Trace element catalyses mineral replacement reactions and facilitates ore formation

AbstractReaction-induced porosity is a key factor enabling protracted fluid-rock interactions in the Earth’s crust, promoting large-scale mineralogical changes during diagenesis, metamorphism, and ore formation. Here, we show experimentally that the presence of trace amounts of dissolved cerium increases the porosity of hematite (Fe2O3) formed via fluid-induced, redox-independent replacement of magnetite (Fe3O4), thereby increasing the efficiency of coupled magnetite replacement, fluid flow, and element mass transfer. Cerium acts as a catalyst affecting the nucleation and growth of hematite by modifying the Fe2+(aq)/Fe3+(aq) ratio at the reaction interface. Our results demonstrate that trace elements can enhance fluid-mediated mineral replacement reactions, ultimately controlling the kinetics, texture, and composition of fluid-mineral systems. Applied to some of the world’s most valuable orebodies, these results provide new insights into how early formation of extensive magnetite alteration may have preconditioned these ore systems for later enhanced metal accumulation, contributing to their sizes and metal endowment.

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EFFECTS OF CHEMICAL REACTION ON THIRD-GRADE MHD FLUID FLOW UNDER THE INFLUENCE OF HEAT AND MASS TRANSFER WITH VARIABLE REACTIVE INDEX

Heat Transfer Research ◽

10.1615/heattransres.2018028397 ◽

2019 ◽

Vol 50 (11) ◽

pp. 1061-1080 ◽

Cited By ~ 13

Author(s):

Ambreen Afsar Khan ◽

Syeda Rida Bukhari ◽

Marin Marin ◽

Rahmat Ellahi

Keyword(s):

Mass Transfer ◽

Fluid Flow ◽

Heat And Mass Transfer ◽

Chemical Reaction ◽

Third Grade

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COUPLED HEAT AND MASS TRANSFER IN FLUID FLOW THROUGH POROUS MEDIA - AN ANALOGY WITH HEAT TRANSFER

10.1615/ihtc4.1150 ◽

1970 ◽

Cited By ~ 1

Author(s):

P.J. Banks ◽

D.J. Close ◽

I.L. Maclaine-cross

Keyword(s):

Heat Transfer ◽

Mass Transfer ◽

Porous Media ◽

Fluid Flow ◽

Heat And Mass Transfer ◽

Flow Through Porous Media ◽

Flow Through

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Going the Distance

10.23943/princeton/9780691150772.001.0001 ◽

2020 ◽

Author(s):

Ron Harris

Keyword(s):

Large Scale ◽

Western Europe ◽

Family Firms ◽

Global Trade ◽

Long Distance ◽

Business Corporation ◽

Modern Economy ◽

Key Factor ◽

Silk Route ◽

Passive Investors

Before the seventeenth century, trade across Eurasia was mostly conducted in short segments along the Silk Route and Indian Ocean. Business was organized in family firms, merchant networks, and state-owned enterprises, and dominated by Chinese, Indian, and Arabic traders. However, around 1600 the first two joint-stock corporations, the English and Dutch East India Companies, were established. This book tells the story of overland and maritime trade without Europeans, of European Cape Route trade without corporations, and of how new, large-scale, and impersonal organizations arose in Europe to control long-distance trade for more than three centuries. It shows that by 1700, the scene and methods for global trade had dramatically changed: Dutch and English merchants shepherded goods directly from China and India to northwestern Europe. To understand this transformation, the book compares the organizational forms used in four major regions: China, India, the Middle East, and Western Europe. The English and Dutch were the last to leap into Eurasian trade, and they innovated in order to compete. They raised capital from passive investors through impersonal stock markets and their joint-stock corporations deployed more capital, ships, and agents to deliver goods from their origins to consumers. The book explores the history behind a cornerstone of the modern economy, and how this organizational revolution contributed to the formation of global trade and the creation of the business corporation as a key factor in Europe's economic rise.

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BASINAL FLUID FLOW THROUGH THE CHALK GROUP IN THE SOUTHERN DANISH CENTRAL GRABEN AS SEEN ON 3D SEISMIC DATA – ANCIENT EXAMPLES OF LARGE SCALE FLUID SEEPAGES

10.1130/abs/2017cd-292534 ◽

2017 ◽

Author(s):

Florian W.H. Smit ◽

◽

Frans S.P. Van Buchem ◽

Jesper H. Holst ◽

Mikael Lüthje ◽

...

Keyword(s):

Fluid Flow ◽

Seismic Data ◽

Large Scale ◽

3D Seismic ◽

Flow Through ◽

3D Seismic Data

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Mass transfer in heterogeneous system enzyme-substrate; Approximate analytical model for the case of liquid substrate-immobilized enzyme

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19823013 ◽

1982 ◽

Vol 47 (11) ◽

pp. 3013-3018

Author(s):

František Kaštánek ◽

Jindřich Zahradník ◽

Germanico Ocampo

Keyword(s):

Mass Transfer ◽

Heterogeneous System ◽

Immobilized Enzyme ◽

Enzymatic Reaction ◽

Analytical Form ◽

Approximate Model ◽

Basic Type ◽

Reaction Interface ◽

Enzyme Substrate ◽

Flow Intensity

Calculation procedure is suggested for flow intensity of substrate toward reaction interface of immobilized enzyme at simultaneous effect of enzymatic reaction and internal diffusion. The approximate model is presented in an analytical form for the basic type of Michaelis-Menten kinetics and for the case of inhibition in excess of substrate.

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