Ferrock chemistry

Ferrock To Be Used In Architecture

Across the world, there is a general awakening to the connection between our lifestyles and their impact on the planet. People are calling for a ban on plastic – which is understandable, as plastic is a problem; in the last 60 years, we have amassed 8 billion tonnes of the stuff. But there is an industry that has an arguably worse impact, producing the same volume every two years – the cement industry. It uses a 10th of the world’s industrial water supply and has contributed to the adverse effects of flooding during severe storms (replacing flood plains which would have soaked up the water). Added to this are the CO2 emissions, which are said to be between 4 and 8% of the world’s CO2. We rely on it because it is solid and dependable. It is everywhere, but at what cost to our environment? There is a sense of urgency as people seek better, sustainable alternatives.

And this is why ‘ferrock‘ is becoming increasingly popular.


What is Ferrock?

Basically, it is the result of a failed environmental chemistry experiment at the University of Arizona. David Stone PhD. was experimenting with iron dust and discovered a unique material that set incredibly hard. Initially, he rejected it. But then he took another look when he realised its significance. He combined ‘waste steel dust’, a by-product of industrial processes, with silica (essentially ground-up glass) to produce a pourable mix that sets harder than concrete. However, the best thing about ferrock is that when poured into a mould it reacts with CO2 in the air and binds it within the mixture to form iron carbonate. Ferrock literally absorbs and locks away CO2 rather than emitting it, making it carbon neutral. In addition, it is more flexible than concrete and is five times stronger. And in marine environments, it really comes into its own; the salt water actually increases its strength.


How is it made?

About 95% of the ingredients are recycled, which immediately makes it an attractive proposition. It is made from the following materials:

  • Limestone – 8%
  • Fly Ash – 20%
  • Iron Dust – 60%
  • Metakaolin – 12%


Are there any downsides?

On the face of it, no. It is a truly sustainable material. However, critics point to the fact that it relies on waste material that is cheaply available – for now. There’s always the risk that the sources of these materials will increase prices along with demand. At the moment, they regard ferrock as only being viable for small-scale projects. Also, there are few builders trained in how to use this new material.

David Stone remains positive, though. He considers his creation to be a step in the process of becoming a greener world and is still devoted to the project with the intention of making improvements. And he points out that scientists are still trying to understand the chemistry of Portland Cement over 200 years after its discovery. The planet needs more carbon-neutral materials like ferrock, and more people like Dr Stone to discover them if we are to achieve a sustainable, concrete-free future.