The method of purification of synthetic ultradispersed diamonds
(57) Abstract:The invention can be used for the recovery of diamonds from the product of detonation synthesis. 100 g diamond blend containing about 40 wt.% diamond, the rest Almazny carbon and metal impurities, place on a baking furnace. Heated to 380-440oWith a speed of 2.5-10.0 deg. /min. and maintained at the maximum temperature for 2-4 hours Exit diamond 38,5 - 39,1 wt. %, the content of non-diamond carbon 0.1 - 0.8 wt.%. The method is simple, does not require the use of toxic environments. The invention relates to technologies for obtaining and purifying synthetic ultradispersed diamonds and can be used to extract diamonds from the products of detonation synthesis.Known methods of chemical cleaning of synthetic diamonds is based on the oxidative effects of solutions, melts or gases (Putyatin A. A., Nikolskaya, I. C., Kalashnikov, I. N. Chemical methods of extraction of diamonds from the fusion products. - Superhard materials, 1982, No. 2, S. 20 - 28). In industrial practice, preference and affordability-oxidants.Known purification method UDA formulations based on sulphuric, nitric acid and sulfuric aldehyde. The processing.%. The ratio of the diamond mixture : the mixture of acids is 1 : (25 - 50) (international application PCT/SU N 90/00169). The main disadvantage of this method is the use of aggressive, concentrated environments, which upon oxidation decays with emission of toxic and reactive gases (NO, NO2N2O5, SO3, CO). Disposal and decontamination waste technology requires high material costs, which leads to a rise in the cost of cleaning product - UDA.There is a method of allocating synthetic ultra-dispersed diamonds (patent of Russia No. 2109683), in which diamond the mixture is subjected to two-stage treatment with an aqueous solution of nitric acid first 50 - 99% concentration at 80 - 180oC, followed by 10 - 40% at 220 - 280oC. Liquid-phase flow process in this way is provided by high pressure. The disadvantage of this method is the necessity of using a special acid-resistant chemical equipment working under pressure.A known method of purification of diamonds from impurities by processing raw materials on the air for 12 - 24 hours at 300 - 550oC in the presence of 5 to 100 wt.% catalyst - lead oxide (patent England N 1115649). The disadvantages of the method are the use of highly toxic soepomo the patent of Russia No. 2004491. This method consists in processing of diamond-containing materials in air at 300 - 550oC in the presence of boric anhydride, which is added in an amount of not less than 9 wt.% content in raw diamonds. The method includes a step of mixing the raw material with a solution of boric anhydride or boric acid and the subsequent drying of the mixture at 210oC to obtain a vitreous boric aldehyde. The mixture is calcined in the pan for 4 to 5 h at 300 - 550oC with periodic stirring and cooled, treated with diluted hydrochloric acid and distilled water. The yield of diamond is 72 - 94%. A multi-stage cleaning process - mixing with boron compounds in water, drying, calcining, with stirring and subsequent removal of the residue of boric compounds makes the method inefficient and futile for industrial applications. Also used in the prototype boron oxide or boric acid have a toxic effect on the human body (maximum allowable concentrations of 5 and 10 mg/m3respectively), resulting in poor working conditions.The task of the claimed invention is to provide a method of cleaning a synthetic tx2">The problem is solved by the proposed method of purification of synthetic ultradispersed diamond on non-diamond carbon, which is thermooxidation diamond mixture in air at 380 - 440oC in the layer, providing the necessary conditions of the heat sink and prevent the burnout of the diamond, with a speed of 2.5 - 10.0 deg. /min, followed by isothermal aging for 2 to 4 hComparison of the proposed technical solution with the prototype shows that it differs from the latter in different thermal conditions of the method, with the exception of process chemical additives, other duration of the process, i.e., this solution meets the criterion of "novelty".In the process of cleaning synthetic ultradispersed diamond from carbon impurities are not used lead compounds, boron or other catalysts, which eliminates phase shift, processing, drying, separation. In accordance with the invention, the oxidation of carbon impurities is carried out in one stage in an atmosphere of air, and heating is performed in a strictly controlled manner, ensuring the stationarity of the process. The condition of stationarity meets this heating rate oxidizable TA consists of carbon forms different patterns from amorphous and carbenoxolone to nano-sized diamond crystals. Part of the diamond particles enclosed in a quasi-spherical carbon shell, representing the transitional carbon structures.The proposed method is based on the difference of thermal-oxidative properties of diamond and non-diamond phase of carbon and takes into account the peculiarities of the mechanisms of oxidation of crystalline and amorphous structures. The claimed mode of oxidation of the diamond charge allows you to control the specific rate of oxidation of the non-diamond carbon, at the initial stage, the temperature is increased in stages, the most oxidized active carbon forms. This process is accompanied by activation of transient surface layers of diamond particles. Isothermal oxidation for 2 - 4 h completes the process of gasification of non-diamond phases.For better implementation of the method of the diamond mixture, it is necessary to oxidize the layer, providing the necessary conditions of the heat sink and prevent the burnout of the diamond. The temperature of oxidation over 440oC will result in the loss of the diamond more than 20%. The increasing heating rate of more than 10 deg./min violates the stationary regime of oxidation, initiating flash and ignition of the charge. Oxidation at temperatures below 380oC or increasing the heating rate is less than 2,Braz, the proposed method of purification of synthetic ultra-dispersed diamond and non-diamond carbon to declare it a set of features allows you to achieve the technical result - cleaning synthetic OUD from non-diamond carbon without the use of toxic environments while maintaining the quality of cleaning. This embodiment of the method of the prior art are not explicitly derived and it was not obvious to the experts, and the differences that directly affect the solution of the problem. It gives the basis to consider this solution as inventive.The method does not cause problems while its industrial implementation, as described techniques and devices for its implementation is easy to reproduce. The necessity in the application of the method of purification of synthetic ultra-fine from non-diamond carbon, allowing to obtain a high quality product without the use of toxic environments, no doubt, and therefore the proposal has industrial applicability.Example 1. 100 g diamond blend containing diamond (40,2 wt.%), Almazny carbon and metal impurities, place a layer, providing the necessary conditions of the heat sink and excluding wygu the temperature of the support in the interval (410 10)oC for 4 h, the Yield of diamond is 38.5, the residual Content of non-diamond carbon of 0.2% (according to x-ray analysis).Example 2. 100 g of the diamond mixture (content of UDA - 39.5 wt.%) layer, providing the necessary conditions of the heat sink and prevent the burnout of the diamond, spread on a baking furnace and heated at a rate of 10 deg. /min to 430oC. After which the specified temperature is maintained within the interval (430 10)oC for 2 h, the Yield of diamond is 38,7, the residual Content of non-diamond carbon of 0.1% (according to x-ray analysis).Example 3. 100 g of detonation diamond mixture (content of UDA - to 42.5 wt. %) layer, providing the necessary conditions of the heat sink and prevent the burnout of the diamond, spread on a baking furnace and heated at a speed of 5 deg./min to 380oC. the Specified temperature stabilize in the range (380 20)oC for 4 h, the Yield of diamond is 39,1, the Content of non-diamond carbon of 0.8% (according to x-ray analysis). The method of purification of synthetic ultra-dispersed diamond and non-diamond carbon by thermal oxidation in air at 380 - 440oC, characterized in that termoeconomia 2 - 4 o'clock
FIELD: carbon materials.
SUBSTANCE: invention concerns manufacture of diamond films that can find use in biology, medicine, and electronics. Initial powder containing superdispersed diamonds with level of incombustible residue 3.4 wt %, e.g. diamond blend, is placed into quartz reactor and subjected to heat treatment at 600-900оС in inert of reductive gas medium for 30 min. When carbon-containing reductive gas medium is used, heat treatment is conducted until mass of powder rises not higher than by 30%. After heat treatment, acid treatment and elevated temperatures is applied. Heat treatment and acid treatment can be repeated several times in alternate mode. Treated powder is washed and dried. Level of incombustible impurities is thus reduced to 0.55-0.81 wt %.
EFFECT: reduced level of incombustible impurities.
4 cl, 3 ex
FIELD: carbon materials.
SUBSTANCE: weighed quantity of diamonds with average particle size 4 nm are placed into press mold and compacted into tablet. Tablet is then placed into vacuum chamber as target. The latter is evacuated and after introduction of cushion gas, target is cooled to -100оС and kept until its mass increases by a factor of 2-4. Direct voltage is then applied to electrodes of vacuum chamber and target is exposed to pulse laser emission with power providing heating of particles not higher than 900оС. Atomized target material form microfibers between electrodes. In order to reduce fragility of microfibers, vapors of nonionic-type polymer, e.g. polyvinyl alcohol, polyvinylbutyral or polyacrylamide, are added into chamber to pressure 10-2 to 10-4 gauge atm immediately after laser irradiation. Resulting microfibers have diamond structure and content of non-diamond phase therein does not exceed 6.22%.
EFFECT: increased proportion of diamond structure in product and increased its storage stability.
FIELD: chemical industry and electronics; production of diamonds.
SUBSTANCE: the invention is intended for chemical industry and electronics. The chemical product is prepared out of the following organic compounds (in weight %): acetamide - 6.7; carbamide - 0.8; ethylene glycol - 2.0; glycolic acid - 11.7; lactamide - 8.8; glycerine - 2.3; hexamethylenetetramine - 11; indene - 7.6; 1,2-dimethylnaftaline - 2.6; 1,4 -diisopropenylbenzol - 3.3; cyclohexylphenylketon - 8.1; 4'-cyclohexylacetophenone - 7.2; 4-(1-adamantyl)phenol - 2.1; 4,4'-methylenebis (2,6-dimethyl phenol) - 2.3; α,α'- bis (4-hydroxyfenyl)-1.4-diisopropylbenzol - 0.2; phenanthrene - 11.0; lauric acid - 6.2; sebacic acid-6.3; eicosanic acid - 9.7. The indicated components are mixed with water in the ratio of 1:(1-2). The mixture is heated up to 150-200°С in vacuum of 10-1-10-6Pa. A reaction sample formed this way is refrigerated in conditions of vacuum and dried for removal of water and the volatile organic substances. The dried reaction sample is heated in vacuum up to 200-400°С for 80 hours. The invention allows to use the raw material being in lower power state as compared with the known methods and to produce the high-clean diamonds.
EFFECT: the invention ensures production of the high-clean diamonds from the raw material of the lower power state.
16 cl, 1 tbl, 1 ex, 4 dwg
FIELD: production of color diamonds.
SUBSTANCE: the invention is pertaining to the field of production of fantasy neon yellow-green diamonds of precious quality produced from the pale (discolored) or so-called "brown" diamonds of the lowest quality. The method provides for placement of a pale natural diamond in the medium capable to transfer the pressure, which then is mold into a "tablet". Then the tablet is placed in the high-pressure press (HP/HT) and exposed to machining at an increased pressure and temperature being within the range of graphite stability or a diamond being on the phase diagram of carbon for the period of time necessary for improvement of a color of the mentioned diamond. In the end the diamond is removed from press. The indicated method ensures production of diamonds of an attractive yellowish-green or yellow-green and neon yellow-green colors.
EFFECT: the invention ensures production of diamonds of attractive yellow-green colors.
22 cl, 4 ex, 2 dwg
FIELD: chemical industry.
SUBSTANCE: the invention is intended for chemical industry. To 1 g of a powder of nanodiamonds of an explosive synthesis add 100 ml deionized water. The mixture is treated with the ultrasonic dispersant for 5 minutes. The produced suspension is added with an electrolyte - NaCl solution in the quantity exceeding sorptive capacity of nanoparticles by ions of sodium, for example, 20 ml of 0.9 M solution. Then separate the disperse medium and the settling. The disperse medium is removed. The settling is added with 100 ml of deionized water and is intensively agitated. The supernatant - hydrosol of nanodiamonds is separated and dried. At multiple add-on of water to the produced powder a stable nanodiamond hydrosol is formed. The share of the surface impurities in the produced nanodiamond is reduced. Simultaneously the share of sodium ions is increased.
EFFECT: the invention allows to reduce the share of the surface impurities in the produced nanodiamond and simultaneously to increase the share of sodium ions.
1 dwg, 1 tbl
FIELD: carbon materials.
SUBSTANCE: invention is designed for use in manufacture of hydrosols, organosols, and suspensions in oils. Nano-size diamond powder is charged into ultrasonic disperser and water and modifier, in particular organic ligand such as EDTA or ethylenebis(oxyethylenenitrilo)tetraacetic acid are then added. Resulting suspension is separated on centrifuge into dispersion medium and precipitate. The latter is treated with water to form suspension, which is centrifuged to give precipitate and hydrosol, which are concentrated separately by heating in vacuum into powderlike form. When concentrating hydrosol, depending on desire, following finished products may be obtained: concentrated hydrosol, cake, or dry black powder. When concentrating precipitate, clear nano-size diamond powder is obtained. Thus obtained products are appropriate to prepare sedimentation-resistant hydrosols and organosols with no ultrasound utilized, which products have no tendency to aggregate upon freezing and thawing, boiling and autoclaving, and which can be repetitively dried and reconstituted. Surface pollution of nanoparticles is reduced.
EFFECT: enabled preparation of hydrosols with precise concentration of nano-size diamonds.
3 cl, 1 tbl, 5 ex
SUBSTANCE: method comprises filling tank (11) with coolant (12) and igniting heating mixture (3) say silicon boride. At the moment of maximum heating of the graphite (5) to be processed, explosive (1), say trinitrotoluene, is initiated. The propagating explosion wave set heated mixture (3) and agent (5) to be processed into motion, and agent (5) enters closed passage between the cooled separated substrate (8) and rod (9). The passage can be diverging to provide additional compression of agent (5) and pressing substrate (8) into conical mandrel (1) under the action of shock wave. Deflecting diaphragm (7) is an insulator, and insulating layer (2) prevents agent (5) to be ignited up to the moment of its maximum heating.
EFFECT: enhanced efficiency and reduced power consumption.
1 cl, 2 dwg
FIELD: power industry, mechanical engineering and environmental control.
SUBSTANCE: the invention is pertaining to the field of high power industry, mechanical engineering and environmental control. In a explosion-proof chamber 1 with double-walls simultaneously feed a gaseous explosive mixture using pipeline 4 through channels 5 and inject hydrocarbons with the nucleuses of carbon crystallization using a pipeline 6 through an injector 7 with formation of a cone-shaped shell 8 with an inert cavity in the central zone. The shell 8 and the explosive mixture 9 form a cumulative charge. Conduct initiation of undermining of an explosive mixture 9, as a result of which the cumulative charge forms a cumulative spray 10 moving at a high speed along the axis of the cumulation. The gaseous products withdraw through pipeline 17. At collision of the cumulative spray 10 with a barrier having channels 11 of the cooling unit 2 the pressure and temperature there sharply increase ensuring growth of the formed crystals of diamond. Simultaneously conduct cooling with the help of pipelines 12 located in metal filings and granules 13. The atomized and cooled cumulative spray gets into the auxiliary chamber 3, where the diamonds 14 are separated, feed through the pipeline 15 to a power accumulator 16, in which they are settling. Separated hot hydrogen is removed for storing or utilization. The invention allows to magnify the sizes of dimensions crystals of diamond up to 800 microns and more, to decrease atmospheric injections, to reduce the net cost of the diamonds, to increase effectiveness of the device.
EFFECT: the invention ensures growth of sizes of diamonds crystals up to 800 microns and more, decrease of atmospheric injections, reduction of the net cost of the diamonds, increased effectiveness of the device.
2 cl, 2 dwg
FIELD: methods and devices used for production of diamonds.
SUBSTANCE: the invention is pertaining to methods and devices for production of diamonds and may be used in materials technology. Assemble a mold. Ignite a thermit grain and heat up the powdered graphite. After that they initiate explosion of a charge. The explosion energy sets in motion a striker, which is directly caulking the powder graphite in the capsule. After that disassemble the mold, extract the produced diamond. The invention allows to miniaturize the sizes of the charge and the mold, to simplify the production process and to use such a mold multiply.
EFFECT: the invention allows to miniaturize the charge and the mold sizes, to simplify the process of diamonds production and to use such a mold multiply.
FIELD: production of the jewelry quality diamonds from the natural low-grade undecoratively colored diamonds.
SUBSTANCE: the invention is pertaining to production of the diamonds of the jewelry quality from the natural low grade undecoratively colored so-called "brown" diamonds, especially from the diamonds of IIa type and IaA/B type, in which nitrogen forms predominantly B-center for improvement of heir color. The invention provides for realization of the rough faceting and molding of the undecoratively colored natural diamond for giving it the streamline form to avoid its breakup in the press of the high-pressure and heating (HP/HT press). The indicated undecoratively colored natural diamond is put in the pressure transferring medium, which then is compacted into the tablet. Then the tablet is put in the HP/HT squeezer under the high pressure and temperature kept in the field of stability of the blacklead or the field of stability of the diamond of the phase diagram of carbon for the time duration sufficient for improvement of the color of the diamond. After the operation is terminated extract the diamond from the squeezer. The method ensures production of the colorless and decoratively colored diamonds.
EFFECT: the invention ensures production of the colorless and decoratively colored diamonds.
25 cl, 6 ex, 2 dwg