JPH0120214B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to rare earth phosphate minerals (which have been conventionally used as raw ores in the smelting of rare earth metals such as Ce, Nd, Pr, La, Gd, and Sm). RPO ₄ , R is a rare earth element, hereinafter referred to as massive monazite or monazite (monazite or RPO ₄ ); or fluorocarbon salt mineral (RFCO ₃ ), bastnaesite (hereinafter referred to as monazite or RPO 4); Bastnaesite or
RFCO ₃ ), other Xenotime (Xenotime,
Processing to obtain rare earth hydroxide or rare earth chloride by treating one type of concentrate powder, mainly yttrium phosphate, _YPO4 ) gadolinite, etc., or a mixed concentrate powder containing one or more types, using a physicochemical treatment method. It relates to an improved method or process or a new treatment method, a kind of physical or electrical and chemical treatment method, which simplifies the treatment process, saves energy and resources, and reduces the types and amounts of chemicals used. It is a low-cost treatment method, and it is also possible to treat concentrate powder both batchwise and continuously, and is also suitable for reduction treatment of mixed concentrate powder of monazite and bastnaesite, for example. The treatment can be carried out regardless of the type of concentrate raw material powder, and according to a more preferred embodiment of the present invention, rare earth hydroxide (R(OH ₃ )) or rare earth chloride ( RCl ₃ ) is an extremely useful treatment that has high treatment efficiency and can extremely reduce the amount of harmful liquids and gases generated during treatment operations and operations, eliminating the need for large-scale pollution treatment equipment. This method is a decomposition and reduction method of rare earth concentrate powder (monazite, bastnasite, etc.).

As a chemical treatment method for rare earth element concentrates, dry methods such as arc furnace method and chlorination treatment method are considered, but wet method sulfuric acid treatment method is generally widely used, and some In this case, the alkaline (caustic soda) method is used.

However, in the above sulfuric acid treatment method and alkaline method, concentrated sulfuric acid such as 93% sulfuric acid and 45%
Not only is it essential to use a strong alkali such as NaOH, but the treatment with the acid and alkali is maintained at a high temperature of 200 to 250°C for the former, and around 150°C for the latter for several hours. It was necessary to carry out processing, which caused various problems.

For example, when treating monazite with a sulfuric acid treatment method, the generation of a large amount of SOx is unavoidable, and for this reason, the alkaline method seems to be frequently used these days, but it has the problem of generating a large amount of alkali mist. On the other hand, the above-mentioned alkaline method cannot be applied to bastnaesite, so it relies on the sulfuric acid treatment method, which generates large amounts of SOx and HF.
The installation of large-scale waste gas treatment equipment is essential, which not only poses problems in terms of energy and resource conservation, but also makes rare earth metals expensive.

As concentrates (powders) of rare earth elements, monazite and bastnasite are often produced and collected separately. In some cases, it is obtained as a mixed concentrate of monazite and bastnaesite (approximately 40% monazite and 60% bastnasite), and in the case of such a mixed concentrate, sulfuric acid, which requires extensive waste gas treatment. Avoid processing methods,
If an alkaline method is applied, the alkaline method is almost ineffective against bastnaesite.
The bastnaesite concentrate was wasted, the yield of rare earth elements was low, and even though large and expensive pollution treatment equipment was required, sulfuric acid treatment was the only method, which caused various problems.

The present invention has been proposed in view of the above-mentioned points. Contains an electrolyte at a lower concentration as necessary than the acid or alkali used in the chemical treatment method using the acid or alkali method, and more preferably in an amount sufficient to decompose and reduce the rare earth compound. By mixing with an aqueous solution of an acid, alkali, or neutral salt electrolyte containing inorganic and organic concentrations as low as possible, muddy, sludge-like,
A mixed or kneaded product in the form of mud and sand, peat, mud, mud lumps, or slurry is heated by supplying high-frequency power to the mixed or kneaded product, and in the mixture or kneaded product. to generate a discharge,
The ore or concentrate powder is brought into contact with a discharge region, preferably a discharge column, to decompose and reduce it, and if necessary, a treatment step such as thorium separation may be added or passed through. , ultimately usually rare earth hydroxide (R(OH) ₃ )
Or, it is a refining treatment to convert electrolytes such as RCl ₃ or R ₂ (SO ₄ ) ₃ into complex salts or double salts. Depending on various conditions, it is possible to raise the overall temperature of the mixed or kneaded product, but it is also possible to process it at a low temperature of around 150°C or lower, for example. In the subsequent refining process such as rare earth metallization, for example, in the case of the rare earth hydroxide, hydrochloric acid is added and acid-dissolved to generate rare earth chloride (RCl ₃ ), and the rare earth chloride is electrolyzed with molten salt to produce crude metal. However, the post-process is as described above. Refining such as metallization is carried out by various conventionally known electrolytic methods, hydrogen reduction methods, metal reduction methods, etc., or further methods such as separation by adsorption on an ion exchange resin.

Figure 1 of the drawing shows heating the mixture or kneading of the rare earth ore powder (recent ore powder) and electrolyte aqueous solution, and heating the mixed or kneaded product individually and locally and over time in the mixed or kneaded product. Electric power for mainly high-frequency induction heating of the mixed or kneaded material (this power can be used at a frequency of about 50 Hz to 100 KHz, but preferably usually 30 KHz to 30 KHz). This is an explanatory diagram of an example in which a high frequency power of about 100 KHz is used, and as described later, for example, a high frequency power of 40 KHz is used. 1 preferably has at least its inner wall surface corrosion resistant such as acid and alkali resistance, and if necessary. It is a sealable processing container having a certain degree of pressure resistance, and has an opening/closing door 1 for inserting, installing, and taking out objects to be processed 2.
a, and a processing installation shelf or stand 1b for the object 2 to be processed. The object to be processed 2 has, for example, 200 to 400
Add and mix the amount of water necessary to mix and knead a predetermined amount of electrolyte and the like into a mesh-sized concentrate powder, such as before and after meshing, to form a uniformly mixed, integrated state, or a slightly larger amount of water. The mixture is kneaded into a kind of clay-like or mud-like mixture, and is stored in a saucer 3 made of a high-resistance material or insulating material, such as ceramics or synthetic resin, which is hardly heated by high-frequency induction heating. and placed on the stand 1b. Reference numeral 4 denotes a high-frequency induction heating coil installed in the container 1 and having a cooling means (not shown) as required, 4a is a high-frequency power source thereof, and 5 is the magnitude of high-frequency power supplied from the power source 4a. energy, supply time,
In addition, there is a control device that controls various supply modes such as intermittent supply, on/off, etc., and 6 is a control device that detoxifies various gases and mist generated by heating and discharging the mixed workpiece 2 as appropriate or constantly. 7 is an exhaust means for exhausting, collecting and transporting the inside of the processing container 1 to promote processing reactions, to prevent fire and other dangers, or to prevent exhaust gas and mist from pollution, etc. This means adjusts and controls the atmosphere by supplying gas or the like in order to facilitate the processing, or to bring the inside of the container 1 into an appropriate state of depressurization or pressurization, heating or cooling.

In addition, when talking about rare earth concentrate powder, raw ore is mined and crushed to obtain concentrate, this powder concentrate is subjected to specific gravity beneficiation to remove silica sand, etc., and then electromagnetic to remove iron ore powder. This seems to refer to concentrate powder with a rare earth content of about 60% after beneficiation, but the treatment method of the present invention usually treats such rare earth concentrate powder and uses heating energy etc. Although it prevents the loss of consumed high-frequency power, it is also effective as a treatment method itself, for example, for those that contain silica sand, iron ore, etc. before specific gravity beneficiation, and have a small content ratio of rare earth concentrate. Therefore, the rare earth concentrate powder includes, for example, those in the concentrate stage containing many impurities, such as coarse concentrate powder.

Although the rare earth concentrate powder itself is a high resistor or an insulator and a high dielectric material, the mixed object 2 has a resistance of about several Ωcm due to the addition and mixing of the electrolyte and water. It is heated using the principle of high-frequency induction heating, and when the mixture to be treated 2 reaches a temperature of around 100℃ or higher, the water contained in the mixture evaporates, and the gas contained therein also gasifies, forming bubbles. is generated in various places inside and released to the outside, and due to the generation of bubbles, the mixture to be processed 2
The eddy current generated by the high-frequency current in the coil 4 is in a kind of disconnected state, and locally minute or spark discharges are dispersed to various parts of the whole.
At first glance, rare earth concentrate powder appears in dots with a bluish-white to red shape, and is exposed to the generated micro-discharge column, where it is decomposed and reduced by the high temperature and the action of the intervening electrolyte, and is then used. Depending on the type of electrolyte, the above electrolyte may be, for example, caustic soda (NaOH).
In this case, rare earth hydroxide (R(OH) ₃ ) will be produced. In other words, since the mixed workpiece 2 contains and contains water, as long as this water remains to a certain extent, it will be heated to a high temperature of approximately 200°C or higher unless it is heated at a particularly high speed and with high energy. It will never become
At around 100℃, some of the concentrate powder is chemically dissolved or reduced in acid or alkali depending on the type of electrolyte, or in a state close to it, and the concentrate powder is dissolved by the generation of the minute or spark discharge. is interposed in an electrically discharged region, preferably in contact with a column of micro or spark discharges, thereby promoting chemical reactions such as decomposition.

FIG. 2 of the drawings shows a method in which the mixture to be treated 2 is heated primarily on the principle of dielectric heating using microwaves of at least MHz order or higher, preferably about 300 MHz to 300 GHz, as the high frequency power, and at the same time generates minute or spark discharge. This is an explanatory diagram of an embodiment in which concentrated ore powder is decomposed and reduced, and the parts given the same reference numerals as in FIG. 1 are the same or have the same functions. 3 houses a mixed workpiece 2 made of a material with low dielectric loss, such as a synthetic resin such as tetrafluoroethylene resin or ceramics such as magnesia, that is, a material that is hardly heated by microwaves or the like. A rotary table 1 on a stand 1b is formed to uniformize high-frequency irradiation to the mixed workpiece 2.
A high-frequency power radiator 8 such as a magnetron is disposed opposite the table 1c, and a rotating blade 10 is provided to disperse and uniformize the high-frequency waves radiated from the radiator 8. Further, 8a is a power source for the high-frequency power radiator 8, and 9 is a control device thereof, which controls the energy such as the size of the radiated high-frequency power, supply time, various supply modes such as intermittent supply, on/off, etc. do.

As the high frequency power, a so-called microwave band with a high frequency of around 1 to 3 GHz is commonly used, and when microwaves are irradiated from the magnetron 8 to the mixed workpiece 2, the mixed workpiece 2 is heated mainly due to dielectric loss. As it is heated, it increases in charge and comes to hold an electric charge, causing minute or spark discharges to occur at various locations within the mixed object 2.

That is, when the mixed workpiece 2 is heated by dielectric heating and maintained at a temperature of around 100°C or higher, the water contained in the mixture is vaporized, and the gas contained therein is also gasified and sequentially released. As long as no special high-energy heating is performed, the mixed material 2 continues to evaporate water without reaching a particularly high temperature.
The irradiated microwave charges up and generates minute or spark discharge, and the concentrate powder is decomposed and reduced in the same manner as in the previous case. The heating and charge-up of the mixed workpiece 2 by microwaves is carried out efficiently because rare earth concentrate powder, etc. and rare earth compounds are generally high dielectric constant materials, and minute or spark discharges can be locally and sufficiently performed in the form of points. The concentrate powder is decomposed and reduced at the high temperature of local discharge without raising the temperature of the entire mixed object 2.

This is the same in the case shown in Fig. 1 above, and since the mixed object 2 is not brought to a high temperature state as a whole, it is naturally necessary to treat exhaust gas such as dust, gas, and steam mist, but harmful It has the advantage of reducing the amount of mist that is difficult to process and requires treatment.
As described below, according to a more preferred embodiment of the present invention, fluorine and fluorine-based gases, phosphorus and phosphorus-based gases,
It is possible to select operating conditions in which the generation of SOx and the above-mentioned liquid mist is small even if the temperature is around 600℃ or higher, and the latter part of the exhaust means 6 is suitable for the amount of decomposition and reduction of rare earth concentrate powder. The gas and mist treatment device provided in the device can be made sufficiently small and simple.

That is, when an alkali such as caustic soda (NaOH) is used as an electrolyte, the generation of harmful gases can be prevented to some extent by this alkali. ~ around 300℃ or more,
For example, high-speed decomposition and reduction can be achieved by heating to a high temperature of around 1000°C.

When heating is mainly performed using the principle of induction heating as shown in FIG. This means that eddy current loss or hysteresis loss is induced in the workpiece 2, and in this case, there is a limit to the depth of penetration of the current, and only the surface layer of the mixed workpiece 2 is affected by the above-mentioned eddy current loss, etc. Therefore, the amount of induction heating high-frequency power used depends on the type and composition of the concentrate constituting the mixed object 2, the type of electrolyte, the water, and the mixing ratio of these. The frequency should not be selected based on the length, but considering the penetration depth of the current for the mixed treatment object 2,
Powder-like shapes, pellet-like shapes such as discs and ellipsoids with a diameter and thickness of about 10 mm x 15 mm, strip-like shapes, short rod-like shapes,
Alternatively, it is necessary to select the shape and dimensions of the rectangular shape, etc., and also consider the arrangement of the magnetic flux distribution within the coil 4.
It is necessary to select the deposition arrangement of the pellet-like material in one or more stages.

In addition, in the case where the principle of dielectric heating is mainly used as shown in FIG. There is a certain difference between the case where waves are irradiated onto the mixed workpiece 2 from a magnetron or the like through a space, but in either case, if the mixed workpiece 2 remains in the form of a large lump, it will not be possible to effectively decompose the mixed workpiece 2. If reduction treatment cannot be performed and the latter uses microwaves, the penetration depth of the irradiated microwaves depends on the wavelength of the microwaves, etc. The size and shape of the pellets must be selected in consideration of these factors, as they vary depending on physical properties. However, it is necessary to generally have a flat pellet shape with a thickness of several tens of mm or less, and it is preferable to avoid arranging the flat pellet-like material in multiple layers facing the magnetron. It is like that.

Next, use electrolyte or electrolyte solution (electrolyte aqueous solution)
For example, potassium acetate (CH ₃ COOK) is extremely useful for electrolytic discharge heating as described in Japanese Patent Publication No. 39-24198, but using an approximately 45% CH ₃ COOK aqueous solution, When the above-mentioned Fig. 1 and Fig. 2 heating discharge decomposition and reduction method using high-frequency power was applied to the mixed material 2 of rare earth concentrate powder, the rare earth concentrate powder monazite, xenotime and Although some of the bastnaesite was reduced, the majority remained almost unchanged (however, the conditions, such as the energy of the supplied high-frequency power and the processing time, were changed from the case of using an effective electrolyte as described below). ) The intended process could not be performed.

For this reason, when the energy of the supplied high-frequency power was increased and the treatment was carried out under heating and discharging conditions such that the temperature of the mixed workpiece 2 was several 100 degrees Celsius, decomposition and reduction were promoted, but
As the temperature increased, harmful gases were generated, and potassium acetate, which was not cheap, was wasted a lot, so there seemed to be no hope for its practical application. In addition, unless otherwise specified in the description below, the explanation will be based on the case where the rare earth concentrate powder is a mixture of monazite or xenotime and bastnaesite, and the mixing ratio is 4 for the former and 6 for the latter. This is to counter the fact that conventional methods are difficult to treat or can only treat one type of substance, but the present invention is also effective for treating one type of substance.

Next, when ammonia (NH ₃ ) was used as an electrolyte, it was more effective than when potassium acetate was used, but when ammonium chloride (NH ₄ Cl) was used as an electrolyte, the decomposition and reduction were significant. The formation of rare earth hydroxide (R(OH) ₃ ) and rare earth chloride (RCl ₃ ) was observed; however, fluorine gas (F ₂ ),
Hydrogen fluoride gas (HF), chlorine gas ( _{Cl2 )} , ammonium fluoride ( _NH4F ), others, _NH4HF2 , _PCl3 ,
Harmful gases such as POCl were generated, and phosphoric acid (H ₃ PO ₄ ) was also produced, but it seems difficult to put it into practical use.

In addition, when common salt (NaCl) is used as an electrolyte, the decomposition and reduction into R(OH) ₃ and RCl ₃ are more effective as in the case where ammonia chloride (NH ₄ Cl) is used, and fluoride Sodium (NaF)
Due to the generation of fluorine-based harmful gases, the generation of
Sodium phosphate (Na ₃ PO ₄ ) was also produced, but Cl ₂ ,
Since PCl ₃ , POCl, etc. are generated, it seems highly likely that countermeasures against these products will hinder practical application.

In addition, when sulfuric acid (H ₂ SO ₄ ) is used as an electrolyte, rare earth concentrate powder becomes sulfuric rare earth (R ₂ (SO ₄ ) ₃ ) through decomposition and reduction, resulting in phosphoric acid (H ₃ PO ₄ ), etc. It is effective because it also generates fluorine-based gases such as F ₂ and HF, and SOx, so unless a cheap and effective method is found to treat the generated gas and waste, it will not be put into practical use immediately. It seems difficult.

Next, it is extremely useful to use sodium carbonate (NaCO ₂ ) as an electrolyte, and rare earth hydroxide (R
The generation of (OH) ₃ ) involves the generation of sodium phosphate (Na ₃ PO ₄ ), and the amount of sodium carbonate is approximately three times the molar amount of rare earth or fluorine in the rare earth concentrate powder. By doing so, sodium fluoride (NaF) is generated, and there is almost no generation of fluorine-based harmful gases, other harmful gases, or mist.
Therefore, if there is no problem with the price of the sodium carbonate (Na ₂ CO ₃ ) used, it would be possible to put it into practical use immediately.

The rare earth concentrate powder in this case may be monazite or xenotime and bastnaesite alone or a mixture of them or both.

However, the most useful electrolyte that the present inventor has tested so far is caustic soda (NaOH).
The most preferred experimental example currently known is the use of caustic soda.

Caustic potash (KOH), which is similar to caustic soda,
is equivalent to caustic soda in its decomposition, reduction, etc. actions, but it is not comparable to caustic soda in terms of price.

Next, to explain the mode of decomposition and reduction when caustic soda (NaOH) is used as an electrolyte, rare earth concentrate powder finely pulverized to about 300 mesh is added to an approximately 50% NaOH aqueous solution at a weight ratio of approximately 1. : Mix in step 2 to make a muddy mixture, heat it by supplying high-frequency power to it, and further supply high-frequency power in the heated state to form a blue or edge-blue color in the muddy mixture. When the concentrate powder is exposed to a discharge column in a state in which fine electric discharges repeat flashing in spots and to a certain degree densely to cause reduction by alkaline decomposition and/or thermal decomposition, the above concentrate powder When it is monazite or xenotime (RPO ₄ ), rare earth hydroxide (R(OH) ₃ ) and sodium phosphate (Na ₂ PO ₄ ) are generated, and no other harmful gases are generated.

When the above concentrate powder is bastnaesite (RFCO ₃ ), rare earth hydroxide (R(OH) ₃ ), sodium fluoride (NaF), and soda carbonate (Na ₂ CO ₃ ) are produced. No particularly harmful gases are generated.

The above concentrate powder is monazite 4 and bastnaesite 6
In the case of a mixture with a ratio of , the decomposition and reduction reactions of the above-mentioned monazite and bastnasite occur simultaneously in a mixed state, and the products obtained when each mineral powder is used are Generate everything.

The rate of decomposition and reduction reactions to the rare earth concentrate powder is considered to be at least 90% or higher, reaching a high rate of around 95% or higher.

That is, using concentrate powder whose rare earth metal (R ₂ O ₃ ) content was weighed in advance, the precipitate containing rare earth hydroxide (R(OH) ₃ ) produced after the heating and discharge treatment was over-recovered, and 100 After washing with water at around 100°C, for example, add hydrochloric acid with a concentration of at least 5% at around 100°C.
Dissolve the solution in acid for about 10 minutes or more, then adjust the pH to 5.8 to 6.0 as necessary to remove precipitates (contains about a few percent of rare earths such as thorium hydroxide and yttrium). When rare earth chloride (RCl ₃ ) obtained by boiling and concentrating and further drying is weighed, caustic soda is added to the above solution to completely neutralize it, and the precipitate (rare earth hydroxide) is collected by filtration. When dried rare earth hydroxide (R(OH) ₃ ) is weighed, the recovery rate (yield) of rare earth metals is approximately 92
This is estimated from the fact that it is ~93%.

Next, to explain the present invention using an example, rare earth consisting of 30% monazite and 70% bastnasite is roughly expressed as rare earth oxide (R ₂ O ₃ ) by volume.
A rare earth concentrate powder containing 60% is crushed so that 99% is -200 mesh, and for 1 mole of the concentrate powder,
So that the proportion of caustic soda (NaOH) is about 3 moles, 2 parts of concentrate powder, 1 part of caustic soda,
and water were weighed and mixed at a ratio of 0.4. Incidentally, the rare earth concentrate may be crushed by grinding during the above-mentioned mixing.

Approximately 60 g of the above slurry mixture was heated in a high frequency induction heating furnace at a frequency of 40 KHz into multiple discs or ellipsoids with a diameter of approximately 30 mm and a thickness of approximately 6 to 8 mm.
Heating and discharging for about 10 minutes at a heating rate of 6.4 Kcal/min. When dissolved in water, the precipitate and excess material were washed 5 times with water at room temperature or about 100°C, and forced drying to decompose about 36.5 g. , a reduced product (rare earth hydroxide) was obtained.
This is mixed with about 300 ml of hydrochloric acid with a concentration of about 35-40% to about 105
Dissolve in acid for about 10 minutes at ℃, perform this acid dissolution twice,
When the supernatant and the precipitate were washed with water three times and the water was recovered, the precipitate residue was approximately 0.8 g, which was approximately
Approximately 97.8% of the 36.5 g was recovered in the form of rare earth chloride, and solid rare earth chloride could be recovered by boiling the supernatant and washing water.

In this case, the temperature during decomposition and reduction is thought to have reached around 500°C or higher due to the low moisture content in the kneaded material before decomposition treatment, but if the amount of mixed water is increased, Although the above temperature is lowered, energy is lost to evaporation of water and processing time becomes longer, so it is not necessarily effective.

Next, about 83 g of pellets similar to those described above were heated and discharged for about 15 minutes by irradiating microwaves of about 2450 MHz from a magnetron at a heating rate of about 6.4 Kcal/min. After washing with water five times in the same manner, it was separated and dried to obtain about 57.5 g of rare earth hydroxide.
When this was acid-dissolved in about 400 ml of 36% hydrochloric acid at about 105°C for about 10 minutes, the residue was about 1.8 g, and the dissolution rate was about 96.9.
It was %.

Furthermore, according to X-ray analysis of rare earth hydroxide (precipitate recovered material) from each of the above treatment steps, monazite and bastnaesite were hardly detected, and each of the monazite and bastnaesite was almost completely decomposed. ,
It has been reduced, etc., and is presumed to be rare earth hydroxide as described above.

As mentioned above, if alkali or NaOH is used as an electrolyte, even if the kneaded material reaches a certain level of high temperature during the heating and discharging process,
Other than the generation of soda carbonate, sodium phosphate, and sodium fluoride, there is almost no generation of harmful gases other than liquid mist, and the liquid mist can be reduced by adjusting the amount of water, and as long as the amount of water is small. In other words, this leads to the advantage that the energy efficiency of processing can be increased.

In addition, in the above case, most of the supplied high-frequency power is used and consumed only for heating the mixture and discharging inside it, so energy efficiency is high and the amount of chemicals consumed is also lower than that of the conventional sulfuric acid method. It has the advantage that it is extremely small in comparison, and that it can be completely decomposed and reduced without making any changes, even if it is difficult to treat conventionally, such as mixed concentrate powder of monazite and bastnaesite.

In the industrial implementation of the method of the present invention, it is of course possible to construct, for example, a continuous appropriate treatment line.

The present invention is still under research, and for example, as an electrolyte, it can be
It is possible that one or more mixed electrolytes with high reduction efficiency and low generation of harmful gases may be found; It is believed that it is necessary to devise an automated treatment device for the mixing process and other steps including acid dissolution and subsequent appropriate steps.

As described above, according to the present invention, rare earth concentrate powder can be decomposed in a simple process with high energy efficiency and at low cost.
According to the present invention,
For example, it can be directly applied to the treatment of mixed rare earth concentrate powder of bastnaesite and monazite or xenotime, and according to a preferred embodiment of the present invention, not only is the treatment efficiency higher, but also the treatment operation This is an industrially useful invention that can extremely reduce the amount of harmful gases and liquids generated during operation.

[Brief explanation of drawings]

FIGS. 1 and 2 are explanatory diagrams of different embodiments of the treatment method of the present invention, respectively. 1 is a processing container, 2 is a mixed processing object, 3 is a saucer,
4 is a heating coil, 5 and 9 are heating control devices, 6 is an exhaust means, 7 is an atmosphere adjustment means, and 8 is a magnetron.

Claims (1)

[Scope of Claims] 1. Adding and mixing an electrolytic solution consisting of an aqueous electrolyte solution to rare earth concentrate powder, kneading the mixture, supplying high-frequency power to the kneaded product to heat it, and generating electric discharge in the kneaded product. A method for processing rare earth concentrate, characterized in that the concentrate powder in contact with the electrolytic solution is decomposed and reduced. 2. Claim 1, wherein the high-frequency power is high-frequency induction heating with a frequency of 30 KHz to 100 KHz, and is supplied to a heating coil in which the kneaded material is placed. The method for processing rare earth concentrates described in . 3. The above-mentioned high frequency power is microwave heating, the frequency is at least on the order of MHz, and the frequency is 300M
2. The method for treating rare earth concentrate according to claim 1, wherein the kneaded material is irradiated with a high frequency of Hz to 300 GHz. 4. The method for treating rare earth concentrate according to any one of claims 1, 2, and 3, wherein the electrolyte is an alkali containing caustic soda (NaOH). 5. The electrolytic solution consisting of the electrolyte aqueous solution is characterized in that it is a separate electrolyte and water, and the kneaded product is obtained by mixing predetermined amounts of the electrolyte, water, and rare earth concentrate powder, respectively. A method for processing rare earth concentrate according to any one of claims 1, 2, and 3. 6. The amount of the electrolyte added and mixed contains a sufficient amount of the electrolyte to decompose and reduce the rare earth compound in the mixed concentrate powder, and the kneaded product is in a water-containing state of sludge-like or higher. Claim 1, characterized in that the water content is adjusted so as not to cause
The method for treating rare earth concentrate according to any one of Items 1, 2, 3, 4, and 5. 7. Claims 1, 2, 3, and 4, characterized in that the rare earth concentrate powder is a mixed concentrate powder of monazite or xenotime and bastnasite, A method for processing rare earth concentrate according to any one of paragraphs 5 and 6. 8. Claim 1, wherein the rare earth concentrate powder is -100 to -200 mesh powder.
The method for treating rare earth concentrate according to any one of Items 1, 2, 3, 4, 5, 6, or 7. 9 Heating of the kneaded material is controlled by controlling the magnitude of the supplied high-frequency power or the supply time.
Claims 1 and 2, characterized in that the temperature is maintained and controlled at around ℃ or below.
The method for processing rare earth concentrate according to any one of paragraphs 3, 4, 5, 6, 7, or 8. 10 Claims 1, 2, 3 and 3, characterized in that the kneaded material is subjected to heat treatment using high frequency power in the form of pellets such as discs and ellipsoids. Section 4, Section 5, Section 6 or Section 7
A method for processing the rare earth concentrate described in any one of the paragraphs.