Q&A – Nigel Cooke

Clay Technology magazine
16 Aug 2018

Dr Nigel Cooke, Director of the UK Quality Ash Association, talks to Gary Peters about his career and the fly ash industry. 

Tell me about your career to date

I’ve been involved in the building materials sector for over 35 years. I worked for Blue Circle and then cement company Lafarge after its acquisition in 2001. I left Lafarge after its merger with building products and solutions company Holcim and have since worked on a consultancy basis as Cementitious Solutions. 

This work also includes a part-time directorship of the UK Quality Ash Association (UKQAA). During my career with Blue Circle/Lafarge, I spent around half of my time outside of the UK in the Far East, Latin America, Paris, and Zurich. Over this time, I was fortunate enough to visit most of the Blue Circle/Lafarge operations around the world.

My first experience with fly ash was in the late 1990s, when Blue Circle and ScottishPower established ScotAsh at Longannet Power Station and I was made Managing Director of the joint venture. ScotAsh was a really rewarding experience and I learned a lot about partnerships with utilities and sharing the benefits, allowing for long-term investment in employees, plants and technologies. 

During this time, ScotAsh won many environmental awards including two Queen’s Awards for innovation and the environment. The success of ScotAsh then led to further partnerships with EDF Energy and RWE npower. I was also involved in assisting Drax Power with fly ash storage and rail load out facilities. 

Until 2010, the main challenge of my time working with fly ash was to create new markets and applications to reduce the amount of the material being sent to landfill.

What are your key objectives as director at the UKQAA?

For the UKQAA its supply, supply, and supply. It is likely that – due to UK Government policy – all coal fired power generation will cease by 2025, if not well before. Indeed, seasonality factors mean that there is little coal fired power generation during summer months, which is the peak of construction activity.

The alternatives to UK production are fly ash imports and developing existing landfill sites of fly ash. We’re exploring both avenues to try and secure supply. 

What changes have you implemented since your appointment? 

The UKQAA has long championed the use of fly ash in the construction sector and that commitment won’t change. However, whereas in the past, the UKQAA was very much involved in the development of standards and technical support, I see my role as more strategically driven with emphasis on future sourcing options.

While the UKQAA can assist members with contacts for fly ash exporters, the main prize is the over 60 million tonnes of fly ash currently deposited in landfills around the country. For me, rather than define them as fly ash landfills, I would re-classify them as future pozzolanic or cementitious reserves and include them under future minerals plans.

In this context, the UKQAA is working with Bridget Rosewell OBE to help us promote the concept of preserving existing fly ash landfill sites as mineral reserves. Rosewell is an experienced director, policy maker and economist, with a track record in advising public and private sector clients on key strategic issues. While we are in the very early stages of this project, conversations to date with numerous potential stakeholders have been very encouraging. 

What attracted you to the role?

It’s an exciting opportunity and I love the challenge of trying to create and develop new opportunities. To be able to get fly ash landfill sites re-designated as future pozzolanic or cementitious reserves for the benefit of UK PLC and future generations would be hugely satisfying. 

Fly ash is a great construction material and currently plays a key role for autoclaved aerated concrete block manufacturers, the grouting industry for ground stabilisation, and finally the cement and concrete industries.

Grouts and aerated concrete blocks account for an annual demand of over 1.5 million tonnes of fly ash. While replacement of the fly ash by sand is an option, the performance of sand is not as good as fly ash and it is certainly not as sustainable. In addition, there would be an impact on the current supply-demand balance for sands, which are scarce in many regions of the UK.

Blast furnace slag is available from Port Talbot and Scunthorpe steel plants, but already there is insufficient supply to meet the growing demand, requiring some 1.5 million tonnes of slag to be imported. Furthermore, identification of available sources of imported slag is becoming harder as it now fills the gap previously occupied by fly ash elsewhere in Europe. Prices of imported slag have also increased significantly over the past three years because of the tight global supply-demand situation and the fact that logistic costs are increasing with some slag now being sourced from China.

How has your experience in the cementitious industry helped?

I’ve worked in the cementitious materials sector for most of my career, so I understand the strategic dynamics together with who buys, sells, and uses fly ash – and why. Having said that, there is always much to learn – the importance of fly ash to the aerated concrete block industry being an example.

Over the years, I have also been involved in looking at several different projects and technologies used to process fly ash, so I hope to be able to leverage my network of contacts when it comes to assisting the UKQAA membership.

How would you describe the outlook for the fly ash industry?

I think the future is challenging to say the least. The key is long-term access to fly ash landfill sites and the ability to economically process such ashes for use in the various construction sectors.

However, if we can achieve this, I am sure that fly ash can play an important role in the construction industry for many years to come.

UK coal-fired power plants are on the decline – is it fair to say the UKQAA is facing its toughest time since its creation in 1997? 

Clearly the answer has to be yes. Though the UKQAA and its members are being pro-active in seeking solutions and a way forward.  

How might Brexit impact the sector?

I do not think that even the most ardent Brexiteers can blame Europe for our lack of investment in infrastructure, the time it takes to get projects accepted, or for the decline in our manufacturing industry.

My main concern over Brexit is that if the economy does slow down, the appetite to invest in fly ash processing technologies is likely to decline in the short term. Even UKQAA funding might be impacted if its members are forced to tighten their belts.

However, the vision of classifying fly ash landfill sites as future pozzolanic or cementitious reserves remains, and this is where the focus will be.

What keeps you awake at night?

Making sure that the UKQAA manages to serve the interests of all its members. Every member can have different strategic interests, so it is important that the UKQAA remains inclusive and continues to have the confidence of its members.

What are some of the most inventive usages of fly ash?

Fly ash has been used in some very exotic high flow concretes for architectural purposes and ultrafine fly ashes (sub 10μm) have replaced silica fume in certain applications.

There has been talk of censospheres – ultra lighteweight fly ash particles that will float on water – being tried for refractories for the space shuttle and for avoiding radar detection on stealth bombers, although this is more anecdotal than having proof