Plasma technologies

The plasma state is one of the four fundamental state of matter, along with gaseous, liquid and solid states.

The plasma state forms at very high temperatures when the energy of a gas, or a mix of gases, is such that electrons can be extracted from the atoms. In such a state, the plasmas display unique properties and behaviors.

In industry, the plasma state has been recently used to heat some media to extreme high temperatures or to inlay a specific property within a material.

This is where the JEMA SA power supplies intervene.

There are several ways to achieve the plasma state. One of them is by use of a controlled Direct Current Electric Arc, which provides a lot of energy locally that can be combined with the thermodynamic expansion of a gas to achieve very high temperatures and very high velocities.

In industry, plasmas are created in a so-called torch that initates and hosts the electric arc, insures the mix of gases and the cooling of the exterior metal parts.

JEMA SA supplies the DC power systems that initiate and control the electric arc in the torch.

Plasma HEATING for Reverse Metallurgy

Reverse metallurgy is the process of recycling metals within the emerging value chain of circular economy. In this way, it is possible to recover pure metals from waste, close to its original high intrinsic value.

Residues containing metal are mechanically crushed and the metallic parts are separated as much as possible from non-metallic parts using mechanical processes. The remaining metal-rich compound is then heated by a plasma torch to very high temperatures that cause the metal to boil and evaporate.

This evaporation leaves the non-metallic parts in the furnace while the vapor condenses further in the process into pure metal that can be reused in industry.

To achieve those extreme high temperature, between 2500 °C and 3000 °C, conventional heating principles are not that effective, so a plasma torch is used to heat a gas to this high temperature, which in turn transfers its heat to a pre-melted metal/waste mix until evaporation.

A plasma torch converts the energy of a controlled electric arc into the heat and velocity of a gas that reaches the state of plasma. This arc is generated between a positive and a negative DC electrode.


JEMA SA designs, manufactures, installs and commissions the complete DC power supply system (3 x 3 MW shown on the picture) that initiates and controls a stable and powerful DC current to the arc in the torch for evaporation of the metal to be recycled.

The JEMA product delivers the regulated DC power to the torch.

Read more about this product


Another application of the plasma torch is plasma coating, also known as plasma thermal spraying, or plasma sputtering.

In this industrial process, specific material made molten by the heat of the plasma is projected with high velocity to a surface to change and improve its behavior. For example, treated surfaces like glass can exhibit water repellent properties or change opacity with intensity of the sun light.

JEMA SA is currently involved in the development of very specific DC power supplies to feed the plasma torch of such industrial processes.

Read more about this product