Ore dressing method

Abstract

Provided is an ore dressing method for separating bastnaesite from an ore containing quartz and fluorite, said method comprising a first reverse flotation step of performing reverse flotation of barite from the ore, a second reverse flotation step of performing reverse floatation of the fluorite, and then a first flotation step of performing floatation of the bastnaesite. At least one of the first reverse flotation step, the second reverse flotation step, and the first flotation step includes an ultrasonic vibration application step of applying ultrasonic vibration to a flotation target liquid. A collecting agent obtained by treating a reaction product of oleic acid and ethyltetraamine with an alkylethylphosphate is used in a second reverse flotation step, and the bastnaesite is floated from the tailings in the second reverse flotation step.

Description

ore dressing method

[0001] The present invention relates to a method for separating bastnaesite from an ore containing barite and fluorite.

[0002] As a conventional technique, for example, Patent Document 1 describes a method for froth flotation of bastnasite from barite, fluorite, and a rare earth composite ore containing bastnasite as a rare earth mineral. Specifically, the method describes conditioning a pulp slurry with a sulfonate collector, recovering barite and fluorite simultaneously by froth flotation before bastnasite, and then conditioning the remainder from which the barite and fluorite have been flotated at a high temperature again to separate bastnasite from other gangue minerals by flotation.

[0003] JP 55-119456

[0004] In conventional techniques, when separating bastnasite from a barite-fluorite-rare earth composite ore containing bastnasite, particularly when the ore has been altered, it has sometimes been difficult to sufficiently separate the barite and fluorite from the altered oxidized ore of barite and fluorite in the step of flotation of the barite and fluorite, making it difficult to efficiently separate the bastnasite.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a dressing method capable of efficiently separating bastnaesite from a composite weathered ore containing barite and fluorite.

[0006] To achieve the above object, the ore dressing method of the present invention is a method for separating bastnasite from an ore containing barite and fluorite, characterized in that it includes a first reverse flotation step for reverse flotation of barite from the ore, a second reverse flotation step for reverse flotation of fluorite, and a subsequent first flotation step for flotation of bastnasite. With this configuration, barite and fluorite can be separated from a composite weathered ore containing barite and fluorite before flotation of bastnasite, thereby enabling efficient separation of bastnasite in the bastnasite flotation step. This allows a high concentration of bastnasite to be obtained in the bastnasite flotation step.

[0007] A further characteristic feature of the present invention is that at least one of the first reverse flotation step, the second reverse flotation step, and the first flotation step includes an ultrasonic vibration application step of applying ultrasonic vibration to the flotation target liquid. With this configuration, ultrasonic vibration can be applied to the flotation target liquid, allowing for rapid and efficient foam flotation, thereby enabling the production of a high concentration of bastnasite in the flotation step of bastnasite.

[0008] A further characteristic feature of the present invention is that a collector obtained by treating a reaction product of oleic acid and ethyltetraamine with an alkyl ethyl phosphate is used in the second reverse flotation step. In this case, the reaction product of oleic acid and ethyltetraamine may be treated with a primary amine, and an ore containing a composite fluorite ore containing calcite, dolomite, barite, or silica may be flotated. With this configuration, the ore containing the composite fluorite ore containing calcite, dolomite, barite, or silica can be separated by flotation before the step of flotation of bastnasite, thereby enabling high-concentration bastnasite to be obtained in the step of flotation of bastnasite.

[0009] A further characteristic feature of the present invention is that bastnasite is floated from the tailings in the second reverse flotation step. In this case, a collector containing 50 to 60 wt% aminated tall oil fatty acid, 10 to 20 wt% sarcosine, and 5 to 8 wt% secondary amine may be used as a collector for bastnasite. With this configuration, foam flotation can be performed quickly and efficiently, and a high concentration of bastnasite can be obtained in the step of flotation of bastnasite.

[0010] It is a flowchart showing an embodiment of the ore dressing method according to the present embodiment. It is a cross-sectional schematic view of a flotation device used in the ore dressing method according to the present embodiment. It is a flowchart showing another embodiment of the ore dressing method according to the present embodiment.

[0011] Hereinafter, an embodiment of the ore dressing method according to the present invention will be described in detail with reference to the drawings. Fig. 1 is a flowchart showing an embodiment of the ore dressing method according to the present invention. The ore dressing method according to the present invention is a method for separating bastnaesite from an ore containing barite and fluorite, and comprises first reverse flotation steps S2 to S5 for reverse flotation of barite from the ore, second reverse flotation steps R2 to R5 for reverse flotation of fluorite, and then first flotation steps T2 to T5 for flotation of bastnaesite, in the order listed.

[0012] The ore dressing method of the present invention makes it possible to separate bastnasite at a high concentration rate from bastnasite ore containing barite, fluorite, silica, and iron oxide. Since deposits containing such ores are abundant in the Pacific region, such as Vietnam and China, the method of the present invention makes it possible to separate bastnasite at a high concentration rate from ore extracted in these regions.

[0013] In the mineral dressing method according to this embodiment, as shown in Figure 1, first, ore is crushed and classified (S0) to a particle size at which individual minerals can be liberated. In this embodiment, the ore is crushed and classified by conventional crushing and classification techniques until the proportion of particles of 45 µm or less becomes 80%.

[0014] The crushed and classified slurry is then conditioned (S1) with sodium silicate and barium chloride. Sodium silicate is used as a gangue inhibitor, and barium chloride is used as a barite activator. These are standard reagents used in the beneficiation of barite-containing ores.

[0015] The slurry is further conditioned (S1) with a collector for barite. For example, the collector is a mixture of 20 to 30 wt % petroleum sulfonate, 20 to 30 wt % sulfosuccinate, and 10 to 30 wt % sulfosuccinamate.

[0016] The above reagents are mixed and dissolved in an aqueous solution, preferably at room temperature or higher, to a concentration of 10 to 20%, and then the emulsion is added to the slurry. After these conditions are met, the barite is selectively floated away from bastnaesite and fluorite in the first reverse flotation step S2 to S5, which reverse flotation the barite. This allows high-quality barite to be recovered with a high recovery rate.

[0017] The first reverse flotation process S2 to S5 is composed of a roughing process S2 and refinement processes S3 to S5. In the refinement processes S3 to S5, three refinement stages are performed. The roughing process S2 is performed using, for example, a Fagergren flotation machine, and the refinement processes S3 to S5 are performed using, for example, a Denver-type flotation machine.

[0018] Figure 2 shows a cross-sectional schematic diagram of the flotation device used in the first reverse flotation steps S2 to S5. The flotation device 1 comprises a rotating shaft 2, an impeller 3 fixed below the rotating shaft 2 and rotating together with the rotating shaft 2, a stationary hood 4 that serves as a circulation passage for circulating the fluid F to be treated and bringing it into contact with air by rotating the impeller 3, a housing 6 capable of containing the slurry F, which is the fluid to be treated, and a power unit 9 that rotates the rotating shaft 2. In addition, an air inlet pipe 41 is disposed above the stationary hood 4, and negative pressure is generated in the bladeless space of the impeller 3 between the impeller 3 and the rotating shaft 2 by the rotation of the impeller 3, and this negative pressure causes outside air to be sucked into the slurry F through the air inlet pipe 41.

[0019] Furthermore, the outer surface of the housing 6 is provided with a plurality of ultrasonic vibration devices 7 that apply ultrasonic vibration to the slurry F, which is the liquid to be flotation-treated. This makes it possible to apply ultrasonic vibration to the slurry F inside the housing 6 and the air sucked into the slurry F. In addition, an air inlet 5 for introducing air is provided on the outer surface of the housing 6. The air supplied from the air inlet 5 is pressurized air, and this air can be introduced into the slurry F in addition to the outside air supplied from the air inlet pipe 41, thereby promoting the separation effect by flotation.

[0020] Returning to Figure 1, in this embodiment, the first reverse flotation steps S2 to S5 include an ultrasonic vibration application step in which ultrasonic vibrations are applied to the slurry F, which is the liquid to be flotation-treated. The ultrasonic vibration application step may be the entire period from the start to the end of each of the first reverse flotation steps S2 to S5, or only the latter half of the entire period from the start to the end of each step. Furthermore, the ultrasonic vibration application step may be provided in either the rough selection step S2 or the refining steps S3 to S5.

[0021] The tailings from the first reverse flotation step S2-S5 are subjected to a conventional desliming process R0, which separates the fine particles containing bastnaesite from the coarse particles. In the fine particle fraction, more than 95% of the particles are less than 6 μm in size.

[0022] The slurry that has been subjected to the desliming treatment R0 is then subjected to a stepwise conditioning R1 using inhibitors and conditioners that are typically used in the flotation of fluorite-containing ores.

[0023] After the condition setting R1, the second reverse flotation steps R2 to R5 are carried out, in which fluorite is floated using a collector suitable for processing complex ores. The fluorite collector is composed of 70% amine oleic acid and 30% alkyl ethyl phosphate. This collector is advantageous in that it improves the selectivity between bastnaesite and fluorite. The removal of fluorite in these second reverse flotation steps R2 to R5 is important for obtaining a high concentration of bastnaesite in the subsequent flotation of bastnaesite.

[0024] The second reverse flotation process R2 to R5 is composed of a roughing process R2 and refinement processes R3 to R5. The refinement processes R3 to R5 comprise three stages of refinement. The roughing process R2 is carried out using, for example, a Fagergren flotation machine, and the refinement processes R3 to R5 are carried out using, for example, a Denver-type flotation machine.

[0025] As with the first reverse flotation processes S2 to S5, the second reverse flotation processes R2 to R5 also include an ultrasonic vibration imparting step in which ultrasonic vibrations are imparted to the slurry F, which is the liquid to be flotation-treated, using the flotation apparatus 1 shown in Figure 2. The ultrasonic vibration imparting step may be the entire period from the start to the end of each of the second reverse flotation processes R2 to R5, or only the latter half of the entire period from the start to the end of each process. Furthermore, the ultrasonic vibration imparting step may be provided only in either the rough selection process R2 or the refining processes R3 to R5.

[0026] The final step in the ore dressing method according to this embodiment is the first flotation step T2-T5, in which bastnaesite is recovered by flotation. By reverse-floating barite and fluorite in the first reverse flotation step S2-S5 and the second reverse flotation step R2-R5, the bastnaesite concentration supplied to the roughing step T2 of the first flotation step increases by approximately four times. As an example, a component test of the ore showed that the REO was approximately 6% before treatment, but after flotation of barite and fluorite, the REO was 25% at the stage of supplying the ore to the roughing step T2 of the first flotation step.

[0027] In the flotation of bastnasite, the tailings from the second reverse flotation steps R2 to R5 are thickened (T0) by a conventional method, and then conditioned (T1) using a standard conditioner. The first flotation steps T2 to T5 are then carried out, in which the bastnasite is floated using a collector suitable for processing complex ores. This collector is composed of 60 to 70 wt% aminated tall oil fatty acids, 20 to 30 wt% sarcosine-based collector, and 10 wt% secondary amine. This collector can improve the selectivity of bastnasite relative to iron oxide and silica stone, thereby increasing the yield of bastnasite.

[0028] The first flotation steps T2 to T5 are composed of a roughing step T2 and cleaning steps T3 to T5. In the cleaning steps T3 to T5, three cleaning stages are performed. The roughing step T2 is performed using, for example, a Fagergren flotation machine, and the cleaning steps T3 to T5 are performed using, for example, a Denver-type flotation machine.

[0029] The first flotation steps T2 to T5 also include an ultrasonic vibration application step in which ultrasonic vibrations are applied to the slurry F, which is the liquid to be flotation, using the flotation apparatus 1 shown in Figure 2, as in the first reverse flotation steps S2 to S5 described above. The ultrasonic vibration application step may be the entire period from the start to the end of each of the first flotation steps T2 to T5, or only the latter half of the entire period from the start to the end of each step. Furthermore, the ultrasonic vibration application step may be provided only in either the rough selection step T2 or the refining steps T3 to T5.

[0030] The following examples demonstrate the effectiveness of the mineral dressing method according to the present invention. Note that the following examples are provided to explain the present invention in detail, and the scope of the invention is, of course, defined by the claims.

[0031] Example 1: A beneficiation test was conducted using the ore dressing method shown in Figure 1 using an ore containing 55% barite, 5% fluorite, and 10% rare earth ore. After pulverization in the crushing and classification step S0, a slurry with a pulp concentration of 45% was prepared. Each conditioning step was performed at a temperature of 80°C for 20 minutes. The conditioned pulp was then subjected to flotation for 8 minutes in each of the rough sorting step and the refinement step. In this example, ultrasonic vibration was applied to slurry F only in the refinement step S5, the refinement step R5, and the refinement step T5. As described above, the refinement efficiency was improved by applying ultrasonic vibration only in the refinement step S5, the refinement step R5, and the refinement step T5. The REO concentration in the refined ore obtained in the third refinement step in the final first flotation step was analyzed, and a REO concentration of 50-60% was achieved.

[0032] (Example 2) This example is based on the flowchart showing another embodiment of the ore dressing method according to the present embodiment shown in Figure 3. The difference from the above embodiment is that the cleaning steps of the first reverse flotation step, the second reverse flotation step, and the first flotation step each have five steps, whereas in the above embodiment there are three steps.

[0033] In this example, the cleaning steps S6 to S7, the cleaning steps R6 to R7, and the cleaning steps T6 to T7 were ultrasonic vibration application steps, and ultrasonic vibration was applied to the slurry F. In this example, by performing ore dressing under the same other conditions as in Example 1, it is believed that the cleaning efficiency can be improved by the ultrasonic vibration application steps in the cleaning steps S6 to S7, the cleaning steps R6 to R7, and the cleaning steps T6 to T7, and that a REO concentration of 85 to 95% can be achieved in the cleaned ore obtained in the fifth cleaning step T7 in the first flotation steps T2 to T7, which is the final step.

[0034] As described above, it is possible to provide a dressing method capable of efficiently separating bastnaesite from a composite weathered ore containing barite and fluorite.

[0035] S6-S7 First reverse flotation step R6-R7 Second reverse flotation step T2-T7 First flotation step

Claims

1. A method for separating bastnaesite from an ore containing barite and fluorite, comprising a first reverse flotation step for reverse flotation of the barite from the ore, a second reverse flotation step for reverse flotation of the fluorite, and then a first flotation step for flotation of the bastnaesite.

2. The ore dressing method according to claim 1, wherein at least one of the first reverse flotation process, the second reverse flotation process, and the first flotation process includes an ultrasonic vibration application process for applying ultrasonic vibration to the flotation target liquid.

3. The method of claim 1 or 2, wherein the second reverse flotation step uses a collector obtained by treating a reaction product of oleic acid and ethyltetraamine with alkyl ethyl phosphate.

4. The method of claim 3, wherein the second reverse flotation step involves flotation of an ore containing a composite fluorite ore containing calcite, barite, or silica.

5. The method of claim 1 or 2, wherein bastnaesite is floted from the tailings in the second reverse flotation step.

6. The method of claim 5, wherein a collector containing 50 to 60% by weight of aminated tall oil fatty acid, 10 to 20% by weight of sarcosine, and 5 to 8% by weight of a secondary amine is used as a collector for bastnaesite.

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