Preparation Method and Process of Nano Copper Powder

Background technique:

Nano copper powder is an indispensable basic raw material for nano copper materials with good conductivity and high strength. Due to its excellent electrical properties, it is widely used in conductive adhesives, conductive coatings, and electrode materials. In recent years, research has found that it can be used to make catalysts, lubricant additives, and even to treat osteoporosis and fractures.

Preparation method and process of nano copper powder

The nano-copper powder has a large specific surface and a large number of surface active centers, and is an excellent catalyst in metallurgy and petrochemical industry. Nano-copper powder catalysts have extremely high activity and selectivity in the hydrogenation and dehydrogenation reactions of high molecular polymers. Nano-copper powders are very effective catalysts in the process of acetylene polymerization used to make conductive fibers. In the process of automobile exhaust purification, nano-copper powder can be used as a catalyst to partially replace the precious metals platinum and ruthenium, convert toxic carbon monoxide into carbon dioxide, and convert nitric oxide into nitrogen dioxide. With the development of the electronics industry, ultra-thin thick film pastes prepared from nano-copper powders will play an important role in large-scale integrated circuits. At the same time, they are cheaper than precious metal silver powders and palladium powders, and have broad application prospects. Nano-copper lubricating oil additive is a new type of lubricating oil additive product based on nano-tribology as the theoretical guide and supported by nano-technology. It has excellent anti-friction, anti-friction and energy-saving and environmental protection effects. Adding copper nano-lubricant additives to automobile engine lubricants can reduce the engine’s starting current and increase cylinder pressure. After the engine has used the additive for a period of time, a protective film is formed on the cylinder liner and the piston ring. at this time. Once the lubrication system fails, the car can still drive safely for a long time, which makes military sense.

The development of nano-copper powder is a key technology that may bring revolutionary changes to copper and its alloys, and has important theoretical significance and practical value. The research of nano copper powder is still in the development stage, and its wide application will make the research of nano copper powder have better market value and market prospect.

At the present stage, the production of nano-sized copper powder is mainly based on coarse-grained copper powder, which adopts improved vibration ball milling and high-energy ball milling. However, due to the better shape of copper, the ball milled nano-copper powder mainly presents flake powder without fluidity. At the same time, due to severe cold processing, large crystal defects, high hardness, reducing annealing, and prone to agglomeration and sintering.

Technical realization elements:

In view of the shortcomings of the prior art, an object of the present invention is to provide a method for preparing nano-copper powder. The nano-copper powder prepared by the method has high purity, uniform particle size distribution, and is easy to use.

To achieve this, the present invention adopts the following technical solutions:

A method for preparing nano copper powder includes the following steps:

1) The atomized copper powder is prepared by the atomization method, and the particle size of the atomized copper powder is controlled below 150um;

2) Add the atomized copper powder to the calcining furnace for calcination, and obtain the copper oxide powder below 150um after calcination;

3) Take out the copper oxide powder and place it in a high-energy ball mill for ball milling to obtain nano-scale copper oxide powder;

4) Put the nano-scale copper oxide powder into the fluidized bed, control the temperature of the fluidized bed at 400 ~ 600 ℃, and pass in the ammonia decomposition atmosphere to reduce the nano-scale copper oxide powder under the fluidized state to obtain nano-scale copper powder .

Preferably, in the step 1), the particle diameter of the atomized copper powder is less than 75um.

Preferably, in the step 2), the calcining furnace is a DHZY rotary calcining kiln.

Preferably, in the step 2), the calcination temperature is controlled to 700 to 900 ° C. and the time is 3-5 hours.

Preferably, in the step 3), the model of the high-energy ball mill is 01-HDDM 750cc, the ball milling time is 45-90min, and the rotation speed is 1800-2200r / min.

Preferably, in step 4), the fluidized bed is a powder fluidized bed, the reduction time is 1.5-2.5 hours, and the reduction temperature is 400-600 ° C.

The invention uses atomized copper powder as a raw material, and has the advantages that:

Atomized copper powder, which is further processed from electrolytic copper, is light rosette-shaped, irregularly packed, spherical, spherical powder, easily oxidized in humid air, soluble in hot sulfuric acid or nitric acid Excellent oxidation resistance. The atomized copper powder is granular or irregular, with small particle gaps and small relative sliding resistance between particles, so the bulk density is high.

Compared with the prior art, the present invention has the beneficial effects that the present invention selects atomized copper powder as a raw material, and calcines it through a high-temperature oxidation furnace to form a copper oxide powder having an oxygen content of 15% to 20%, and then the copper oxide powder is Through high-energy ball milling, air flow sieving is used to obtain nano-scale copper oxide powder. The nano-scale copper oxide powder is charged into a fluidized bed, and the ammoniated decomposition gas is passed into the fluidized bed, so that the copper oxide is in a fluidized state, and the temperature of the fluidized bed is controlled At 400-600 ° C, the nano-copper oxide is in a fluidized state and is not agglomerated to obtain nano-scale copper powder. The nano-copper powder prepared by the preparation method of the present invention has uniform components, high density, excellent fluidity, and easy molding, and solves the problems of tableting and agglomeration in the traditional preparation method. The preparation process is simple and easy to operate. The nano-copper powder of the present invention can be applied to the production of microelectronic devices, used to manufacture multilayer ceramic capacitor terminals, and can also be used as catalysts in the reaction process of carbon dioxide and hydrogen to methanol, and conductive coatings on metal and non-metal surfaces. Processing, conductive paste, used as petroleum lubricant and pharmaceutical industry.

detailed description

The technical solutions of the present invention will be further described below through specific embodiments.

Unless otherwise specified, the various raw materials of the present invention are commercially available or can be prepared according to conventional methods in the art.

Example 1

A method for preparing nano copper powder includes the following steps:

1) The atomized copper powder is prepared by the atomization method. The particle size of the atomized copper powder is controlled below 75um, and the purity is controlled above 99.5%;

2) The atomized copper powder is added to a calcining furnace for calcination. The calcining furnace tube is a corundum furnace tube. After calcining, a copper oxide powder smaller than 75um is obtained;

3) Take out the copper oxide powder and place it in a high-energy ball mill for ball milling to obtain nano-scale copper oxide powder;

4) The nano-sized copper oxide powder is put into a fluidized bed, the temperature of the fluidized bed is controlled at 560 ° C, and an ammonia decomposition atmosphere is passed in, so that the nano-sized copper oxide powder is reduced in a fluidized state to obtain nano-sized copper powder.

In 2), the calcining furnace is a DHZY rotary calcining kiln, the calcining temperature is controlled to 780 ° C, and the time is 4 hours.

3) The model of the high-energy ball mill is 01-HDDM 750cc, the ball milling time is 1 hour, and the rotation speed is 2000r / min.

The fluidized bed in 4) is a powder fluidized bed, the reduction time is 2 hours, and the temperature is 500 ° C.

Table 1: According to the MPIF sampling method, the measured parameters of the four different positions of the nano-copper powder of Example 1 are shown in the following table:

Example 2

A method for preparing nano copper powder includes the following steps:

1) The atomized copper powder is prepared by the atomization method. The particle size of the atomized copper powder is controlled below 75um, and the purity is controlled above 99.5%;

2) The atomized copper powder is added to a calcining furnace for calcination. The calcining furnace tube is a corundum furnace tube. After calcining, a copper oxide powder smaller than 75um is obtained;

3) Take out the copper oxide powder and place it in a high-energy ball mill for ball milling to obtain nano-scale copper oxide powder;

4) The nano-sized copper oxide powder is put into a fluidized bed, the temperature of the fluidized bed is controlled at 400 ° C, and an ammonia decomposition atmosphere is passed in, so that the nano-sized copper oxide powder is reduced in a fluidized state to obtain nano-sized copper powder.

2) The medium calcining furnace is a DHZY rotary calcining kiln. The calcining temperature is controlled to 900 ° C and the time is 3 hours.

3) The model of the high-energy ball mill is 01-HDDM 750cc, the ball milling time is 1.5 hours, and the rotation speed is 1800r / min.

The fluidized bed in 4) is a powder fluidized bed, the reduction time is 2.5 hours, and the reduction temperature is 400 ° C.

Table 2: According to the MPIF sampling method, the measured parameters of the four different positions of the nano-copper powder of Example 2 are shown in the following table:

Example 3

1) The atomized copper powder is prepared by the atomization method. The particle size of the atomized copper powder is controlled below 75um, and the purity is controlled above 99.5%;

2) The atomized copper powder is added to a calcining furnace for calcination. The calcining furnace tube is a corundum furnace tube. After calcining, a copper oxide powder smaller than 75um is obtained;

3) Take out the copper oxide powder and place it in a high-energy ball mill for ball milling to obtain nano-scale copper oxide powder;

4) The nano-sized copper oxide powder is put into a fluidized bed, the temperature of the fluidized bed is controlled at 600 ° C, and an ammonia decomposition atmosphere is passed, so that the nano-sized copper oxide powder is reduced in a fluidized state to obtain nano-sized copper powder.

2) The medium calcining furnace is a DHZY rotary calcining kiln, and the calcining temperature is controlled to 700 ° C for 5 hours.

3) The model of the high-energy ball mill is 01-HDDM 750cc, the ball milling time is 45min, and the rotation speed is 2200r / min.

The fluidized bed in 4) is a powder fluidized bed, the reduction time is 1.5 hours, and the temperature is 600 ° C.

Table 3: According to the MPIF sampling method, the parameters measured at four different positions of the nano-copper powder of Example 3 are shown in the following table:

Comparative Example: Using coarse-grained copper powder as a sample, an improved vibratory ball mill and high-energy ball mill were used to obtain flake-shaped ball-milled nano-copper powder.

Table 4: The parameters of the four different positions of the flake nano-copper powder of the comparative example are shown in the following table:

From the above test data, it can be known that the nano-copper powder prepared by the present invention has high purity, uniform particle size distribution, and is easy to disperse and use. It has better fluidity than flake copper powder. In addition, the process for preparing nano-copper powder by this method is simple and cost low.

The above are only the preferred embodiments of the present invention, but the scope of protection of the present invention is not limited to this. Any person skilled in the technical field is within the technical scope disclosed by the present invention, according to the technical solution of the present invention. The equivalent replacement or change of the invention concept should be covered by the protection scope of the present invention.

Technical characteristics:
A method for preparing nano-copper powder, comprising the following steps:

1) The atomized copper powder is prepared by the atomization method, and the particle size of the atomized copper powder is controlled below 150um;

2) Add the atomized copper powder to the calcining furnace for calcination, and obtain 150 mesh copper oxide powder after calcination;

3) Take out the copper oxide powder and place it in a high-energy ball mill for ball milling to obtain nano-scale copper oxide powder;

4) Put the nano-scale copper oxide powder into the fluidized bed, control the temperature of the fluidized bed at 400 ~ 600 ℃, and pass in the ammonia decomposition atmosphere to reduce the nano-scale copper oxide powder under the fluidized state to obtain nano-scale copper powder .

The method for preparing atomized copper powder according to claim 1, wherein in the step 1), the particle diameter of the atomized copper powder is less than 75um.

The method for preparing copper oxide powder according to claim 1, characterized in that in the step 2), the calcining furnace is a DHZY rotary calcining kiln.

The method for preparing copper oxide powder according to claim 1, characterized in that, in the step 2), the calcination temperature is controlled to 700 to 900 ° C, and the time is 3-5 hours.

The method of claim 1, wherein the model of the high-energy ball mill in step 3) is 01-HDDM 750cc, the ball milling time is 45-90min, and the rotation speed is 1800- 2200r / min.

The method of claim 1, wherein the fluidized bed in step 4) is a powder fluidized bed, the reduction time is 1.5-2.5 hours, and the reduction temperature is 400 ~ 600 ℃.

Technical summary
The invention discloses a method for preparing nano-copper powder. The invention selects atomized copper powder or electrolytic copper powder as a raw material, and calcines it through a high-temperature oxidation furnace to form a copper oxide powder with an oxygen content of 15% to 20%. The copper oxide powder is passed through a high-energy ball mill and sieved with air to obtain nano-scale copper oxide powder. The nano-sized copper oxide powder is charged into a fluidized bed, and the ammoniated decomposition gas is passed into the fluidized bed, so that the copper oxide is in a fluidized state and fluidized. The bed temperature is controlled at 400 ~ 600 ° C, and the nano-sized copper oxide is reduced and not agglomerated in the fluidized state to obtain nano-sized copper powder. The nano-copper powder prepared by the method has high purity, uniform particle size distribution, and is easy to disperse and use. The nano-copper powder of the present invention is used for the production of microelectronic devices, used for manufacturing multilayer ceramic capacitor terminals, and can also be used for catalysts, metal and non-metallic surface conductive coatings in the reaction process of carbon dioxide and hydrogen to methanol. , Conductive paste, used in petroleum lubricants and pharmaceutical industries.