Effect of Micro-Bubbling on Settling Behavior of Fine Particles for Deep-Sea Mining

2015 ◽  
Author(s):  
Tetsuo Yamazaki ◽  
Naoki Nakatani ◽  
Rei Arai ◽  
Yuta Yamamoto
Keyword(s):  
Environmental Impacts ◽  
Deep Sea ◽  
Fine Particles ◽  
Gray Scale ◽  
Tank Experiment ◽  
Suspension Effect ◽  
Settling Behavior

A preliminary tank experiment for clarifying the effect of micro-bubbles on settling behavior of fine particles was conducted. The behavior of the particles was continuously photographed by a still camera and the images were analyzed by the gray scale intensity. From the results the authors found a suspension effect of micro-bubbles for the settling of fine particles. The effect should be studied in detail for preventing some serious environmental impacts during deep-sea mining.

A numerical calculation method of environmental impacts for the deep sea mining industry – a review

2018 ◽  
Vol 20 (3) ◽  
pp. 454-468
Author(s):  
Wenbin Ma ◽  
Cees van Rhee ◽  
Dingena Schott
Keyword(s):  
Numerical Calculation ◽  
Environmental Impacts ◽  
Calculation Method ◽  
Deep Sea ◽  
Mining Industry ◽  
Mineral Resources ◽  
Gradual Decrease ◽  
The World ◽  
Numerical Calculation Method

Since the gradual decrease of mineral resources on-land, deep sea mining (DSM) is becoming an urgent and important emerging activity in the world.

scholarly journals Comparison of Environmental Impacts of Deep-sea Tailings Placement Versus On-land Disposal

2019 ◽  
Vol 230 (12) ◽  
Author(s):  
Y. T. John Kwong ◽  
Simon C. Apte ◽  
Gert Asmund ◽  
Michael D. E. Haywood ◽  
Elisabetta B. Morello
Keyword(s):  
Environmental Impacts ◽  
Waste Disposal ◽  
Deep Sea ◽  
Mine Waste ◽  
Viable Option ◽  
Ore Grades ◽  
Land Disposal

AbstractWith increasing metal prices and declining ore grades, new mines are getting larger and mine waste disposal and management have become more difficult, particularly from an environmental perspective. While technologies keep on improving, the available space for terrestrial mine waste disposal is limited. Thus, several coastal countries still consider deep-sea tailings placement (DSTP) as a viable option. This brief review compares the environmental impacts of DSTP versus on-land disposal and suggests several factors to consider in selecting the most suitable options for mine waste disposal.

SHOULD THE AREA BE MINED? THE PRECAUTIONARY PRINCIPLE AND THE ENVIRONMENTAL IMPACTS ON DEEP-SEA MININGA ÁREA DEVERIA SER MINERADA? O PRINCÍPIO DA PRECAUÇÃO E OS IMPACTOS AMBIENTAIS DA MINERAÇÃO EM FUNDOS MARINHOS

2020 ◽  
Vol 10 (19) ◽  
Author(s):  
Felipe Kern Moreira ◽  
Felipe de Macedo Teixeira
Keyword(s):  
Environmental Impacts ◽  
Precautionary Principle ◽  
Deep Sea ◽  
Document Analysis ◽  
Analysis Procedure ◽  
Mining Activities ◽  
The Precautionary Principle ◽  
International Seabed Authority

The purpose of this paper is to analyze the role of the precautionary principle in the regulations of seabed exploitation activities. In order to do this, it relates the current Mining Code with the events that served as the basis for the Code negotiation. The methodology applied in this research is predominantly qualitative and of the document analysis procedure. The documents examined are the rules and jurisdictional decisions emanated from the International Seabed Authority. In summary, this article analyzes the adoption of the precautionary principle in recent normative and decisional constructions regarding mining activities and environmental impacts in the deep seabed. In conclusion, it is pointed to the construction of a normative arrangement of jurisdictional consolidation of the precautionary principle in the exploration activities of the deep seabed. Moreover, given the uncertain nature of the consequences that mining in the deep seabed will bring, the adoption of the principle arises to ensure the reduction of environmental impacts.

Segmenting Fly Ash Particles Using Image Processing Techniques

2017 ◽  
Author(s):  
Ali Asmari ◽  
L. L. Hoberock
Keyword(s):  
Fly Ash ◽  
Cross Sections ◽  
Fine Particles ◽  
3D Models ◽  
Micro Computed Tomography ◽  
Gray Scale ◽  
Imaging Device ◽  
Concrete Production ◽  
The Cross ◽  
Contrast Stretching

Fly ash is one of the residues generated in combustion, and comprises the fine particles that rise with flue gases. In the US about 43% is recycled and is often used to supplement Portland cement in concrete production. Fly ash can improve the concretes mechanical properties and decrease cost. Depending upon the source and makeup of the coal being burned, the components of fly ash vary considerably. These variations affect the quality of the final product. Accordingly, it is important for cement manufacturers to know the amount and type of the components in these particles. The objective of this project is segmentation of images of fly ash particles acquired using a micro computed tomography (μCT) imaging device. A set of grayscale images is produced, with each image representing a particular slice of the particle. The desired segmentation operation should identify particles and label regions of a given image based on similarity, as perceived by human observers. In this paper, two techniques are proposed for segmenting different phases of material in these images. The first technique uses Contrast Stretching and Histogram Matching and is based solely on the gray scale value of the pixels in the image slices. In the second proposed technique, Circular Gabor Filters (CGF) are used to segment the regions with porous textures in the cross section of the particle. We have also proposed a technique for designing the CGF such that when applied to the gray scale images, the filter passes the porous regions of components accurately, while blocking non-porous regions. By combining these techniques, we have developed a program that is able to segment different types and regions of impurities in the cross sections of a fly ash particle and create 3D models of these particles, presenting the locations and sizes of different phases of material.

Numerical assessment of the environmental impacts of deep sea cage culture in the Yellow Sea, China

2020 ◽  
Vol 706 ◽  
pp. 135752 ◽  
Author(s):  
Yunxia Zhao ◽  
Jihong Zhang ◽  
Yi Liu ◽  
Ke Sun ◽  
Cong Zhang ◽  
...  
Keyword(s):  
Environmental Impacts ◽  
Yellow Sea ◽  
Deep Sea ◽  
The Yellow Sea ◽  
Cage Culture ◽  
Numerical Assessment ◽  
Sea Cage

scholarly journals Prospects for Gulf of Mexico Environmental Recovery and Restoration

Oceanography ◽  
2021 ◽  
Vol 34 (1) ◽  
pp. 164-173
Author(s):  
Denis Wiesenburg ◽  
◽  
Bob Shipp ◽  
Joel Fodrie ◽  
Sean Powers ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Environmental Impacts ◽  
Salt Marshes ◽  
Deep Sea ◽  
Marine Ecosystem ◽  
Ecosystem Processes ◽  
Future Research ◽  
Environmental Recovery ◽  
Starting Point

Previous oil spills provide clear evidence that ecosystem restoration efforts are challenging, and recovery can take decades. Similar to the Ixtoc-I well blowout in 1979, the Deepwater Horizon (DWH) oil spill was enormous both in volume of oil spilled and duration, resulting in environmental impacts from the deep ocean to the Gulf of Mexico coastline. Data collected during the National Resource Damage Assessment showed significant damage to coastal areas (especially marshes), marine organisms, and deep-sea habitat. Previous spills have shown that disparate regions recover at different rates, with especially long-term effects in salt marshes and deep-sea habitat. Environmental recovery and restoration in the northern Gulf of Mexico are dependent upon fundamental knowledge of ecosystem processes in the region. Post-DWH research data provide a starting point for better understanding baselines and ecosystem processes. It is imperative to use the best science available to fully understand DWH environmental impacts and determine the appropriate means to ameliorate those impacts through restoration. Filling data gaps will be necessary to make better restoration decisions, and establishing new baselines will require long-term studies. Future research, especially via NOAA’s RESTORE Science Program and its state-based Centers of Excellence, should provide a path to understanding the potential for restoration and recovery of this vital marine ecosystem.

scholarly journals Deep-Sea Mining May Have Deep Economic, Environmental Impacts

Eos ◽  
2020 ◽  
Vol 101 ◽  
Author(s):  
James Dacey
Keyword(s):  
Environmental Impacts ◽  
Deep Sea ◽  
Environmental Concerns ◽  
The Creation

A new report supports the creation of a compensation fund for nations that rely on terrestrial mining, but it fails to dispel environmental concerns over deep-sea mining.

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