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1

Study on the three-phase flow of the water transfer export elbow of natural gas hydrate

Chen Wei, Xu Hai-Liang, Wu Bo, Yang Fang-Qiong

Archives of Mining Sciences

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2022

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Vol. 67, no. 2

239--258

EN

The Euler multiphase flow and population equilibrium model were used to simulate the three-phase flow field in the bubble expansion stage of the outlet curved pipe section. The influence of the ratio of the bending diameter and the volume fraction of the gas phase on the pressure loss is revealed, and the safety range of the optimum bending diameter ratio and the volume fraction of the outlet gas phase is determined. The results show that the three-phase flow in the tube is more uniformly distributed in the vertical stage, and when the pipe is curved, the liquid-phase close to the pipe wall gathers along the pipe flank to the outside of the pipe, the solid phase is transferred along the pipe flank to the inside of the pipe, and the gas phase shrinks along the pipe flank to the inner centre. The maximum speed of each phase of the three-phase flow in the elbow is at the wall of the tube from 45° to 60° inside the elbow, and the distribution law along the axial direction of the pipe is about the same as the distribution law of volume fraction. The pressure loss of the elbow decreases with the increase of the bend diameter ratio, when the bend diameter ratio increases to 6, the pressure loss of the pipe decreases sharply, and the pressure loss decreases slowly with the increase of the bend diameter ratio. When the gas phase volume score in the elbow reaches 70%, there will be an obvious wall separation phenomenon, to keep the system in a stable working state and prevent blowout, the gas phase volume score should be controlled within 60%.

2

Chemical and morphological characterization of polymetallic (Mn-Fe) nodules from the Clarion-Clipperton Zone in the Pacific Ocean

Kozłowska-Roman Agata, Mikulski Stanisław

Geological Quarterly

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2021

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Vol. 65, No. 4

art. no. 57

EN

Geochemical studies (WD-XRF, ICP-MS, and GF-AAS) have shown that polymetallic nodules from the eastern Clarion-Clipperton Zone (CCZ) in the Pacific Ocean are enriched in several metals such as Cu (mean 1.16%), Ni (1.15%), Co (0.15%), and Zn (0.14%), as well as remarkable contents of Mo (0.059%), V (0.04%), Ce (0.019%), Nd (0.011%), Li (0.015), and Pt (43 ppb). The average content of REE, together with Y and Sc, is 620 ppm. In nodules from the CCZ metal concentrations are often much higher than those reported in nodules from other ocean basins in the world. The bulk-nodule mean value of the Mn/Fe ratio is 5.3, which is characteristic for a mixed (hydrogenetic and diagenetic) origin of the nodules. Microprobe investigation revealed two different chemical compositions of the layers, and ascertained their general metal content. The nodules analyzed are composed mainly of concentric-collomorphic laminae of Mn and Fe (oxy)hydroxides which crystallized around mineral nuclei (e.g., quartz, clay minerals), bioclasts or rock fragments. They are from 3.3 to 7.6 cm in diameter. The chemical and physical properties of the laminae allowed distinction of two genetic types: hydrogenetic and diagenetic. Those formed as a result of hydrogenesis had increased values of Co, Si, Cl and S, while formed diagenetically showed increased levels of Cu, Ni, Mg, Zn and K. These lamina types are characterized by different growth structures, reflectivity, density and Mn/Fe ratios. The ratio of the diagenetic layers to hydrogenetic layers (192/53) in representative polymetallic nodules shows that the nodules of this study are of mixed hydrogenetic-diagenetic type. A mixed genesis was also shown by discriminant diagrams, with these CCZ samples being located at the transition between typical hydrogenetic and diagenetic fields.

3

Dynamic states equations of transport pipeline in deep-sea mining

Sobota Jerzy, Jianxin Xia, Kirichenko Evgeniy

Archives of Mining Sciences

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2021

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Vol. 66, no. 3

385--392

EN

The transport pipeline of lifting the underwater minerals to the surface of the water onto the ship during the movement of the vessel takes in the water a curved deformed shape. Analysis of the state of stability of the pipeline showed that if the flow velocity of fluid in the pipeline exceeds a certain critical value Vkr, then its small random deviations from the equilibrium position may develop into deviations of large amplitude. The cause of instability is the presence of the centrifugal force of the moving fluid mass, which occurs in places of curvature of the axis of the pipeline and seeks to increase this curvature when the ends of the pipeline are fixed. When the critical flow velocity is reached, the internal force factors become unable to compensate for the action of centrifugal force, as a result of that a loss of stability occurs. Equations describing this dynamic state of the pipeline are presented in the article.

4

Metale nieżelazne z dna oceanów - nowe źródło surowców dla Polski?

Paulo Andrzej, Wołkowicz Stanisław

Rudy i Metale Nieżelazne Recykling

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2019

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R. 64, nr 1

3--13

PL

Coraz więcej krajów angażuje się w rozpoznanie dna oceanicznego nie tylko w swej wyłącznej strefie ekonomicznej, ale i na obszarze wód międzynarodowych. W 2018 r. Polska uzyskała prawo do eksploracji Grzbietu Środatlantyckiego (MAR), gdzie spodziewa się odkrycia złóż siarczków polimetalicznych. Wieloletni Program Rozpoznania Geologicznego Dna Oceanów (PRoGeO) otwierający nowe perspektywy zaopatrzenia gospodarki polskiej w surowce mineralne, znajduje się w stadium popularyzacji i konsultacji. Autorzy czują się w obowiązku sprostować niektóre opinie prasowe i przedstawić tradycyjne źródła zaopatrzenia w te metale nieżelazne, które można odkryć w MAR. Omówiono typy złóż występujące w głębinach oceanów, postępy ich badania i stan wykorzystania oraz doświadczenia realizacji podmorskich projektów górniczych. Złoża siarczków polimetalicznych cechują się małymi zasobami i na ogół wysoką zawartością cynku, miedzi i srebra, niekiedy złota. Żaden z kontraktorów pionierskich koncesji głębokowodnych nie podjął dotąd wydobycia, pomimo trwających 15–30 lat prac badawczych, na skutek splotu przeszkód technicznych, ekologicznych i prawnych, które nie zostały dotąd usunięte. Koszty raportowane przez niektóre firmy pionierskie prowadzą do wniosku, że ekscytujący projekt badań dna MAR nie gwarantuje bezpiecznego zaopatrzenia kraju w metale nieżelazne ani nie rokuje jeszcze sukcesu finansowego.

EN

More and more countries are involved in the exploration of the ocean floor not only in their exclusive economic zone but also in the area beyond national jurisdiction. In 2018, Poland obtained the right to explore the Mid-Atlantic Ridge (MAR), where it expects to discover polymetallic sulfide deposits. The long-term Ocean Geological Survey Program (PROGeO) opening new perspectives for supplying the Polish economy with mineral resources is at the stage of popularization and consultation. The authors feel obliged to rectify some press opinions and present traditional sources of supply for such non-ferrous metals that can be found in the MAR. The types of deposits occurring in the depths of the oceans, the progress of their research as well as the state of development and experience of implementation of submarine mining projects were discussed. Polymetallic sulfide deposits are characterized by fairly low resources and generally high content of zinc, copper and silver, sometimes gold. None of the pioneering contractors of deep-sea leases has so far undertaken extraction despite 15-30 years of research work, due to a combination of technical, ecological and legal obstacles that have not yet been resolved. The costs reported by some pioneering companies lead to the conclusion that the exciting project does not guarantee secure supply of the country with non-ferrous metals or promise financial success.