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A method for preparing spherical molybdenum powder

A powder and spherical technology, applied in the field of preparing spherical molybdenum powder, can solve the problems of complicated process, various additives, secondary pollution of molybdenum powder, etc. Effect

Active Publication Date: 2015-10-21
JINDUICHENG MOLYBDENUM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method adds polyethylene glycol, polyvinyl alcohol, ethanol and other substances, and the addition amount is large (more than 10%), which is easy to cause secondary pollution of molybdenum powder, and the subsequent sintering temperature is high (greater than 1550 ° C), which is not only harmful to Sintering plants place high demands and are not conducive to energy saving
CN201210082935 discloses a method for preparing spherical metal molybdenum particles for cold spraying. This method limits the particle size of the initial molybdenum powder raw material, and at the same time, the variety of additives complicates the process. In addition, the purpose of sintering in this invention is only to improve Particle strength, so the molybdenum powder prepared by this method is limited to the field of cold spraying

Method used

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  • A method for preparing spherical molybdenum powder
  • A method for preparing spherical molybdenum powder
  • A method for preparing spherical molybdenum powder

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] Step 1. Using ball milling, 3000g of conventional reduced molybdenum powder is ball milled for 240min under the condition that the ball-to-material ratio is 1:1;

[0037] Step 2, dissolving 61.2g of polyvinyl alcohol into 1230mL of deionized water to prepare an aqueous solution of polyvinyl alcohol;

[0038] Step 3, adding the molybdenum powder pulverized in step 1 into the polyvinyl alcohol aqueous solution described in step 2, and stirring evenly to make a slurry;

[0039] Step 4: Spray-dry the slurry described in Step 3 to obtain granulated powder; the air inlet temperature of the spray-dried drying tower is 220°C, the air outlet temperature is 120°C, and the rotational speed of the centrifugal atomizing disc is 10500rpm;

[0040] Step 5. Degrease the granulated powder described in step 4 at 900°C for 2 hours under a wet hydrogen atmosphere with a dew point of 35°C, then heat-treat at 1200°C for 8 hours under a hydrogen atmosphere, and finally crush it through a -100...

Embodiment 2

[0043] Step 1. Using jet milling method, 3000g conventional reduced molybdenum powder is subjected to high-energy fluidized bed collision jet milling, the rotating speed is 10000r / min, and the processing time is 80min;

[0044]Step 2, dissolving 70g of polyvinyl alcohol into 1400mL of deionized water to prepare an aqueous solution of polyvinyl alcohol;

[0045] Step 3, adding the molybdenum powder pulverized in step 1 into the polyvinyl alcohol aqueous solution described in step 2, and stirring evenly to make a slurry;

[0046] Step 4: Spray-dry the slurry described in Step 3 to obtain granulated powder; the air inlet temperature of the spray-dried drying tower is 230°C, the air outlet temperature is 150°C, and the rotational speed of the centrifugal atomizing disc is 11500rpm;

[0047] Step 5. Degrease the granulated powder described in step 4 at 800°C for 4 hours under a wet hydrogen atmosphere with a dew point of 40°C, then heat-treat at 1300°C for 6 hours under a hydrogen ...

Embodiment 3

[0050] Step 1. Using ball milling, 3000g of conventional reduced molybdenum powder is ball milled for 20min under the condition that the ball-to-material ratio is 4:1;

[0051] Step 2, dissolving 58g of polyvinyl alcohol into 1200mL of deionized water to prepare an aqueous solution of polyvinyl alcohol;

[0052] Step 3, adding the molybdenum powder pulverized in step 1 into the polyvinyl alcohol aqueous solution described in step 2, and stirring evenly to make a slurry;

[0053] Step 4: Spray-dry the slurry described in Step 3 to obtain granulated powder; the air inlet temperature of the spray-dried drying tower is 250°C, the air outlet temperature is 115°C, and the rotational speed of the centrifugal atomizing disc is 11000rpm;

[0054] Step 5. Degrease the granulated powder described in step 4 at 700°C for 8 hours under a wet hydrogen atmosphere with a dew point of 55°C, then heat-treat at 1400°C for 4 hours under a hydrogen atmosphere, and finally crush it through a -100 to...

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Abstract

The invention discloses a method for preparing spherical molybdenum powder. The method includes the following steps: pulverizing the molybdenum powder; preparing polyvinyl alcohol aqueous solution; adding the pulverized molybdenum powder into the polyvinyl alcohol aqueous solution, stirring the solution to be even and preparing the solution to be sizing agent; performing spray drying on the sizing agent to obtain granulation powder; and firstly performing ungrease treatment on the granulation powder, secondly performing heat treatment on the granulation powder, and eventually performing crushing and sieving to obtain the spherical molybdenum powder. The method for preparing the spherical molybdenum powder is simple in process, low in cost, high in finished product rate, and wide in application range. By adoption of the method, the microstructure of the molybdenum powder can be effectively improved, the properties including apparent density, mobility and the like of the powder can be improved, the apparent density of the prepared spherical molybdenum powder is 2.0-4.5g / cm<3>, the mobility is 15s / 50g-30s / 50g, the quality purity is larger than or equal to 99.95%, and the finished product rate is larger than or equal to 90%.

Description

technical field [0001] The invention belongs to the technical field of molybdenum powder preparation, and in particular relates to a method for preparing spherical molybdenum powder. Background technique [0002] The refractory metal molybdenum is located in group VIA of the periodic table of elements and has an A2-type body-centered cubic structure. Compared with other refractory metals such as Ta, Nb, Co, etc., molybdenum not only has excellent thermal conductivity, electrical conductivity, and corrosion resistance, but also has a low thermal expansion coefficient, high hardness, and good high-temperature strength. Therefore, it is widely used in high-tech fields such as electronics, aerospace, energy, and nuclear reactors. [0003] In recent years, with the rapid development of modern technology, especially high-end technologies such as electronic information and aerospace, the demand for high-performance, miniature and special-shaped molybdenum-based products has increa...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B22F9/08
Inventor 付静波张晓庄飞
Owner JINDUICHENG MOLYBDENUM CO LTD