Atomized metal powder: the revolution of the precious metals market
How atomised powder is transforming the precious metals and alloys industry and their applications.
What is atomization?
It is an industrial process of transforming metals, including precious metals, into very fine powders, whose single grains have a diameter ranging from 10 to 100 microns.
The starting material is metal in a solid state. It is placed inside a crucible, where it is melted. Once the right temperature is reached, the metal bath is poured through a perforated die and "bombarded" by multiple jets of water or gas at very high pressures which pulverize it.
There are two types of atomization units: water atomizers produce powders with a higher granulometry (grain size) and with a more elongated and dendritic morphology (grain shape) while gas atomizers generate finer products with a more spherical shape.
Both systems can use inert atmospheres or a vacuum in the melting chamber.
Why atomized powder?
The global market is turning more and more towards atomized metal powders for various applications such as HIP (Hot Isostatic Pressing), Additive Layer Manufacturing (3D printing) or sintering.
Water technology is mainly used for sintering or HIP as the dendritic form tends to cling more. While gas atomization allows greater smoothness of the powders in the deposition phase of the layers in 3D printing, given the sphericity of the grains.
They are used in a growing number of sectors, not only in metallurgy, but also in the glass and ceramic industries or in medicine or the electronics industry.
If we talk about ultra-powder - a "pure" atomized powder with a particle size ranging from 15 to 45 microns which allows for better amalgamation of the alloys - we end up in the aerospace, artificial prostheses or dentistry industries.
Alloys created with ultra-powders are called superalloys. Used in 3D printing, they allow for the creation of pieces with a high level of finish, with a 100% degree of product quality repeatability. Results of this kind would be unthinkable with other technologies.
The most interesting aspect of this technology is the possibility of bonding naturally insoluble materials such as graphite and silver, a typical product for electrical contacts
The use of these powders generates less waste, offers opportunities to obtain perfect and replicable items, employs less machinery and tools and therefore speeds up processes.
In the refining of precious metals, this last point is particularly evident: using powder instead of grains will reduce dissolution times because the acids "attack" the atomized particles more quickly, precisely because the particle size is much smaller, so the interaction volume increases.
The Italimpianti atomizers
Italimpianti Orafi produces a range of gas and water atomizers suitable for both small laboratories and industrial production (up to 200 kg/cycle).
The specific geometry of the die allows to produce spherical and dendritic metal powders of high quality and with a high degree of repeatability.
The chemical composition and homogeneity of the alloys are perfectly guaranteed by means of induction generators.
The melting process, depending on the type of atomizer of the customer's needs, can be carried out in air or in a controlled atmosphere, as well as under vacuum or at normal atmospheric pressure, thus allowing the atomization of a wide range of metals, including those that are easily oxidized.
Precious metals, PGMs, copper, zinc, aluminum, brass and other metals, including precious alloys can be melted.
All our machines are entirely developed, built and tested in the company with proprietary technology and have been designed to allow the operator to quickly and easily change the crucible. To avoid cross-contamination, the crucibles are also easy to clean and handle.