- Written by Najran Cement Company
Najran Cement Company (NCC) was established in 2005 as a Saudi Closed Joint Stock Company with a paid up capital of US$306m. The objective was to be a main supplier of cement in the southern region of the Kingdom of Saudi Arabia (KSA) and be an important exporter to Yemen. It was anticipated that locating the plant and facilities close to Najran city would greatly contribute to the fast development of the region. The company has a quarry license from the Ministry of Petroleum and Minerals for an area of 30km2 that is endowed with huge deposits of limestone, clay, sandstone and gypsum - sufficient for more than 100 years.
NCC was initially planned as a single integrated unit of 6000t/day of clinker at Sultana, around 240km north east of Najran at the tip of the Empty Quarter desert. As the project moved along a decision was taken to expand the clinker plant to 9000t/day by adding one more line of 3000t/day at Sultana to make full use of the vast raw material deposits. This was supplemented by a standalone grinding unit of 2.0Mt/yr at Aakfa, 70km to the west of Najran on the main highway to Asir region.
- Written by M D Mirolli, Recurrent Engineering LLC & T B Gibbons, Consultant in materials technology
In this article the opportunities to recover useful energy from various sources of low-grade heat are considered in the context of the advantages offered by the Kalina Cycle® technology. In the Kalina Cycle, a binary fluid is used to extract useful work from the heat source. Typical low-grade heat sources are those associated with waste heat from industrial processes such as steelmaking and cement manufacturing that are energy intensive and where waste heat recovery can make a significant impact on energy-efficiency.
The various Kalina Cycle systems now operating worldwide are briefly described and the critical operating parameters are considered in the context of the basic principles underlying the technology associated with the use of ammonia-steam as the working fluid. The performance of the materials used in the manufacture of the various components in a Kalina Cycle system is assessed and the relevance of the potential degradation mechanisms is briefly described. It will be shown that the technology has now advanced to the stage where high availability can be achieved routinely in various types of operating environment. The potential to extend application of the Kalina Cycle technology to the recovery of waste heat in the cement industry is outlined.
- Written by Peter Edwards, Global Cement Magazine
Following the Ecobuild Exhibition at the ExCel Exhibition Centre in London, UK, Global Cement Magazine interviewed Lafarge UK's National Commercial Technical Manager, Bill Price. Looking into UK-specific aspects of Lafarge's cement operation, the interview explores environmental aspects of production, the current economic climate and how it has been affected by the Lafarge Group's recent restructuring to a country-based organisational structure.
Global Cement (GC): "Lafarge UK was the only conventional cement producer present at Ecobuild 2012. What does the company's presence at the event say about Lafarge in the UK?"
Bill Price (BP): "The pavilion at Ecobuild was an integrated Lafarge UK pavilion that had representation from cement, concrete, aggregates, asphalt and contracting. I think what it says is that we have a joined-up approach to sustainability in construction and that we at Lafarge are proud of our record of producing more and more sustainable cements and sustainable construction solutions."
"As a leader in our industry, facilitating and encouraging sustainable construction is at the top of our agenda after health and safety, which is why we value showcasing our sustainable offers and propositions at events such as Ecobuild so highly."
- Written by Edwin A R Trout, Cement Industry Suppliers’ Forum
Introduction
The lie of the land
In the British cement industry restructuring has been prompted partly as a response to the ongoing challenge of weak market conditions. In 2009 the UK saw a sharp decline into recession, in 2010 it saw the first tentative suggestions of a return to stability and in 2011 it saw hopes of a modest revival, albeit at much lower level than in the early to mid-2000s.
2011 saw surprisingly robust performance in the first two quarters, with a subsequent tailing off of confidence, greater fragility and now a slip into a new 'double-dip' recession at the start
of 2012.
- Written by Global Cement Staff
John Kline, VP of technical expertise at Lafarge, gave a well-received paper at the 54th IEEE-IAS PCA Cement Industry Technical Conference in San Antonio, Texas, on 14 - 17 May 2012 entitled 'Cement and CO2 - a victim of success.'
John pointed out that global CO2 emissions were 29Bt (billion tonnes) in 2007 and will be 57Bt in 2050 with a business-as-usual approach. The cement industry will need to achieve very substantial reductions in total CO2 emissions (in the order of a 23% fall) to help achieve a target of less than 14Bt by 2050, 'in order to limit any temperature increase to 3°C.'
By comparison concrete accounts for 83% by weight of all the construction materials used around the world. John said that concrete can be used to produce energy efficient housing, particularly if used in insulated concrete forms. He also pointed out that the CO2 emission from cement manufacture makes up a very small total amount ot total emissions, given the huge amounts of concrete produced. John stated that there is still great potential for the substitution of clinker in cement.
He concluded that the industry needs to actively promote the overall carbon efficiency of concrete and to make sure that everyone knows that at least for today, cement and concrete are the most CO2 efficient building materials.
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