METHOD FOR OBTAINING SYNTHETIC DIAMONDS FROM SACCHAROSE AND AN EQUIPMENT FOR CARRYING OUT SAID METHOD

Abstract

The invention relates to a method for obtaining synthetic diamonds from sucrose, and to a device for carrying out said method, the method comprising: introducing sucrose or a solution of water and sucrose into a hermetic capsule without air, which is surrounded by an external container that keeps the volume of the capsule constant during the entire process; increasing the pressure inside the capsule by breaking down the sucrose inside the capsule, either by increasing the temperature or by combining the sucrose with sulfuric acid, until the carbon resulting from said pressure conditions of the capsule is transformed into diamond; and controlling the pressure generated inside the capsule, using containing means that apply pressure externally around the container of the capsule. In addition, extra carbon is added, increasing the dimensions of the diamond.

Claims

1. A method for obtaining synthetic diamonds from saccharose, comprising: introducing saccharose in a watertight capsule and without air surrounded by an external container maintaining volume of the capsule constant during the whole process; increasing the pressure within the capsule by the decomposition of saccharose inside the capsule until carbon resulting from these pressure conditions within the capsule turns into diamond; controlling pressure generated within the capsule by externally applying pressure around the container of the capsule.

2. The method according to claim 1, wherein the decomposition of saccharose for causing a pressure increase is achieved by increasing the temperature of the capsule until the saccharose hosed inside decomposes by pyrolysis into hydrogen, oxygen and carbon, and causing the hydrogen and oxygen to react for providing supercritical water that further increases the pressure within the capsule in order for the carbon resulting from those pressure conditions in the capsule to transform into diamond, and the supercritical water dissolves the debris existing in the transformed carbon.

3. The method according to claim 2, wherein the saccharose introduced in the capsule is combined in a water solution in order to introduce a greater quantity of saccharose within a same volume and thereby incrementing the pressure while guaranteeing absence of air inside the capsule.

4. The method according to claim 2 further comprising complementary providing of carbon inside the capsule together with the saccharose or a mix of saccharose and water in order for the reaction carbon to be added thereto for increasing dimensions of the diamond obtained.

5. The method according to claim 1, wherein the decomposition of saccharose for causing the pressure increase is achieved by a combination of the saccharose introduced in the capsule with sulfuric acid, the result being carbon, water and sulfuric acid, since the pressure increase within the capsule is caused by dehydration produced by the sulfuric acid.

6. The method according to claim 1, wherein the controlling of the pressure generated within the capsule is performed by at least one of a hydraulic fluid system and a mechanical system.

7. (canceled)

8. The method according to claim 1, wherein, in order to contain an inside pressure of 7 GPa in a capsule having a radius of 5 cm, an external pressure of 100 MPa is applied to an equipment having semi spheres with a radius of 41.83 cm, maintaining a relationship with the radius of the semi spheres 70 times larger than the radius of the capsule.

9. A device for obtaining synthetic diamonds from saccharose comprising: two external jackets, a right jacket and a left jacket, between which is housed a spherical container divided into two contention semi spheres, a lower semi sphere and an upper semi sphere, inside which, in turn, comprises two interior semi spheres, a lower interior semi sphere and an upper interior semi sphere, separated by a chamber having hydraulic fluid, wherein the lower interior and upper interior semi spheres house a mixing capsule and a heating system capable of increasing temperature inside the mixing capsule.

10. The device according to claim 9, further comprising a hydraulic valve at an upper part of the chamber having fluid, connected to a hydraulic supply duct which, in turn, is connected to a hydraulic supply unit.

11. The device according to claim 9, further comprising a thermocouple sensor for measuring the temperature within the inside of the interior semi spheres having a measurement range of up to 1000 C. or more.

12. The device according to claim 9, wherein the heating system is connected to an electric transform system and a thermocouple is connected to a control system managing the operation of the electric transform system and a hydraulic system.

13. The device according to claim 9, wherein the external right and left jackets are incorporated on a guide support for easing displacement thereof.

14. The device according to claim 9, wherein the interior semi spheres are equidistally separated from the contention semi spheres by separating ribs defining the chamber containing hydraulic fluid.

15. The device according to claim 9, wherein the capsule is made of tungsten.

16. The device according to claim 9, wherein the interior semi spheres are made of tungsten.

17. The device according to claim 9, wherein the lower contention semi sphere and the upper contention semi sphere are made of high resistance steel capable of withstanding pressures of 100 MPa.

18. The device according to claim 9, wherein the left exterior jacket and the right exterior jacket are made of high resistance steel capable of withstanding pressures of 100 MPa.

19. The device according to claim 9, wherein, in order to prevent fluid leaks, between the lower contention semi sphere and the upper contention semi sphere an external watertight seal is provided, and between the lower interior semi sphere and the upper interior semi sphere an internal watertight seal is provided, both having a resistance capable of withstanding pressures over 100 MPa and temperatures over 600 C.

20. The device according to claim 9, wherein the heating system is an induction type system.

21. The device according to claim 14, wherein the separating ribs defining the chamber between the interior semi spheres and the contention semi spheres are tungsten elements serving as guides for the semi spheres at a moment of extracting or positioning the mixing capsule.

Description

DESCRIPTION OF THE DRAWINGS

[0080] In order to complement the present description, and with the aim to aid in a better understanding of the characteristics of the invention, the present specification includes a set of drawings which, merely for illustration, non-limitative, purposes, show the following.

[0081] FIG. 1 shows, in a schematic drawing, the ability of saccharose to occupy half its volume when mixed with water that the method of the invention takes advantage of.

[0082] FIGS. 2A and 2B show respective schematic representations of the reaction of the mix of saccharose and water when discomposed and its container allows for increasing its volume or not. FIG. 2A show said reaction with a volume increase and FIG. 2B show the pressure increase when the volume cannot increase.

[0083] FIGS. 3A and 3B show schematic representations of the same reaction of the mix of saccharose and water when decomposed as in FIGS. 2A y 2B, with a volume increase or a pressure increase, in this case represented in the spherical mixing capsule according to the method of the present invention. FIG. 3A shows the mix with a volume increase and FIG. 3C shows the mix in the capsule with a pressure increase.

[0084] FIGS. 4A, 4B, 4C and 4D show schematic representations of the reaction phases of the mix of saccharose and water contemplated in the method of the invention shown in the previous figures, in this case represented with the mixing capsule housed within the container of the disclosed equipment and having a carbon nucleus for obtaining a greater size diamond. FIG. 4A shows the capsule before the reaction within the container, FIG. 4B shows the capsule with the carbon nucleus, FIG. 4C shows the reaction forces within the capsule, and FIG. 4D shows the formation of the diamond and the water obtained.

[0085] FIG. 5 shows a schematic and cross-section view of an example of the elements of the equipment of the invention for carrying out the method for obtaining synthetic diamonds from saccharose, where the main parts and elements, as well as the configuration and structure thereof are seen.

[0086] FIG. 6 shows a cross-section view of the mixing capsule comprising the equipment shown in FIG. 5, represented in the reaction phase, showing by means of arrows the pressure force exerted radially on the semi spheres surrounding it.

[0087] FIG. 7 shows again a cross-section view of the mixing capsule shown in FIG. 6, in this case the arrows show the radial pressure the semi spheres exert on the oil layer surrounding them.

[0088] FIG. 8 shows another cross-section view of the mixing capsule shown in FIG. 7, in this case the arrows show the radial pressure the oil layer exerts on the container supporting the pressure.

[0089] FIG. 9 shows a cross-section view of the mixing capsule shown in FIG. 8, in this case represented with the external jacket of the container, showing by means of arrows the cancelling of the force exerted thereon by the container for keeping the volume constant.

[0090] FIG. 10 shows a diagram of the carbon-diamond phases indicating the pressure and temperature range where the process must be to obtain diamonds.

[0091] FIG. 11 shows a phase diagram of water indicating, by means of arrows, the process in each moment of the decomposition of the mix and the state of water in each stretch.

DETAILED DESCRIPTION

[0092] In view of the figures, and according to the reference numbers provided, the figures show, in addition to the representation of some phases of the method of the invention for obtaining synthetic diamonds from saccharose, an exemplary, non-limiting embodiment of the equipment for carrying out said method, which comprises the parts and elements indicated and disclosed in detail hereinbelow.

[0093] Therefore, in connection with FIGS. 1 to 4D, the operation principle upon which the method of the invention is based for obtaining synthetic diamonds is shown. Thus, FIG. 1 shows a scheme showing the property of saccharose to admit a great quantity of sugar in water. In particular, two volumes A of dry saccharose or sugar (s) can be contained in a single volume A when mixed with an identical volume A of water (a). This is because there is a great amount of air between dry sugar grains. When the sugar gets wet in water, the sugar grains become compact and the air between them disappears. Thus, a given volume A can be occupied by two volumes A of dry sugar (s) plus one volume of water (a).

[0094] Therefore, we introduce in the same container a larger amount of sugar, in a smaller volume.

[0095] FIGS. 2A and 2B show an illustration of the reaction of the mix of sugar and water (s/a) when the temperature raises, where the mix decomposes into carbon (c) and water (a) and occupies a greater volume A than initially, FIG. 2A. This volume A will depend on the proportions of sugar and water in the mix. If volume A of the container remains constant, a pressure rise will take place inside the container.

[0096] FIGS. 3A and 3B show a mixing capsule (7), that is, containing the mix of sugar and water (s/a), which in the preferred embodiment has an spherical configuration since, once decomposed when heated, the volume increases and a radially exterior force F appears, FIG. 3A. If this same spherical capsule (7) is, in turn, contained in a container sphere (7) capable of withstanding said force, the volume increase will remain constant, thus increasing the inside pressure, the pressure generating a radial force directed towards the centre of the sphere, FIG. 3B.

[0097] FIG. 4A shows the container sphere (7), having an inner diameter (Rm), and FIG. 4 shows a mixing capsule (7) having the same diameter (Rm) where a carbon nucleus (n) having a diameter (RC) has been added. FIGS. 4C and 4D show how the mix in the capsule (7), when it starts to decompose when getting hot, generates pressure and a force directed towards the carbon nucleus (n). The force applied to the surface of the mixing capsule (7) is the same as the force applied to the surface of the carbon nucleus (n), however, since the surfaces are different (the surface of the capsule is greater than the surface of the nucleus), the pressure against the surface of the carbon nucleus (n) will be much greater than the pressure against the walls of the container (7), always in case greater size diamonds are desired.

[0098] In turn, FIG. 5 shows a preferred embodiment of the equipment according to the invention for surrounding the mixing capsule (7) and containing the pressure generated inside during the reaction, comprising essentially the following elements:

[0099] A guide support (1), making up the platform on which respective exterior jackets are incorporated, a left jacket (14) and a right jacket (5), between which a spherical container divided into two contention semi spheres, a lower semi sphere (3) and an upper semi sphere (10) joined together by means of a joint (4) for opening and closing, inside which, in turn, the provision of two further semi spheres, a lower semi sphere (2) and an upper semi sphere (9), is contemplated, referred to as inner semi spheres in order to distinguish them from the abovementioned contention semi spheres (3, 10), which are equidistantly separated from said contention semi spheres (3, 10) by a number of separating ribs (6) defining a chamber containing hydraulic fluid, in particular a layer of oil (15), the mixing capsule (7) being snugly fitted inside said semi spheres (2, 9).

[0100] Further, the equipment contemplates the provision of a hydraulic valve (8) at the upper part of said chamber having the oil layer (15), connected to a hydraulic supply duct (20) which, in turn, is connected to a hydraulic supply unit (19), as well as a heating system (11) capable of increasing the temperature of the inside of the mixing capsule (7), connected, by means of wiring (16), an electric transform system (17), and a thermocouple sensor (12) installed, for example, in the lower semi sphere (2), connected, by means of a line (13), to a control system (18) managing the operation of the electric and hydraulic system.

[0101] FIGS. 6 to 9 show the different operation phases of the equipment. Thus, FIG. 6 shows how the pressure exerted by the mixing chamber (7) is transmitted to the inner semi sphere (2) and to the upper semi sphere (9) by means of a radial force. Since the exterior radius is greater than the interior radius, the exterior pressure to be contained will be much lower than the inner pressure produced.

[0102] FIG. 7 shows the radial force applied through the inside of the lower semi sphere (2) and to the upper semi sphere (9). Since the interior radius is much greater than the exterior radius, the exterior pressure will be much lower than the interior pressure, and it will be contained by an oil layer (15) under pressure.

[0103] FIG. 8 shows how the pressure the oil layer (15) is subjected to is contained by the lower contention semi sphere (3) and the upper contention semi sphere (10). These contention semi spheres (3, 10) have a thickness capable of withstanding the pressure exerted by the oil layer (15). They are fitted so that no oil can escape towards the outside, although for economic reasons an external watertight seal (21) for preventing oil leaks can be provided. Further, preferably an inner watertight seal (22) preventing oil leaks towards the inside is contemplated preferably between the semi sphere (2) and semi sphere (10) on which said oil layer (15) is provided.

[0104] And FIG. 9 shows how the pressure exerted by the oil layer (15) on the surface of the lower contention semi sphere (3) and the upper contention semi sphere (10) produces a force indicated by means of black arrows which is cancelled by the exterior jackets (5) and (14), thus preventing the system from opening, the system being thus watertight and capable of keeping a constant volume at all times.

[0105] In the preferred embodiment of the equipment of the invention, when choosing the materials, the pressures to be contained/withstood and the melting points thereof have been taken into account.

[0106] Thus, preferably, the mixing chamber (7) is preferably made of tungsten, since the resistance to compression of said material reaches 7 GPa, and it also has a high melting point and a high thermal conductivity. In the inside, pressures generated by the decomposition of saccharose of near 7 GPa, necessary for the formation of diamonds, will take place.

[0107] Similarly, preferably the upper interior semi sphere (9) and the lower interior semi sphere (2) surrounding the mixing capsule (7) are made of tungsten, since the resistance to compression of said material reaches 7 GPa, and it also has a high melting point and a high thermal conductivity. In the inside, pressures near 7 GPa will be contained and on its external surface, the pressures generated in the inside will be contained by applying thereon pressures of 100 MPa by means of the hydraulic system.

[0108] On the other hand, the lower contention semi sphere (3) and upper contention semi sphere (10) are made of steel with a high resistance to compression and capable of supporting pressures of 100 MPa, and also having a high melting point and a high thermal conductivity. The surface of these elements will withstand pressures of 100 MPa. The oil layer (15) is provided between said contention semi spheres (3, 10) and the upper (9) and lower (2) semi spheres. Thus, it is critical that the thickness of both the lower (3) and upper (10) contention semi spheres be capable of supporting a pressure of 100 MPa.

[0109] Also, the left exterior jacket (5) and the right exterior jacket (14) are made of steel having a high resistance to compression, capable of withstanding a pressure of 100 MPa, and also having a high melting point and a high thermal conductivity. The surface of both jackets (5, 14) will withstand a pressure of 100 MPa and will prevent displacement of the lower container (3) and upper container (10).

[0110] Still defining additional features of the equipment for carrying out the method of the invention, it is worth mentioning that the function of the guide support (1) is to facilitate the displacement of the left exterior jacket (5) and the right exterior jacket (14) for opening it when appropriate, and it is preferably made of steel due to its great resistance.

[0111] The function of the thermocouple sensor (12) is to measure the temperature inside the two semi spheres (2, 9), and in order to do so it preferably has a measurement range of up to 1000 C., although thermocouples for greater temperatures can be employed.

[0112] The function of the exterior watertight seal (21) and the interior watertight seal (22) is to prevent oil leaks, they have a resistance high enough for withstanding a pressure minimum at the greater than 100 MPa and temperatures over 600 C.

[0113] The heating system (11), whose function is to heat the capsule (7) up to a temperature of 600 C., is preferably of induction type and it is controlled by means of an alternating current frequency and current intensity control system (18). The function thereof is limited by means of the thermocouple (12), which will detect whether the 600 C. are reached. In case the capsule (7) needs to be cooled off, the heater (11) will stop operating.

[0114] It must be understood that the heating system (11) disclosed may be of a different type, and the induction type is preferred because it is cleaner than other types of systems.

[0115] The function of the oil regulation valve (8) is limited to controlling the entry and exit of oil from the hydraulic supply unit (19). When 100 MPa are reached, the valve closes, and the oil layer (15) is kept under pressure. The valve (8) opens to allow the opening of the whole interior assembly and the extraction of the mixing capsule (7).

[0116] The electric supply wiring (16), electric supply unit (17) and hydraulic electric control system (18) is a common system for supplying electric current for the induction heater (11). The electric wiring provides the current from the electric system to said heater, and receives the signal from the thermocouple (12) to the control system (18). Said electric system also provides electric current to the hydraulic supply unit (19).

[0117] Preferably, the separation ribs (6) defining the oil layer chamber (15) between the inner semi spheres (2, 9) and the contention semi spheres (3, 10) are tungsten bars serving as guides for said semi spheres when extracting or positioning the mixing chamber (7).

[0118] The equipment may also comprise a hydraulic supply duct (20) consisting of a tube transporting the hydraulic fluid from the hydraulic supply unit (19) to the chamber making up the space contained between the inner semi spheres (2, 9) and the contention semi spheres (3, 10), which is built having a resistance capacity high enough for withstanding a pressure of 100 MPa.

[0119] The fluid making up the oil layer (15) enters under a pressure of 100 MPa in the aforementioned chamber between the inner semi spheres (2, 9) and the contention semi spheres (3, 10). As to the geometry of the disclosed elements of the equipment of the invention, the following for calculating the existing relationships between the capsule sides of the mixing capsule (7) and the radius of the semi spheres, as well as the relationship between the radius of the mixing chamber (7) and the carbon nucleus (n) if present, is worth mentioning.

[0120] Therefore, in order to calculate the surface of the mixing chamber (7) we will use formula 4R.sup.2, having a surface of 150 cm.sup.2. Said surface will receive a pressure of 7 GPa, and therefore we must calculate the radius of the inner semi spheres (2, 9) surrounding it for receiving an inside pressure of 7 GPa and for containing it by means of an external pressure of 100 MPa provided by the oil layer (15). Knowing that the surface of a sphere is 4R.sup.2 and solving the following formula:

P.sub.1XS.sub.1=P.sub.2XS.sub.2

[0121] Where P.sub.1 is the pressure generated inside the capsule, S.sub.1 is the surface of the spherical capsule where pressure P.sub.1 is produced.

[0122] Where P.sub.2 is the pressure of the hydraulic system, and S.sub.2 is the surface where the pressure of the hydraulic system P.sub.2 is applied.

7 GPa4R.sub.1.sup.2=100 MPa4R.sub.2.sup.2

710.sup.94R.sub.1.sup.2=10010.sup.64R.sub.2.sup.2

[0123] Then, if we solve this we obtain: 710.sup.94R.sub.1.sup.2=10010.sup.64R.sub.2.sup.2

P.sub.1/P.sub.2=R.sub.2.sup.2/R.sub.1.sup.2

[0124] 70=R.sub.2/R.sub.1 will be the relation ship between the radiuses using this contention method.

[0125] That is, in case we wanted to contain a pressure of 7 GPa generated by the capsule by means of the application of an exterior pressure using a 100 MPa hydraulic system, we then have to use a mixing capsule (7) having a radius 70 times smaller than the radius of the inner semi spheres (2, 9).

[0126] We can then say that, in order to contain an inside pressure of 7 GPa in a capsule having a radius of 5 cm, we must apply an external pressure of 100 MPa to two semi spheres having a radius of 41.83 cm.

[0127] Once the main dimensions of the elements making up the system are defined, we will describe the process itself. We will initially define a transformation method for synthetic diamonds for a capsule having a radius of 5 cm, obtaining a mix of saccharose and water suitable for a pressure of 7 GPa. Thereafter, we will define a process where a capsule having a radius of 5 cm is used, where the pressures can be withstood and where a larger synthetic diamond is obtained thanks to the addition of carbon. [0128] As an example, we start from a watertight spherical tungsten capsule (7). The dimensions of the sphere radius inside is 5 cm, and therefore the inside volume of the sphere is 523.58 cm.sup.3. [0129] As mentioned above, we introduce a volume of water (523.58 cm.sup.3), and in order to obtain a suitable inside pressure we introduce 900 cm3 of saccharose, instead of the allowable 1047.16 cm.sup.3 of saccharose. [0130] Once the capsule (7) is full, it is closed in a watertight manner. In this moment, the capsule is ready for being housed between the inner semi spheres (2, 9) and the contention semi spheres (3, 10). [0131] The capsule is placed (7) within the lowersemi spheres (2, 3) and the upper semi spheres (9, 10) are coupled thereon, where the latter are lowered by means of a hydraulic harm. Once the capsule (7) is covered by the inner semi spheres (2, 9) and the contention semi spheres (3, 10), these are closed by means of the right jacket (14) and the left jacket (5), and they begin to be heated while compressed oil is provided through valve (8). [0132] Once the capsule reaches a temperature over 186 C., the mix contained inside the mixing capsule (7) will start to decompose, thus building up pressure therewithin. In order to guarantee a controlled reaction between the decomposition hydrogen and oxygen, the autoignition temperature of the hydrogen must be reached as soon as possible, this temperature being over 565 C. Thus, all the oxygen and hydrogen produced will react for making up water. We would then have the following reaction:

[0133] 1404 g of C.sub.12H.sub.22O.sub.11 (saccharose in the mix)+523.58 g of H.sub.2O (water in the mix).fwdarw.decompose into.fwdarw.591.15 g of C.sub.(D) and 1336.42 g of H.sub.2O.

[0134] Starting form an initial volume of 523.58 cm.sup.3, when the graphite turns into diamond, the final volume to occupy will be 356.11 cm.sup.3, and therefore the pressure within the capsule once transformed into diamond will be of 6.06 GPa.

[0135] Watching the phase diagrams of carbon (FIG. 10) and water (FIG. 11) at a pressure of 6.06 GPa and 560 C. we see, in the case of carbon, as a diamond, and in the case of water as a liquid. If we slowly decrease the temperature, the carbon will be in a diamond phase, and water will turn from a liquid state to a solid state, guaranteeing a complete transformation of carbon into diamond. In this case, we obtain a diamond of 167.47 cm.sup.3.

[0136] FIG. 10 shows a phase diagram corresponding to carbon-diamond, which indicates the range of pressure and temperature needed for obtaining diamonds.

[0137] FIG. 11 shows a phase diagram corresponding to water indicating, by means of arrows numbered from 1 to 5, the method at each moment during the decomposition of the mix and the state of the water at every stretch.

[0138] In case a larger diamond was needed, we will start from a 523.58 cm.sup.3 capsule where we will introduce a carbon nucleus of 150 cm.sup.3 and a mix of 373.58 cm.sup.3 of water and 747.16 cm.sup.3 of saccharose. [0139] We start, for example, with a tungsten spherical capsule (7) having a watertight closure. The dimension of the radius of the sphere inside it is 5 cm, and therefore the inside volume will be 523.58 cm.sup.3. [0140] A carbon volume of 150 cm.sup.3 is introduced therein, as well as a mix of 373.58 cm.sup.3 of water and 747.16 cm.sup.3 of saccharose. [0141] Once the capsule is full (7), it is closed under pressure by means of a watertight closure. At this moment, the capsule is ready for being housed between the inner semi spheres (2, 9) and the contention semi spheres (3, 10). [0142] The capsule (7) is placed within the lower semi spheres (2, 3) and the upper semi spheres (9, 10) are coupled thereon, where the latter are lowered by means of a hydraulic arm. Once the capsule (7) is covered by the inner semi spheres (2, 9) and the contention semi spheres (3, 10), these are closed by means of the right jacket (14) and left jacket (5), and the are heated while compressed oil is supplied through valve (8). [0143] Once the capsule reaches a temperature over 186 C., the mix contained inside the mixing capsule (7) will start to decompose, thus building up pressure therewithin. In order to guarantee a controlled reaction between the decomposition hydrogen and oxygen, the autoignition temperature of hydrogen must be reached as soon as possible, this temperature being over 565 C. Thus, all the oxygen and hydrogen produced will react for making up water. We would then have the following reaction:

[0144] 1165.56 g of C.sub.12H.sub.22O.sub.11 (saccharose in the mix)+373.58 g of H.sub.2O (water in the mix)+339 g (carbon nucleus).fwdarw.decompose into.fwdarw.828.45 g of C.sub.(Diamond) and 1048.38 g of H.sub.2O.

[0145] Starting form an initial volume of 523.58 cm.sup.3, when the graphite turns into diamond, the final volume to occupy will be 288.89 cm.sup.3, and therefore the pressure within the capsule once transformed into diamond will be of 5.78 GPa.

[0146] Watching the phase diagrams of carbon (FIG. 10) and water (FIG. 11) at a pressure of 5.78 GPa and 560 C. we see, in the case of carbon, as a diamond, and in the case of water as a liquid. If we slowly decrease the temperature, the carbon will be in a diamond phase, and water will turn from a liquid state to a solid state, guaranteeing a complete transformation of carbon into diamond. In this case, we obtain a diamond of 234.68 cm.sup.3.

[0147] Once the nature of the invention is sufficiently disclosed, as well as the way to put it into practice, we consider that no further description is necessary for a skilled person to understand the scope and the advantages deriving therefrom, and within its essentiality it can be put into practice according to different embodiments having diverging details with respect to the examples shown, and these will also be protected as long as its main principle is not changed, modified or altered.