CN85100812A - Use metallothermic reduction of rare earth oxides with calcium metal - Google Patents
Use metallothermic reduction of rare earth oxides with calcium metal Download PDFInfo
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Abstract
Rare earth oxide can be reduced into rare earth metal by a kind of novelty, metallothermic reduction technology efficiently.It is in the fused salt slurry of matrix that rare earth oxide is spread in calcium chloride with the calcium metal, stirs above-mentioned fused salt slurry, allows the calcium metal that rare earth oxide is reduced into rare earth metal.Institute's reductive metal forms discrete layer in reactor.
Description
This invention system adopt up-to-date metallothermics with rare earth oxide particularly neodymium oxides directly be reduced into rare earth metal.The working method of this economy is particularly useful for the production of neodymium-iron-boron magnets raw material-neodymium metal.
Background
The most powerful commercial permanent magnet is once with five cobalt samarium (SmCo
5) sintered powder is raw material.In recent years, the magnet that magnetic force is strong is more also made with lightweight rare earth element especially neodymium, praseodymium and iron, boron alloy.Above-mentioned alloy and the method that is processed into magnet have been done introduction in No. 414936 patents of the U.S. (filing on September 3 nineteen eighty-two), No. 508266 patents (filing on June 24 nineteen eighty-three), No. 544728 patents (filing on October 26 nineteen eighty-three), No. 520170 patents (filing on August 4 nineteen eighty-three) and No. 492629 patents (filing on May 9 nineteen eighty-three).Wherein first three patent is Ke Laoteshi (Croat) patent, and 520170 is Li Shi (Lee) patent, and No. 492629 is Ke Laoteshi and Li Shi patent.Above-mentioned patent right has all transferred General Motors Overseas Corporation.
Ordination number is that 57 to 71 rare earth element and ordinal number are that 39 yttrium all comes from bastnaesite and solitary ore in sand form in the periodic table of chemical element.Beneficiating method by several routines can extract lucium from above-mentioned ore in sand form, the new rare earth that extracts can be separated with liquid-common process such as liquid extracting by elution.
The rare earth oxide of separating should be reduced into metal with as permanent magnet primitive by higher purity (atomic percentage be not less than 95% this will decide on the number of impurity).In the past, this terminal reducing process is promptly complicated, and cost is high again, thereby the price of rare earth metal is very expensive.
Electrolytic reduction and metallothermics are used to the reduction of rare earth metal always.Electrolytic reduction has two kinds: the anhydrous rare earth oxide that (1) will dissolve in alkali slurry or alkaline earth salt slurry is decomposed; (2) rare earth oxide that will be dissolved in the molten slurry of rare earth fluoride salt decomposes out.
The shortcoming of above-mentioned two kinds of electrolytic process is: (1) adds the electrode that must use expensive price and consumer man-hour; (2) must use anhydrous chloride or villiaumite to prevent the generation of rare-earth oxidation salt (as neodymium oxychloride); (3) must carry out high-temperature service (usually above 1000 ℃); (4) current efficiency is low and the power consumption expense is increased; (5) product recovery rate low (rate of recovery has only 40% at most).Give out corrosive chlorine when (6) rare earth oxide reduction is handled, (7) and reduction need careful control electrolysis temperature so that rare earth metal tuberculosis is solidified when handling rare earth fluorine.And an advantage of this method is, as long as the extraction element of reducing metal is set and replenishes the fused salt slurry, the electrolytic reduction operation just can be carried out continuously.
The step of metallothermics (non-electrolytic reduction) includes two kinds: (1) is with calcium metallic reducing rare earth fluorine (being called calciothermy); (2) with hydrolith or calcium metallic reducing-diffusion rare earth oxide.The shortcoming of metallothermics is to be used for continuity production, and must operate in oxygen-free environment, thereby power consumption is bigger.The powdery rare earth product that reduction-diffusion generates must be purified and can use through aquation.Two kinds of technologies are divided equally multistep and are implemented.An advantage of metallothermics is that the revert back yield of rare earth metal from oxide compound or fluorochemical usually is higher than 90%.
All have rare earth fluorine or muriate to participate in when reacting, and should anticipate rare earth oxide to produce halogenide.Set up the cost that this operation will increase rare-earth products.
Along with the appearance of lightweight rare-earth-iron alloy permanent magnet, the demand of the rare earth metal that people are lower to price, purity is higher increases greatly.Yet, none rate of recovery that can reduce the production cost of rare earth metal significantly or improve this magnet level metal of existing rare earth compound reduction method.Therefore, providing a kind of novel and high-efficiency and comparatively economic rare earth metal extraction method is aim of the present invention.
General introduction:
Preferentially implementing this according to the following steps invents described method and is expected to obtain certain effect.
Reactor by resistance heater or other well heater heat supplies is set, the most handy metal of reactor or height inertia and the harmless heat-stable material of reactive component made.
The rare earth oxide input of pre-determined quantity is filled the reactor that fused salt mixt is starched (containing the calcium chloride of 70% above weight part and the sodium-chlor of 5-30% left and right sides weight part), and above-mentioned fused salt slurry plays a part the reduction reaction media.Number with rare earth oxide is a foundation, and the calcium metal that surplus is arranged on stoichiometry is added the fused salt slurry.Preferably a certain amount of iron or zinc are added in the fused salt slurry, make it to form low melting point alloy with the temperature that reduces reduction reaction and under liquid condition, extract the rare earth metal product with the reductive rare earth metal.
In reduction process, the Heating temperature of reactor is higher than the fusing point (about 675 ℃) that reacts composition.After the fusing of reaction composition, should stir rapidly, so that various compositions are in contact with one another in reaction process.Can in the fused salt slurry, replenish calcium chloride in case of necessity, so that make its weight part account for 70% of calcium chloride and sodium-chlor gross weight.If the concentration of calcium chloride is lower than 70% during reaction, the rate of recovery of rare earth metal will descend rapidly.
During reduction reaction, occur good several antagonistic chemical reactions in the reactor, but the reduction of rare earth oxide is estimated to realize by following empirical response formula:
In the formula, RE is a rare earth metal, and n and m are the mole number of reaction composition, and the relation of n and m depends on the oxidation situation of rare earth element.
The density of the metal that reduction generates is about 7 gram per centimeters
3And the poor density of salt is 1.9 gram per centimeters
3After stopping to stir, the reductive rare earth metal forms purified metal level in the bottom of reactor.This metal level can be discharged when fusing, also can separate from molten salt layer after curing.
This shows that this technology is more superior than look-ahead technique in many aspects: when the reduction temperature lower (about 700 ℃) that this technology is used, particularly rare earth metal and zinc or iron formed low melting point alloy, its reduction temperature was lower; Use comparatively cheap rare earth oxide, calcium chloride, sodium-chlor and sodium metal reactant; Do not need in advance rare earth oxide to be changed into muriate or fluorochemical, need not use expensive pure calcium or hydrolith (CaH yet
2) reductive agent; This technology is not electrolysis process, thereby power consumption seldom, and can be fine enforcement under 700 ℃ the condition of normal pressure in temperature preferably.This technology both can be used for the also original production of batch of rare earth metal, can be used for also original production of continuity again, and the by product that calcium chloride, sodium-chlor and calcium oxide produced in the reaction process is easy to dispose.In addition, rare earth metal can be in reactor be melt into the rare-earth-iron low melting point alloy with the iron that adds, and also can not need further in addition expensive purification process directly making the rare-earth-iron alloy magnet afterwards.
Describe in detail
Can understand the purpose and the advantage thereof of this invention preferably by following detailed description and diagram:
Figure 1 shows that the device that is applicable to the anti-former reaction of rare earth oxide.
Figure 2 shows that neodymium oxides (Nd
2O
3) technical process of generation low melting point neodymium alloy with the calcium reaction.
Figure 3 shows that the neodymium metal is from neodymium oxides (Nd
2O
3) in the function curve diagram that reverts back the calcium oxide per-cent in the molten slurry of yield and flux.
This invention relates to the advanced method that rare-earth compound is reduced into rare earth metal.Thulium comprises No. 39, the 57th to No. 71 element, i.e. yttrium (Yt) scandium (Sc), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) and lutetium (Lu) in the periodic table of elements.Rare earth oxide generally is the colored powder that generates in the metal separation process.So-called herein " lightweight rare earth " refers to lanthanum, cerium, praseodymium and four kinds of elements of neodymium.
When implementing this invention, rare earth oxide is general to be used once separated, but also can calcine earlier to remove the excessive moisture or the carbonic acid gas of the occlusion of oxide compound institute.In the test examples hereinafter, rare earth oxide is dried about 2 hours sides earlier and is come into operation under 1000 ℃ the condition in baking oven.Repone K and sodium-chlor as the fused salt slurry belong to reagent grade and stand 500 ℃ oven dry in about 2 hours before use.At the experiment initial stage, the author strictly controls reactor, does not allow moisture content enter reactor in order to avoid sodium or calcium and moisture content produce hazardous reaction.When adding to calcium in the fused salt slurry that contains sodium-chlor, reaction generates a small amount of sodium metal, and its reaction formula is as follows:
Neodymium oxides (Nd
2O
3) when mixing with the fused salt slurry, reaction generates oxychloride, its reaction formula is as follows:
The existence meeting of this class rare earth oxychloride reduces the rate of recovery of rare earth metal when electrolytic reduction reacts.Yet this invention can utilize calcium metal reduction of rare earth oxides and rare earth oxychloride easily.In fact the formation of rare earth oxychloride is very helpful, because this rare earth oxychloride can float the surface of reductive rare earth metal.But, the density of rare earth oxide and reduction of rare earth metal similar, thereby it may become impurity and carries over and make the reductive metal can't be used as the magnet raw material.The author institute reductive rare earth metal belongs to the anaerobic metal largely.
The fusing point of pure neodymium metal is about 1025 ℃, and the fusing point of other rare earth metal is also very high.Temperature of reaction can transfer to above-mentioned melting temperature to the greatest extent and can obtain the high yield pure rare-earth metals.But be preferably in the reactant and add a certain amount of iron, zinc or other is nonmetal, make it and the rare earth metal that reclaims forms liquid low melting point alloy.For example, iron can form low melting point alloy with neodymium (weight part of iron is 11.5%; The fusing point of alloy is about 640 ℃), zinc also can form low melting point alloy with neodymium, and (weight part of zinc is 11.9%; The fusing point of alloy is about 630 ℃).If at neodymium oxides (Nd
2O
3) adding the iron of capacity in the restoring system, the reductive metal will melt when 640 ℃ of left and right sides.Making the neodymium-iron low melting point alloy of magnet can directly produce by adding iron and boron, and this magnet has best neodymium iron boron (Nd
2Fe
14B) magnetic phase (seeing last described United States Patent (USP)).
Desire reduces the fusing point of the rare earth metal that is reclaimed and removes to reducing the metallic element that fusing point adds, and boiling point can be added in the reactor well below the metal that reclaims rare earth.For example, the boiling point of zinc is 907 ℃, and the boiling point of neodymium is 3150 ℃.Can easily the lower boiling metal separation in the alloy be come out by simple distillating method.
The material that is used for reactor answers carefulness to select, because the rare earth metal that the rare earth metal of fusing particularly is retained in the salt flux environment has corrodibility.The aluminium nitride of yttrium and boron nitride material do not react and are very heat-resisting, thereby are often used as reactor.Go back height in hand inert tantalum (Ta) or materials such as expendable but avirulent iron in addition and make heat-resisting reactor.The irony reactor can be used to contain the reductive rare earth metal and is melt into alloy to be used as the magnet raw material with the heel rare earth.The author has proposed a kind of novel method of utilizing the sodium metal to come reduction of rare earth oxides on the basis of this invention.When adopting this method, must make calcium and rare earth oxide the fusing and react, its reaction formula is as follows:
If, then temperature should be controlled at the waste that increases sodium below 910 ℃ in order to avoid sodium-chlor and calcium react salify to the reactor pressurization.Be preferably under the condition of normal pressure and carry out.Best working temperature is between 650-750 ℃.Under the said temperature condition, the wearing and tearing of reactor are not too serious.The said temperature scope is suitable for neodymium oxides (Nd
2O
3) to the neodymium alloy reduction, because the fusing point of neodymium-iron and neodymium-zinc low melting point alloy is lower than 700 ℃.In addition, when 700 ℃ of left and right sides, but the solubility of calcium metal in the fused salt slurry is about 1.3% mole percent.But this solubility has been enough to make rare earth oxide to be reduced into metal rapidly.
Desire to make the reductive metal to have well with flux and separate, temperature of reaction should be higher than the fusing point of reducing metal or be higher than rare earth alloy or the fusing point of coreduction rare earth metal.Rare earth metal that this density is bigger and alloy just can be with fixed attention in the bottoms of reactor after settling out.The reduction of rare earth metal can be discharged when fusing, or takes out after curing.Table 1 has been listed the rare earth element that this invention uses and molecular weight, density, fusing point and the boiling point of rare earth compound under 25 ℃ of conditions.
Table 1
Molecular weight density fusing point (℃) boiling point (℃)
Neodymium 144.24 7.004 1,024 3300
Neodymium oxides (Nd
2O
3) 336.48 7.28 1900-
The neodymium oxychloride
b(NdOCl) 195.69 5.50
Calcium 40.08 1.55 850 1494
Calcium oxide 56.08 3.25 2,927 3500
Iron 55.85 7.86 1,537 2872
Zinc 65.37 7.14 419.6 911
Calcium chloride 110.99 2.15 772 1940
Sodium-chlor 58.45 2.164 801 1465
55 weight part calcium chloride-1.903*
45 weight part sodium-chlor
Sodium-chlor 1.569*
Calcium chloride 2.104*
The b-calculated value
*-numerical value when 1000 ° of K
Figure 1 shows that the device that is applicable to this invention, several tests cited herein are implemented with this device just.
All tests all are to carry out in dark burner hearth (20), and the burner hearth internal diameter is 12.7 centimetres, and the degree of depth is 54.6 centimetres.Burner hearth is installed on the loft drier table top (4), and table top is fixing with bolt (6).During test, be filled with helium in the loft drier, wherein the content of oxygen, nitrogen and moisture content all is controlled at below the 1PPm.
Smelting furnace is by three sections tubulose clamshell electricradiators (8,10,12) heat supply.The internal diameter of well heater is 13.3 centimetres, and total length is 45.7 centimetres.The inwall of burner hearth and bottom all are surrounded by high temperature insulation thing (14).On vertical each position of burner hearth (20) outer wall (16) thermopair (15) is housed.The thermopair and the direct ratio district temperature regulator (not retouching out) that are installed on the central position cooperatively interact with Automatic Centering Control's clamshell well heater (10).Its excess-three thermopair is monitored by the digital temperature indicating system, and top and bottom clamshell well heater (8,12) are then by manually controlling with the temperature in the whole smelting furnace of equilibrium by transformer.
Reduction reaction is carried out in reactor (22), and reactor jacket is loaded in the Stainless Steel Crucible (18), and crucible then is set in the stainless steel burner hearth (20), and crucible (18) external diameter is 10.2 centimetres, and dark 12.7 centimetres, wall thickness is 0.15 centimetre.If do not add explanation in addition in test examples, reactor (22) is all made with metal.
Tantalum matter agitator (24) is used for stirring the metal melt in the reduction reaction process.Long 48.32 centimetres of the axostylus axostyle of agitator is welded with a slice agitating vane (26) on the axostylus axostyle.Agitator is no more than 100 watts of variable speed motors (28) of 700 rev/mins by rotating speed and drives.Motor is installed on the bearing (30), thereby the degree of depth of agitating vane in reactor can be adjusted.The neck of agitator axostylus axostyle is equipped with axle sleeve (32), and axle sleeve is fixed in the annular ledge (34), and bearing is clamped by neck ring (35), and burner hearth (20) then is fastened on the neck ring by bolt (37).Water coolant coiled pipe (36) is installed with the condensation of quickening the volatilization composition near burner hearth (20) top and is prevented that volatile composition from escaping.Cone-shaped stainless steel flow blocking piece (38) the sodium steam that is used for refluxing.The product that refluxes flows down on bottom the flow blocking piece (42) by pipeline (40).
Stir if when reaction finishes, stop, reaction composition in the smelting furnace will form stratiform and be separated from each other, wherein rare earth alloy layer (40) will form at bottom, rare earth oxychloride, calcium chloride or sodium-chlor molten salt layer (43) form on alloy layer, and unreacted sodium and calcium metal level (44) then are in the superiors.
Fig. 2 is the neodymium oxides (Nd that has idealized according to the principle of this invention
2O
3) be reduced into the technical process of neodymium metal.With neodymium oxides (Nd
2O
3) drop into reactor by proper proportion with sodium-chlor, add eutectic metals such as calcium and an amount of iron or zinc in addition again to make approximate eutectiferous alloy.During reduction reaction, stir molten slurry rapidly at least 1 hour, stirring velocity is about 300-700 rev/min, and temperature is about 700 ℃, and the top of reactor preferably charges into noble gas (as helium).Neodymium oxides (Nd
2O
3) be reduced after, should stop then stirring with about 100 rev/mins stirred 1 hour than jogging speed, allow the various compositions in the reactor form stratiforms.The reductive low melting point alloy is because of the maximum bottom that is deposited on reactor of density, and remaining fused salt and unreacted calcium then are deposited on above the neodymium alloy, and this class composition is separating with alloy with being easy to after reactor cooling after the curing.Neodymium-iron alloy of producing thus can form alloy and produce the permanent magnet composition with the element that adds.Above-mentioned coupernick can fuse-revolve makes magnet, also can clay into power, and then smelt into magnet.
Example 1
With 265 gram purity is that 99% neodymium metal block and 50 gram purity are that 99.9% zinc metal is knocked down the matter crucible and made 315 grams and be similar to eutectiferous alloy.Crucible is heated to 800 ℃ to produce neodymium-zinc alloy after packing into burner hearth.
After the temperature of smelting furnace is lowered to about 720 ℃, add 150 gram sodium-chlor and 350 gram calcium chloride, make the weight part of calcium chloride in the fused salt slurry become 70%, add 234 gram (0.7 mol) neodymium oxides (Nd subsequently
2O
3).104 gram (2.6 mol) calcium metals are added crucible and stirred about 2 hours, continue to stir 1 hour with 60 rev/mins speed then with 300 rev/mins rotating speed.After finishing, take out crucible, place it on the loft drier table top and cool off.
Neodymium-zinc alloy of collecting from furnace bottom obtains 189 gram purity and surpasses 99% metal after distillation.The rate of recovery of the neodymium metal that reclaims from oxide compound is 94%.
Example 2
With 350 gram purity is that to drop into wall thickness be to be melt into 414 grams in 6 millimeters the soft steel reactor to be similar to eutectiferous alloy for 99% neodymium metal block and 64 gram electrolytic irons.Reactor packs into and is heated to 800 ℃ and neodymium and iron are melt into alloy behind the burner hearth.
After being reduced to the temperature of smelting furnace about 720 ℃, adding 300 gram sodium-chlor and 700 gram calcium and make the weight part of calcium chloride in the fused salt slurry become 70%, add 117 gram (0.35 mol) neodymium oxides (Nd subsequently
2O
3), add 46 gram (1.15 mol) calcium metals and 10.8 gram (0.47 mol) sodium then and stirred 135 minutes with 300 rev/mins speed, at this moment, add 117 gram (0.35 mol) neodymium oxides (Nd more in addition
2O
3), 46 gram (1.15 mol) calcium metals and 108 gram (0.47 mol) sodium stirred 114 minutes with 300 rev/mins speed.The speed of using 60 rev/mins thereafter instead stirred 1 hour.At last crucible is taken out from smelting furnace and is placed on the loft drier table top and cool off.Unreacted calcium-sodium metal level forms on molten salt layer.
Neodymium-the iron alloy that reclaims is 594 grams, and purity is 97%.This alloy once reclaim can be directly and iron and boron fuse into ideal neodymium-iron-boron alni magnet material.180 gram purity are higher than 99% neodymium metal and can be reduced to the Nd-Fe alloy.This example is shown to the fusion of calcium metal and sodium metal, can be at 1CaCl
2Reduction of rare earth oxides in the flux pool of-NaCl.
Example 3
Table 2 has been listed with calcium metallic reducing 234 gram neodymium oxides (Nd
2O
3) time required various compositions quantity, test method is identical with example 2, different is earlier with 300 rev/mins speed reaction stirred 4 hours, stirs 1 hour with 60 rev/mins speed again.
Table 2
The total fused salt calcium of sample calcium chloride sodium-chlor sodium eutectic extracts and reclaims
Numbering (weight ((the weight rate in the weight (gram) (gram) (gram)
Per-cent) per-cent) amount per-cent) (gram) (%)
1＊????65.5????34.5????740????66.7????-????88.9????62.2????65.2
2????90????10????786????91.7????-????88.2????170.5????85.3
3????90????10????1178????104.2????-????90.2????195.7????97.8
* 117 restrain neodymium oxides (Nd
2O
3)
Calcium chloride and the sodium-chlor weight percent in fused salt slurry is respectively 60% and at 40% o'clock, the rate of recovery of neodymium metal has only 49.5%, weight percent is respectively 65.5% and at 34% o'clock, the rate of recovery brings up to 65.2%, the weight percent of calcium chloride is 70% or surpasses at 70% o'clock, and the rate of recovery of neodymium all surpasses 85% and usually above 95% in all cases.Fig. 3 demonstrates, and is funtcional relationship with respect to the neodymium metal recovery rate of neodymium oxides and the weight percent of the calcium chloride in the initial fused salt slurry of the two components of sodium-chlor-calcium chloride.The author finds that from table 2 and Fig. 3 desire improves the rate of recovery of neodymium metal, the weight percent of calcium chloride must be remained on more than 70%.In addition, the volume ratio of fused salt and rare earth oxide should not be lower than 2: 1, so that provide enough flux to disperse rare earth oxide.The author has found that, along with of the increase of fused salt slurry with rare earth oxide capacity ratio, stirring velocity can corresponding reduction so that in the specific time, obtain the same rate of recovery.The fused salt slurry that contains calcium chloride is the marrow of this invention.
Once with the mixed use of several samples and by vacuum distilling removal zinc wherein.Analytical results shows that the purity of the rare earth alloy that is reclaimed is high by 99%, and wherein the content of aluminium is 0.4%, silicon 0.1%, impurity such as the zinc of calcium 0.01% and trace, magnesium and iron.The neodymium metal of producing thus enters vacuum oven with electrolytic iron and ferroboron and is fused into alloy, and the content of wherein various nominal compositions is respectively: neodymium 15%, boron 5%, iron 80%.This class alloy revolves by the described method fusing of No. 414936 patents of the U.S. makes superfine crystal zone, and the Coercive Force of its as-quenched condition is about 10 mega gaussorersteds.
Although this invention relates generally to the reduction problem of neodymium oxides, this technology is equally applicable to the reduction of other simple substance or composite rare-earth oxide, and its reason is that calcium oxide is all stablized than other any rare earth oxides.The people who no doubt is skillful in this industry can determine the relative free energy of rare earth oxide and calcium oxide in the past, but before this invention was come out, nobody knew that rare earth oxide can be reduced by the calcium electrolytic etching of metal under liquid-phase condition.The oxide compound of transition metal such as iron and cobalt can reduce simultaneously by this technology and rare earth oxide where necessary.
In a word, the author has invented a kind of novelty, efficient and expensive less method so that rare earth oxide is reduced into rare earth metal.When using this method, must prepare with calcium chloride is the fused salt slurry of matrix, and rare earth oxide is stirred therein, and the deal of calcium metal is wherein wanted to make rare earth oxide be reduced into metal.After stopping to stir, the component in the fused salt slurry is deposited as discrete layer, this discrete layer cold unload and solidify after can be separated from each other.Another kind method is to discharge reductive rare earth metal liquid from the bottom of reactor.After molten metal is discharged, can replenish flux to carry out continuity production to reactor.
Though I have referred to the concrete implementation issue of this invention, but the stager can be applied in a flexible way to other forms.Therefore, this scope of invention only is subjected to the restriction of following claim.
Claims (17)
1, by metallothermics the rare earth oxide in the fused salt slurry is reduced into rare earth metal, its reaction formula is as follows:
In the formula, RE is a kind of or several rare earth elements, and n and m are numeral, and its relative value is decided by the oxidation situation of rare earth.
2, by metallothermics the neodymium oxides in the fused salt slurry is reduced into the neodymium metal, its reaction formula is as follows:
3, by non-electrolytic reduction rare earth oxide is reduced into rare earth metal.Comprising concrete grammar have: the flux of calcium chloride is melt into salt slurry; The rare earth oxide of pre-determined quantity is added in the above-mentioned fused salt slurry; Add in the above-mentioned fused salt slurry according to the number of fused salt slurry middle-weight rare earths oxide compound and with the calcium metal that surplus is arranged on the stoichiometry; Make above-mentioned fused salt slurry keep molten state also to be stirred, so that allow the calcium metal that rare earth oxide is reduced into rare earth metal.
4, by non-electrolytic reduction neodymium oxides is reduced into the neodymium metal.Method wherein is: the flux that contains calcium chloride is melt into the salt slurry; The neodymium oxides of pre-determined quantity is added in the above-mentioned fused salt slurry, add in the fused salt slurry according to the number of fused salt slurry middle-weight rare earths oxide compound and with the calcium metal that surplus is arranged on the stoichiometry again; Make above-mentioned fused salt slurry be in molten state and also stirred, to allow the calcium metal that neodymium oxides is reduced into the neodymium metal.
5, by non-electrolytic reduction rare earth oxide is reduced into rare earth metal.Method wherein is: the flux that contains 70% above weight part calcium chloride is melt into the salt slurry; The rare earth oxide of pre-determined quantity is added in the above-mentioned fused salt slurry, add in the above-mentioned fused salt slurry according to the number of fused salt slurry middle-weight rare earths oxide compound and with the calcium metal that surplus is arranged on the stoichiometry again; Make above-mentioned salt slurry be in molten state and also stirred, to allow the calcium metal that rare earth oxide is reduced into rare earth metal; Stop to stir, make rare earth in the fused salt slurry, form discrete metal level.
6, the rare earth oxide in the described method of claim 5 means a kind of or several rare earth oxides, and this type oxide is lanthanum-oxides, cerium oxide, praseodymium oxide and neodymium oxides.
7, with neodymium oxides (Nd
2O
3) method that is reduced into the neodymium metal is: will contain the calcium chloride of 70% above weight part and the flux of taring thing sodium-chlor and be melt into the salt slurry; A certain amount of neodymium oxides (Nd
2O
3) add in the fused salt slurry, its capacity is lower than 50% of fused salt slurry capacity; According to the number of neodymium oxides in the fused salt slurry calcium metal that surplus is arranged on the stoichiometry is added in the fused salt slurry; The temperature that above-mentioned fused salt is starched is higher than the fusing point of fused salt; Stir above-mentioned fused salt slurry so that various composition mixes mutually, continue to stir, until most neodymium oxides (Nd
2O
3) be reduced into till the neodymium metal; Stop stirring and make the reaction composition be in molten state, do not contain neodymium oxides (Nd to allow reductive neodymium metal form therein
2O
3) the discrete metal layer of impurity.
8, the method that a kind of or several rare earth oxides is reduced into rare metal is: earlier calcium chloride and sodium-chlor are melt into the salt slurry, wherein the weight percent of calcium chloride is at least 70%; A certain amount of rare earth oxide is added above-mentioned fused salt slurry, and its addition is no more than 50% of fused salt slurry capacity; Add a certain amount of calcium metal subsequently in fused salt slurry, its addition should be enough to reduce rare earth oxide wherein; The temperature that fused salt is starched is higher than the fusing point of flux; Stir above-mentioned fused salt slurry, wherein each kind of composition mixed mutually; Continue to be stirred to rare earth oxide basically Restore All become till the metal; Stop stirring and make the fused salt slurry be in molten state, make the reductive rare earth metal form discrete metal level therein.
9, the method that makes a kind of or several rare earth elements and iron form alloy is: weight percent is at least 70% calcium chloride and the sodium-chlor of 5-30% is melt into the salt slurry; The rare earth oxide of pre-determined quantity is added in the above-mentioned fused salt slurry, add a certain amount of calcium again, the addition of calcium should be enough to make rare earth oxide reduction wherein; Making above-mentioned fused salt slurry be in molten state is also stirred to allow the calcium metal that rare earth oxide is reduced into rare earth metal; A certain amount of iron is added in the above-mentioned fused salt slurry, and its addition should be enough to form the iron-rare earth alloy of fusing point well below the rare earth metal fusing point; Stop to stir, allow iron-rare earth alloy be deposited as discrete layer.
10, the rare earth oxide in the described method of claim 9 means a certain in lanthanum-oxides, cerium oxide, praseodymium oxide and the neodymium oxides or several.
11, the rare earth oxide in the described method of claim 9 means neodymium oxides.
12, the method that makes a kind of or several rare earth elements and zinc form alloy is: weight percent is at least 70% calcium chloride and the sodium-chlor of 5-30% is melt into the salt slurry; The rare earth oxide of pre-determined quantity is added in the above-mentioned fused salt slurry, add a certain amount of calcium again.The addition of calcium should be enough to make rare earth oxide reduction wherein; Making above-mentioned fused salt slurry be in molten state is also stirred to allow the calcium metal that rare earth oxide is reduced into rare earth metal; A certain amount of zinc is added in the above-mentioned fused salt slurry, and its addition should be enough to form the zincium-rare earth alloy of fusing point well below the rare earth metal fusing point; Stop to stir, make the zincium-rare earth alloy deposition become discrete layer.
13, the rare earth oxide in the described method of claim 12 means a certain in lanthanum-oxides, cerium oxide, praseodymium oxide and the neodymium oxides or several.
14, the rare earth oxide in the claim means neodymium oxides.
15, make a kind of or several rare earth elements and method a kind of or that several non-rare earth metals form low melting point alloys be: weight percent to be at least 70% calcium chloride and the sodium-chlor of 0-30% is melt into the salt slurry; The rare earth oxide of pre-determined quantity is added in the above-mentioned fused salt slurry; Adding according to the number of fused salt slurry middle-weight rare earths oxide compound has the calcium of surplus metal on the stoichiometry; Make above-mentioned fused salt slurry be in molten state and also stirred, to allow the calcium metal that rare earth oxide is reduced into rare earth metal; The non-rare earth metal of some amount is added in the above-mentioned fused salt slurry, and its addition should be enough to form the rare earth-non-rare earth alloy of fusing point well below the rare earth metal fusing point; Stop to stir, allow rare earth-non-rare earth alloy be deposited as discrete layer.
16, the rare earth oxide in the described method of claim 15 means a certain in lanthanum-oxides, cerium oxide, praseodymium oxide and the neodymium oxides or several.
17, the rare earth oxide in the claim 15 means neodymium oxides.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US65970284 | 1984-10-05 | ||
| US695,702 | 1991-05-03 |
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|---|---|
| CN85100812A true CN85100812A (en) | 1986-09-03 |
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| CN 85100812 Pending CN85100812A (en) | 1984-10-05 | 1985-04-01 | Use metallothermic reduction of rare earth oxides with calcium metal |
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- 1985-04-01 CN CN 85100812 patent/CN85100812A/en active Pending
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