scholarly journals Challenges and new insights for exploitation of deep underground metal mineral resources

2021 ◽  
Vol 31 (11) ◽  
pp. 3478-3505
Author(s):  
Peng LI ◽  
Mei-feng CAI
Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1906
Author(s):  
Jiaqi Zhu ◽  
Shunchuan Wu ◽  
Haiyong Cheng ◽  
Xiaojie Geng ◽  
Jin Liu

Cemented paste backfill is critical for the development of green mines, the safe exploitation of mineral resources deep underground, and the efficient disposal of solid wastes produced by mining. In this paper, the mechanism underpinning how the pumping agent works was studied. The number, area, and fractal dimension of pores in the microstructure of fresh paste were quantitatively analyzed using scanning electron microscopy (SEM), image processing, and fractal theory, and the response of flocs was investigated. The results show that floc networks disintegrated and the liquid network became the dominant structure under the action of the pumping agent, which enhanced the lubrication and promotion of multi-scale particles. In addition, the force chains became fragile and scattered, diminishing the yield stress of the paste. The pores had a more homogenized dimension and the porosity was 15.52% higher. The increase in the fractal dimension of the pores indicated that there was a higher self-similarity, in terms of microstructure, with a strengthened liquid network. The migration of floc structures contributed to the enhancement of the fluidity and rheology of the paste. This study provides insights into the effects of floc and liquid networks on the performance of paste, and it is of engineering significance in terms of realizing safe and efficient CPB operations.


2019 ◽  
pp. 169
Author(s):  
Nadiia Maksimentseva

Laws and regulations backing and governing public administration in subsoil use and protection in Ukraine is gradually gaining priority and importance given incoming energy security and resource self-sufficiency risks alerts for the State as one of the warrants for political and economic independence and guarantees for the people of Ukraine to enjoy and plenipotentiary implement its propitiatory rights set forth in the Constitution of Ukraine with regard to natural resources and benefits that constitute the genuine wealth of the nation. The article is written with the application of inductive reasoning and performance of various research methods, such as case studies, phenomenological study with some focus on nature and source of laws and administrative functions, grounded theory study; also a deep comparative analysis of domestic and overseas legal patterns is carried out. The article is devoted to the research of problems with regard to public administration in the field of subsoil use and protection in Ukraine. The author emphasizes that determination of public administration in the field of subsoil use and protection is a form of public managerial activities of public administration authorities (state authorities, local self-government bodies, self-governing public organizations with the respective competence). It is suggested that these activities are aimed at implementation of the policies in the field of geological exploration of mineral resources, mineral extraction, construction of underground and terrestrial facilities not related to the extraction of minerals, subsoil and environmental protection and they are based on the principles of interaction between subject and object of public administration, discretion, mutual responsibility, self-governance and decentralization when public services are provided. Also, the article presents many judicial practice of the European Court of Human Rights and Citizen, the Supreme Court in the field of public administration in the field of subsoil use and protection. In concluding notes amendments to Subsoil Code of Ukraine, methodology for calculating the initial selling price for the sale of special permit, selection procedures for open special permit tender bid winners and responsibility for subsoil use abandonment costs are suggested by the author.


Author(s):  
A. L. Dergachev ◽  
V. I. Starostin

Important trends in development of world's mineral complex at the beginning of the 21st century are increase of supply and demand for mineral materials differentiated for various metals and nonmetallic mineral resources, regions and countries; concentration of production of mineral commodities in small number of countries; falling availability of economic reserves of raw materials for world economy even at current level of material extraction. The tendencies should be taken into account when working out strategy of development of Russian mineral base.


2019 ◽  
Vol 21 (1) ◽  
pp. 68 ◽  
Author(s):  
Bojie Wen ◽  
Yuchuan Chen ◽  
Gaoshang Wang ◽  
Tao Dai
Keyword(s):  

2010 ◽  
Vol 6 (1) ◽  
pp. 39-44
Author(s):  
V.P. Nagornyi ◽  
◽  
I.I. Denisyuk ◽  
L.O. Volgin ◽  
◽  
...  

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