On 6 February 2017 a group of university researchers ventured out into the Peak District but this was no ‘walk in the park’. This was one of the biggest cement research groups visiting the biggest cement plant in the UK.
HOPE Cement Works is situated in the centre of the Peak District National Park (Derbyshire) it is currently part of the Breedon Group and employs 165 people. It produces approximately 1.5 million tonnes of cement per year(approximately 0.05% of the world’s cement production!). Cement manufacture is the world’s third largest contributor of man-made carbon dioxide emissions, which promote climate change by gradually warming our planet; these industrial emissions are exceeded only by electricity generation and deforestation. Cement production has such a high carbon dioxide count mainly because cement is the second most consumed commodity in the world after water (which is also mixed with cement to make it set and harden). Due to this large demand for cement, there is a lot of pressure on the industry to reduce its environmental burden.
The morning started with a health and safety briefing, presentations from both HOPE Cement Works and the University of Sheffield personnel followed by a visit to the limestone quarry. After lunch, we visited the cement labs where their reliance on X-ray diffraction and X-ray fluorescence techniques was heavily stressed. After touring the labs, we went around the plant stopping next to and discussing most of the key unit operations.
The day in pictures
Figure 1: Upon arrival at HOPE Cement Works, we were given a safety briefing and issued with personal protective equipment (PPE).
Figure 2: After watching a few videos and presentations about HOPE Cement Works, we were driven to the quarry. Imad took this opportunity to capture an usie (group selfie)!
Figure 3: At the limestone quarry (left), the quarry manager explained to us in detail the quarrying process. Gosh it was freezing up there but it was well worth it!
Figure 4: After being removed from the ground via controlled explosions and excavation, the limestone goes through three levels of crushing before it is ready to be pyro-processed at temperatures up to 1500°C. After the primary crushing stage, the angular rock is piled up ready for transport (left). The crushed stone is transported to the works via conveyor (right) where it undergoes secondary and tertiary crushing before it is blended with shales to a specified recipe and fed into the kiln (furnace) system via pneumatic pumps.
Figure 5: HOPE Cement Works have 2 suspension pre-heater kilns shown in this picture. These kilns are approximately 5 meters in diameter and 70 meters in length! All the visitors on the day from the University of Sheffield are also in this group photo (in light orange high-visibility tops and bottoms). The works production manager is also seen in this photo (furthest left). A special thanks goes to Spencer (HOPE optimization manager) for capturing this awesome photo.
Figure 6: During the visit, one of kilns was shut down for maintenance. Its burner (left) was removed; the people at the edge of the photo give you an idea of the size of this burner. After the cement clinker leaves the kiln and is cooled in a cooler; it is ground in a ball mill (right) which is several meters in diameter before being blended with gypsum (to control setting time) and other additives.
Figure 7: Personnel at HOPE did not only show us around but also explained the key unit operations in detail. Left: Dr. Edward Cavanagh (production manager) demonstrates fundamentals of the cement manufacturing process. Right: Ed lights up the end of the burner with his headlamp to explain the purpose of each cavity.
Figure 8: HOPE cement works do their bit to promote industrial sustainability. Apart from UK coal, they burn alternative fuels such as used tire chips (top left), livestock waste (top right), granulated plastic waste (bottom left), and waste paper and cloth (bottom right).
Figure 9: HOPE Cement Works has been continuously upgraded over the years and currently boasts a kiln control room (left) equipped with live digital monitoring facilities. Most of the cement made at HOPE is transported by rail (right) to depots all over the country ensuring the product is delivered as sustainably as possible.
HOPE Cement Works spends a couple of million pounds a month on fuel and power. Every day a kiln is off-line at HOPE, it costs the company approximately £200,000 in lost revenue. It is therefore evident that even minor improvements can have major impacts on the industry and as a result on society.
This is not to say that the industry does not do its part, they do. For example quarried stone at HOPE that cannot be utilized in the manufacturing process due to high quantities of fluorine or “unreactive” silica are respectively processed for toothpaste production and used as landfill. However, there is still plenty of room for research and development in the field of cement production
At the end of the day some of the visitors from the University of Sheffield and staff from HOPE took a minute to express their thoughts:
“It is a fantastic trip. The first time for me to know the industrial production line of Portland cement. This trip bridges my academia research with the industrial, giving me a chance to know what they are thinking and doing, what challenges the industry are facing.”– Zhijun Tan – Research Associate – Materials Science & Engineering
“I really enjoyed it. HOPE were really hospitable and very accommodating – we asked a lot of questions and they were very happy to answer all of them. The tours (quarry/kilns) were my highlight; they allowed me to develop a greater understanding of how cement formulations are monitored to ensure chemical stability of supply.” – Sarah Kearney – PhD candidate – Materials Science & Engineering
“It was a very interesting tour. I learned a lot about cement production in just a few hours, as well as the challenges of keeping a plant of this size fully operational” – Neil Lowrie – Business Development Manager – Materials Science & Engineering
“The most impressive thing, though, was the respect Hope Cement factory shows to the environment: rehabilitation plans during and after extraction, biodiversity insurance, use of alternative fuels such as solid waste fuel and burning tire chips are implemented in the cement process aiming at the preservation of our environment and the well-being of its habitats. Thanks Hope Cement for this unique experience!” – Niki Trochoutsou – PhD candidate – Civil & Structural Engineering
“I think everybody got something out of it – a very interesting day. I love big, noisy and dirty machinery!” – Katrin Thomson – Learning Technologist – Materials Science & Engineering
“It is always a pleasure to meet nice people and discuss about cement in a pleasant environment. During the visit I also developed new ideas for future research projects!” – Theodore Hanein – Research Associate – Materials Science & Engineering
“I’m glad you all appeared to enjoy it – it’s generally a pleasure when we see people willing to engage.” Edward Cavanagh – Production Manager – HOPE Cement Works
The visitors to HOPE gratefully acknowledge Eunice Lawton from Think Ahead and Stewart Husband from the Engineering Research Society at the University of Sheffield arranging funding the trip. We would also like to acknowledge the efforts of our coach driver for the day (Ben). Last but not least, we would like to acknowledge all personnel at HOPE for their time, willingness to discuss their work and of course for the yummy lunch!
By Theodore Hanein, Department of Materials Science & Engineering