KFT have designed a modular rectifier assembly which allows multiple units to be connected when larger currents are required by the process.

We have experience in the design of rectifiers up to 60 MVa and 1200 volts DC.


SHORT DC ARC TECHNOLOGY developed by Keech Furnace Technologies is called brush arc technology.

The arc only “brushes” the charge and is typically between 2mm and 10mm in length.

The advantage of this technology is that little energy is lost during the smelting process resulting in lower energy consumption therefore more cost effective and increases production.

To date, these short arc DC furnaces are manufactured in the current facilities.

No other facility in the world has technology to successfully deploy these units into the market.


In 1980, Barry Keech began working with Arc furnaces with two three phase furnaces for Dimbaza foundries, later to become part of the Scaw group.

Managed to upgrade the furnace by replacing the control system to an electronic regulator, which in turn reduced the energy consumption by 30% and the smelting time by 40%.

This technology was then widely used and enabled the foundries to improve their delivery times and costs.

To date, KFT has fitted these unique control systems in most electric arc furnaces in Southern Africa and our clients have been satisfied as they own unrivaled fully automated furnaces


In 1995, KFT designed and manufactured its first DC Arc Furnace to recover Silicon for Nimag, this yielded positive results. Silicon for their process

KFT manufactures both AC and DC furnaces for a variety of minerals processes which were until then not technically or economically possible.

The very high temperatures achieved in a DC furnace bring many opportunities to process minerals which were until then only achievable by Hydrometallurgical methods.

KFT has developed single, two and three poles DC furnaces, the number of poles is based on the type of minerals being processed. Three pole three phase AC furnaces are generally used for relatively lower temperature melting and smelting of Tin, Copper, Zinc, and Lead.


To modify the distortion, we manufacture and install harmonic filters to all our Furnaces power supplies.

Capacitors are used in this process to stabilise the load and act as power factor correction devices

The overall results is power factor correction coupled with reduction of the harmonic content of the Furnace

This technology achieves power factors of 0.999 for DC furnaces as opposed to the smelting power factors of 0.8 to 0.9.