RU2234547C1 - Method and apparatus for reprocessing of oil-bearing briquettes of active high-melting point metals and alloys - Google Patents

Abstract

FIELD: metallurgy of active high-melting point metals and alloys, including rare-earth metals and actinides.

SUBSTANCE: method involves charging briquettes into melting crucible mounted in heating furnace; providing pressurization and vacuumizing of system; removing oil and moisture from briquettes by increasing heating temperature within the range of 200-600⁰C at heating rate of 5-15⁰C/min for 2-2.5 hours, with waste gas or vapor pressure being maintained at value below 2,000 Pa and vent gas inleakage at pressure of 130-400 Pa/min being provided before beginning of metal melting process; casting ingot. Apparatus has melting crucible mounted in heating furnace, vacuumizer, condenser, and is further equipped with working volume made in the form of isolated jig cavity constructively separated from furnace volume, system for sucking oil vapors and moisture from crucible, inert gas emergency admission system and vent gas suction system. Working volume and said systems are interconnected via pipelines.

EFFECT: increased fire and explosion safety of process, increased efficiency of vacuumizer and method.

7 cl, 3 dwg, 1 tbl

Description

The invention relates to the field of metallurgy of active refractory metals and alloys, including rare, rare earths and actinides, in particular to methods for processing oil-containing briquettes of chips of the above metals, alloys (waste) and devices for their implementation.

Currently, a significant amount of briquetted shavings of active refractory metals and alloys contaminated with industrial oil and water (coolant components) are stored at Russian enterprises. These associated contaminants do not allow safe and without complications remelting of the above chips into an ingot using known technologies.

The presence of a large amount of oil and moisture in the briquetted chips leads to re-precipitation of oil condensate on the water-cooled elements of the furnace when it is re-melted in a vacuum induction furnace, to the formation of hydrocarbon gases and hydrogen in the furnace’s working volume, which significantly increases the fire and explosion hazard of the melting process, and reduces the quality of the melted metal, due to the repeated contact of oil condensate on hot or molten metal, and also reduces the efficiency of the vacuum system of the furnace due to Adan liquid oil and water fractions in the vacuum system.

Long-term storage of oil-containing briquetted shavings of active refractory metals and alloys is impractical due to its pyrophoricity and ability to liberate hydrogen at room temperature.

A known method of processing oil-containing chips from zirconium and its alloys, including emulsion cleaning, washing with cold water, alkaline cleaning, washing with cold water, etching with hydrochloric acid, washing with cold water, alkaline cleaning, washing with cold water, etching with nitric acid, washing with cold water, washing hot water, drying with hot air followed by smelting of the ingot / Zirconium metallurgy. Ed. G.A. Meerson, Moscow: IL, 1959, p. 157 /.

The known method is used for processing unbricked "loose" chips from zirconium and its alloys, which is washed quite well with degreasing and pickling solutions and is easily dried with hot air.

The known method cannot be used for processing oil-containing briquetted chips, because the heterogeneity of the particle briquette in terms of particle size and chemical composition, the degree of compaction does not completely remove oil and moisture from it during processing with degreasing and pickling solutions. So, even with a 10-fold circulation of the degreasing solution through a layer of briquetted chips at T: W = 1: (1-3), the fraction of the removed oil does not exceed 20-25% of its initial content in the briquette.

In addition, the known method is characterized by low productivity and high costs for the process of removing oil and moisture from the surface of the chip.

Improving the efficiency of washing briquetted chips from oil can be achieved by crushing the briquetted chips into smaller parts in order to improve contact of the surface of the chip with degreasing and pickling solutions. However, this will lead to additional costs, lower productivity, more complex hardware design of the process, and increased fire and explosion hazard of the process due to increased reactivity of fine particles of active refractory metals and their hydrides.

A known method of processing oil-containing chips from zirconium and its alloys, including immersion in a solution of trichlorethylene and multiple mixing of chips, air drying, etching in solutions of various acids, washing with cold water, air drying followed by smelting of the ingot / Zirconium metallurgy. Ed. G.A. Meerson, Moscow: IL, 1959, p. 157 /.

The known method cannot be used for processing briquetted chips due to the fact that the oil is retained in dense bundles of chips. In addition, the known method is characterized by low productivity, high cost of the process, low environmental friendliness and low quality of the metal obtained in the ingot due to its pollution with carbon.

A known method of preparing for the shavings of aluminum alloys, including grinding, two-stage drying in vacuum, and in the first stage - at 50-80 ° C and a residual pressure of -200-400 mm RT. Art., and on the second - at 100-180 ° C and a residual pressure of -10-30 mm RT. Art. followed by screening and magnetic separation. / A.s. No. 478885, C 22 V 7/00. A method of preparing for the shavings of aluminum alloys, 1975 / The known method cannot be used for processing briquetted shavings of refractory metals and alloys due to the fact that the oil is trapped in dense bundles of chips. In addition, the known method is characterized by low productivity, high costs for the process, caused by the use of additional operations of vibration, screening and magnetic separation.

Known vacuum installation for the direct production of metals, containing a reactor in which at least one grid is installed, cavities under and above the grid, respectively connected with discharge and vacuum devices, a heating device, a volatile gas condenser, reactor tubes with regulating bodies for supplying and discharging raw materials, respectively and waste and installation control unit. Moreover, the installation contains the main and additional valves associated with the control unit, and the volatile gas condenser is connected by a pipeline with a cavity under the grid / application No. 94001969, C 22 V 5/00, F 27 B 15/00. Vacuum installation for direct production of metals, publ. 02/27/97. Bull. No. 61 /.

The known installation allows you to process pure metal waste with the accumulation of molten metals and discharge them into the molds, as well as remove volatile gases from the melting of metals from the reactor into the condenser.

However, the disadvantages of this installation is that it does not allow the processing of oil-containing briquettes shavings of refractory metals and alloys due to the inability to ensure fire and explosion safety of the process under conditions of formation of hydrocarbon gases and hydrogen in the heating zone.

A known method of evaporating predetermined components from initial multicomponent mixtures or systems at a pressure lower than atmospheric in a vacuum chamber, comprising placing in it individual portions of a multicomponent mixture or multicomponent system in several tiers in ring crucibles to remove vapors of the corresponding component or components boiling at a lower temperature through at least one vapor vent, wherein the ring crucibles are heated for the time necessary to obtain at least at least one of the specified components of a multicomponent mixture or multicomponent system with the highest possible purity. A device for its implementation includes a vacuum chamber and a furnace casing in which annular crucibles having at least one opening for vapor recovery and a pipe for vapor recovery are located in several tiers / RF Patent No. 2187565, C 22 V 9/04, F 27 B 14/04. Method and device for the evaporation of components from multicomponent mixtures and multicomponent systems, 2002 Bull No. 23 /.

The known method and device allow partial evaporation of oil and moisture from pure metal waste. However, the disadvantages of the known method and device is that they do not allow the processing of oil-containing briquettes shavings of refractory metals and alloys due to the impossibility of providing explosion and fire safety of the process under conditions of formation of hydrocarbon gases and hydrogen in the heating zone.

The closest analogue for the proposed group of inventions is G.A. Meerson, Zirconium Metallurgy, M .: Foreign Literature Publishing House, 1959, p.148-150, 156-157, which describes a method for processing oil-containing briquettes of chips of active refractory metals and alloys and a device for its implementation.

The disadvantages of the known analogue are:

1. During the smelting of an ingot from oil-containing briquettes of chips, the formation of hydrocarbon gases and hydrogen occurs, which sharply reduce the fire and explosion safety of the melting process.

2. When oil-containing briquettes of chips are heated, a significant amount of oil and moisture from the briquettes condenses on the lid of the furnace and other water-cooled plant elements, from the surface of which they can re-fall onto hot or molten metal, which can lead to a decrease in the quality of the ingot metal.

3. The products of thermal decomposition and oxidation of the oil, as well as liquid fractions of the oil accumulate in the vacuum system, which reduces the efficiency of the vacuum installation.

4. The preliminary removal of oil and moisture from the briquettes of chips requires significant labor and costs for materials and energy and is characterized by low productivity of the process.

5. This device does not allow the processing of oil-containing briquettes of chips due to the impossibility of ensuring fire and explosion safety of the process under conditions of formation of hydrocarbon gases and hydrogen in the heating zone.

6. This device does not exclude contamination of the vacuum system by the products of thermal decomposition and oxidation of oil, which reduces the efficiency of the vacuum system and reduces the quality of the metal ingot.

The claimed technical solution is aimed at increasing the fire and explosion safety of the process, increasing the efficiency of the vacuum system, reducing labor and material costs, and increasing the productivity of the process.

The specified problem is solved as follows.

1. In contrast to the known method of processing briquettes of active refractory metals and alloys, including loading briquettes into a melting crucible installed in a heating furnace, sealing and evacuating the system and smelting the ingot, according to the claimed technical solution, before the smelting, the ingot removes oil and moisture from the briquettes by increasing temperature in the range of 200-600 ° C at a speed of 5-15 ° C / min for 2-2.5 hours, while maintaining the pressure of the exhaust vapors and gases no more than 2000 Pa, while the leakage of venting gas 130 -400 Pa / min is carried out before the start of metal melting.

2. In contrast to the known device for processing briquettes of shavings of active refractory metals and alloys, containing a melting crucible, a mold, a vacuum system and a condenser placed in a heating furnace, according to the claimed technical solution, it contains the working volume of the melting unit structurally separated from the furnace volume by the pipelines a unit in the form of an isolated cavity of a snap-in, a gas suction system for oil vapor and moisture from a crucible, an inert gas emergency inlet system, a ventilating system suction g the basics.

3. In addition, according to the claimed technical solution, an inert gas or air is used in the vent gas system.

4. In addition, according to the claimed technical solution, the gas suction system containing vapor and moisture condenser removed from the furnace, pressure sensors, a trap, a shutter, a check valve, a block of vacuum pumps and fans can be connected to the melting crucible cavity through an installed in its upper part is a nozzle closed by a lid.

5. In this case, according to the claimed technical solution, the lid may be provided with a shutter with channels for ventilation of the working volume of the crucible.

6. In addition, the inventive device may be further provided with an umbrella mounted above the safety valve of the furnace.

7. The solution of this problem can also be achieved as a result of the fact that the gas suction system in the inventive device further comprises a mixer nozzle installed between the vacuum pump and the fan and connected by pipelines.

When analyzing patent and scientific and technical sources, no technical solutions have been identified that possess the entire set of essential features of the claimed technical solution.

Thus, the claimed technical solution according to the results of the analysis of the prior art is unknown and meets the criteria of patentability of the invention of "novelty."

Comparison of the claimed solutions not only with the prototype, but also with other technical solutions in the art showed that no technical solutions have been identified that fully contain all the claimed essential features.

Known technical solutions that partially contain some of the essential features of the proposed solution. So, it is known that the components are evaporated in a vacuum and trapped in a condenser, while the volatile gas condenser is connected by a pipe to the cavity of the heating device, the use of a damper is known / RF Patent No. 2187565, C 22 V 9/04, F 27 B 14/04, 2000 ., application No. 94001969, C 22 B 5/00, F 27 B 15/00, 1997 /.

However, in the claimed technical solution, only a combination of known and unknown significant features allows to obtain a new positive effect, which consists in the possibility of processing oil-containing briquettes of chips of active refractory metals and alloys (waste) metallurgically in one cycle of loading the briquettes into the furnace without first having to clean them from oil outside furnaces while ensuring a high level of fire and explosion safety of the process with the result of commodity production (metal ingots).

The claimed technical solution does not explicitly follow from the prior art, because to identify complex dependencies between the essential features of the proposed solution, on the one hand, and the fire and explosion safety of the process, the efficiency of the vacuum system, labor and material costs and productivity of the process, on the other hand, as well as to optimize the identified dependencies, a significant number of complex experiments.

Thus, the claimed technical solution meets the criteria of patentability of the invention "inventive step".

Depending on the oil content in the initial briquettes from 1 kg of chips under normal conditions, 1-2.5 dm ^{3 of} hydrogen is released. The presence in the inventive device of the gas exhaust system from the melting crucible allows you to remove from the briquettes chips up to 99.9% of the oil at a temperature of 200-600 ° C and output it to the condenser. Moreover, the design of the device prevents the release of a significant amount of oil into the furnace volume. The concentration of hydrogen in the exhaust gases decreases in the mixing nozzle of the pump and fan unit from 60-85% (vol.) To a safe level (0,01-0,05% vol.), Which significantly increases the fire and explosion safety of the process. The rest in the form of low molecular weight pyrogas is also removed by vacuum pumps through the appropriate mixer nozzles. The design of the condenser ensures the complete capture of droplet-dispersed particles from the gas stream. Therefore, liquid fractions of oil do not enter vacuum pumps, which increases the efficiency of the vacuum system. The presence in the inventive device of the emergency inert gas inlet system and nozzle-mixers allows in emergency situations to quickly fill the working volume of the furnace with inert gas and exclude the possibility of explosions and "pops", which further increases the fire and explosion safety of the process.

The combination of two processes in one installation: distillation of oil and water from briquettes of chips of active refractory metals and alloys and smelting of an ingot can significantly increase the productivity of the process of obtaining an ingot from briquetted chips, without compromising the quality of the metal base of the chip.

The declared parameters of the process of removing oil and moisture from briquettes of chips, namely: temperature range - 200-600 ° C, heating rate - 5-15 ° C / min, the time of removal of oil decomposition products for 2-2.5 hours, exhaust pressure vapors and gases - not more than 2000 Pa and the flow of venting gas 130-400 Pa / min, carried out before the start of metal melting, provide optimal conditions for removing oil from briquetted shavings of active refractory metals and alloys and removing products of its decomposition from the working volume of the furnace.

The presence in the inventive device of an umbrella above the safety valve of the furnace can improve the safety of its operation in an emergency due to the effective mixing of hydrogen discharged through the safety valve with air in safe concentrations.

The absence in the claimed solution of degreasing and pickling solutions, washing water, drying with hot air in the process of removing oil from briquetted chips, high productivity of the process can significantly reduce labor and material costs.

Figure 1 schematically shows the inventive device.

Figure 2 shows in cross section the design of the melting unit.

Figure 3 shows a cross section of the nozzle-mixer.

In accordance with the description of the device, a plant for the processing of briquetted chips was created at ChMZ OJSC.

Device description

The inventive device consists of an induction vacuum furnace (1), inside of which a melting crucible (2) is installed. On the upper part of the crucible body, an extension (3) is fixed, closed with an insulating cover (4) with a plug for the inspection hole (not shown), forming a kind of cap for the initial collection and evacuation of vapors and gases. If necessary (for example, for introducing a punch into the crucible or for sucking in the leakage air or inert gas through the crucible cover), the inspection hole cap in the cover (4) can be replaced by a valve with ventilation channels that covers the inspection hole in the crucible cover for the duration of stripping oils. For gas extraction, a nozzle (5) is connected to the furnace body (1), through which the internal cavity of the equipment is vacuumized, as well as the removal of hydrogen, water vapor and oil. The connection of the pipe (5) with the extension (3) is carried out through the adapter (6). The joints of the pipe, adapter and extension are sealed by means of kaolin wool seals, tightened with a nut (not shown). To ensure optimal parameters and process safety at the stage of distillation of water and oil from chip briquettes (as well as in emergency situations), the claimed device is equipped with a vacuum system and filling the working volume of the furnace with inert gas, which includes the following elements:

1. A six-seater gas ramp (7), designed to reduce the inert gas pressure to 5 · 10 ⁵ Pa using a gearbox (not shown). During normal operation of the inventive device use 1 gas cylinder (7), the remaining cylinders must be full and in readiness for emergency filling of the working volume of the furnace (1) with inert gas in case of emergency.

2. The gas preparation unit (8) is designed to trap droplet moisture from inert gas coming from cylinders, and to further reduce the inert gas pressure to 1.15 · 10 ⁵ Pa. The pressure drop at the inlet to the furnace is controlled using a pressure switch (setting 3 · 10 ⁵ Pa) (not shown). The emergency filling of the working volume of the furnace with inert gas to a pressure of 1.15 · 10 ⁵ Pa (absolute) and the continuous supply of inert gas at this pressure with a flow rate of 30 m ³ / h are provided in the gas preparation unit (8) by installing six balloon reducers (not shown ), powered in parallel. The estimated time of filling the working volume of the furnace with inert gas when the chips are fully loaded into it is 8 minutes. To protect against high pressure, the gas preparation unit (8) is equipped with a safety valve (not shown) with a pressure setting of 1.2 · 10 ⁵ Pa.

3. The leakage nozzle (9) is designed to create a relatively weak gas flow in the working volume of the furnace, eliminating the breakthrough of volatile oil fractions from the internal cavity of the equipment into the furnace retort and their condensation on the water-cooled surfaces of the equipment. At the same time, ventilation is also carried out inside the equipment cavity. The inert gas flow is controlled in the range of 50-150 dm ³ Pa / s. Typically, the pressure in the working volume of the furnace rises due to the inlet of the venting gas by 130 Pa (1 mmHg).

4. The condenser (10) is used to cool the steam-gas stream leaving the furnace crucible, to condense oil vapor and trap droplets in the annulus (flow from top to bottom). Heat transfer in the condenser occurs both on the side surface equipped with a cooling jacket, and on the condenser cover, which is made integrally with a bundle of pipes through which water circulates. The lower removable part of the condenser housing serves as a reservoir for collecting condensate. This design of the condenser allows you to fully distinguish the drip entrainment of oil from the gas-vapor stream and it is easy to disassemble it to clean it from pollution. To control the pressure at the inlet to the condenser and in the furnace, absolute pressure sensors are installed.

5. The trap (12) is made in the form of an expansion tank. It is intended for additional trapping of condensate drops in case the personnel allowed their passage through the condenser.

6. The vacuum pump unit (13) and the backup pump unit (14) are designed to effectively evacuate the furnace and remove evolved gases. For safe mixing of “exhaust” from vacuum pumps with air, these blocks are equipped with special nozzles-mixers (15). The air flow through the mixer nozzle is determined by its diaphragm and fan operation (16), which provides air supply to the mixer nozzle in the amount necessary for the formation of an air-hydrogen mixture of explosive concentration in it. The gas flow rate in the ducts is controlled and should be at least 2 m / s.

To prevent the ingress of oil and air into the working volume of the furnace when the vacuum pumps (13, 14) suddenly stop, each pump is equipped with a check valve (17).

To increase the technological capabilities of the vacuum system, the vacuum pump paths (13) and (14) are connected by an additional line to the shutter (18).

7. An umbrella (19) is used to divert a mixture of gases ejected from the working volume of the furnace through an emergency valve.

The inventive device operates as follows.

Oil-containing chip briquettes are loaded into a melting crucible (2) installed in a heating furnace (1). The furnace is sealed and include a vacuum pump (13). Upon reaching a pressure of 130-400 Pa in the working volume of the furnace, a valve is opened on a gas cylinder (7) with inert gas or air. Gas is supplied through the gas preparation unit (8) and the leak (9) to the working volume of the furnace (1) to prevent breakthrough of oil vapor and moisture from the internal cavity of the extension (3) into the working volume of the furnace (1). Chip briquettes are heated. Vapors of moisture and oil released from the chip briquettes rise from the melting crucible (2) to the nozzle (3), from which they enter the condenser (10) through the adapter (6) and the nozzle (5).

The control of the pressure of the exhaust vapor is carried out by the sensor (11). Gases cleaned from oil and moisture from the condenser (10), through a trap (12), through a shutter (18), a check valve (17), a vacuum pump (13) or (14) are ejected through the mixer nozzle (15) by a fan (16) ) in atmosphere. The hydrogen concentration in the air-hydrogen mixture at the outlet of the fan (16) is safe and amounts to 0.01-0.05 vol.%. Chip briquettes cleaned of moisture and oil are heated to the melting temperature and the ingot is melted.

At the end of the operation of the inventive device, the heating of the furnace (1) is turned off, the vacuum pump (13) is turned off, the valve on the gas cylinder (7) is closed.

In an emergency, 6 gas cylinders (7) of inert gas simultaneously operate in the inert gas filling system of the furnace with inert gas.

To verify the claimed technical solution, the following work was carried out. Oil-containing briquettes of chips of zirconium alloy E110 were processed.

According to the prototype, an oil-containing briquette of chips of E110 zirconium alloy was loaded into a vacuum induction furnace, the furnace was sealed, evacuated, and the briquette was heated under standard operating conditions of E110 alloy smelting.

When the briquette was heated with increasing temperature, moisture and oil vapors began to be released from it, which were deposited on the water-cooled parts of the furnace, and the concentration of hydrogen in the gas mixture on the “exhaust” from the vacuum pump increased sharply to an explosive concentration. In this case, the heating was stopped and the shutter speed was maintained until an explosion-proof hydrogen concentration was reached on the "exhaust". After that, the heating was resumed again and the cycles of turning on and off the heating continued to the maximum possible level of moisture and oil removal from the briquette. Then the ingot was smelted according to standard conditions. When the ingot was smelted, "pops" were observed, i.e. a sharp (spasmodic) increase in pressure in the furnace retort, associated with the ingress of oil condensate on the surface of a hot or molten metal.

According to the claimed technical solution, the work was carried out on a pilot plant. An oil-containing briquette of E110 alloy chips was loaded into the unit and the process of removing moisture and oil from the briquette and subsequent smelting of the ingot in normal conditions were carried out.

In this case, the process parameters were varied:

- heating temperature: 180, 200, 400, 600, 625 ° С;

- briquette heating rate: 3; 5; 10; fifteen; 18 ° C / min;

- pressure of exhaust vapors and gases: 2100; 2000; 1800 Pa;

- heating time: 1.5; 2; 2.5; 3 hours.

- leakage of venting gas: 66, 130, 266, 400, 465 Pa / min.

In the course of this work, we determined the concentration of hydrogen on the “exhaust” from the vacuum pump, the presence of a breakthrough of liquid oil fractions into the vacuum pump, material and labor costs, as well as the productivity of the process by known methods. The research results are presented in the table.

Analysis of the results shown in the table shows that the inventive method and device differ from the prototype in higher fire and explosion safety of the process (the absence of "claps" in the smelting of the ingot and a safe concentration of hydrogen at the exhaust from the vacuum pump of 0.01-0.05 vol. % of the proposed solution and the presence of "pops" in the process of smelting the ingot and a dangerous concentration of hydrogen on the "exhaust" from the vacuum pump 80.7 vol.% of the prototype), higher efficiency of the vacuum system (no breakthrough of the liquid oil fraction in the vacuum the smart pump of the proposed solution and the presence of a slip of the liquid oil fraction into the vacuum pump of the prototype, which is explained, in particular, by the decomposition and grinding of oil in this case), higher productivity, lower material and labor costs (130.7-131.2% , 82.1-82.3% and 86.4-86.9%, respectively, of the proposed solution, 100%, 100%, 100%, respectively, of the prototype and 66.8%, 110.2% and 124.5%, respectively at the analogue).

The optimal parameters of the process of removing oil from briquettes of chips are the following:

- temperature 200-600 ° C (experiments No. 4-6, 24-29);

- the rate of temperature increase 5-15 ° C / min (experiments No. 4-6, 9-11, 24-29);

- the pressure of the exhaust vapors and gases is not more than 2000 Pa (15 mm RT. Art.) (experiments No. 13, 24-29);

- the duration of the oil removal process is 2-2.5 hours (experiments No. 4-14, 16, 17, 24-29);

- leakage of ventilating gas 130-400 Pa / min (experiments No. 20-22, 24-29);

- the duration of the leakage of venting gas - before the melting of the metal.

A decrease in the temperature of heating briquettes below 200 ° C (experiment No. 3) leads to incomplete removal of oil from the briquettes of chips and a decrease in the yield of metal in the ingot.

An increase in the temperature of heating briquettes over 600 ° C (experiment No. 7) leads to an unjustified increase in energy consumption, because a temperature of 600 ° C is the limit for the distillation of oil. And at this temperature almost all fractions of the oil are distilled off and you can proceed to the implementation of the metal smelting process.

A decrease in the briquette heating rate of less than 5 ° C / min (experiment No. 8) leads to an unjustified delay in the process and an increase in energy consumption.

An increase in the briquette heating rate of more than 15 ° C / min (experiment No. 12) leads to a significant increase in the hydrogen concentration at the "exhaust" of the vacuum pump due to overheating of the oil and its decomposition.

An increase in the pressure of the exhaust vapors and gases of more than 2000 Pa (15 mm Hg) (experiment No. 14) leads to a significant increase in the concentration of hydrogen at the "exhaust" of the vacuum pump and in the furnace. In case of emergency depressurization of the furnace in this case, the achievement of hydrogen and hydrocarbon concentrations below the concentration level of the explosive limit is not ensured.

Reducing the duration of briquette heating less than 2 hours (experiment No. 15) leads to incomplete removal of oil from the briquette and a decrease in the yield of metal in the ingot.

An increase in the duration of briquette heating for more than 2.5 hours (experiment No. 18) leads to a significant increase in energy consumption without a significant improvement in the completeness of oil removal from chip briquettes. When the venting gas flows less than 130 Pa / min, and the leakage time is less than what is required before the metal melts (experiment No. 19), a slip of liquid oil fractions into the furnace volume is noticeable, and the oil, decomposing on the graphite equipment of the furnace, gives an additional volume of hydrogen-containing gas. When the venting gas flows above 400 Pa / min (experiment No. 23), slip of liquid oil fractions into vacuum pumps is possible, the residual pressure in the furnace increases, which adversely affects the oxidation of the metal.

According to the claimed technical solution, OAO CHMZ created a PBS installation for processing briquetted chips and conducted its industrial tests. Tests of the PBS installation showed its effectiveness, the reliability of its individual components and the high quality of the metal smelted in the ingot. The resulting metal is suitable for long-term and safe storage or can be processed into commercial products in accordance with customer requirements.

Claims (7)

1. A method of processing oil-containing briquettes of chips of active refractory metals and alloys, including loading the briquettes into a melting crucible installed in a heating furnace, sealing and evacuating the system, smelting the ingot, characterized in that before smelting the ingot, oil and moisture are removed from the briquettes by raising the heating temperature in the range of 200-600 ° C at a speed of 5-15 ° C / min for 2-2.5 hours while maintaining the pressure of the exhaust vapors and gases no more than 2000 Pa, while the vent gas flowing 130-400 Pa / min stvlyayut prior to the metal melting. 2. Device for processing oil-containing briquettes of chips of active refractory metals and alloys, containing a melting crucible placed in a heating furnace, a vacuum system, a condenser, characterized in that it contains the working volume of the melting unit, which is structurally separated from the furnace volume, in the form of an isolated cavity accessories, gas exhaust system for oil vapor and moisture from the crucible, emergency inert gas inlet system, vent gas intake system. 3. The device according to claim 2, characterized in that inert gas or air is used in the vent gas system. 4. The device according to claim 2, characterized in that the gas extraction system contains a vapor and moisture condenser removed from the furnace, pressure sensors, a trap, a shutter, a check valve, a vacuum pump and fan unit, and is connected to the melting crucible cavity through the nozzle installed in its upper part, closed by a cover. 5. The device according to claim 4, characterized in that the cover is provided with a shutter with channels for ventilation of the working volume of the crucible. 6. The device according to claim 2, characterized in that it further comprises an umbrella mounted above the safety valve of the furnace. 7. The device according to any one of claims 2 to 4, characterized in that the gas extraction system further comprises a mixer nozzle mounted between the vacuum pump and the fan and connected by pipelines.

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