Metallocherpitsy the method of extracting rare earth metals from their fluoride to obtain alloys and charge for this

 

(57) Abstract:

The invention relates to a method for extracting rare earth metals from their fluoride to obtain alloys comprising preparing a mixture of fluorides, aluminum powder, metal calcium and supplements, initiation metallothermic response to receiving the molten metal and slag phases, cooling, unloading and separation of the ingot from the slag. When preparing the mixture in it enter oxide additive, and optionally, calcium fluoride, and 3-7 min after initiation of metallothermic reaction formed in the crucible, the melt is separated from the environment by a metal lid until the completion of cooling, while simultaneously covering the crucible cover its walls circumference is subjected to dynamic effects within 2-3 minutes the Mixture to extract rare earth metals from their fluorides metallothermic method contains fluorides of rare-earth metals, aluminum powder, metal and calcium Supplement. It additionally contains calcium fluoride and as an additive oxide additive in the following ratio, wt.%: aluminum powder 1-25, metal calcium 25-35, oxide additive 14-35, Tulcea rare earth metals and the ingot. 2 S. and 2 C.p. f-crystals, 2 tab.

The invention relates to metallurgy, in particular to metallotrejderskogo to extract rare earth metals to produce ingots of alloys for further use in various industries.

The known method metallotrejderskogo extract rare earth metals from their oxides to obtain alloys and charge for this (C. A. Powergen, C. A. Neronov and B. N. Reckin. Study of the process of the joint recovery of oxides of cerium and Nickel aluminum. Some regularities of the joint recovery of oxides of cerium and molybdenum aluminum. - Collection "Metallurgical processes in chemistry and metallurgy.- Novosibirsk, 1971, S. 274-281). As follows from this article, fusion is well-known metallothermic way in which the charge is mixed, loaded into a graphite crucible, and then initiate metallothermic reaction by electric blasting and firing the mixture. The heat generated in metallothermic reaction, provides a fusion of the mixture with the formation of the metal and slag phases. After cooling, the products of fusion are unloaded and separating the strand from the slag. Using the mixture containing uksiksid Nickel in the following ratio of components, wt.%:

The oxides of rare earth metals - 5-20

Aluminum powder - 22-64

The addition of Nickel oxide - 28-65

This method and applied the mixture of the composition provide the extraction of rare earth metals in bullion only within 40-55%. This is due to poor thermal conditions of the process associated with significant losses of heat by radiation through the open neck of the reaction crucible, and the formation of crust on its cold walls. Recovery is extremely thermodynamically stable oxides of rare-earth metals aluminum powder runs efficiently enough, not high enough thermal effect and the formation of refractory slag (aluminum oxide). All of this together provides such a low extraction of REE in the ingot.

Higher rates have metallocherpitsy the method of extracting rare earth metals from their fluorides with obtaining magnetic alloys and the composition of the charge for this by the patent of Russia No. 2060290, which are the closest to the claimed invention. In accordance with this patent, the method includes preparation of a mixture of fluorides of one or more rare earth metals, additives of the CFT is e reductant for fluorides of rare earth metals and aluminum, as a reducing agent to the transition metal fluoride, and loading the mixture in the crucible is carried out in two layers.

As compounds of rare-earth and transition metals use the products of fluorination of the oxides of these metals with gaseous fluorine. At the same time, the fluorides of rare earth and transition metals is maintained up to 10% of impurities in the form of their oxides, acceptedof and other compounds. Fluoridation of oxides of these metals is carried out with gaseous fluorine containing 0-10% hydrogen fluoride at a temperature 350-580oAnd 5-30% excess of fluorine with respect to the stoichiometric required.

The reduction is carried out in a graphite crucible. The loading of the charge in the crucible is carried out in two layers. The bottom layer in the form of fluorides of rare earth metals and a reducing agent is calcium, and the upper layer formed from fluorides of transition metals with aluminum as a deoxidizer and alloying additives, which are mainly used Bor. Before loading charge calculation determines the amount of transition metal in the form of fluoride compounds and in the elemental form, is required in the charge to ensure the temperature of the recovery process in the AU.% from his total. When the transition metal in the charge used in the form of powder with particle size of not more than 150 μm. Metal-reducing agent may be in the form of chips, wafers or pellets. In particular, 15-20 wt. % of calcium is used in the form of two plates, one of which is placed at the border of upper and lower layers of the charge, and the second inside the bottom layer of the charge.

The quantitative composition of the mixture in terms of the metals chosen in accordance with the desired composition of the final alloy. Compounds of rare earth metals may be added to the mixture with a slight excess (up to 7 wt.%), and aluminum in the quantity stoichiometrically required for the recovery of transition metals.

After loading of the charge, the crucible is installed in the reactor. The reactor is sealed, vacuum and filled with argon. To eliminate the possibility of the emission of the products of the reaction process is carried out at a gauge pressure of argon in 5-10 MPa. Metallothermic initiate the reaction by using electric blasting and firing the mixture. After completion of process and cooling products smelting reduce the excess pressure in the reactor, lasermedizin it. The crucible is then removed from the reactor and carry out the separation of the ingot from the slag. The formed slag consists mainly of mixtures used in this blend provide a fairly high recovery of rare earth metals in ingot and the ingot. Above all, however, the method is extremely difficult to implement due to the complexity of the preparation of the charge, the layer it resides in the crucible, and the process in the reactor in an inert gas under positive pressure. Achieved values of the degree of extraction of REE in the ingot and the ingot is not high enough, that is due to poor thermal conditions of the process. This is due to heat loss from the melt by radiation through the open mouth of the crucible and the continuous removal of heat from the surface of the melt with an inert gas due to the receipt in its place a new volume of cold gas, as well as due to the formation of crust on the cold walls of the crucible. Recovery of fluorides of transition metals aluminum flows efficiently enough, not high enough thermal effect and the formation of refractory slag. In addition, the mixture is not thoroughly mixed, resulting in a poor contact of the original components of the charge. The presence in the mixture of metallic calcium along with all the positive properties and has a negative value. Resulting from the reaction of calcium oxide passes into the slag phase and has a fairly high concentrat the rare earth metals with oxides of rare-earth metals, passing into the slag, resulting in losses of rare-earth metals from the slag. All of this together and reduces the extraction of REE in the ingot and the ingot.

The present invention was used to develop metallocherpitsy the method of extracting rare earth metals from their fluoride to obtain alloys and charge for this, which would be carried out in such manner and using such charge, to provide a simplified method was achieved by increasing the extraction of rare earth metals in bullion, as well as increased the total yield for the ingot.

The technical result of the invention is to increase the extraction of rare earth metals in ingot and improve the overall output of the ingot.

The technical result is achieved due to the fact that in metallothermic the method of extracting rare earth metals from their fluorides with obtaining alloys comprising preparing a mixture of fluorides of rare-earth metals, aluminum powder, metal calcium and additives, mixing, loading of the charge in the crucible, initiation metallothermic response to receiving the molten metal and slag phases, the subsequent cooling, unloading and separation of the ingot is C 3-7 min after initiation of the reaction formed in the crucible, the melt is separated from the environment by a metal lid to finish cooling with simultaneous dynamic force on the walls of the crucible within 2-3 minutes

The closing of the crucible metal cover within the specified time period provides the process flow without any heat loss, with full respect for security. Dynamic effects (impacts) provide knocking down the crust formed on the cold walls of the crucible into the melt. The crust melts to form additional quantities of the metal. Thanks to all of this and provides an increase in the extraction of rare earth metals in bullion, as well as increases the overall output of the ingot.

The new method is that the stirring of the mixture is carried out for 10-20 minutes

Stirring of the mixture during this period of time provides a uniform distribution of initial components throughout and, hence, provides better contact of the reacting substances. Thanks to this additionally increases the extraction of rare earth metals in ingot and improve the overall output of the ingot.

The technical result is also solved due to the fact that in the charge to extract rare earth metals from their fluorides metallothermic method containing fluorides of rare-earth metals, aluminum powder, metal is Cai oxide additive in the following ratio of components, wt. %:

Aluminum powder - 1-25

Metal calcium - 25-35

Oxide additive - 14-35

Calcium fluoride - 1-10

Fluorides of rare earth metals - Rest

The introduction of the mixture of calcium fluoride in the specified quantity reduces the melting temperature and viscosity of the resulting slag. In addition, calcium fluoride reduces the concentration of calcium oxide in the slag phase, and accordingly lowers the intensity of the reverse reaction of calcium oxide with metal REM, reducing their losses. Because of this and provides an increase in the extraction of rare earth metals in bullion, as well as increases the overall output of the ingot.

New in the charge is that as the oxide additives it contains oxides of Nickel, iron, manganese, niobia, tantalum, vanadium, titanium, cobalt, chromium, molybdenum, zirconium, boron, barium, or mixtures thereof.

Use as oxide additives of oxides of these metals or their mixtures provides an introduction to the composition of the obtained alloys. While these metals or their combinations ensure the alloys of any required properties.

The inventive method is carried out as follows.

The components of the x components throughout and, consequently, provides better contact of the reacting substances. While stirring the mixture less than 10 minutes will be observed uneven distribution of the reducing agent (metal calcium) in the whole volume of the mixture and consequently bad its contact with the recovered compounds that will lead to reduction process. Mixing more than 20 minutes will also lead to deterioration by removing the REM in the ingot and the total output ingot. This is due to rasshifrovka components according to the weight, additional oxidation of calcium and reduced chemical reaction as a result of friction.

After stirring the mixture loaded into a graphite crucible. Beginning metallothermic reactions initiated by electric blasting and firing the mixture. The heat generated in metallothermic reaction, provides a fusion of the mixture with the formation of the metal and slag phases. 3-7 min after initiation of metallothermic reaction crucible covered by a metal lid, separating the resulting melt from the environment. By this time completed the process of recovery of REE from their fluorides. The closing of the crucible lid prevents heat loss radiation is ü metals from the slag. The time interval of closure of the crucible cover (3-7 min) after initiation of the reaction is explained by the need to guarantee the completion of all metallotrejderskih and other chemical reactions of the process. The closing of the crucible until the end of the chemical reactions will lead to the emission of the charge, and late closure (over 7 min) reduces the efficiency of the process, because the products of melting by this time have time to cool down. Simultaneously with the covering of the crucible cover its walls around the circumference of the subject within 2-3 min dynamic effects (shock). Dynamic impact exercise to beat crust formed on the cold walls of the crucible. The crust is a mixture of slag, metal and unreacted mixture. The collapsed skull gets in the warm melt and melt. The metal of the crust settles to the bottom of the crucible. Thus dynamic effects further enhance the extraction of REE and the ingot. Dynamic effects during a specified period of time to ensure complete collapse of the crust in the melt.

After cooling, the lid is removed and the products of melt discharged from the crucible. After unloading carry out the mechanical separation of the ingot obtained alloy melts with different modes on the mixture of the following composition, wt.%:

Fluorides of rare-earth metals (RF3) - 25

Aluminum powder (Al) - 20

Metal calcium (CA) - 20

Oxide additive (NiO) - 30

Calcium fluoride (Caf2) - 5

The components of the mixture of this composition was weighed, loaded into the mixer, and then was stirred for different period of time in the time interval from 9 to 21 minutes After mixing, the mixture is poured into the crucible and slightly condensed. Metallothermic the reaction was initiated using electric blasting and firing a mixture consisting of KMPO4+Al powder or HLW2CA+. After reduction exothermic reactions, characterized by cessation of smoke emission, the reaction crucible covered with a lid. Closing time the crucible was carried out at different points in time from 2 to 9 min from the beginning of the reaction. Simultaneously with the closing of the crucible lid on his wall and struck with a wooden stick for 2 to 4 minutes After cooling the products of melting were unloaded and made the mechanical separation of ingots from the slag. Data modes carried out of the bottoms and any resulting extraction of REE in the ingot are shown in table. 1.

As can be seen from the specific examples, the inventive method provides a high (96,9 of 97.4 wt. %)of metal from their fluorides metallothermic method contains fluorides of rare-earth metals, aluminium powder, metal calcium oxide additive metal oxides or mixtures thereof, and calcium fluoride in the following ratio, wt.%:

Aluminum powder - 1-25

Metal calcium - 25-35

Oxide additive - 14-35

Calcium fluoride - 1-10

Fluorides of rare earth metals - Rest

Use in the composition of the mixture of fluorides of rare earth metals in combination with the use of metallic calcium as a reducing agent provides for metallothermic reaction high recovery of REE in the ingot. Use in the composition of the mixture of fluorides of rare-earth metals with oxide additive allows for the heat to get a fusible slag, consisting mainly of a mixture of fluoride and calcium oxide. The introduction of the mixture of calcium fluoride reduces the melting temperature and viscosity of the resulting slag (TPL1350-1400oC). This improves the processes of lithoprobe and separation of the phases, thereby improving the overall yield on the ingot. In addition, calcium fluoride reduces the concentration of calcium oxide in the slag phase, and accordingly, reduces the intensity of the reverse reaction of calcium oxide with metal REM, reducing their losses. Thanks atabaki mixture contains oxides of Nickel, iron, manganese, niobia, tantalum, vanadium, titanium, cobalt, chromium, molybdenum, zirconium, boron, barium or mixtures thereof.

Use as oxide additives of oxides of these metals or their mixtures provides an introduction to the composition of the obtained alloys. While these metals or their combinations ensure the alloys obtained any required properties.

Introduction the composition of the charge, and hence the composition of the resulting alloy metal calcium gives the alloy a high fascilitating ability and modifying effect.

The limits of the content of fluorides of rare-earth metals can fluctuate within the range of 20-40 wt.%. The limits of their content and the content of the oxide of the additive in the charge due primarily to the heat generated when recovering a calcium and composition of the formed slag phase. With the increasing content of fluorides of rare-earth metals, more than 40 wt.% and the decrease in the concentration of the oxide supplements below 14 wt.% sharply decreases the specific heat effect of the process. In addition, when the content in the charge of more than 40 wt.% fluoride REM decreases the extraction of rare earth metals in bullion. The excess content of the oxide of the additive over 35% or lower concentrations of REE fluorides below 20% p is, therefore, deterioration of the technological parameters of the process.

Aluminum powder in this case plays the role of inert additives, contributing to the formation of centers of crystallization of the alloy. However, the increase of its concentration in the mixture is more than 25 wt.% reduces the specific heat effect of the process.

Metallic calcium is introduced into the mixture from the stoichiometric calculation required for the restoration of REM with 10-20% surplus for slovoobrazovanie.

Calcium fluoride, as noted above, contributes to the decrease of the melting temperature and viscosity of the slag and to reduce the concentration of calcium oxide, which enters into reaction with the metal REM. Introduction the composition of the charge is less than 1 wt.% calcium fluoride does not affect the properties of the resulting slag and process indicators. Introduction the composition of the charge is more than 10 wt. % calcium fluoride will lead to a significant reduction of the specific heat effect of the process and its metrics.

Specific examples of compounds of the charge in the claimed boundaries of the content of its ingredients, as well as data on the extraction of rare-earth metals in ingot and the output of the ingot are shown in table. 2. When this operation is conducting Ali melting modes N 5, the above table. 1.

As can be seen from the data given in table. 2, the inventive mixture when it is determined in accordance with the inventive method provides for the increase of extraction of REE in the ingot and the ingot.

From the specific embodiments of the claimed invention to any expert in this field there is a clear opportunity to implement them with the simultaneous solution of the set task. However it is also clear that when implementing the invention can be made small changes, which, however, will not go beyond the invention defined by the following claims.

The inventive method is simple to implement, and the mixture does not contain expensive components. The use of fluorides of rare-earth metals in combination with an excess amount of calcium and supplementation with oxides of the above metals or their mixtures provides making alloys obtained any required properties. The obtained alloys can be found the widest application. Most successfully obtained in this way, the alloys can be used in the foundry industry as ligatures.

1. Metallocherpitsy way of toridol rare-earth metals, aluminum powder, metal calcium and additives, mixing, loading the mixture in the reaction crucible, initiation metallothermic response to receiving the molten metal and slag phases, the subsequent cooling, unloading and separation of the ingot from the slag, characterized in that the charge injected calcium fluoride and as an additive oxide additive, and 3-7 min after initiation of the reaction formed in the crucible, the melt is separated from the environment by a metal lid to finish cooling with simultaneous dynamic force on the walls of the crucible within 2-3 minutes

2. The method according to p. 1, characterized in that the stirring of the mixture is carried out for 10-20 minutes

3. The mixture to extract rare earth metals from their fluorides metallothermic method containing fluorides of rare-earth metals, aluminum powder, metal calcium and additives, characterized in that it further comprises calcium fluoride and as an additive oxide additive in the following ratio, wt. %:

Aluminum powder - 1-25

Metal calcium - 25-35

Oxide additive - 14-35

Calcium fluoride - 1-10

Fluorides of rare earth metals On the Lesa, manganese, niobium, tantalum, vanadium, titanium, cobalt, chromium, molybdenum, zirconium, boron, barium or mixtures thereof.

 

Same patents:

The invention relates to the production of master alloys for permanent magnets, metal-based

The invention relates to alloys of gallium
Magnetic alloy // 2119967
The invention relates to the field of magnetic materials, namely, magnetic alloys based on rare earth metals
Magnetic alloy // 2119545
The invention relates to the field of magnetic materials, namely, magnetic alloys based on rare earth metals
The invention relates to a method of producing alloys based on rare-earth metals, scandium and yttrium metallothermic recovery

The invention relates to ferrous metallurgy, in particular, to the extraction and concentration of scandium from multicomponent solutions for the processing of various industrial raw materials, mainly unprocessed red mud from alumina production, waste melts titanium chlorinators, waste mother solutions of zirconium production
The invention relates to hydrometallurgical processing ore concentrates, and more particularly to the processing of loparite concentrate

The invention relates to the field oxide technologically resistant materials, in particular to the processing of ash waste from coal burning, with the purpose of extraction of rare earth and radioactive metals

The invention relates to the hydrometallurgical processing of ore concentrates, and more particularly to the processing of loparite concentrate
The invention relates to hydrometallurgy rare metals and can be used in the technology of extraction of scandium from waste products of titanium and zirconium, when cleaning of scandium from titanium concentrates
The invention relates to a process of producing compounds of rare earth elements (REE) by integrated processing of Apatite

The invention relates to ferrous metallurgy and can be used to obtain a rare non-ferrous metals

The invention relates to ferrous metallurgy and can be used to produce rare metals

The invention relates to the hydrometallurgical processing of ore concentrates, and more particularly to the processing of loparite concentrate

The invention relates to ferrous metallurgy, in particular to the production of sponge titanium magnesium manner, and can be used in the process of reduction of titanium tetrachloride with magnesium

The invention relates to the field of metallurgy production of refractory materials - carbonitrides, namely the creation of a method of obtaining titanium carbonitride, allowing you to create a homogenous product specified composition with a minimum content of free carbon

The invention relates to ferrous metallurgy, in particular to devices for cleaning of titanium sponge from the impurities of magnesium and magnesium chloride by vacuum high-temperature sublimation

The invention relates to the field of metallurgy gallium, and in particular to a method for producing gallium is recovered from geliysoderzhaschih oxides of rare earth metals
Up!