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Topic Review
Appications of Natural Clinoptilolites Based on Ion Exchange
There are many natural zeolites, of which a small number, including clinoptilolite, chabazite, mordenite, erionite, ferrierite, and phillipsite offer the greatest promise for industrial applications. Natural clinoptilolites have been the subject for different modifications in order to improve their use potentialities, where the ion exchange property has been a key role for their different applications. Application of ion exchange to modify clinoptilolites, cation selection, mono- and polycationic exchange to create new functional materials for specific applications are key issues.
  • 583
  • 03 Jan 2023
Topic Review
Evaluation Index System for Mine Ventilation System
The mine ventilation system is an indispensable component to improve coal mining efficiency and ensure the safety production. Only by clearly grasping the comprehensive evaluation quality of ventilation system can effective countermeasures be formulated. This paper establishes an evaluation index system for mine ventilation system by combining qualitative survey with quantitative research. Specifically, the primary indicators are screened through R-type clustering and coefficient of variation method. The weight of each index is determined by the entropy weight method. Moreover, the TOPSIS method are used to evaluate the quality of the mine ventilation system. Finally, this evaluation system is used to evaluate the ventilation renovation project in the production mining area of the Sihe mine. The evaluation results verify the effectiveness of the establishment of mine ventilation evaluation index system and evaluation methods.
  • 569
  • 28 Mar 2022
Topic Review
Illite-Age-Analysis
The Illite-Age-Analysis (IAA) method was first proposed by Pevear (1992, 1999)for the catalytic dating of sedimentary basins. After van der Pluijm et al. (2001) discovered a new application for defining the age of fault-thrust development with the IAA method, it has been applied to the shallow faults of various tectonic environments by a number of researchers for the past 20 years, and has played a decisive role in the study of tectonic evolution and understanding of seismic phenomena. In particular, the development of the WILDFIRE© program by Reynolds (1994)has made great strides in the quantitative analysis of illite polytype by simulating the 1M/1Mdpolytype patterns.
  • 563
  • 11 Nov 2021
Topic Review
Microorganisms in the Nucleation of Carbonates
Microbially induced carbonate precipitation (MICP) is an important process in the synthesis of carbonate minerals, and thus, it is widely explored as a novel approach with potential for many technological applications. The processes and mechanisms involved in carbonate mineral formation in the presence of microbes are not yet fully understood. This research covers the current knowledge regarding the role of microbial cells and metabolic products (e.g., extracellular polymeric substances, proteins and amino acids) on the adsorption of divalent metals, adsorption of ionic species and as templates for crystal nucleation. Moreover, they can play a role in the mineral precipitation, size, morphology and lattice. By understanding how microbes and their metabolic products promote suitable physicochemical conditions (pH, Mg/Ca ratio and free carbonate ions) to induce carbonate nucleation and precipitation, the manipulation of the final mineral precipitates could be a reality for (geo)biotechnological approaches. The applications and implications of biogenic carbonates in areas such as geology and engineering are presented and discussed in this research, with a major focus on biotechnology.
  • 549
  • 03 Jan 2023
Topic Review
Artisanal and Small-Scale Gold Mining
The aim of this work is to explain the concepts of sustainability with respect to small artisanal gold mining. For this, a qualitative approach with a descriptive scope was used, for which the bibliographic review technique was conducted. In this sense, articles, theses, books and institutional documents, and any contribution related to the research topic were taken into consideration. Likewise, this documentation contributed to the delimiting aspects that allowed a contrast between the proposed definitions and small artisanal mining in the Northeast Antioquia region in Colombia. Based on the reviewed sources, different needs were recognized in artisanal small-scale gold mining in Northeast Antioquia that still need action. In conclusion, through the exposition of sustainability theories, three common factors were identified within the various positions that were raised—the environmental, economic, and sociocultural dimensions. 
  • 537
  • 27 Aug 2021
Topic Review
Sustainability Reporting in Extractive Industries
Sustainability reporting is one of the tools that contribute to incorporating sustainable development in the design of extractive operations (i.e., “Design for Sustainability”), and the demand for sustainability reports is increasing due to the increased focus on sustainable development and sustainable financing efforts. The extractive industries are believed to have unique strengths to contribute to achieving the Sustainable Development Goals. Nonetheless, companies are expected to be transparent and accountable not only to investors but to all stakeholders, including communities, suppliers, clients, employees, and governments. Therefore, extractive industries require effective sustainability accounting and reporting to transition and contribute to sustainable development.
  • 536
  • 16 Sep 2021
Topic Review
Oxide Minerals
The oxide mineral class includes those minerals in which the oxide anion (O2−) is bonded to one or more metal alloys. The hydroxide-bearing minerals are typically included in the oxide class. The minerals with complex anion groups such as the silicates, sulfates, carbonates and phosphates are classed separately. Simple oxides: Hydroxide subgroup:
  • 530
  • 08 Nov 2022
Topic Review
Sulfide Minerals
The sulfide minerals are a class of minerals containing sulfide (S2−) or persulfide (S22−) as the major anion. Some sulfide minerals are economically important as metal ores. The sulfide class also includes the selenides, the tellurides, the arsenides, the antimonides, the bismuthinides, the sulfarsenides and the sulfosalts. Sulfide minerals are inorganic compounds.
  • 525
  • 24 Oct 2022
Topic Review
Sulfate Minerals
The sulfate minerals are a class of minerals that include the sulfate ion (SO42−) within their structure. The sulfate minerals occur commonly in primary evaporite depositional environments, as gangue minerals in hydrothermal veins and as secondary minerals in the oxidizing zone of sulfide mineral deposits. The chromate and manganate minerals have a similar structure and are often included with the sulfates in mineral classification systems. Sulfate minerals include:
  • 509
  • 06 Oct 2022
Topic Review
Mineralogy and Geochemistry of Ferromanganese Crusts
Late Pleistocene–Holocene rocks from the western part of Cocos-Nazca Spreading Centre (C-NSC) include ferromanganese crusts that elucidate the geochemistry and mineralogy of a deep-sea geological setting. Geochemical, mineralogical and petrological signatures indicate complex formation influenced by mild hydrothermal processes. These crusts consist mostly of mixed birnessite, todorokite-buserite, and Mn-(Fe) vernadite with traces of diagenetic manganates (asbolane), Fe-oxides and oxyhydroxides or hydrothermally associated and relatively pure Mn-oxyhydroxides (manganite). The average Mn/Fe ratio is 2.7, which suggests predominant mixed hydrogenous-early diagenetic crusts with hydrothermal influences. The mean concentrations of three prospective metals (Ni, Cu and Co) are low: 0.17, 0.08 and 0.025 wt %, respectively. The total content of ΣREY is also low, and ranges from 81 to 741 mg/kg (mean 339 mg/kg).
  • 494
  • 27 May 2022
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