FR2539146A1 - Mineral concretioning of structures, components and structural elements - Google Patents

Abstract

In accordance with the invention a direct electrical current is established between electrodes in an electrolyte such as seawater, calcium carbonates, magnesium hydroxides and hydrogen precipitate at the cathode while oxygen and chlorine are obtained at the anode. The electrodeposition of minerals and the natural deposits of organic matter or of matter of organic origin are employed for coating, constructing or upgrading structures, components or structural members, by deposition of a relatively soft matter (crushing strength of 0 to 68 kg/cm<2>). To deposit the minerals on a structure or on a component or structural element, a substrate consisting of an electrically conductive material is placed in an electrolyte bath, such as seawater, to act as a cathode; one or more anodes are arranged near the cathode, and a direct electrical current is passed between the electrodes for a sufficiently long period of time to form the desired mineral layer.

Description

Mineral concreting of structures, components and construction elements.

The present invention relates generally to construction materials and methods; it relates more particularly to the electrodeposition of minerals in order to constitute a material of relatively soft consistency (compressive strength of 0-68 kg / cm2) suitable for serving as a building material for structures, components, or elements. Mineral deposits can also be used as protection to prevent bio-fouling, oxidation and chemical attack of structures, components or building elements. In other applications,) mineral deposits can serve as a support for the growth of marine vegetation, on artificial reefs for example.

Seawater contains nine major elements: sodium, magnesium, calcium, potassium, strontium, chlorine, sulfur, bromine and earbone. These elements contain more than 99.9% of the salts dissolved in the sea (see Millinan, Marine Carbonates,
Springer-Verlag, NY, 1974; Sedrup, Les Océanes: their physics, chemistry and general biology, Prentiss-Hall,
Inc. NJ 1942 and Cucklin & Goldberg, Vol. I, Chemical oceanography, p. 121-196, Academic Press, London).

The constancy of rates between major dementias, in all oceans, has long been well known (Dittmar, Challenger Reports, Physics and Chemistry, pp. 1-252, 1884).

Lower marine organisms use the dissolved minerals that surround them to form structural formations. Mollusc shells, for example, are generally made up of calcium carbonate crystals enclosed in an organic matrix. A significant proportion of soluble matrix protein is created following a repetitive cycle involving the separation of aspartic acid, either by glycine or serine (see Jope, Vol. 26, Ensemble Biochimie, p. 749, Elsevier, Amsterdam, 1971). This sequence, involving the regular repetition of negative charges, can fix Ca2 and ions, and thus perform an important function in the mineralization of the support (Weiner and Hood,
Volume 190, Science, p. 987-989, 1975).

According to the principle of the present invention, a relatively soft material, suitable for use in the construction, enhancement, and protection of structures, elements or building components, is obtained by agglutination created by the electrodeposition of the materials. materials on a pre-formed support immersed in an electrolytic medium. Preferably, the electrolyte will be sea water or salt water, having a chemical composition making it possible to constitute the material which consists mainly of calcium carbonates and brucite.

However, any liquid containing minerals can be used.

Still according to the principle of the present invention, it is possible to produce a structure, a component, or a construction element made of a relatively soft material by placing a support composed, at least partially, of an electrically conductive material Osse and having the configuration general of the structure, of the component, or of the building element, in an electrolyte volume, said support serving as a cathode, and by placing an anode in the electrolyte close to the rough shape, and in then establishing a direct electric current between the electrodes.

In order for material to deposit on most structures, components or building elements, the electric current density must be greater than 3 amps per m2 of cathode area, with an electric field potential between the electrodes of up to 20,000 volts.

Finally, in accordance with the present invention, there is a method making it possible to constitute a structure, a component, or a construction element, by placing a rough shape in a volume of electrolyte, this support serving as a cathode, and by placing an anode in the vicinity of the rough shape, and then establishing a continuous electric current between the cathode and the anode for a period of time long enough to deposit on the shape - or fill it - with a structural material of relatively soft consistency .

The more time passes, the more this relatively soft material hardens, reaching a compressive strength of over 100 kg / cm2. In the event of failure, the structure, component or construction element can be repaired by a new application of electric current.

A more complete appreciation of the invention can be obtained by referring to the accompanying drawings.
Figure 1: this figure represents a qualitative model
theoretical with regard to the processes
electro-mechanical involved in depots
of minerals.

Figures 2 and 3 show a support form used
for the construction of an artificial reef.

Figures 4 and 5 represent the coating and the mineral
sation of a wooden pillar.

A. General discussion
The oceans contain great resources of matter in solution, acting as links in the perpetual and vital cycle of exchange between the continents and the sea. Every year, rivers discharge 2.73 x 109 metric tons of freshly dissolved solids into the sea. In the 70.8% of the earth's surface covered with water, there are more than 60 x 1024 tonnes of mineral resources (Wenk, E. Jr.

"Physical Resources of the Oceans", Oceans, W.H.

Freeman and Co., 1969).

Aside from oxygen and hydrogen, one cubic mile of seawater contains:
Chlorine 89,500,000 t
Sodium 49,500,000 t
Magnesium 6,125,000 t
Suffers 1,880,000 t
Calcium 1,790,000 t
Potassium 7,609,000 t
Bromine 706,000 t
Carbon 132,000 t and 51 other minerals and elements.

The use of processes identical to those manifested in the structural mechanisms of living organisms and non-living environments, such as caves, produces mineral deposition technology that involves the deposition and calcification of minerals in solution for structural purposes. For example, by the electrolytic process (diagenesis), and then by the biological phase (biogenesis), unstructured materials are deposited by electrolysis on conductive forms and chemically transformed by biological organisms into materials with structural capacities.

The deposition and calcification of minerals in the environment is made possible by the fact that the medium in which they are suspended, in this case water, is an ampholyte - a substance which can behave like an acid or as a base - which makes it the universal solvent. This unique quality is illustrated much more simply by the structural and destruetural system of the caves. When water contains carbon dioxide, which combines with water to produce carbonic acid, matter is dissolved. When carbon dioxide is released, water becomes a base and matter precipitates to form stalactites and stalagmites. Identical non-living processes occur throughout the environment following cycles of shifting and shifting. reprise.

Electrolytic processes can be used to selectively precipitate material on suitable surfaces.

A certain electrical potential between electrodes will cause negative ions to deposit on the anode and positive ions to deposit on the cathode. During the electrodeposition process, there are three modes in which material can potentially be deposited on the cathode.
1. Concentration gradients
2. Ionic attraction, and
3 Electrical migration
Although concentration gradients are the most likely to cause deposition, the combinations of the three methods cannot be ruled out. The basic principle of electrochemical reactions is shown in sorted simplified form in FIG. 1. In FIG, 1, the reetangular boxes represent either the mineral compounds precipitated from a solution by the above methods, or the ga? released,
The arrows represent the course of the reactions according to the activity profile.

In addition to attracting ions, the electrolysis of seawater produces heat on the surfaces of the electrodes. It is on these surfaces that the resistance is greatest; the temperature is therefore higher, and the PH increases.

First, thermal decomposition removes carbonic acid (H2CO3) which allows carbon dioxide (CO2) to be released, causing the carbonate - hydrogen balance to tilt towards the carbonate side. The increase in the carbonate concentration, combined with the increase in temperature and salinity, increases the ionic production of calcium carbonate crystals, and initiates precipitation. However, as the solution becomes more alkaline (has a PH greater than A 9), the ionic production of brucite (Mg (OH) 2) exceeds the solubility product and brucite, as well as carbonates, precipitate. . In this case, structural development would be inhibited.It is also possible that the amorphous material enveloping the cathode, as well as the presence of other crystals such as phosphates, hydroxides, or sodium carbonate, inhibit the precipitation of caleium carbonate and prevent the crystals that form from continuing to grow.

It appears, by X-ray diffraction tests and by chemical titration analysis. that the largest percentage of material formed is constituted by brucite. It is found in two of its three distinct forms: plate / or foliate form, and massive form. Brucite, in its foliated form, is harder than talc or gypsum, and is not elastic. In its massive form, it has a soapy appearance. It is possible that a small percentage of the composition is CA portlandite (0H2), which is isostructural with brucite. The rapid precipitation of compounds from seawater usually gives brucite as a massive material.An essential factor in the removal of Mg2 + as Mg (OH) 2 is the pressure reduction of CO2 increases. up to the normal value, thus lowering the PH, Mg (EO) 2 becomes MgCO3. In addition, MgCO3 crystallizes in the nuclei - available, that is to. say aragonite and calcite.

B. electroderosition of minerals on structures, comno-
health and construction elements.

To illustrate the use of mineral electroplating for the construction or enhancement and embedding of structures, components and building elements, we will give an example involving cathode surfaces. As used herein, the term "relatively soft material" refers to a material having a compressive strength of 0 - 68-kg / cm 2.

FIGS. 2 and 3 represent, in plan and in elevation respectively, a pre-formed element 10, made in an accordion shape and which constitutes an artificial reef. The read form consists of a wire mesh, with steel, iron and carbon (2U) rods, which are connected to the wire mesh. Its dimensions are 20 m in width and 60 m in length. It is laid out on the bottom, but could also be floating. 30 is an electric cable connecting the structure to the negative terminal of a direct current source. 40 is a floating anode held by an anchor line 50, and retained by a float 60. 70 is an anode placed on a wooden or plastic stake (80) driven into the seabed.

90 is the electric cable connecting the anodes to the positive terminal of a direct current source. 100 are the cable connections to the anodes and the cathode. the anodes can be carbon, graphite, platinum, colombium, lead, tantalum, and other conductive materials.

To ensure that minerals naturally present in seawater and with an initial compressive strength of 0 - 68 kg / cm2 are deposited on this structure 10, an electric field potential of between 0.3 and 20,000 volts, with a current density of 33,000 A / m2 cathode surface A specific current density can be chosen to deposit relatively soft non-structural minerals over a period of months, weeks, or days. When the electric current is interrupted, matter hardens and becomes structural Biological materials can become established on and in the deposited minerals, and can change their chemical and structural properties In the event of chemical or physical damage to the mineral layers removed, the restoration of the electric current makes it possible to repair the cracks and to replace the losses of material. Electrical resistivity is lower at damaged areas; the exposed cathode metal attracts more minerals than the metal. covered with minerals. In order to deposit a uniform layer of minerals, or so as to selectively obtain thicker layers of minerals deposited on the support (10), the anodes (60) and (70) can be moved and placed in various locations
Figures 4 and 5 give a second example of a deposit of minerals producing a relatively soft mineral material.

A wooden or metal stake (10) is covered with an electrically conductive material consisting of a wire mesh or carbon fiber (20). The conductive material and rel.é, via an electric cable (30), to the negative terminal of a direct current source, thus constituting a cathode. Near the cathode, one or more anodes (40) are placed, connected by a cable to a positive terminal of a direct current source.

To electrochemically precipitate minerals with an initial compressive strength of 0 - 68 kg / cm 2 on the cathode, an electric field potential of between 0.3 and 20,000 volts can be established with a density of. current of 3 - 3000 A / m2 of cathode surface. You can choose a specific current density to deposit a relatively soft mineral layer that will harden over time. Once the mineral layer has been deposited, the cables (30) and (50) can be removed, as well as the anode (40).

The two examples above describe an electrochemical and chemical process for depositing minerals on cathode materials.

However, these mineral layers also confer. corrosion protection by being alkaline and preventing the access of oxygen to this mistletoe which was previously the cathode. In addition, in the example given from 4 and 5, it is assumed that the deposited minerals will mineralize the outer perimeter of the wood and fill the holes in the boreholes and other voids due to organisms attacking the wood.

The minerals envelop the wooden stake from a level below the slime mark to the medium high water mark, producing an alkaline medium in the wood itself and acting as a barrier preventing attack on the stake by marine organisms.

In the event that the mineral deposit is made on a new plet treated with chemicals such as creosote or other toxic substances, the mineral shell will prevent the leaching of these chemicals, thus protecting the wood stake.

Once the mineral deposit is complete on the cathode, marine organisms can attach themselves to and in the electrolytically deposited material. By transforming the. From cathode to anode, chlorine gas is produced which can be used to kill biological materials in and on deposited minerals.

C. Specific applications.

The mineral deposition process has the potential to contribute significantly to solving huge engineering problems that will be encountered in the oceans such as the construction of Thermal Energy Conversion plants.
Oceanic (CETO). It is obvious, for example, that the use of traditional building materials such as steel, reinforced concrete with fiberglass, plastics, and steel for tubes for the realization of the pipes of cold water supply of the CETO plants will incur enormous costs as the circuits will have to be over-dimensioned in order to take into account unknown or only vaguely defined parameters.

In contrast, a relatively light aquadynamic cathode ray tube configuration allowing the assembly of the plant on site can be subjected to a selective mineral deposit so as to effectively withstand unpredictable and changing forces (change in the configuration of ocean currents for example. ).

In the event of a slow attack or sudden damage to the wall, the tube can be repaired by placing an anode in the vicinity of the damaged part, which facilitates, for example, the cementation of cracks, the replacement of the lost material, and the reinforcement of previously deposited mineral layers.

Another foreseeable field of application relates to the construction and maintenance of mariculture facilities. It is possible to build, maintain and repair fixed or mobile artificial reefs through the mineral deposition process. These structures can last a very long time in water; the electro-deposited materials are stable in aqueous medium.

D. Advantages of mineral deposition technology.

Shaped construction methods, as used today, have inherent limitations.

Examples: A concrete or steel element submerged in seawater becomes useless once broken or degraded because it cannot meet its basic specifications if it is not repaired. In most cases, the repair requires the removal of the element and its re-installation on site, which entails very high costs.

On the other hand, a structural element produced by the electroplating of minerals can be repaired or reconditioned on site after damage. By reapplying the electric current we can recreate the same conditions and reuse the same resources as those initially used to create the element. This characteristic is not found in commonly used construction methods or materials.

When, for example, a reinforced concrete structure is taken and leaves its formwork, its characteristics initiate.

and structural can only be changed by major works. Therefore, this places strict limits on the adaptability of the element to varying conditions.

The applications of the electrochemical mineral deport process are obvious: floating habitats and industrial islands by the use of waste clay, sand, gravel, or water as a building material, stabilized by mineral deposit, sitting on the banks, mountains. marine, and continental shelf, mariculture facilities, submerged storage boxes, dams and jetties, pipelines, bridges, tunnels, airport runways, artificial beaches, sea walls, current diversion, construction elements for land use, reefs man-made, hulls of ships and barges, installations for marinas, closure of atolls, anchoring points, energy converters of currents, observation and research installations, buoys, docks, protective coating for wooden pillars, bulkheads , structures, components and elements for land use etc ... protection and enhancement of structures, construction elements and elements using electro-deposited minerals relatively soft and which will harden over time to a material having structural integrity for explanatory and illustrative purposes.

It should be understood, however, that many modifications and changes to the product or article and my method of making can be made for the practice and use of the present invention, without departing from the idea to use. minerals deposited by electrolysis. For example, it is envisioned to use preformed elements made of solid materials rather than mesh. It is also envisaged to produce: pre-formed structures with structural sub-elements such as steel reinforcing bars.

Claims (27)

Claims 1. A process for the construction, the covering or the development of structures, for the realization of components or elements of construction, which consists in putting in place a preformed support comprising surfaces internal and external in an electrolyte, the said support serving as a cathode. place an anode in the nearby electrolyte prd-formd support. establish a continuous electric current between the cathode and the anode for a sufficient time to carry out the deposit of a solid mass of relatively soft mineral matter by electrolysis around the support and cover the internal and external facea according to a desired thickness, so that the support is embedded in the material thus filed. 2. The method according to claim 1, characterized in that the potential of the electric field between the electrodes is 0.3 - 20,000 volts. 3. The method of claim 1, characterized in that the density of the electric current is more than 3 Amps per m2 of cathode surface. 4. The method of claim 1, characterized in that the electrolyte is a liquid containing minerals. 5. The method of claim 1, characterized cn that the pre-formed support is at least partially made of an electrically conductive material. 6. A structure, element, or building component, consisting in part of a relatively soft material obtained by - arranging a support formed according to the configuration desired for the structure, element or component of construction, and whose internal and external surfaces are immersed in an electrolytic bath, the said support serving as cathode. that the support is embedded in it. until the desired thickness is obtained, so shaped and covers internal and external surfaces electrolytically deposited strip, which envelops the support hard enough to attract a mass of mined material the shaped cathode support and the anode for a proximity to the shaped support, and - by circulating a continuous electric current between - placing one or more anodes in the electrolyte, Q ' 7. The object of claim 6, wherein the support is at least partially made of an electrically conductive material. 8. A structure, element or building component of relatively soft consistency obtained by - placing a support of non-structural material formed according to the desired configuration for the structure, the element o the building component, in an electrolyte volume, and serving as a cathode. electrodes. electric field of 0.3 - 20,000 Volts between at 3 amps per m2 of cathode surface, with a potential desired, the electric current having a higher density internal and external faces until the thickness is obtained soft tissue deposited by electrolysis covering the on concretion of a solid mass of relative mineral matter electrodes for a sufficient period of time to obtain the shaped port - passing a continuous electric current between - having an anode in the electrolyte near the sup 9. A process for the construction of structures, elements or building components, and comprising depositing a relatively soft material on a preform support having internal and external surfaces by electrodeposition of minerals, the deposited material covering the internal and external surfaces. until the desired thickness is obtained. 10. A process for the construction of structures, elements or building components, comprising covering a preformed non-structural support having internal and external surfaces with a relatively soft material by means of an electroplating process, the internal surfaces. and the exterior of the support being covered until the desired thickness is obtained. 11. A process for the construction of structures, elements or building components, consisting in covering a pre-formed non-structural support having internal and external surfaces, with a hard and resistant material, of high structural integrity, obtained by - placing the support in a volume of electrolyte, the said cathode holder - placing an anode in the electrolyte, close to the support - passing a continuous electric current between the cathode and anode for a period sufficient to deposit the solid material cover on the faces internal and external support. 12. A process for the construction of structures, elements and building components, comprising - placing a support having internal and external surfaces. dull in a volume of electrolyte, the said support serving as a cathode - place an anode in the electrolyte t near the support preformed, and - to pass an electric current between the cathode and the anode, for a period sufficient to make deposit a layer of relatively soft material on the internal and external surfaces of the holder - interrupt the electric current between the cathode and the anode for a certain period of time - restore direct electric current between the cathode and the anode. 13.. The method defined in 12, in which the sequence of interrupting the current between the cathode and the anode 9 and the reestablishment of the current between the cathode and the anode, is repeated multiple times until a layer of material deposits a solid of the desired thickness and composition on the external and internal surfaces of the support 14. A method for the construction of structures, elements and building components, consisting in - placing a support with internal and external surfaces in a volume of electrolyte, the said form serving as an electrolyte - placing a second electrode in the electrolyte, a pro7. and external support. solid mineral of desired thickness on internal surfaces between the electrodes, in order to obtain the deposit of a mass between the electrodes, in the opposite direction, and - restore the initial polarity of the electric current contir ' electrodes to establish a continuous electric current one way, for a while - reverse the polarity of the electric current between the mity of the support - establish a continuous electric current between the electre 15. A process for the construction of structures; construction elements or components, consisting of - placing a support with internal and external surfaces in a volume of electrolyte, said support serving cathode - place an anode in the electrolyte near the support - establish a direct electric current between the cathode and anode, and - vary the electric current density to make deposit a solid layer of thick mineral matter desired strength and composition on external surfaces and internal support. 16. A process for the construction of building structures, elements or components, consisting in - placing a support with internal and external surfaces in a volume of electrolyte, the said support serving as a cathode - placing an anode in the electrolyte near the support establishing a direct electric current between a cathode and the anode in order to obtain a mineral deposit with a resistance compression from 0 to 68 kg / cm2 - interrupt the electric current - hardening of the material over time, in order to obtain a minimum compressive strength of 100 kg / cm2 17. A process for enveloping and mineralizing construction structures, elements and components, comprising: placing a support having internal surfaces and external in a volume of electrolyte, the said support serving as cathode - place an anode in the electrolyte n near the support - establish a direct electric current between a cathode e + the anode in order to obtain a mineral coating of a resistance has a compression of 0 to 68kg / cm2, which will also allow to mineralize the outer layer of an bob structures, components and construction elements, and to complete the voids created in wood by living organisms or by chemical or physical attacks - interrupt the electric current - allow the material to harden over time in order to obtain a compressive strength of 10C kg / cm2 minimum. 18. A process for repairing and maintaining construction structures, elements and components, including: - placing a support having internal surfaces and external in a volume of electrolyte, the said support serving as a cathode - place an anode in the electrolyte near the support - establish a continuous electric current between the cathode and the anode - interrupt the electric current - in the event of subsequent damage to the deposited minerals: tdta electric current to replace matter lost or to fill voids or cracks. 19. A process for killing organisms residing in and on deposited material and in material to be protected by layers of mineral deposits, such as wooden piles or wooden partitions, consisting of - placing a support with internal surfaces and external in a volume of electrolyte, said support serving as a cathode - placing an anode in the electrolyte near the support - establishing a continuous electric current between the cathode and the anode - when a sufficient mineral deposit has formed on the cathode, possibility of reversing the polarity of the electric current so that the old cathode becomes the anode - ie chlorine gas forming at the anode produces acid hydrochloric acid which destroys the organisms established in and on agglomerated minerals. In the case of recou green mineral deposit, organisms present in 1 wood will be killed. 20. A process for the construction of component structures or building elements, consisting in - removing mineral deposits produced by a device capable of operating in the open sea or in a tank, and application of these minerals on a support form located in water, or which will subsequently be submerged in a body of water - allow mineral deposits to harden over time, so to obtain a structural material. power cut - hardening of deposited minerals over time. cathode - mineral spite will continue to occur, until immersed in a volume of electrolyte, and which. will become the application of these minerals on a support which will then be capable of operating at sea or in a tank, and 21, A process for the construction of structures, construction elements or components, consisting in - removing mineral deposits produced by a device 22. A process for carrying out a cathodic envelopment of wooden structures, in order to prevent the leaching or dilution of chemicals and toxins used to impregnate the wood, consisting in - applying a support or a cathodic envelope formed carbon or graphite fibers on a <-t structure wood or concrete, or on an element or component of c @ ns truction, in the electrolyte, or before immersion in the electrolyte - place an anode in the electrolyte, near the support - establish a direct current between the cathode and the anode in order to obtain a mineral deposit of sufficient thickness to prevent chemicals or toxins with which the wooden structure has been impregnated do not escape. 23. A process for the construction of structures. construction elements and components, consisting of - placing a support having internal surfaces t external, with fibrous materials attached to these surfaces, in a volume of electrolyte, said support serving as cathode - place an anode in the electrolyte near the cathe establish a continuous electric current between the cathode and 1 anode - interrupt the electric current. 24. A process for coating metal, concrete or plastic structures, elements and building components, consisting of: - placing a support having internal surfaces and external, with braids or fibers in conductive material or non-conductive fixed on said surfaces, '3 ".ns un volume of electrolyte, the support serving as cathode - place an anode in the electrolyte near the support, braids or fibers - establish a continuous electric current between the cathode and the anode in order to obtain a mineral deposit of a thickness sufficient to envelop the structure, or the elements / building components. 25. A process for repairing damaged or broken structures, components or construction elements made of concrete - in an electrolyte volume, and consisting in - connecting the iron or steel reinforcement to the negative terminal a source of direct electric current, by making iron or steel reinforcement a cathode place an anode in the electrolyte near the steel or iron reinforcement - establish a continuous electric current between the cathod and the anode in order to deposit minerals on ex broken or cracked parts of the structure, element or the construction component made of reinforced concrete or ferro-cement. settle on and inside mineral deposits. the anode to make the mineral deposit of the desired thickness interrupt the electric current allow sufficient time for the marine organisms cathode front place an anode in the electrolyte near the support - establish a direct current between the cathode e + external in a volume of electrolyte, the said support will be 26 A method for the construction of building structures, elements or components, comprising placing a support having internal surfaces and 27. A process for the construction of structures, components and building elements, comprising placing a support having internal surfaces and ex dull in a volume of electrolyte, the di @ servan support; cathode - place an anode in the electrolyte near the support establishing a direct current between the anode and the cathode - introduce minerals, chemicals, dyes, nutrients or toxins in the electrolyte integrate these minerals or chemicals into ï min @ raux deposited on the cathode interrupt the electric current.