Mines Repository (Colorado School of Mines)
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Aragonite var. flos ferri
No full textPhotographed by Ron Wolf.Flos ferri (variety of aragonite) in twisting white tube shapes
Phenakite
No full textPhotographed by Ron Wolf.White translucent rounded cube of phenakite on white and brown matrix
Analcime with stilbite
No full textPhotographed by Ron Wolf.Blocky vitreous white analcime with small brown prisms of stilbite
Application of predictive blasting model to improve grade control and optimize blast value
No full textIncludes bibliographical references.2024 Spring.Each block in the geological block model has an economic value. The block economic value (BEV) distinguishes economic (ore) and uneconomic blocks (waste). A block will be economic to mine if its BEV is positive and uneconomic if it is negative, assuming there are no waste blocks on top of it.
Reconciliation is a process to verify the resource model against actual production data. The grade control model as an important part of reconciliation process is a model developed for daily ore/waste selection to determine where each material mined should go. It is crucial to avoid sending the block of material to the wrong destination as the consequences can be overall ore loss and dilution which lead to loss of value.
Blasting is a process of breaking rock mass using explosives. Blasting can break a large amount of rocks at a low cost. However, regardless of how well-controlled the blasting is, rock displacement will occur due to the forces applied. The blasting for rock breakage will result in movement of ore and waste blocks in the grade control block model from their pre blast positions into new post blast positions. This can affect the definition and accuracy of the ore and waste boundaries used for grade control within the resulting post blast muck pile compared to pre blast definition of ore and waste boundaries. Accurate definition of precise post blast grade control polygons is vital for the economics of any mine.
The vital question is, "What is the impact of blasting on grade control value and how can the most value be captured by considering the probable changes caused by the blast?" Orica developed OREPro™ 3D Predict ("The Predictive Model"), a real-time blast movement prediction model that uses complex physics algorithms to predict rock movement and the post blast muckpile in minutes allowing one to be able to predict the post blast location of individual blocks within the grade control block model. The Predictive Model utilizes these new block locations within the grade control polygon optimizer tool to generate post blast grade control polygons that maximize value of the extracted resource before initiating the blast.
This thesis investigates and evaluates the potential application of the Predictive Model to improve grade control model and optimize blast value. Additionally, variables were identified and reviewed when utilizing the Predictive Model in various blasting conditions
Multi-scale modeling and analysis of utility-scale reversible protonic ceramic electrolyzer system operating in renewable-dense electricity grids
No full textIncludes bibliographical references.2024 Summer.The importance of seasonal energy storage is becoming evident with the increasing integration of renewables into electricity grids due to seasonal storage’s ability to perform beyond intra-day energy shifting. At the same time, owing to its multiple end uses and projected cost-effectiveness, renewable energy-powered electrochemical hydrogen production is emerging as a promising method for achieving seasonal energy storage. This dissertation focuses on three key areas.
The first area advances the state-of-the-art in computationally efficient, model-predictive tools through an experimentally validated, quasi-2D, transient, dual-channel cell model for a novel protonic ceramic electrochemical cell technology that conducts multiple charges. This analysis predicts that operating the electrolyzer system at high feedstock steam concentrations (≥40%), low operating temperatures (≤873K), and low cell voltages (≤1.28V) results in high average faradaic efficiency, high cell energy efficiency, increased hydrogen production per cell, and a levelized cost of hydrogen marginally higher than that of solid-oxide technology.
The second focus is on analyzing various generic methodologies tested on modified IEEE 5-bus and RTS electricity test grids to improve seasonal energy storage dispatch at minimal computational cost increment. These methodologies aim to capture net load (load minus available renewable energy) variations beyond the intra-day time scale, addressing the limitations of the traditional approach (one day plus one day look-ahead) in solving production cost models with long duration and seasonal energy storage devices. This analysis shows that up to a 40% reduction in the total electricity production cost is possible due to improved dispatch of seasonal and long-duration storage devices, depending on the choice of methodology and the nature of the electricity grid.
Finally, the third study combines findings from the first two studies to further our understanding of the operation of a reversible protonic ceramic electrolyzer system as seasonal energy storage in a renewable-dense electricity grid. This study shows that operating a reversible protonic ceramic electrolyzer system is beneficial in a solar-driven electricity grid from both grid and storage operator viewpoints. Overall, the research covers different aspects of electrochemical hydrogen generation, ranging from a button cell to a regional electricity grid
Calaverite, gold, coloradoite & magnetite in quartz
No full textPhotographed by Ron Wolf.Metallic yellow-white calaverite, gold, magnetite and coloradoite in grey white vitreous quartz, Kalgoorlie district, Western Australia
Martite (hematite pseudo magnetite)
No full textPhotographed by Ron Wolf.Brown-black vitreous martite: hematite pseudomorph after magnetite
Synthesis and characterization of polymer charge transport materials for applications in high efficiency and stability perovskite solar cell technologies
No full textIncludes bibliographical references.2024 Fall.Perovskite solar cells (PSCs) have shown great promise as a low-cost and efficient renewable energy source since their conception in the late 2000s, recently achieving over 26% power conversion efficiencies (PCE) for single junction devices. The hole transport material (HTM) plays an integral part in the performance of PSCs; however, previous studies have shown that the HTM interface with adjacent perovskite/ITO layers can often be a bottleneck for device efficiency and long-term stability. Avenues for improving HTMs include addressing issues with energetic alignment, physical contact with adjacent layers, and lowering manufacturing costs1. Previous attempts to address these issues have included the synthesis of different carbazole and fluorene-based polymers via the Buchwald-Hartwig amination, whose modified backbone allowed for varying thermal and optical properties. This existing inexpensive polymer HTM family was modified with polar side-chain moieties containing methoxyethoxyethyl (O), alkyl oxetane chain (Ox) N,N-dimethyl aminopropyl (N), butanoate (COOCH3), and butanenitrile (CN) in order to improve the interaction with adjacent layers. The synthesis and characterization of monomers and polymers are reported and the effects of these wettable monomer additions on optical, thermal, molecular weight properties, and increased device performance were measured
Transformation and quantification of poly- and perfluoroalkyl substances
No full textIncludes bibliographical references.2024 Spring.Poly- and perfluoroalkyl substances (PFASs) are a class of manmade chemicals that have become infamous for their widespread environmental contamination, and adverse health effects in humans. Aqueous film forming foams (AFFFs) have been identified as one of the largest sources of PFASs to the environment. AFFF formulations are known to contain structurally diverse groups of PFASs. Perfluoroalkyl acids (PFAAs) are the most studied compound class amongst PFASs and are routinely measured. However, much of the fluorinated mass composing AFFFs often goes unmeasured. Additionally, evidence shows many non-PFAA fluorinated derivatives contained in AFFFs (precursors) are capable of transforming to PFAAs through a variety of pathways.
The first goal of this dissertation was to evaluate the relevance of precursor transformation via abiotic pathways. Photochemically generated hydroxyl radicals (•OH), dilute AFFF, and current high resolution mass spectrometry techniques (HRMS) were used to simulate and measure abiotic transformations of PFASs found in AFFFs. The results indicated fluorinated derivatives contained in AFFFs were capable of transforming to PFAAs with environmentally relevant doses of hydroxyl radical. Additionally, based on the observed rate constants between hydroxyl radical and AFFF-derived PFASs, abiotic transformations are expected to occur much faster than biotic transformations in specific environmental contexts (i.e. reduced iron rich subsurface sediments).
The second and third goals of this dissertation were to assess current and proposed analytical protocols on their abilities to quantify all PFASs (ΣPFASs) accurately and precisely at AFFF-impacted sites, particularly soils, where PFAS-relevant chemical diversity is usually the greatest. Three AFFF-impacted soil composites were analyzed using draft EPA Method 1633 (1633), a method proposed by Nickerson et al. 2020, and a new proposed methodology, the BAMBINO Method. Additionally, three other laboratories (2 commercial and 1 government) participated in analyzing the AFFF-impacted soil composites utilizing their own internally validated 1633 methodology. Results from these assessments indicate when 1633 is used to quantify ΣPFASs at AFFF-impacted sites, a large portion of the PFAS mass may be missed due to sample preparation bias and a narrow analyte list. The proposed BAMBINO Method yielded more accurate results in the context of ΣPFASs while retaining many methodological similarities with 1633. When the data for only the 1633 analyses were compared across four laboratories, results indicate low interlaboratory variation except for perfluorosulfonic acids (PFSAs). It is hypothesized that samples with abundant branched isomers likely increases variability between laboratories
Satellite analysis of the Los Angeles fires
No full textThe Payne Institute's Earth Observation Group conducts world class satellite data analysis and insights. This Commentary considers the deadly fires in and around Los Angeles, USA. The situation is rapidly evolving, of course. What we display here is an important tool in both analyzing and fighting these fires