Method and device for producing heavy metal powders by ultrasonic atomization

A method for production of heavy metal powders by ultrasonic atomization, wherein heavy metal is defined as any electrically conductive metal of density >8500 kg/m3 and melting temperature (liquidus) >1073 deg K=800 C at 1 barA, the method comprising:

• providing a heavy metal raw material in the vicinity of a heat source, the heat source having an electrode, and generating an electric arc,
• heating the heavy metal raw material by the electric arc, so as to create a molten metal pool on a sonotrode, the molten metal pool having a temperature equal to or greater than the melting temperature of the heavy metal raw material, but below the vaporization temperature of the heavy metal raw material,
• providing ultrasonic mechanic vibrations by the sonotrode to the molten metal pool, so as to cause heavy metal droplets to be ejected from the molten metal pool,
• directing the ejected heavy metal droplets away from the molten metal pool, so as to cause the heavy metal droplets to freely cool down at least by radiation within a predetermined distance and transform to a heavy metal powder,
• collecting the heavy metal powder,
• the electrode being a cathode and the sonotrode being an anode, the electric arc being of the length in the range from 5 to 40 mm, the electric arc length being measured between a tip of the cathode and the sonotrode center, the power supplied to the electric arc does not exceed 15 KW per 1 cm2 of the area of the molten metal pool, the ultrasonic mechanical vibrations velocity on a hot end of the sonotrode being at least 0.2 m/see 0-peak in frequency range 15 to 1000 kHz, so as to collect at least 75% of the heavy metal raw material in the form of the heavy metal powder.