JPS6327060B2 - - Google Patents

Description

[Detailed description of the invention]

The disclosed technique belongs to a technique in magnetic separation of rare earth oxides in which rare earth oxides are caused to flow through a high gradient magnetic field applied with a pulsed magnetic field via gravity and are sorted based on the difference in magnetic susceptibility. Therefore, this invention relates to a magnetic field separation method in which rare earth oxides are magnetically separated by flowing through a sorting field by gravity. Rare earth-containing minerals obtained after separation and removal by magnetic beneficiation or unseparated minerals are passed through a multi-stage pulsed magnetic field generating gradient high gradient magnetic field with magnetic fine wires via gravity. This relates to a method for separating rare earth oxides in a magnetic field, in which those that are easier to separate are separated in the horizontal direction by receiving a pulsed magnetic field biasing force due to the difference in magnetic susceptibility of the rare earth oxides. As is well known, rare earth metals have been widely used for deoxidation and hydration reactions in the steel industry, and have also been used industrially for lighter flints, etc.
Recently, in addition to consumer products such as televisions and pigments, abrasives,
It has been developed and adopted in new industrial fields for lasers, and has also come to be used as a superconducting material, research material for nuclear power, and recently as a high-energy magnet. Demand is rapidly increasing. Therefore, in order to meet these needs, it has become desirable to develop highly efficient and pollution-free selection technology from mining. By the way, rare earth metals are generally produced in the form of oxides from alluvial deposits, and are separated and sorted from mined ores through ordinary magnetic beneficiation using their weak magnetism against ferromagnetic minerals such as iron and manganese. is being used. For rare earth oxide-containing minerals separated as described above, for example, NaOH, Hcl,
Extracted with C ₂ O ₄ H ₂ or H ₂ SO ₄ , etc.
Next, oxalic acid is added to the acidic solution to precipitate oxalate, and the precipitate is then roasted to form rare earth oxides, which are dissolved and separated by sedimentation to form La.
First, divide it into two parts: system and Ce system. La-based materials are precipitated and separated by molten salt electrolysis, and Ce-based materials are further treated with acid.
It is divided into two types: Ce-based and La, Nd, Pr, Sm-based. The former Ce-based is precipitated and separated by molten salt electrolysis, and the latter is separated by base treatment or DZEPA treatment.
_La , _Nd ,
Pr or Sm is separated by precipitation or converted into R ₂ O ₃ by ion exchange resin treatment after the above-mentioned DZEPA treatment, and then separated by performing steps such as precipitation separation operations similar to those described above. However, since the above-mentioned conventional mutual separation methods are chemical or physicochemical separation methods, the separation processing steps are extremely complicated and diverse, as described above.
There are disadvantages in that the amount and variety of processing chemicals are large, the cost is high, and it is also difficult to control the process. Further, as mentioned above, since there are many chemical treatment steps, there is a risk that secondary pollution may occur if the waste liquid is treated incorrectly. As mentioned above, it is extremely difficult to separate useful rare earth metals such as Pr, Nd, and Sm at the final stage, resulting in disadvantages such as difficulty in supplying magnet catalysts and laser materials, and high costs. The purpose of this invention is to remove ferromagnetic substances such as iron and manganese from mined minerals by magnetic separation in advance in the conventional manner, in view of the problems with the separation method of rare earth oxide-containing minerals based on the above-mentioned conventional technology, and to remove residual rare earth oxides from mined minerals. Minerals or extracted and roasted rare earth oxides are allowed to flow down a slope by gravity, and a pulsed current is applied to an electromagnet interposed with magnetically thin wires diagonally installed on the slope to generate a high magnetic field. By forming a gradient magnetic field and passing the pulsed high gradient magnetic field, a lateral separation force is applied impulsively based on the difference in magnetic susceptibility of the rare earth oxides, so that each rare earth oxide is separated in the horizontal direction. The purpose of the present invention is to provide an excellent magnetic field separation method for rare earth oxides. Next, embodiments of the present invention in accordance with the above object will be described below with reference to the drawings. First, in the principle of the present invention, attention is paid to the fact that rare earth elements and rare earth oxides are weakly magnetic substances, and that the latter has a higher magnetic susceptibility. Incidentally, the magnetic susceptibility X is illustrated in the following table.

[Table] Therefore, it can be seen that the absolute value of the difference in magnetic susceptibility between the two is larger in the case of oxides. By the way, recently, a new so-called high gradient magnetic field separation system has been developed, and the present invention applies this high gradient magnetic field separation. The basic process is as shown in Figure 1. A rare earth oxide-containing ore 1 that has been mined in a specified manner goes through a well-known extraction process 2, a roasting process 3, and a residual rare earth oxide separation process 4, which will be detailed next. Process as desired. As shown in FIG. 2, the separation device 5 used in the separation process includes a set number of hoppers 8, 8, . On the other hand, a chute 9 is provided on the upper edge of the slope 7, and a vibrating plate 10 for supplying the material to be separated is provided on the upper edge of the chute 9 in conjunction with a vibrator 11 as appropriate. A water pipe 13 in which a large number of water jet nozzles 12, 12, . . . are bored is connected to a water supply source (not shown). A vibrating plate 10 is placed above them.
A belt conveyor 14 is connected to a cutting vibrating feeder (not shown) in parallel with the belt conveyor 14, and a scraper 15, which is connected to a vibrating feeder (not shown), is provided at a portion corresponding to the vibrating plate 10 via a phase difference so as to be able to scrape the entire width.
15... are provided in multiple stages in a predetermined number. Then, as shown in the figure, the plastic slope 7 is
As shown in FIGS. 2 and 3, the plastic slope 7 is
Fine stainless steel wires 16, 16... are mixed into the plastic, glass, etc. with set widths, intervals, and angles when viewed from the front of the slope 7 so as not to impair the surface smoothness of the surface. Further, an electromagnet 17 is attached to the back surface of the plastic slope 7, and each stainless steel thin wire 16 has both poles in contact with each other so that the polarities thereof are opposite to each other. And the electromagnetic coil 1 wound around each electromagnet 17
8 are connected in series and connected to a power source 22 via a switch 20 such as a well-known thyratron or SCR in a case 19 attached to the separation device 5, and a resistor 21.
A 1KHz pulse signal 23 is applied to each electromagnetic coil 1 in parallel with a parallel interposed capacitor 24.
8, 18, . . . are discharged intermittently to excite pulsed current. For such a device, a pulse signal 23 is applied to the switch 20, and each electromagnetic coil 18, 18
Applying an oscillating voltage to..., the thin stainless steel wire 16,
16... oscillates a pulsed magnetic field, and the water pipe 1
3 and jets out water from the nozzles 12, 12, . Therefore, the rare earth oxide is scraped off on average by the scrapers 15, 15, . The slurry is mixed with water to form a kind of slurry and is dropped onto the slope 7 via the chute 9. Therefore, the rare earth oxide 1 sliding down the slope 7 is lowered by the electromagnets 17, 17, . . . in the process of falling by gravity.
It passes through the magnetic field formed by ..., and because the magnetic field is a pulsed magnetic field, it is periodically subjected to an impulsive lateral biasing force, which also affects the magnetic susceptibility of the rare earth oxide as mentioned above. Due to the difference in magnetization, they receive different degrees of magnetization, and are separated laterally in order of ease of separation. Therefore, when it reaches the lowest end, it is sufficiently separated and separated into hoppers 8, 8, . . . . Then, filters are appropriately attached to the lower ends of the hoppers 8, 8, . Incidentally, in order to effectively separate each oxide particle, separation accuracy can be improved by performing multi-stage processing by descending from the upper starting end (right end) side of the slope 7 in the figure. According to an experimental example based on the above example, 500#
Bastnaesite's heated and oxidized rare earth oxide ore is used as the separation raw material, and a stainless steel thin wire of about 4μ is used as the high gradient magnetic field core.A glass slope coated with 3μ resin is formed on the surface, and a high gradient magnetic field is generated by an electromagnet at 4KHz. When a pulsed magnetic field was formed and separation processing was performed, Pr ₆ O ₁₁ Nd ₂ O ₃ ,
Sm ₂ O ₃ , Ce ₂ O ₃ , La ₂ O ₃ etc. can be separated reliably.
For example, separation of La ₂ O ₃ and Sm ₂ O ₃ was obtained with 95% accuracy in a one-pass process. Note that the embodiments of the present invention are not limited to the embodiments described above, and various embodiments are possible, and various changes in design are possible. As described above, according to the present invention, when separating rare earth oxides, ferromagnetic substances such as iron and chromium are previously separated and removed from mined ores by ordinary magnetic separation, and the remaining rare earth oxides are placed in a high gradient in multiple stages. By causing the magnetic field to fall through gravity and applying a pulsed magnetic field to the high gradient magnetic field, basically each of the magnetic fields in the high gradient magnetic field is Rare earth oxides are more easily separated due to different lateral bias forces, and therefore, the magnetic susceptibility is used as an index, and the difference can be used to reliably separate the oxides from each other. Furthermore, by applying a pulsed magnetic field to the high gradient magnetic field, a lateral biasing force is repeatedly and impulsively applied to the flowing rare earth oxide, which has the excellent effect of further promoting the lateral separation. It has the advantage of being extremely effective in conjunction with a multi-stage high gradient magnetic field. Therefore, unlike conventional chemical separation operations, this method has the advantage that separation can be easily performed in one process, no chemicals are used for treatment, there is no pollution, and the equipment is simple and inexpensive.

[Brief explanation of the drawing]

The drawings are explanatory diagrams of one embodiment of the present invention; FIG. 1 is an explanatory diagram of the processing flow, FIG. 2 is a perspective explanatory diagram of the apparatus, and FIG. 3 is an explanatory diagram of the high gradient magnetic field mechanism.

Claims (1)

[Claims] 1 In a magnetic field separation method in which rare earth oxides are magnetically separated by a process of flowing through them by gravity, rare earth oxide-containing minerals obtained by previously removing ferromagnetic oxides from mined ores by magnetic separation are arranged in a sloping plane. The electromagnetic high gradient magnetic field is made to flow through the multi-stage electromagnetic high gradient magnetic field set up by gravity, and in the flow process, the electromagnetic high gradient magnetic field is turned into a pulsed magnetic field, and those that are easier to separate are separated by the difference in magnetic susceptibility. A method for magnetic field separation of rare earth oxides.