Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Assunto principal
Intervalo de ano de publicação
1.
Sci Total Environ ; 714: 136701, 2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-31982746

RESUMO

Phosphorus is unique, given its characteristic of being essential for all life on Earth. The element is non-substitutable and finite in the form of highly concentrated phosphate-rock deposits. Thus, humankind should strive to utilize this resource in the most-efficient and sustainable manner. Losses, as well as overlooked opportunities, can be found all along the supply chain in various forms and to distinct extents. Avoiding these by closing the loops all along the supply chain is a key approach for keeping phosphorus flows available for economic use while reducing negative environmental impacts such as eutrophication. Changes to the current, mostly linear approach require multidimensional innovations that address products, processes, structures, and decision-makers along the supply chain as well as societal stakeholders. Our work focuses on the mining phase, covering extraction and beneficiation, whereby we discuss innovation potential in the contexts of i) improving P2O5 recovery, ii) utilizing waste, and iii) recovering by-products within the boundaries of sustainable development as generalized strategies on the macro level. Furthermore, we show that there is no "one-size-fits-all" solution to overcome current and future challenges within phosphate-rock mining, as the geological composition and processing of ores differs fundamentally among global deposits. Therefore, we perform, based on previously unpublished primary data, an economic breakdown of production-cost structures covering 85 active phosphate-rock mines and show significant differences between the two main deposit types (i.e., igneous and sedimentary), underground and open-pit mining as well as within each type.

2.
Environ Sci Technol ; 54(3): 1287-1289, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-31940185

Assuntos
Urânio , Fosfatos
3.
Sci Total Environ ; 677: 511-523, 2019 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-31063894

RESUMO

Phosphorus's essentiality for all life on Earth is beyond doubt. As one of the three major macronutrients, it is a crucial building block of modern-day mineral fertilizers and, thus, an essential production factor for global food security. Its almost-exclusive primary sources are phosphate-rock deposits of either sedimentary or igneous origin. The currently known deposits are widely scattered over the globe in large numbers but not necessarily in commercially feasible phosphate-rock quantities. Europe, in particular, possesses negligible considerable reserves; currently, only one Finnish igneous mine is in operation. Thus, phosphate imports are inevitable. Countermeasures like to foster phosphorus recycling from wastewater systems, will reduce rather than substitute imports. Phosphate trade of any form relies on bilateral commercial agreements as it is not traded on commodity exchanges. Therefore, questions regarding supply security and, particularly, the safeness of supply for import-dependent countries, must also address the issues of market concentration, the dynamic reserve-resource situation, and respectively their development over time. We provide a state-of-the-art fundamental analysis all along the supply chain by applying the Hirschman-Herfindahl Index (HHI) to quantify market concentrations as well as reserve-to-production ratios to evaluate developments over recent decades. Thereby, we overcome the unfavorable nature of these static measures. Results suggest medium to highly concentrated markets for the production of phosphate rock, phosphoric acid, and phosphate fertilizers (MAP, DAP) with increasing trends for the overall supply chain. However, these findings should not be interpreted as alarming developments for import-dependent regions, given that the export-market concentrations for phosphate fertilizers have shown significant decreases since the early 1980s.

4.
Sustain Sci ; 13(4): 1001-1015, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30147793

RESUMO

Recent research supports that a person's self-reported explicit attitude is not necessarily consistent with their implicit attitude. However, in sustainability research, implicit cognitive measures are still at their early stages, and consider primarily singular aspects of sustainability. Here, we pose that the degree of congruence of individuals' implicit and explicit attitudes represents the foundation of any organization's sustainability culture. Although many organizations assert that sustainable development represents an important dimension of their vision and strategy, in reality, sustainable development often translates simply into explicit self-presentation and reputation. Traditional methods such as surveys lack information on implicit measures and-since they collect data based solely on the explicit knowledge of the respondents, which may be biased by social desirability and impression management-can therefore not determine the degree of congruence between explicit and implicit attitudes. We implemented a browser-based application of the Implicit Association Test (IAT) regarding sustainability as a reaction time-based cognitive measure supported by an interactive and activating process that was completed by 114 executives. Additionally, a questionnaire-based survey was conducted among them to investigate their explicit attitudes. We calculated Pearson correlation coefficients and conducted repeated measures MANOVA and principle component analysis. Our data analysis demonstrated low congruence between explicit and implicit sustainability orientations (Pearson's r ranging from - 0.10 to 0.31). Potential explanations for our findings relate to the effects of impression management and individuals' lack of cognitive processing of their own sustainability orientation. In sum, exploring the potential incongruence between explicit and implicit sustainability orientations helps narrow an important knowledge gap and provides a basis for rethinking the impact of internal and external learning processes within and between organizational systems, society, and science.

5.
Sci Total Environ ; 642: 250-263, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-29902623

RESUMO

Big Data, blockchains, and cloud computing have become ubiquitous in today's mass media and are universally known terms used in everyday speech. If we look behind these often misused buzzwords, we find at least one common element, namely data. Although we hardly use these terms in the "classic discipline" of mineral economics, we find various similarities. The case of phosphate data bears numerous challenges in multiple forms such as uncertainties, fuzziness, or misunderstandings. Often simulation models are used to support decision-making processes. For all these models, reliable and accurate sets of data are an essential premise. A significant number of data series relating to the phosphorus supply chain, including resource inventory or production, consumption, and trade data ranging from phosphate rock to intermediates like marketable concentrate to final phosphate fertilizers, is available. Data analysts and modelers must often choose from various sources, and they also depend on data access. Based on a transdisciplinary orientation, we aim to help colleagues in all fields by illustrating quantitative differences among the reported data, taking a somewhat engineering approach. We use common descriptive statistics to measure and causally explain discrepancies in global phosphate-rock production data issued by the US Geological Survey, the British Geological Survey, Austrian World Mining Data, the International Fertilizer Association, and CRU International over time, with a focus on the most recent years. Furthermore, we provide two snapshots of global-trade flows for phosphate-rock concentrate, in 2015 and 1985, and compare these to an approach using total-nutrient data. We find discrepancies of up to 30% in reported global production volume, whereby the major share could be assigned directly to China and Peru. Consequently, we call for a global, independent agency to collect and monitor phosphate data in order to reduce uncertainties or fuzziness and, thereby, ultimately support policy-making processes.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...