Geoscience Reference
In-Depth Information
Table 1.3 Action of Hydrothermal Fluid (High-Temperature and High-Pressure Aqueous
Solution/Vapor) on Solid-State Materials
S. No Classified
Action
Application
1.
Transfer
medium
Transfer of kinetic
energy, heat and
pressure forming, etc.
Erosion, machining abrasion, HIP
2.
Adsorbate
Adsorption/desorption at
the surface
Dispersion, surface diffusion,
catalyst, crystallization, sintering,
ion exchange, etc.
3.
Solvent
Dissolution/precipitation
Synthesis, growth, purification,
extraction, modification, degradation,
etching, corrosion, etc.
4.
Reactant
Reaction
Formation/decomposition (hydrates,
hydroxides, oxides), corrosion, etc.
Figure 1.1 Action of hydrothermal
fluid on solid substances
[21]
.
High-temperature-high-pressure solution/vapor
2. Adsorbate/Adsorbent
1. P, T medium
(mechanical energy
transfer medium)
H
2
O
(reaction accelerator,
catalyzer)
H
H
HH
HIP
OO
H
OO
M
M
O
H
M
OO
M
M
OOO
M
M
3. Solvent
4. Reagent/Reactant
(dissolution,
precipitation)
(hydration,
hydrolysis, etc.)
HH
OH
M
OH
M
OH
O
H
H
H
OH
M
M
OH
M
O
M
O
H
OH
M
OH
M
OH
O
HH
temperature, and hence the size of the crystals or minerals obtained in all the early
hydrothermal experiments of the nineteenth century did not exceed thousandths or
hundredths of a millimeter. Therefore, the search for other suitable mineralizers
began in the nineteenth century itself. A variety of aqueous and nonaqueous solu-
tions were tried to suit the preparation of a particular compound
[29]
. The selection
of the mineralizers and their role in hydrothermal systems with suitable examples
