Experimental and Numerical Modelling of Deep-Sea-Mining-Generated Turbidity Currents

Renewable energy installations and energy storage solutions require significant quantities of critical raw materials such as nickel, cobalt and rare earth metals. The supply chains of these raw materials face many difficulties, such as the continuous decrease of mineral ore grades on land. In view o...

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Main Authors: Mohamed Elerian, Cees van Rhee, Rudy Helmons
Format: Article
Language:English
Published: MDPI AG 2022-04-01
Series:Minerals
Subjects:
Online Access:https://www.mdpi.com/2075-163X/12/5/558
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author Mohamed Elerian
Cees van Rhee
Rudy Helmons
author_facet Mohamed Elerian
Cees van Rhee
Rudy Helmons
author_sort Mohamed Elerian
collection DOAJ
description Renewable energy installations and energy storage solutions require significant quantities of critical raw materials such as nickel, cobalt and rare earth metals. The supply chains of these raw materials face many difficulties, such as the continuous decrease of mineral ore grades on land. In view of these complications, the motivation to search for new resources has grown, with the deep sea being seen as a potential source of these minerals. Polymetallic nodule mining generates turbidity currents, which could negatively impact the deep-sea environment. For that reason, we investigate this type of current experimentally and numerically in order to characterize the generated turbidity current. Various non-cohesive sediment types, i.e., different particle sizes, and different concentrations are tested using a lock-exchange set-up. Three sediment types (glass beads, silica sand and a 50/50 blend of glass beads and silica sand) with seven initial sediment concentrations are examined. Additionally, for the numerical work, a drift–flux modelling approach is used to simulate the performed lock-exchange experiments. The results show that the front velocities of the currents resulting from the three sediment types increases with increasing initial concentrations inside the lock regardless. Moreover, using the same initial concentration, the difference in front velocities between the generated currents of the three sediment types decreases as the initial concentration increases. When using an initial volumetric concentration of 2.5% and 3%, the difference in front velocities between the generated current of the three sediment types vanishes. Finally, by comparing the numerical and experimental results, the drift–flux model is proven to be a reliable numerical model for predicting the current.
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spelling doaj.art-6f020aa99c444399ba9e554a582ff31d2023-11-23T12:18:34ZengMDPI AGMinerals2075-163X2022-04-0112555810.3390/min12050558Experimental and Numerical Modelling of Deep-Sea-Mining-Generated Turbidity CurrentsMohamed Elerian0Cees van Rhee1Rudy Helmons2Section of Offshore and Dredging Engineering, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, 2628 CN Delft, The NetherlandsSection of Offshore and Dredging Engineering, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, 2628 CN Delft, The NetherlandsSection of Offshore and Dredging Engineering, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, 2628 CN Delft, The NetherlandsRenewable energy installations and energy storage solutions require significant quantities of critical raw materials such as nickel, cobalt and rare earth metals. The supply chains of these raw materials face many difficulties, such as the continuous decrease of mineral ore grades on land. In view of these complications, the motivation to search for new resources has grown, with the deep sea being seen as a potential source of these minerals. Polymetallic nodule mining generates turbidity currents, which could negatively impact the deep-sea environment. For that reason, we investigate this type of current experimentally and numerically in order to characterize the generated turbidity current. Various non-cohesive sediment types, i.e., different particle sizes, and different concentrations are tested using a lock-exchange set-up. Three sediment types (glass beads, silica sand and a 50/50 blend of glass beads and silica sand) with seven initial sediment concentrations are examined. Additionally, for the numerical work, a drift–flux modelling approach is used to simulate the performed lock-exchange experiments. The results show that the front velocities of the currents resulting from the three sediment types increases with increasing initial concentrations inside the lock regardless. Moreover, using the same initial concentration, the difference in front velocities between the generated currents of the three sediment types decreases as the initial concentration increases. When using an initial volumetric concentration of 2.5% and 3%, the difference in front velocities between the generated current of the three sediment types vanishes. Finally, by comparing the numerical and experimental results, the drift–flux model is proven to be a reliable numerical model for predicting the current.https://www.mdpi.com/2075-163X/12/5/558deep sea miningpolymetallic nodulesturbidity currentssediment–water dischargewater entrainmentsediment deposition
spellingShingle Mohamed Elerian
Cees van Rhee
Rudy Helmons
Experimental and Numerical Modelling of Deep-Sea-Mining-Generated Turbidity Currents
Minerals
deep sea mining
polymetallic nodules
turbidity currents
sediment–water discharge
water entrainment
sediment deposition
title Experimental and Numerical Modelling of Deep-Sea-Mining-Generated Turbidity Currents
title_full Experimental and Numerical Modelling of Deep-Sea-Mining-Generated Turbidity Currents
title_fullStr Experimental and Numerical Modelling of Deep-Sea-Mining-Generated Turbidity Currents
title_full_unstemmed Experimental and Numerical Modelling of Deep-Sea-Mining-Generated Turbidity Currents
title_short Experimental and Numerical Modelling of Deep-Sea-Mining-Generated Turbidity Currents
title_sort experimental and numerical modelling of deep sea mining generated turbidity currents
topic deep sea mining
polymetallic nodules
turbidity currents
sediment–water discharge
water entrainment
sediment deposition
url https://www.mdpi.com/2075-163X/12/5/558
work_keys_str_mv AT mohamedelerian experimentalandnumericalmodellingofdeepseamininggeneratedturbiditycurrents
AT ceesvanrhee experimentalandnumericalmodellingofdeepseamininggeneratedturbiditycurrents
AT rudyhelmons experimentalandnumericalmodellingofdeepseamininggeneratedturbiditycurrents