Raw Material Crushing and Blending
The raw martial is flash dried and crushed using ball mills that were provided by Polysius (TKIS) and have a combined capacity of 1419 Kt per year. The material enters the mills and is grinded until the correct grain size is reached. This is classified and tested for quality. The meal then moves into four 600 t blending silos where the homogenisation can begin. The material is tested offline and then depending on the test result the the material is then moved to one of four 2900t raw meal silos.. The raw meal is circulated around to the kilns with a constant excess ensuring smooth down stream operation.
Kiln 2 was manufactured by Polysius (TKIS) and measures 3.916 m x 59 m with a capacity of 1000 tpd. Kiln 3 in comparison was manufactured by FLSmidth and has a capacity of 1100 tpd and is slightly larger at 4.15 m x 60 m. Each of the kilns operates a semi-wet process where the previously dried raw meal is wetted and formed into circular nodules. The nodules of material move into the drying chamber at 200°C before beginning calcination at 400°C – 950°C. The material moves along the 60 m kiln reaching temperatures as high as 1600°C at the clinker cooler. The material then drops into the fall chute at the end of the line. FLSmidth shell scanners have been installed along the roof of the building scanning the internal profile of the kiln. Greco provided the main burner for each of the kilns.
The material is subsequently cooled on the cooler grate utilising five large fans. The faster the clinker can cooled the better. Each kiln utilises electrostatic precipitator to conform with the operating permits keeping dust to a minimum. Two coal crushing ball mills are utilised to grind coal for the main burners. However the site has the benefit of burning RDF and Liquid fuels, drastically reducing the use of fossil fuels.
The site used to produce multiple products but now just produces CEM 1 and CEM 2 via two close circuit ball mills. Cement mill 4 is the larger of the mills and is capable of 70 tph produces CEM1. The smaller mill 3 produces CEM 2 by the addition of flyash. These products are then transported to the silos for storage before being moved out of the site to customers via road. The site utilises the local ports to enable shipment of cement to be taken by sea.
Every element of the production process is monitored from a control centre. The old office block was made unusable by the flooding and engineers as well as the administration, laboratories and welfare facilities are currently housed in temporary portacabins. A new office block is currently under construction and represents another move to centralise operations by Cemex. The new control centre will be based on the top floor of the new block and will be fitted with the latest FLSmidth monitoring technology. It is now approximately one year since both kilns were restarted and the evidence of Cemex’s bid to modernise and centralise is clear throughout the site.
The flooding that devastated the South Ferriby site and the surrounding area is a one in one hundred year event statistically. Cemex has worked closely with the Environmental Agency to change and improve flood defences to protect themselves but also to benefit the wider community in the event of future flooding. Cemex’s efforts of recovery and improvement in their South Ferriby site is evidence that through hard-work and clever organisation, an organisation can not only be saved from disaster but can use the event as an opportunity to streamline and modernise its operation.
This is part three of a three-part article written for World Cement’s Ports and Terminals Supplement and abridged for the website. Subscribers can read the full April issue by signing in, and can also catch up on-the-go via our new app for Apple and Android. Non-subscribers can access a preview of the April 2016 issue here.
Read the article online at: https://www.worldcement.com/special-reports/28032016/rising-deep-cemex-part-three/