Device and method for preparing coarse-grained cobalt hydroxide sample

Abstract

The invention discloses a device and a method for preparing a coarse-grained cobalt hydroxide sample, the device comprises a vibrating feeder, a grinding cabin and a material receiving barrel which are sequentially arranged from top to bottom, a rotary tool bit is rotatably connected in the grinding cabin, and a standard sieve is arranged in the circumferential direction of the inner wall of a cabin body of the grinding cabin by taking the rotary tool bit as the center. The sample preparation step comprises vibration screening, cutting and grinding, screening and collecting, and sample preparation and sealing. Coarse-grain cobaltous hydroxide is cut and crushed by adopting the rotary tool bit, it is ensured that the coarse-grain cobaltous hydroxide is cut around the rotary tool bit as far as possible after being subjected to centrifugal force and negative pressure suction force in the cutting process, the cut coarse-grain cobaltous hydroxide is ground through the grinding cabin, automatic screening is combined with the standard screen, and undersize samples fall into the material collecting barrel; cutting, grinding and sieving are carried out at the same time, the problems that traditional sample preparation is large in labor intensity and makes contact with much dust are solved, and the sample preparation efficiency and the sample preparation quality are improved.

Description

Technical Field

[0001] The invention relates to the technical field of metal sample sampling and sample preparation, and in particular to a device and method for preparing a coarse-grained cobalt hydroxide sample. Background Art

[0002] Cobalt is an extremely important strategic metal, which is widely used in battery manufacturing, aerospace, high-temperature alloys and magnetic materials. In recent years, with the rapid development of new energy industry and aviation technology, the cobalt smelting industry has an increasing demand for cobalt raw materials. However, my country's cobalt resources are seriously scarce, the grade of cobalt ore is low, and most of them are polymetallic associated ores. Therefore, a large amount of cobalt raw materials needs to be purchased, which is costly.

[0003] Coarse cobalt hydroxide is one of the raw materials for cobalt production. To ensure the fairness of transactions, it needs to be accurately tested and analyzed. The representativeness of the sample is a decisive factor in improving the accuracy of chemical analysis. At present, the preparation method of crude cobalt hydroxide samples is mainly based on grinding. Grinding is an important step in sample preparation. The grinding particle size and sample quality directly affect the accuracy of cobalt hydroxide sample analysis. The grinding operation process is to first mix the sample thoroughly, use the grid method to reduce the sample to no less than 2kg, determine the moisture content and prepare the component sample, wait for the sample to reach constant weight after it is completely dried, and then use a disc crusher to grind the sample. However, the following problems exist in the grinding process: (1) The feed port of the disc mill is small, and the feed particle size is required to be ≤6mm, so the sample needs to be added in batches and screened while adding. If there is material on the sieve, continue grinding until all the samples pass through the 100-mesh standard sieve. The entire grinding process takes at least 25 minutes, which is time-consuming and labor-intensive. In addition, the weight of a single sample bowl is about 5-10kg, and the operator has high labor intensity in the process of moving the sample bowl; (2) There is serious sample residue after grinding, and the loss rate is ≥8%, which greatly reduces the representativeness of the sample and reduces the fairness of the trading parties; (3) High temperature is generated during the grinding process, which easily leads to high-temperature oxidation of the sample. Therefore, the grinding time for each time does not exceed 3 minutes. After multiple grindings, the sample bowl itself will also heat up, which will further aggravate the high-temperature oxidation of the sample; (4) The grinding gap of the disc mill is difficult to control. Improper adjustment of the disc gap will directly affect the sample particle size, thereby affecting the sample preparation efficiency. In addition, the sample preparation process and time rely solely on the work experience of the sample preparation personnel. The operating standards vary greatly, and manual errors are inevitable. Summary of the invention

[0004] The invention provides a device and method for preparing a coarse-grained cobalt hydroxide sample, aiming to solve the problem that the existing grinding sample preparation method is time-consuming and labor-intensive, has a high loss rate, and the high temperature generated during the grinding process easily leads to high-temperature oxidation of the sample, thereby affecting the representativeness of the sample.

[0005] To achieve its purpose, the present invention adopts the following technical solution: A device for preparing a coarse-grained cobalt hydroxide sample comprises a vibrating feeder, a grinding chamber and a receiving barrel which are arranged in sequence from top to bottom; the vibrating feeder comprises a feeding hopper arranged on the top of a machine body, and a discharge port at the bottom of the feeding hopper is connected to a feeding port of the grinding chamber through a slide plate; the grinding chamber comprises a rotating cutter head which is rotatably connected in its chamber body, and a standard screen is arranged along the circumference of the inner wall of the grinding chamber with the rotating cutter head as the center; the discharge port at the bottom of the grinding chamber is communicated with a feeding port at the top of a receiving barrel, and a powder variable frequency conveyor is arranged in the receiving barrel; the powder variable frequency conveyor comprises a pneumatic motor and a pressure converter, the pneumatic motor is connected to an input end of the pressure converter, and an output end of the pressure converter is connected to a pressure storage tank, a negative pressure tank and a cyclone collector in sequence.

[0006] Furthermore, the lower end of the slide is inclined toward the grinding chamber feed port, and the inclination angle is 10-15°.

[0007] Furthermore, the grinding chamber body of the grinding chamber is in a horizontal cylindrical shape.

[0008] Furthermore, the feed inlet of the grinding chamber is a quadrangular pyramid structure that is larger at the top and smaller at the bottom.

[0009] Furthermore, the standard sieve is provided with a plurality of equidistantly arranged sieve holes, and the inner circle of the sieve holes is convex on one side close to the rotating cutter head and has a sharp edge.

[0010] Furthermore, the standard sieve is cylindrical and has a sieve opening of 100 meshes.

[0011] Furthermore, the rotary cutter head is a turbine type rotary cutter head with a rotation speed of 2800-3200r / min.

[0012] A method for preparing a coarse cobalt hydroxide sample using the above device comprises the following steps: S1: vibration screening; firstly, the coarse cobalt hydroxide raw material is mixed and then reduced, and then the reduced coarse cobalt hydroxide raw material is evenly poured from the feeding funnel into the vibrating feeder for vibration screening and feeding; S2: cutting and grinding; after all the coarse cobalt hydroxide particles after the vibrating screening and feeding in step S1 have flowed into the grinding chamber, a high-pressure air gun is used to blow toward the feeding port of the grinding chamber for 10-15 seconds; then the rotating cutter head in the grinding chamber is started to cut and crush the coarse cobalt hydroxide particles; S3: Sieving and collecting; the coarse cobalt hydroxide ground in step S2 falls into the standard sieve in the grinding chamber for screening, and the screened sample passes through the pressure storage tank, the negative pressure tank and the cyclone collector in turn under the action of the wind pressure motor and falls into the receiving barrel. During the sample collection process, the wind pressure of the wind pressure motor is controlled by the pressure converter to perform frequency conversion transportation of the powder; after the screening is completed, the rotating cutter head in the grinding chamber is turned off, the standard sieve is removed, and the coarse cobalt hydroxide remaining on the inner wall of the grinding chamber is swept into the receiving barrel with a brush; S4: Sample preparation and sealing; pour the coarse cobalt hydroxide in the collecting barrel into the sample mixing bag, mix and divide into 4 parts according to the quartering method to obtain coarse cobalt hydroxide samples, and then seal them separately in aluminum foil bags.

[0013] Furthermore, in step S1, the reduction amount of each portion during mixing and reduction is ≥2000g; and in step S5, the reduction amount of each portion during sample preparation is ≥150g.

[0014] Furthermore, the vibration screening time in step S1 is 10-20 minutes.

[0015] The beneficial effects of the present invention are as follows: 1. This device uses a high-speed rotating turbine rotary cutter head to cut and crush the coarse cobalt hydroxide, ensuring that the coarse cobalt hydroxide is cut around the rotary cutter head as much as possible after being subjected to centrifugal force and negative pressure suction during the cutting process. The coarse cobalt hydroxide after cutting is then ground in the grinding cabin and automatically screened with a standard sieve. The screened sample passes through the pressure storage tank, negative pressure tank and cyclone collector in turn under the action of the wind pressure motor and falls into the receiving barrel. During the sample collection process, the wind pressure of the wind pressure motor can be controlled by a pressure converter to achieve the purpose of variable frequency conveying of powder. Cutting, grinding and screening are carried out simultaneously, which solves the problem of high labor intensity and high dust contact in traditional sample preparation, and improves the efficiency and quality of sample preparation.

[0016] 2. The device for preparing coarse-grained cobalt hydroxide samples provided by the present invention has a 100-mesh standard sieve arranged in the grinding chamber along the outer periphery of the rotating cutter head, so that the coarse-grained cobalt hydroxide after grinding can meet the particle size standard of the standard sample after one grinding, and the particle size of the sample preparation is effectively controlled. In addition, a plurality of sieve holes are arranged at equal intervals on the standard sieve, and the inner circle of the sieve holes is convex and has sharp edges near the rotating cutter head. The coarse-grained cobalt hydroxide with large particles can also be crushed for a second time when passing through the standard sieve, which further improves the cutting efficiency of the coarse-grained cobalt hydroxide, saves time and effort, and does not affect the properties of the sample, and the prepared sample is representative.

[0017] 3. The feeding method of this device is continuous feeding. During the high-speed rotation of the rotary cutter head, the coarse cobalt hydroxide particles falling down can be brought into the grinding chamber through the grinding chamber feed port, which solves the problem of limited sample preparation amount and further improves the sample preparation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of a coarse-grained cobalt hydroxide sample preparation device of the present invention; Figure 2 It is a schematic structural diagram of the powder variable frequency conveyor of the present invention; Figure 3 It is a schematic diagram of the standard screen structure of the present invention; In the figure: 1-vibrating feeder; 2-grinding chamber; 3-collecting barrel; 4-feeding funnel; 5-slide; 6-rotating cutter head; 7-standard screen; 8-negative pressure tank; 9-pressure storage tank; 10-pressure converter; 11-wind pressure motor; 12-cyclone collector. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with the accompanying drawings: A device for preparing a coarse cobalt hydroxide sample comprises a vibrating feeder 1, a grinding chamber 2 and a receiving bucket 3 which are arranged in sequence from top to bottom. The vibrating feeder 1 comprises a feeding hopper 4 arranged on the top of the machine body, and a discharge port at the bottom of the feeding hopper 4 is connected to a feeding port of the grinding chamber 2 through a slide plate 5, wherein a lower end of the slide plate 7 is inclined 15° toward the feeding port of the grinding chamber 2. The grinding chamber 2 includes a rotating cutter head 6 rotatably connected in the chamber. The rotating cutter head 6 uses a turbine type rotating cutter head with a rotation speed of 3000r / min. A standard screen 7 is arranged along the circumference of the inner wall of the grinding chamber 2 with the rotating cutter head 6 as the center. The grinding chamber and the standard screen 4 are both horizontally cylindrical, and the feed port of the grinding chamber 2 is a four-sided pyramid structure with a large top and a small bottom. The standard screen 7 is provided with a plurality of 100 mesh sieve holes arranged at equal intervals, and the inner circle of the sieve holes is convex near the rotating cutter head 6 and has sharp edges. The discharge port at the bottom of the grinding chamber 2 is connected to the feed port at the top of the receiving barrel 3, and a powder variable frequency conveyor is arranged in the receiving barrel 3. The powder variable frequency conveyor includes a wind pressure motor 11 and a pressure converter 10. The wind pressure motor 11 is connected to the input end of the pressure converter 10, and the output end of the pressure converter 10 is connected to the pressure storage tank 9, the negative pressure tank 8 and the cyclone collector 12 in sequence.

[0020] When using the preparation device provided by the present invention to prepare a coarse cobalt hydroxide sample, first check that the grinding chamber 2 is clean, then install the rotating cutter head 6 in the grinding chamber 2, then close the door of the grinding chamber 2 (the prior art, not shown in the figure), turn on the power switch of the device, and start sample preparation after idling for 20 seconds. The sample preparation steps are as follows: S1: vibration screening; firstly, the coarse cobalt hydroxide raw material is mixed and then reduced, and then the reduced coarse cobalt hydroxide raw material is evenly poured from the feed hopper 4 into the vibrating feeder 1 for vibration screening and feeding; S2: cutting and grinding; after all the coarse cobalt hydroxide particles after the vibrating screening and feeding in step S1 flow into the grinding chamber 2, a high-pressure air gun is used to blow toward the feed port of the grinding chamber 2 for 10 seconds; then the rotating cutter head 6 in the grinding chamber 2 is started to cut and crush the coarse cobalt hydroxide particles; S3: Sieving and collecting; the coarse cobalt hydroxide ground in step S2 falls into the standard sieve 7 in the grinding chamber 2 for screening, and the screened sample passes through the pressure storage tank 9, the negative pressure tank 8 and the cyclone collector 12 in sequence under the action of the wind pressure motor 11 and falls into the receiving barrel 3. During the sample collection process, the wind pressure of the wind pressure motor 11 is controlled by the pressure converter 10 to perform frequency conversion transportation of the powder; after the screening is completed, the rotating cutter head 6 in the grinding chamber 2 is turned off, the standard sieve 7 is removed, and the coarse cobalt hydroxide remaining on the inner wall of the grinding chamber 2 is swept into the receiving barrel 3 with a brush; S4: Sample preparation and sealing; pour the coarse cobalt hydroxide in the collecting barrel 3 into the mixing bag, weigh to obtain 1142g of sample, ignore sample loss, mix and reduce it into 4 portions according to the quartering method, and obtain coarse cobalt hydroxide samples with a reduced weight of 285.5g per portion, and then seal them in aluminum foil bags respectively.

Claims

1. A device for preparing a coarse cobalt hydroxide sample, characterized in that: The invention comprises a vibrating feeder (1), a grinding chamber (2) and a collecting barrel (3) which are arranged in sequence from top to bottom; the vibrating feeder (1) comprises a feeding hopper (4) arranged at the top of the machine body, and the bottom discharge port of the feeding hopper (4) is connected to the feeding port of the grinding chamber (2) through a slide plate (5); the grinding chamber (2) comprises a rotating cutter head (6) rotatably connected in the chamber body, and a standard screen (7) is arranged along the circumference of the inner wall of the grinding chamber (2) with the rotating cutter head (6) as the center; the bottom discharge port of the grinding chamber (2) is connected to the top feed port of the collecting barrel (3), and a powder variable frequency conveyor is arranged in the collecting barrel (3); the powder variable frequency conveyor comprises a pneumatic motor (11) and a pressure converter (10), the pneumatic motor (11) is connected to the input end of the pressure converter (10), and the output end of the pressure converter (10) is connected to the pressure storage tank (9), the negative pressure tank (8) and the cyclone collector (12) in sequence.

2. The device for preparing a coarse cobalt hydroxide sample according to claim 1, characterized in that: The lower end of the slide (7) is inclined toward the feed opening of the grinding chamber (2), and the inclination angle is 10-15°.

3. A device for preparing a coarse cobalt hydroxide sample as claimed in claim 2, characterized in that: The grinding chamber body of the grinding chamber (2) is in the shape of a horizontal cylinder.

4. A device for preparing a coarse cobalt hydroxide sample as claimed in claim 3, characterized in that: The feed inlet of the grinding chamber (2) is a four-sided pyramid structure that is larger at the top and smaller at the bottom.

5. The device for preparing a coarse cobalt hydroxide sample according to claim 4, characterized in that: The standard sieve (7) is provided with a plurality of equidistantly arranged sieve holes, and the inner circle of the sieve holes is convex on one side close to the rotating cutter head (6) and has a sharp edge.

6. The device for preparing a coarse cobalt hydroxide sample according to claim 5, characterized in that: The standard sieve (4) is cylindrical and has a sieve opening of 100 meshes.

7. The device for preparing a coarse cobalt hydroxide sample according to claim 6, characterized in that: The rotary cutter head (6) is a turbine type rotary cutter head with a rotation speed of 2800-3200 r / min.

8. A method for preparing a coarse cobalt hydroxide sample using the device according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1: vibration screening; firstly, the coarse cobalt hydroxide raw material is mixed and then reduced, and then the reduced coarse cobalt hydroxide raw material is evenly poured from the feeding funnel (4) into the vibrating feeder (1) for vibration screening and feeding; S2: cutting and grinding; After all the coarse cobalt hydroxide particles fed by the vibration screening in step S1 have flowed into the grinding chamber (2), a high-pressure air gun is used to blow toward the feed port of the grinding chamber (2) for 10-15 seconds; then the rotating cutter head (6) in the grinding chamber (2) is started to cut and crush the coarse cobalt hydroxide particles; S3: Sieving and collecting; the coarse cobalt hydroxide particles ground in step S2 fall into the standard sieve (7) in the grinding chamber (2) for screening, and the samples under the sieve pass through the pressure storage tank (9), the negative pressure tank (8) and the cyclone collector (12) in sequence under the action of the wind pressure motor (11) and then fall into the collecting barrel (3). During the sample collection process, the wind pressure of the wind pressure motor (11) is controlled by the pressure converter (10) to perform frequency conversion transportation of the powder; after the screening is completed, the rotating blade (6) in the grinding chamber (2) is turned off, the standard sieve (7) is removed, and the coarse cobalt hydroxide particles remaining on the inner wall of the grinding chamber (2) are swept into the collecting barrel (3) with a brush; S4: Sample preparation and sealing; pour the coarse cobalt hydroxide in the collecting barrel (3) into the sample mixing bag, mix and divide into 4 parts according to the quartering method to obtain coarse cobalt hydroxide samples, and then seal them in aluminum foil bags respectively.

9. A method for preparing a coarse cobalt hydroxide sample according to claim 8, characterized in that: In the step S1, the amount of each portion reduced during mixing and reduction is ≥2000g; and in the step S5, the amount of each portion reduced during sample preparation is ≥150g.

10. A method for preparing a coarse cobalt hydroxide sample according to claim 9, characterized in that: The time of vibration screening in step S1 is 10-20 minutes.

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