Method for diamonds purification

FIELD: chemistry.

SUBSTANCE: method includes stagewise diamonds treatment in autoclave at increased temperature and pressure under the action of microwave radiation: in the first stage -with mixture of nitric acid and hydrogen peroxide, in the second stage- with mixture of concentrated nitric, chlorhydric and hydrofluoric acids. The treatment in both stages is carried out in acids gas phase at autoclave filling 45-55%, in the first stage the volume ratio nitric acid/hydrogen peroxide is 4:1 respectively, the treatment is carried out at temperature 215-250°C during 15-60 min. In the second stage the volume ratio nitric acid/chlorhydric acid/hydrofluoric acid is 5:4:1 respectively; the treatment is carried out at the same temperature during 15-150 min. In the third stage the mixture is treated with 5% solution of chlorhydric acid/ during 5-15 min and temperature not more than 160°C.

EFFECT: efficiency enhancing of diamonds purification process along with increase of the used equipment productivity and decrease of reagents consumption.

2 ex

 

The invention relates to the purification of diamonds and diamond powders and can be used for high-quality purification of natural diamonds from surface contamination and remove foreign impurities.

A known way to clean diamond (No. 1104791, publ. 20.12.2000,, bull. No. 35, SW 31/06), including the diamond, when heated with a mixture of nitric and hydrochloric acids at an elevated pressure in the reaction vessel made of fluoropolymer, and the mixture is further added hydrofluoric acid at a volume ratio of concentrated nitric, hydrochloric and hydrofluoric acids

3:1:(1-2), respectively, at 220-250°C for 1.5-3 hours.

This method allows you to clear the diamonds only from contaminants contained on the surface of the crystals and the resultant enrichment of diamondiferous rocks, which are presented in the form of traces of metals, inorganic compounds and oils.

The disadvantage of this method is that it does not provide high-quality cleaning of mixed origin, which appeared during the growth of diamond or later as a result of various secondary reactions as redox potential of the reaction mixture used is insufficient for the oxidation of the bitumen. In addition, the disadvantages of this method may include the duration of the PTS process is resource - up to 3 hours and high consumption of acid.

The closest technical solution is the way to clean diamond (RU # 2285070 A1, 27.04.06, SW 33/04), including multi-stage processing in an autoclave at elevated temperature and pressure under the influence of microwave radiation with a mixture of hydrochloric acid, nitric and hydrofluoric, while in the first stage, a mixture of nitric acid and hydrogen peroxide at a volume mixing ratio 10:1, respectively, and in the second phase volume ratio mixture of concentrated nitric, hydrochloric and hydrofluoric acids is 6:2:1 respectively, the duration of each stage is not more than 40 minutes the Temperature to be maintained in the autoclave, is not more than 210°C., a pressure of 25 ATM, the capacity of the furnace microwave - 1200 watts, the duration of each stage is not more than 40 min when the fill factor of the autoclave of 1:10. When implementing this method is quite effective cleaning of diamonds from bitumen contamination. However, only 57% of those in need of cleaning diamonds cleared completely, 31% partially. In 12% of the crystals in the complete destruction of bitumen contamination in their place appear transparent red-brown spots (dirt in the cracks), shifting the color of the crystals in the region of the brown color, which reduces the price of diamonds. On some Chris who allow of the dirt red (presumably iron oxides) in the treatment withdrew from cracks, but lies on the surface of diamond crystals, which required additional input stage of treatment.

The disadvantages of this method should also include a large amount of highly toxic oxidizing mixture for recycling. In addition, the need to completely fill the diamonds reagent increases the flow rate of the mixture of acids, limits the amount of simultaneously processed crystals in autoclaves up to 3-5 cm3and several times reduces the service life of the equipment due to the high pressures that develop in the reaction chamber during the evaporation of the acid. All this accordingly reduces the performance and lifetime of the installation, requires a large amount of manual labor, which ultimately makes this method not effective enough when used in a production environment for processing large quantities of diamond crystals.

The technical problem solved by the invention is to increase the efficiency of the cleaning process diamonds for improving performance of the equipment used and reduced reagent consumption.

This technical result is achieved in that in the method of purification of diamonds, including sequential processing of diamonds in an autoclave at elevated temperature and pressure under the influence of microwave radiation: the first stage is a mixture of nitric acid and peroxide in Dorada, in the second, a mixture of concentrated nitric, hydrochloric and hydrofluoric acids, processing the first and second stages are in the gas phase acids when filling volume of the autoclave 45-55%, nitric acid and hydrogen peroxide for the first stage, take in a volume ratio of 4:1 respectively and are processed within 15-60 minutes at a temperature of 215-250°C, nitric, hydrochloric and hydrofluoric acid for the second stage take in a volume ratio of 5:4:1 respectively and the treatment is carried out at the same temperature for 15-150 min, and then at the third stage handle 5%-s ' solution of hydrochloric acid at a temperature not exceeding 160°C for 5-15 minutes

Processing of rough diamonds not in the liquid reagent, and a gas generated by evaporation of the acid and formation of highly active compounds (gases: chlorine, nitrosyl, nitrosylchloride, nitrosulfonic), which are more effective oxidant than the original acid, allows you to activate the process gas environment is formed by molecules with more kinetic energy than molecules in solution, and, accordingly, the process is carried out more efficiently.

The total pressure of saturated vapor (gas) in an autoclave under heat is generated due to the partial pressure of the components of the reagent and the newly formed hee is practical components. The pressure saturated steam is the greatest pressure exerted pair reagent at a given temperature. To withstand the required temperature, it is necessary to reduce the amount of reagents used. In the case of its complete evaporation of the gas pressure will be less busy. Thus, by performing the cleaning process of the diamond crystals in the gas generated by evaporation of the acid, it becomes possible to create the desired temperature in less than a high pressure inside the autoclave.

Conducting the process in a gas environment can increase the filling of the autoclave up to 45-55% (compared with 9% in the prototype), and hence to increase the productivity of the equipment used, i.e. the volume of autoclaves for the purification of large quantities of diamond crystals. In addition, processing of diamond crystals in a gas environment can reduce the consumption of acid used for treatment, 15-20 times. The degree of filling of the autoclave 45-55% was tested experimentally and corresponds 60-85 ml bulk volume of processed diamonds for autoclave with a capacity of 100 ml.

Additional processing of diamonds weak (5%) solution of hydrochloric acid at a temperature not exceeding 160°C for 5-15 min allows you to effectively clean them from acidic OS is Atkov, in the cracks.

Volume ratio two-component mixture of nitric acid and hydrogen peroxide in the first processing stage, equal to 4:1, and a three-component mixture of nitric, hydrochloric and hydrofluoric concentrated acids is 5:4:1 used in the second stage of purification of crystals of diamonds, the most rational for use with the full operation of the components exposed to microwave radiation at a power of microwave oven 1200 watts and allow to dissolve compounds of different mineralogical composition. The increase in the ratio of acid number of hydrochloric acid increases the cleaning effect of diamond crystals from ozelenenie (inclusions of metallic impurities).

The first stage of processing (15-60 min) and the second stage of processing (15-150 min) are selected experimentally depending on the degree and type of contamination diamonds (individually for each field).

The temperature of the first and second stage processing support equal 215-250°C. the Temperature range was chosen based on the fact that more than 250°C Teflon loses its physical-mechanical properties and deformation, and at a temperature of less than 215°C. the purity of the diamond crystal surface does not exceed 85% (according to the patent, the state Treasury and GIREDMET, see No. 1104791, publ. 20.12.2000,, bull.№ 35, SW 31/06).

Taken together, the awn of the signs of this technical solution is not identified from the patent documents and scientific-technical information which is indicative of inventive step of the claimed technical solution.

An example of a specific implementation

For full disclosure of technical nature and advantages of the present invention are examples where the source data for the implementation of the proposed method adopted in the following. Purification was subjected to shipment of diamonds size

-6,7+4,7 mm from two deposits (indigenous and placer). When this was treated as a problem of diamond crystals (having cracks with dirt), and the diamond crystals without visible contamination. The crystals of each field were processed separately.

For diamond processing used a microwave decomposition under pressure Speedwave MWS-3+. This system is equipped with an 8 autoclaves

DAK-100 PTFE TFM capacity of 100 ml each with a maximum temperature of 250°C, allowing the amount to handle up to 5000 carats of diamonds. For washing diamonds used autoclaves DAP-240 capacity of 250 ml with a maximum temperature of 160°C.

Processing the mixture of acids is conducted in three stages under the influence of microwave radiation with the use of microwave ovens. Capacity microwave oven does not exceed 1200 watts (during purification capacity varies depending on the amount of processed crystals and set temperature).

The processing modes of diamonds to the military and gravel deposits are somewhat different. The differences are more processing time in the second stage of treatment for diamonds from alluvial deposits. This is due to the greater degree of contamination data diamond ozelenenie.

The first stage is used primarily for cleaning diamonds from bitumen and process fats. In our case we use a mixture of concentrated nitric acid and hydrogen peroxide. Concentrated nitric acid partially dissolves the bitumen from the formation of red-brown solution. Hydrogen peroxide is used to enhance the oxidizing properties of nitric acid and cleavage of the molecules of hydrocarbons. In the latter case, the formation of oxygenated compounds, mainly organic acids. A typical composition of the mixture used for decomposition of hydrocarbons, HNO3:H2O2=4:1.

The second stage is used to clean diamonds from ozelenenie and various pemasok located on the surface and in the cracks of diamonds. To increase cleaning of diamonds from ozelenenie composition of the used reagent was changed in the direction of increasing the volume of hydrochloric acid. Volume ratio of the new structure were the following: nitric acid : hydrochloric acid : hydrofluoric acid = 5:4:1. A further increase in the ratio of the volume of hydrochloric acid was metselaar the EIT effect of development used in autoclaves maximum allowable pressure. As the results of the experiments conducted with these acids is established that the greatest partial pressure in the autoclave is created by hydrochloric acid.

1. Processing of diamonds from the indigenous field

In the first phase of diamond crystals were placed in Teflon-glass autoclave along the entire height of the reaction chamber (capacity of 60 cm3), and poured a small portion of the reaction mixture of nitric acid and hydrogen peroxide at a volume ratio of components 4:1 to create a gas medium (6 ml reagent), and closed the lid.

The autoclaves were placed in a microwave. Asked a temperature of 230°C. Purification was performed within a 60 minutes after heating, the autoclave was cooled, the diamonds were washed with bidistillate and filled with a mixture of concentrated nitric, hydrochloric and hydrofluoric acid at a volume ratio of 5:4:1 and processed similarly to the first stage at the same temperature for 60 minutes, the Amount of solution mixture of concentrated acids was 6 ml.

After re-cooling the autoclave and wash diamonds bidistillate in the third stage, the diamonds were loaded into the autoclave DAP-240, the crystals were completely filled with reagent - 5%solution of hydrochloric acid and kept at a temperature of 160°C for 15 min in the liquid phase. The amount of reagent at 60 cm3/sup> crystals of the sample was 40 ml At the end of the third stage of processing diamonds were dried and viewed under a stereomicroscope by mineralogists.

You can increase the number of cycles of heating-cooling within each stage of purification of crystals diamonds depending on the degree of contamination.

In the mineralogical assessments found that when the data processing modes diamonds indigenous field size -6,7+4,7 mm was completely clear to 94.3%.

2. Processing of diamonds from alluvial deposits

Diamonds from alluvial deposits are characterized by a greater degree of contamination: ozelenenie, compared with crystals from the primary sources.

In the first phase of diamond crystals were placed in Teflon-glass autoclave along the entire height of the reaction chamber (capacity of 60 cm3), and poured a small portion of the reaction mixture of nitric acid and hydrogen peroxide at a volume ratio of components 4:1 to create a gas medium (6 ml reagent), and closed the lid.

The autoclaves were placed in a microwave. Asked a temperature of 230°C. Purification was performed within a 60 minutes after heating, the autoclave was cooled, the diamonds were washed with bidistillate and filled with a mixture of concentrated nitric, hydrochloric and hydrofluoric acid at a volume ratio of 5:4:1, and processed similarly to the first stage at the same temperature for 120 minutes The amount of solution mixture of concentrated acids was 6 ml.

After re-cooling the autoclave and wash diamonds bidistillate in the third stage, the diamonds were loaded into the autoclave DAP-240, the crystals were completely filled with reagent - 5%solution of hydrochloric acid and kept at a temperature of 160°C for 15 min in the liquid phase. The amount of reagent at 60 cm3crystals of the sample was 40 ml At the end of the third stage of processing diamonds were dried and viewed under a stereomicroscope by mineralogists.

You can increase the number of cycles of heating-cooling within each stage of purification of crystals diamonds depending on the degree of contamination.

In the mineralogical assessments found that when the data processing modes diamonds from alluvial deposits of size -6,7+4,7 mm fully cleansed 77,01%.

The consumption of reagents is not dependent on the type of deposits, and 10,000 carat diamond products with three-stage purification obtained the following: nitric acid - 145,6 ml of hydrochloric acid - 67,7 ml; hydrofluoric acid to 11.2 ml) and hydrogen peroxide is 22.4 ml, while the prototype: 3160 ml, 440 ml, 240 ml and 180 ml, respectively.

Comparative analysis of cost estimates crystals before and after treatment showed that the cost of problematic stones increased by 10-14%, and the whole party rose from 1.0 up to 1,5% (depending on the fields).

The way to clean diamonds, including sequential processing of diamonds in an autoclave at elevated temperature and pressure under the influence of microwave radiation: the first stage is a mixture of nitric acid and hydrogen peroxide, the second mixture of concentrated nitric, hydrochloric and fluoride-hydrogen acids, wherein processing the first and second stages are in the gas phase acids during filling of the autoclave 45-55%, nitric acid and hydrogen peroxide for the first stage, take in a volume ratio of 4:1 respectively and are treated at a temperature of 215-250°C for 15-60 min, nitric, hydrochloric and fluoride-hydrogen acid for the second stage take in a volume ratio of 5:4:1, respectively, and the treatment is carried out at the same temperature for 15-150 min, and then at the third stage handle with 5%hydrochloric acid solution for 5-15 minutes at a temperature of not more than 160°C.



 

Same patents:

FIELD: production of diamonds for electronics.

SUBSTANCE: diamond is produced from gas phase by chemical deposition on diamond substrate whose surface is practically free from any defects in crystal lattice in flow of carrier gas in atmosphere containing nitrogen at concentration lesser than 300 part/109. Diamond thus produced is chemically pure with no defects in crystal lattice at enhanced electronic characteristics as compared with purest natural diamonds.

EFFECT: enhanced purity and improved electronic characteristics.

32 cl, 8 dwg, 1 tbl, 4 ex

FIELD: production of diamond layers.

SUBSTANCE: diamond layer at thickness more than 2 mm is obtained through chemical deposition from gaseous phase. Method includes homo-epitaxial growth of diamond layer on surface of backing at low level of defects in atmosphere containing nitrogen at concentration lesser than 300 billion parts of nitrogen.

EFFECT: improved quality of diamond layers.

36 cl, 10 dwg, 1 tbl, 4 ex

The invention relates to the optical instrument and is intended to create complex diffractive optical elements (DOE) - kinoforms, pokushalov, proofreaders and t

FIELD: chemistry.

SUBSTANCE: present invention relates to chemical engineering, and to high-pressure technology of making diamonds, particularly for growing large crystals, the process of which is long. The high-pressure apparatus has a multiple-punch unit, which is enclosed in a sealed elastic casing 6. In the first version the multiple-punch unit is fitted on a sealed hollow platform 1, which has at least two sealed cavities 10, at least one of which is linked through a valve with the external environment for filling with water when submerged. In the second cavity there is a motor 11, with a pump for pumping water from the first sealed cavity when raising the apparatus. In the second version the sealed cavities can be made in the sealed hollow platform and in one of the punches. In the third version the sealed cavities can be made in at least two punches of the multiple-punch unit.

EFFECT: no use of load-carrying structures and compressors in the apparatus due to the possibility of using natural water column pressure, created by the Earth gravitational field.

15 cl, 2 dwg

FIELD: chemistry, technological processes.

SUBSTANCE: invention allows to obtain memorial diamond from pale-yellow to light-blue tint depending on content of admixture in it, which is identified with exact person and is an object, which reminds of him/her. Method includes processing of biological material belonging to exact individual, and growing on its basis artificial diamond by acting on it with high pressures and temperatures. Processing is performed by mechanical grinding, preliminary drying, chemical processing in hydrochloric acid, chemical processing with complex-former Trilon-B, chemical processing with mixture of mineral acids - hydrofluoric and nitric or sulfuric acids, repeated washing after each chemical processing with said reagents to neutral reaction, filtration and drying until pure highly-dispersive carbon of biological origin is obtained.

EFFECT: obtaining carbon of high purity with characteristic microelements for exact individual.

6 cl, 3 tbl

FIELD: technological processes.

SUBSTANCE: invention claims diamond tool manufactured with monocrystallic diamond, synthesised under high pressure by temperature gradient method, so that the claimed diamond crystal contains not more than 3 parts per million of nitrogen. The tool features a blade with its edge oriented in plane (110), so that Knoop scale hardness at the plane (100) in direction <110> is higher than in direction <100>. Such synthetic monocrystallic diamond is synthesised by temperature gradient method under superhigh pressure and high temperature, and its crystals contain nickel atoms introduced by atomic substitution or boron and nickel atoms introduced by atomic substitution.

EFFECT: obtaining cheap synthetic monocrystallic diamonds with reduced flaw number.

24 cl, 4 ex, 2 tbl, 7 dwg

FIELD: technological process.

SUBSTANCE: invention pertains to the technology of obtaining plates made from monocrystalline diamond, grown using a chemical vapour deposition method (CVDM) on a substrate. The grown diamond is divided across the surface of the substrate and the plate is obtained. Its main surfaces are located across the surface of the substrate.

EFFECT: obtaining plates with large area, which do not have natural defects.

41 cl, 4 ex, 6 dwg

FIELD: technological process.

SUBSTANCE: invention pertains to the technology of obtaining monocrystalline diamond material and can be used in optics for making optical and laser windows, optical reflectors and refractors, diffraction grating and calibration devices. The diamond material is obtained using chemical vapour deposition method (CVDM) in the presence of a controlled nitrogen level, which allows for controlling development of crystal defects and therefore obtain diamond material with basic characteristics, necessary for use in optics.

EFFECT: material with basic characteristics, necessary for use in optics.

75 cl, 8 tbl, 15 ex, 9 dwg

Coloured diamonds // 2328563

FIELD: technological process.

SUBSTANCE: invention is related to the field of coloured diamonds preparation, which are used, for instance, in decorative purposes. Method of coloured single crystal diamond transformation into different colour includes stages, at which coloured single crystal diamond is prepared by method of chemical depositing from steam phase (CDSP) and prepared diamond is thermally treated at temperature from 1200 to 2500°C and pressure that stabilises diamond, or in inert or stabilising atmosphere. Prepared single crystal may be shaped as thick layer or fragment of layer, which is cut as precious stone.

EFFECT: allows to prepare diamonds with wide range of colour gamma.

61 cl, 8 ex, 5 dwg

FIELD: chemistry.

SUBSTANCE: process of hard monocrystalline diamond preparation compises fixing of inoculating diamond in the holder and its growing by the way of chemical deposition from gaseous phase induced by microwave plasma. The process is implemented at temperature ca 1000°C - 1100°C in medium N2/CH4=0.2-5.0 and CH4/H2=12-20% at total pressure 120-220 torr. Derived monocrystalline diamond has the hardness in the range 50-90GPa and fracture strength 11-20MPa m1/2.

EFFECT: increasing of diamond hardness.

7 cl, 4 dwg

FIELD: carbon materials.

SUBSTANCE: monocrystalline diamond grown via chemical precipitation from gas phase induced by microwave plasma is subjected to annealing at pressures above 4.0 GPa and heating to temperature above 1500°C. Thus obtained diamonds exhibit hardness higher than 120 GPa and crack growth resistance 6-10 Mpa n1/2.

EFFECT: increased hardness of diamond product.

12 cl, 3 dwg, 5 ex

FIELD: crystal growth.

SUBSTANCE: method comprises separating the inoculation from the source of carbon by a metal-dissolver made of an alloy of ferrous, aluminum, and carbon when a 20-30°C temperature gradient is produced between the carbon source and inoculation. The growth zone is heated up to a temperature higher than the melting temperature of the alloy by 10-20°C, and the melt is allowed to stand at this temperature for 20 hours. The temperature then suddenly increases above the initial temperature by 10-25°C and decreases down to the initial value with a rate of 0.2-3 degree per minute.

EFFECT: improved quality of crystal.

1 tbl, 2 ex

FIELD: inorganic chemistry; mining industry; electronics; other industries; methods of the synthesis of the needle-shaped and lengthened diamonds.

SUBSTANCE: the invention is pertaining to the field of the inorganic chemistry, in particular, to the method of production of the needle shape synthetic diamonds and may be used in the industrial production of the special-purpose diamonds, for example, for manufacture of the boring crown bits and the dressers, and also in the capacity of the blocks details of the audio-video playback equipment, for manufacture of the feeler probes, in the micro-mechanical devices etc. The method provides for commixing of the fusion charge composed of the alloy of Mn-Ni-Fe in the mass ratio of 60±5÷30±5÷10±5 and the powder of the carbon-containing substance and treatment of the mixture at the pressure exceeding 40 kbar and the temperature over 950°С at heating rate less than 100°C/minutes. In the capacity of the carbon-containing substance use the needle-shaped coke or graphite on the coke basis with the single-component anisotropic structure with the degree of graphitization of no less than 0.55 relative units. The invention allows to simplify the production process of the synthesis of the needle-shaped and lengthened diamonds and to increase the percentage of their output within one cycle of the production process.

EFFECT: the invention ensures simplification of the production process of the synthesis of the needle-shaped and lengthened diamonds, the increased percentage of their output within one cycle of the production process.

2 ex, 2 dwg

FIELD: chemistry.

SUBSTANCE: invention can be used in chemical and electronic industry. Silicon hydride monosilane is resulted from reaction of magnesium silicide and mineral acids. Magnesium silicide is prepared by thermal reaction of the mixture containing disperse silicon oxide particles 1 wt fractions, silicon particles to 10 wt fractions, and bulk magnesium 3.5 to 4 wt fractions in continual stirring. Silicon oxide particle size does not exceed 3 mm, and silicon oxide particle to bulk magnesium size ratio is 1:(10-20). Reaction in stirring is performed at temperature interval 550 - 680°C.

EFFECT: extended raw materials base of monosilane process and cost reduction.

3 cl, 1 ex

FIELD: chemistry.

SUBSTANCE: industrial silicon with industrial methanol react in the presence of a catalyst at high temperature. From the products of the reaction, hydrogen-containing methoxysilane in a mixture with tetramethoxysilane is separated. Monosilane is obtained through catalyst disproportioning of hydrogen-containing methoxysilanes, and cleaned through adsorption on active carbon. Temperature fall between the stages of separating hydrogen-containing methoxysilanes and subsequent catalyst disproportioning does not decrease by less than 60°C. Purifying monosilane from carbon-containing impurities is done through throttle discharge of monosilane from high pressure of 60 kg/cm2 to low pressure of 1-3 kg/cm2, providing for lowering temperature of gaseous monosilane with impurities to temperature not higher than minus 10°C and formation of a dispersed phase of tetramethoxysilane. Through hydrolysis of tetramethoxysilane, silicon dioxide is obtained, which is reduced to silicon and returned to the stage of direct synthesis of trimethoxysilane.

EFFECT: lower content of carbon-containing impurities in monosilane and low consumption of raw materials and energy.

2 ex

FIELD: organosilicon compounds technology.

SUBSTANCE: method of preparing monosilane, useful in production of "sun" silicon, comprises catalytic disproportionation of trichlorosilane to form monosilane, silicon tetrachloride, and chlorosilanes in countercurrent reactor with catalyst. Gradual condensation of disproportionation reaction products to separate gaseous monosilane is carried out while recycling formed condensate to evaporator through catalyst bed in reaction zone in reactor. Condensate is heated in evaporator to form chlorosilane vapors, which are then directed to reaction zone of reactor in countercurrent to descending condensate flow. Liquid product is withdrawn from evaporator and, after posttreatment, is used in manufacture of silicon dioxide. Monosilane is sent to rectification column to remove chlorosilane traces. Catalyst in countercurrent reactor is disposed in tubular elements. Starting trichlorosilane is preliminarily treated with liquid product stream leaving evaporator and liquid product is then passed to tubular space of countercurrent reactor and discharged from top of reactor.

EFFECT: enhanced process efficiency, including optimized disproportionation process temperature conditions, intensified main process, and improved quality of monosilane at minimum power and material expenses.

1 dwg

FIELD: separation of volatile agent mixtures in chemical technology; separation of mixtures of chlorosilanes, hydrides, fluorides and organic products at selection of target product.

SUBSTANCE: proposed method includes fractionated distillation in batch-operated rectifying column provided with center feed reservoir. Column operates in mode of selection of fractions from upper and lower points at separation of concentrate of target product by parallel selection of target and non-target fractions upon attaining preset composition till target product is completely exhausted from starting mixture. Proposed method increases productivity by more than 2 times at maximum extraction of target material. Target product is subjected to cleaning to obtain required purity.

EFFECT: enhanced efficiency.

3 cl, 2 tbl, 1 ex

FIELD: organosilicon materials.

SUBSTANCE: invention relates to a process for production of high-purity monosilane suitable to form thin-film semiconductor products as well as high-purity poly- and monocrystalline silicon for a variety of applications (semiconductor engineering, solar power engineering). Process is accomplished as follows. Trialkoxysilane is prepared by etherification of hydrogen bond-containing chlorosilanes by an alcohol or via direct reaction of alcohol with powdered commercial silicon in presence of catalyst. Trialkoxysilane is preliminarily purified to remove alcohol and other undesirable impurities and the routed to catalytic disproportionation to produce monosilane. 1-2% solution of potassium tert-butylate in tetraalkoxysilane is used as catalyst. Solution of catalyst and that of trialkoxysilane are taken at ratio 1:(10÷20) with pH from neutral to weakly alkaline and passed into lower part of reactor in continuous mode at normal temperature and pressure. Gaseous monosilane with vapors of organic and organoelemental impurities is then subjected to absorption treatment followed by removal trace impurities via adsorption on activated carbon, chemisorption, and condensation of high-purity monosilane.

EFFECT: reduced trialkoxysilane disproportionation time, increased trialkoxysilane conversion, enhanced efficiency of removal of impurities from monosilane, and universalized monosilane sorption treatment system.

2 tbl, 7 ex

FIELD: organoelemental synthesis.

SUBSTANCE: invention relates to technology of producing pure semiconductor silane useful in power electronics as well as to silicon plates for manufacturing superlarge integral schemes and to form various layers and film coatings in microelectonics area. For that purpose, lithium silicide is placed into drum-type reactor, which is then evacuated and heated, after which distilled water vapors is injected into interior of reactor at 90-95°C. Three hours later, a few drops of distilled water re added to further recover silicon in the form of silane. Overall yield of silane is 50-53%.

EFFECT: reduced purity of product and increased blasting safety of the process.

FIELD: silane production from natural quartzite.

SUBSTANCE: method for silane production includes interaction of silicium-containing compound (e.g. quartzite) with lithium hydride. Backing is carried out at 790-8200C followed by crushing of fusion cake. Fusion cake is placed on continuously renewed surface of moving ice plates made from distilled water. Claimed method is useful in production of high pure semiconductor silicium for electronic industry.

EFFECT: silane synthesis from economy raw materials; safe technology.

1 ex

Up!