes and shorter contact times with overburden fill resulted in lower masses of selenium desorbed from geomorphic fills as compared to conventional techniques. When results were normalized by varying fill areas and volumes, the geomorphic valley-fill exhibited 23% lower surface infiltration, 27% lower discharge volumes and 39% lower selenium discharge loads as compared to the conventional reclamation. To achieve these advantages in geomorphic reclamation, infiltration must be reduced through both the construction of curvilinear slopes of the fill surface and the creation of a low infiltration-capacity reclaimed stream.

scholarly journals Surface and Underground Ultra Low-Level Liquid Scintillation Spectrometry

Radiocarbon ◽  
2004 ◽  
Vol 46 (1) ◽  
pp. 97-104 ◽  
Author(s):  
Wolfango Plastino ◽  
Lauri Kaihola
Keyword(s):  
Gamma Radiation ◽  
Nuclear Physics ◽  
Cosmic Radiation ◽  
High Performance ◽  
Liquid Scintillation ◽  
National Laboratory ◽  
Liquid Scintillation Spectrometer ◽  
Low Level ◽  
Sample Count ◽  
Rock Overburden

Cosmic background and its variation have been removed in the Gran Sasso National Laboratory (National Institute of Nuclear Physics) by its 1400-m rock overburden. Stable, high-performance liquid scintillation counting conditions are obtained when any remaining variable components of the environmental background, such as radon, are eliminated. The ultra low-level liquid scintillation spectrometer Quantulus™ has an anti-Compton guard detector (guard for short) that allows monitoring of gamma radiation in the background. The guard detector efficiency in radiocarbon background reduction is 8% in the Gran Sasso National Laboratory, while 80% is observed in surface laboratories. Thus, atmospheric pressure variations in surface laboratories cause variation in cosmic radiation flux. The Quantulus anti-Compton detector is highly efficient in detecting cosmic radiation, and the sample count rate remains stable in long-term counting. Also, correlation of sample backgrounds with environmental gamma radiation in various laboratories is examined.

scholarly journals Optimization of the Excavator-and-Dump Truck Complex at Open Pit Mines – the Case Study

2018 ◽  
Vol 41 ◽  
pp. 01006 ◽  
Author(s):  
Nuray Demirel ◽  
Amir Taghizadeh ◽  
Samer Khouri ◽  
Ekaterina Tyuleneva
Keyword(s):  
Hard Rock ◽  
Open Pit ◽  
Dump Truck ◽  
Optimal Parameters ◽  
Empirical Formulas ◽  
Open Pit Mines ◽  
Technological Processes ◽  
Complex Optimization ◽  
Rock Overburden

The transition to the use of the new equipment requires a revision of previously established dependencies, which constitute the methodological basis for optimization to ensure the highly efficientoperation of technological equipment of the excavator-and-dump truckcomplex that performs all technological processes of overburden. The imperfection of the existing methods of optimization is due to the use, as a rule, of empirical formulas for the obsolete equipment installed to calculatethe performance, so replacing or partially adjusting these dependencies, including methods and tools for determining process parameters, is anurgent task. Therefore, it is important to establish the parameters of each ofthe conjugate technological processes for the development of hard rock and half-rock overburden, which together provide the optimal results of the entire excavator-and-dump truck complex. The article considers the use of excavator-and-dump truck complex optimization as a criterion for the average weighted size of pieces of exploded rock mass, which allows determining the optimal parameters of each of the associated technological processes, their costs, as well as the total costs of the technology as a whole.

scholarly journals Construction of a tunnel under thin rock overburden in Middle Marsyangdi Hydroelectric Project, Central Nepal

2004 ◽  
Vol 29 ◽  
Author(s):  
Kaustubh Mani Nepal
Keyword(s):  
Rock Mass ◽  
Support System ◽  
Deformation Monitoring ◽  
Actual Condition ◽  
Support Design ◽  
Tunnel Support ◽  
Hydroelectric Project ◽  
Central Nepal ◽  
Rock Overburden ◽  
Smooth Blasting

This paper deals with an application of New Australian Tunnelling Method (NATM) in low cover tunnelling in Lesser Himalaya of Nepal. The length of the tunnel is 365.8 m with a 8.2 m finished diameter. The average thickness of the rock overburden is 16- 18 m with a maximum of 30 m, whereas average side cover is 40 m. Top heading and multiple benching methods were applied for tunnelling work. The rational support design techniques were conceived together with Bieniawski's Support Guideline for each standard support classes. Standard initial support system was designed according to NATM, to provide complete stabilization of excavation. It consisted of a combination of systematic rock bolts and shotcrete.  The smooth blasting technique was adopted for the tunnel excavation. The specific charge was 1.39-1.47 kg/m3 A special emphasis was given in the collection of discontinuity data so that the rock mass could be evaluated effectively. Geomechanics classification for rock mass was used for the rock mass evaluation. The rock mass was also back evaluated by using Q and GSI classification on the basis of installed support. After the careful assessment of the data, the rock mass in the tunnel was classified into fair to poor according to RMR and Q and blocky / disturbed to very blocky / fair according to GSI. The rock mass parameters collected during the construction stage agree with the data collected at surface during feasibility and tendering stages. The rock mass classification based on the surface outcrop survey and drillings was a considerable success and found to be very close to the actual condition. The effectiveness of revised support system with steel rib was found to be negligible or minimum for tunnel support. Rock support deformation monitoring in the tunnel was regularly carried out to determine the efficiency and adequacy of the installed support.

scholarly journals Geoneutrinos from the rock overburden at SNO+

2020 ◽  
Vol 1342 ◽  
pp. 012020
Author(s):  
V. Strati ◽  
S.A. Wipperfurth ◽  
M. Baldoncini ◽  
W.F. McDonough ◽  
S. Gizzi ◽  
...  
Keyword(s):  
Rock Overburden
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