Calix Zero Emissions Steel Technology-pre-FEED and FEED Study

April 18th, 2024

Calix Zero Emissions Steel Technology (ZESTY)-pre-FEED and FEED Study

Calix has progressed development of their ZESTY H-DRI process to the preparation of a FEED study for a commercial demonstration plant.

Main proponents:


Main end-use classification:

Industrial use – iron making


Under development

Estimated cost:

AUD$1.96 million (pre-FEED and FEED study)

Other involvement:


Production details:

Not applicable


Victoria, Australia

Announced funding:

AUD$947,000 – Australian Renewable Energy Agency (ARENA)

Project description

Most of the CO2 footprint of the iron and steel industry is associated with the production of iron, as around 90% of all iron is produced by metallurgical coal-and coke-fuelled blast furnaces.

The alternative electric arc furnace is a steel making plant that melts iron sources such as scrap and direct reduced iron (DRI) using electric energy. Iron produced via direct reduction of iron ore makes use of a ‘shaft furnace’ that is filled with lump ore and pellets. A ‘syngas’ of carbon monoxide (CO) and hydrogen dissolve out the oxygen in the iron ores. Unlike in a blast furnace, these reduction gases do not result from the combustion of coke but rather these reducing agents are produced from natural gas by catalysis outside the shaft furnace. This method is a less CO2 intensive method than blast furnace operations; however, it uses large amounts of electricity, and this process route has traditionally been more expensive.

Methods to lower the carbon footprint of iron production using low-emissions hydrogen as the major reductant instead of natural gas and coal are progressing.

The use of hydrogen in blast furnaces is being tested, but there are limits on the amount of coal it could replace due to a reduction in the conversion rate of iron ore to iron.

The HYBRIT (Hydrogen Breakthrough Ironmaking Technology) process developed in Sweden by SSAB, LKAB and Vattenfall uses a ‘fossil-free’ value chain for iron and steel production; the technology involves replacing the blast furnace process with a direct reduction process with use of ‘fossil-free’ hydrogen. Further details on the HYBRIT initiative can be found here.

The ZESTY process developed by Calix can use green hydrogen to reduce iron ore within Calix’s renewable powered electric Calix Flash Calciner (e-CFC). The project proponent indicates that the Calix indirect heating method aims to deliver efficient electrification of iron ore processing, minimise the amount of hydrogen required in the production process compared to competing technologies and removes the need for ore pelletisation pre-processing.

The project proponent notes that the ZESTY process can produce green iron from multiple ore types for use in either conventional blast furnaces for lower carbon steel products or directly in electric arc furnaces. Further information on the ZESTY process can be found here.

The ZESTY process has progressed through the laboratory stage and the follow-up pilot plant stage is completed; the Calix (modified) e-CFC plant at Bacchus Marsh in Victoria tested the ZESTY process using various ores to produce hydrogen-direct reduced iron (H-DRI) at an equivalent throughput of 2,000 tonnes per annum.

ARENA has co-funded the next phase of technology development – delivery of a pre-Front-End Engineering Design (FEED) and FEED study for a commercial demonstration plant of the order of 30,000 tonnes per annum H-DRI.

In a Half Year Results FY2024 presentation in February 2024, the project proponent notes that the ZESTY FEED study for a 30,000 tonne per annum demonstration facility and an extended ore testing program has been completed. The project proponent also notes that it is progressing the site selection and commercial arrangements necessary to reach a final investment decision for the project.


November 2022: ARENA announce an award of AUD$947,000 to support delivery of a pre-FEED and FEED study for a 30,000 tonnes per annum H-DRI commercial demonstration plant using the Calix ZESTY process.


Updated: April 2024