Key Engineering Materials
ISSN: 1662-9795, Vols. 336-338, pp 1918-1920
doi:10.4028/www.scientific.net/KEM.336-338.1918
© 2007 Trans Tech Publications, Switzerland
Online: 2007-04-15
Practice of Simulation to Formation of Rock Theory
Feng Xiangpeng, Sun Henghu∗ and Liu Xiaoming
Department of Materials Science and Engineering, State Key Lab of New Ceramics and Fine
Processing, Tsinghua University, Beijing 100084, People’s Republic of China
Keywords: sialite technology, simulation to formation of rock, rock-forming liquid, corroding-welding
Abstract. The utilization of industrial solid wastes as building materials has been thought of as the best
way to solve the problems caused by high waste production, high resource consumption and high
pollution that is inherent with the primary industries of China. However, due to the low level of usage by
previous technologies, these serious problems of the primary industries still persist. Hence, it is urgent to
seek an effective way to solve these problems. In this paper, based on the understanding of the theory of
simulation to formation of rock and the research advances of sialite technology, it is concluded that sialite
technology can achieve the effective usage of industrial solid wastes.
Introduction
The rapid development of the economy has effectively prompts the growth of primary industries.
However, the ensuing problems such as the high exhaustion of energy and resource, along with the
massive discharge of wastes and the pollution of the environment have seriously exacerbated the
dilemma between “demand” and “protection” during the process of social development. Hence, it has
become crucial to create a positive cycle among resource, energy and environment in order to get
better economic developments. Due to the intrinsic commonness between industrial solid wastes and
construction materials, the utilization of the former to produce the latter has become the most
prospective approach for solving those problems [1].
Inspiration from the Formation of Igneous Rock
The formation of volcaniclastic rock can be divided into two steps. First, sialic clay is spew out from
the stratum by the volcanic eruption, which dehydrates through the intense heat to form debris at a
metastable state. Then these various kinds of volcanic debris would be transformed into rocks through
various geological means. The fact that volcanic debris can turn into rocks naturally over a hundred
million years of geological change indicates that the formation of rocks from metastable materials is
feasible according to thermodynamics. Remarkably, many kinds of high-temperature solid wastes
from industrial processes are just like magma; they have stored abundance energy in the course of
production. In fact, many industrial processes unconsciously replicates the natural formation of pozzolana, by making various kinds of artificial “pozzolana” that are commonly considered as “wastes”.
Inspiration from the Formation of Sedimentary Rock
Conglomerate is a type of the clastic sedimentary rock, which is formed by the existing rocks in the
earth’s crust through three steps: first, the rocks undergo physical processes, chemical changes, and
weathering; then they are corroded, moved and deposited under various conditions; finally, by
concretion and diagenesis under normal temperature and pressure, the rocks are cemented by
noncrystalline or cryptocrystalline materials. Conglomerate is almost identical to modern concrete in
their macrostructures (Fig.1). Based solely on appearance, one can even consider natural conglomerate as “natural concrete.” Fig. 2 displays a cross-sectional view of a piece of conglomerate. Hence,
based on the theory of simulation to formation of rock, it is feasible to model the natural rock-forma∗
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Key Engineering Materials Vols. 336-338
Fig. 1 Comparison of the concrete (left) and
conglomerate (right)
1919
Fig. 2 Corrosion phenomenon of the large
diameter gravel in the conglomerate
tion at normal temperature and pressure. However, the rock-forming process requires an extended
period of time. Thus, finding a method to accelerate the transformation from solid waste to stone so as
to shorten the rock-forming process becomes a key matter to realize rock-formation simulation.
Synergistic Effect of Rock-Forming Liquid
Through systematic and comprehensive research into the characteristics of diagenetic liquids and by
deep mathematical analysis, we recognize the synergistic effect of all kinds of compositions within
the diagenetic liquid. This synergistic effect can magnify the diagenetic liquid’s reaction ability with
respect to silicate minerals thousands or even millions of times. Thereby, the latent chemical activity
of the minerals will unleash easily. By artificially manufacturing various kinds of diagenetic liquid,
sialite technology has utilized this powerful effect to release the potential energy stored up in hightemperature solid wastes. Under the effect of diagenetic liquid, silicate grains are bonded together,
creating non-crystal or microcrystalline silicate network structures similar to that of conglomerate.
Principle of Simulation to Formation of Rock
The durability of ancient architectures is blessed in the fact that the hydrates of the cementitious
material used were rock-forming minerals. Therefore, we can model the process of natural rockformation by analyzing rock-forming principles and causes. In addition, it is theorized in geology that
the rocks in earth’s crust are constantly undergoing changes due various geological forces, much alike
how industrial solid wastes are produced. Hence, under the guidance of "dualization,” it is feasible to
transform solid wastes to stone at normal temperature and pressure in a shortened period of time [2].
"Melt-state transformation" of high-temperature solid wastes replicate the formation of rock from
“superheated magma"; "granulated-microcrystalization" is the process of creating unstable crystalline
substances by rapidly cooling the molten materials, which models the natural “formation of
pozzolana”. The concept of "Dualization" is used to optimize proportioning of raw materials, to
unleash their latent energy, and to control of performance, cost and environmental benefits; this is an
imitation of the natural "weathering and erosion /denudation and separation"; "Petrifaction of sialite”
imitates natural "sedimentation". Crystalline sialite is a type cementitious material created with
mainly industrial solid wastes; it turns into stone at normal temperature and pressure in a shortened
period time, making sialite a realization of rock-geosimulation theory. The rock-forming process and
the transformation in type and lithology of the rocks produced are lasting processes that relate both to
the chemical and mineral compositions of pozzolana and the rock-forming environment. This
two-part basis inherent in nature provides an inspiration for the concept of “dualization” in both
proportioning and clean production of sialite technology. In summary, sialite concrete is produced by
combining crystalline solid wastes with diagenetic liquid to form a of type artificial conglomerate at
normal temperature and pressure.
Microstructure Analysis of Conglomerate and Concrete
Figs. 3, 4, and 5 are the SEM micrographs and energy spectra of natural conglomerate, sialite concrete
and traditional concrete (A: aggregate particles, B: cementitious material). Fig. 3 shows the macro-
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High-Performance Ceramics IV
Fig.3 SEM image and energy
spectrum of natural conglomerate
Fig 4 Sialite Concrete’s SEM
image and energy spectrum
Fig.5 SEM image and energy
spectrum of cement concrete
scopic view of a piece of conglomerate, while Fig. 4 displays the corresponding SEM micrograph and
energy spectra. As one can see from the macroscopic view, some of the larger aggregate particles in
the conglomerate have already been corroded and that the parts that have been corroded away have
already been filled with particles of greater corrosion resistance. The aggregate particles and cementing materials in Fig. 3 are compacted in a “corroding-welding” structure. The energy spectrum shows
aluminosilicate compounds as the cementitious materials in natural conglomerate. These aluminosilicate compounds have a structure that can regenerate itself after dissociation. This explains why
during the process of rock formation, the cementitious materials can dissolve and re-crystallize in
order to bond with the larger aggregate grains and to fill up any empty voids. Therefore, the natural
formation of conglomerate does not actually involve the process of cementation, but relies on the
diagenetic admixture to dissociate and re-crystallize grains of aluminosilicate minerals, which is
similar to the welding process in the steel industry. Comparing Figs. 3 and 4, we can see that the
aggregate particles (ie. stones) and the sialite have tightly bonded together through a “corrodingwelding” structure, which is similar to the natural conglomerate. From the energy spectra, two conclusions can be drawn. First, although calcium element is present in sialite, but its content is lower when
compared to that of Portland cement. Second, sialite is an aluminosilicate material, which is similar
the element composition of earth’s crust. Different from natural conglomerate and sialite, conventional cement concrete (shown in Fig.5) has no chemical or structural bonds between the cement and
aggregate. Instead, the cement simply “wraps” around the aggregate particles; there are obvious gaps
between the two bodies, which result in a loose connection. Furthermore, different from natural rocks
and the high aluminosilicate content of sialite, Portland cement has a large proportion of calcium
element, making it into a high-calcium containing material, which does not match the proportioning
of elements in earth’s crust. This is the reason why conventional concrete has poor durability.
Hence, the grains of conglomerate are tightly “welded” together with aluminosilicate minerals
through the Si-O covalent bonds. This type of bonding is intrinsically different from that of the
Portland cement, which works by “wrapping” aggregate particles using C-S-H gel and then “gluing”
them together with Van der Waals force. Similar to natural conglomerate, in sialite concrete, the
structure formed by cementitious materials and aggregate particles is also in the form of “corrodingwelding”, which is formed by covalent bonds.
Results
Instead of the high polluting, energy exhaustive “twice milling and once cremation” technique of
Portland cement, sialite’s “once milling” technique allows its production process to be almost
pollution free. Furthermore, sialite can consume large amounts of solid wastes and the concrete
produced with it possesses better integrated qualities than cement concrete. Hence, the actualization
of sialite technology will play a significant role in the following aspects: protection of resources,
energy supplies, and the natural environment.
References
[1] H. Sun, Y. Li: Rare Metal Mater. Eng. Vol. 33 [Suppl. 2] (2004), pp. 32.
[2] H. Sun, H. Li: Rare Metal Mater. Eng. Vol. 33 [Suppl. 2] (2004), pp. 105.
High-Performance Ceramics IV
10.4028/www.scientific.net/KEM.336-338
Practice of Simulation to Formation of Rock Theory
10.4028/www.scientific.net/KEM.336-338.1918