Reviewed by Nino Mancino and Joe Kellam
London
Thistle Charing Cross Hotel, 10-11 December 2007
The inaugural Global Refractories Conference for Cement and Lime successfully took place on 10-11 December 2007 at the Thistle hotel, Charing Cross, London. 95 delegates attended from 24 countries including Bahrain, Brazil, Canada, Germany, Mexico, Poland, Russia, Turkey, the UK and the US. Over the two days a total of 17 presentations were delivered on a variety of refractory issues within the cement and lime industries, including alternative fuels, wear mechanisms, materials chemistry and refractory anchors. |
 Above: 95 delegates attended from 24 countries including Bahrain, Brazil, Canada, Germany, Mexico, Poland, Russia, Turkey, the UK and the US. |
Day One The conference was officially opened at 1pm by chairman and co-convenor Dr Robert McCaffrey with a keynote presentation that focused on the global cement and lime industries. Mention was made of the source of key cement producers which dominate the world market, namely Lafarge, Holcim, Cemex, HeidelbergCement and CRH. These companies are run on a highly centralised operating model that focuses extensively on the bottom line, environmental impact and global trade, often moving their products to areas where profits are highest. This vertically integrated approach has made them incredibly successful, but has created a tendency to act conservatively in order to lessen risks, a mentality that has, in the opinion of some, stifled innovation. |
The next speaker on the podium was Alan Hey of the Institute of Refractories Engineers. Mr Hey gave a brief history of the Institute from the time of its foundation in 1961, and discussed the key challenges it faces in retaining and expanding its membership. These challenges are as a result of the considerable changes that have taken place in the refractories industry over the last three decades. As organisation, technology and markets have expanded to become truly global in scope, the Institute is charged with keeping up with these changes. The next presentation was given by Tahir Abbas of Cinar Ltd. Dr Abbas
spoke about unfavourable combustion conditions for refractory materials
and how these issues can be solved by computational modeling. Dr Abbas
gave a selection of case studies whereby Cinar has worked closely with
cement producers to optimise the calcination of materials. This has been
achieved by taking advantage of the power of computational fluid dynamics
in designing and testing burners and combustion chambers with varying
configurations and different types of fuel. Dr Abbas also touched briefly
on the subject of flameless or green flame oxidation as a means of reducing
NOx emissions and refractory wear while returning good calcination and
petcoke burnout levels. |
The first of two ‘meet the delegates’ sessions then took place, with participants introducing themselves, their company and who they hoped to meet at the conference. The session revealed the presence of a good mix of cement producers and refractory suppliers, and gave everyone present a better insight into who was representing which company, cutting out some of the ‘randomness’ involved in networking at the event. The coffee break that immediately followed allowed delegates to follow up on these leads. Jacek Szczerba from Poland was the next speaker. His presentation focused on the changes made to the magnesia spinel structure of bricks when using alternative fuels in cement kilns. The research showed that the protective coatings that line refractory bricks are weakened by large quantities of volatile components in the kilns. This effect varies depending on the different type of Portland clinker and fuel used. |
 Above: Jacek Platek of Zaklady Magnesytowe 'Ropczyce,' Poland, introduces himself during a 'meet the delegates' session. The sessions revealed the presence of a good mix of cement producers and refractory suppliers. |
 Above: Delegates enjoy refreshments and networking in the busy exhibition area. |
The penultimate presentation of the first day was delivered by Wagner Moulin Silva of Brazilian company Magnesita S.A. His talk focused on the corrosion of refractory bricks in lime kilns by the influence of impurities in the burning fuel. Mr. Silva’s work involved testing different temperature regions within a brick (cold, intermediate and hot) for density, elastic modulus, porosity, in addition to chemical and mineralogical analysis, in order to determine the extent of attack. The results showed that the high level of impurities present in low-grade alternative fuels (e.g. sulphur and fluoride) can negatively affect the performance of the refractory by inducing the formation of mineral phases that harm the original texture of the brick. The final presentation on the first day was a joint effort by René Ebbesen and Claus Reich-Petersen of FLSmidth, which showcased the Danish firm’s success in developing alternative fuel technology for the cement and lime industries. Their presentation focused on the Hotdisc fuel burner. The Hotdisc is a house-sized machine, weighing between 100 and 200t, which is designed to burn alternative fuels. The Hotdisc is integrated into pre-existing pre-calcination towers and works by having a stationary round combustion chamber with a rotating floor. FLSmidth claims that the Hotdisc can reduce fossil fuel costs, burn untreated waste within 10-45 minutes, is able to handle several types of waste (e.g. tyres, wood, plastic) whilst minimising CO2 emissions. Since its conception in 1999 the Hotdisc has gone through two more design iterations, and is currently being used in four operations in Europe, the US and Brazil. |
Gala Dinner On the first evening of the conference, delegates donned their black tie and sipped on a martini (shaken, not stirred) at the Bond-themed casino and gala dinner. The band performed a repertoire of Bond themes and other classics while gamblers tried their hand at roulette and blackjack. Diana Vasquez of Spanish company Insertec put the rest of the party to shame with a sterling performance in the casino, grabbing an award for amassing the biggest stack of chips. Day two On day two, David Jarvis kicked off the second session (‘Dealing with reality: Problems and solutions for cement and lime refractories’) with his paper ‘Refractories engineering in practice.’ Mr Jarvis summarised recent refractory trends – in the UK, monolithics are on the increase compared to bricks, with total refractory tonnage decreasing as improvements in refractory manufacture increase their lifetime. The presenter described the links between material, design and operational practice, spoke about the emergence and benefits of precast blocks, compared cast-in-situ and precast products, and went on to introduce SIFCA™ (Wahl Refractories Inc’s patented ‘Slurry Infiltrated Fiber Castable’).
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 Above: Casino-goers are shaken but not stirred at the Bond-themed casino and gala dinner. |
 Above: David Shepherd of Whitehopleman presents his paper ‘Refractories engineering in practice.’ |
Chris Windle of DSF Refractories & Minerals followed with ‘The stresses and strains of a rotary kiln brick,’ presenting the results of two case studies. In the first, raw materials were carefully selected to produce a new kiln brick which would show a controlled level of expansion for a tight lining, while allowing some deformation to absorb any pinch stresses and prevent spalling (“tight, but not too tight,” in Mr Windle’s words). The second case study detailed the use of chemically-bonded semi-insulating products in cement and lime rotary kilns, noting their benefits, especially the ability to absorb mechanigcal stress without fracture. “The ‘rubber brick’ doesn’t exist,” said Mr Windle, “but we’re getting closer.” Diana Vasquez of Insertec – one of the registered licensees of SIFCA – then spoke about ‘SIFCA for the cement industry,’ the benefits of which include high resistance to impact and thermal shock, according to Ms Vasquez. The presentation included step-by-step photographs of the installation of a SIFCA nose ring. The nose ring is installed at a rate of around 20 minutes per block, with complete installation of the nose ring possible in a single day. After the second ‘meet the delegates’ session which followed, David Shepherd of Whitehopleman drew on his experience in the remediation of refractory problems to give a critique of refractory design and installation techniques, with his paper ‘Refractories engineering in practice.’ “This is a Cinderella industry,” he said, “– design lags behind requirements.” Mr Shepherd stressed the need for “real detective work – you won’t be able to fix the problem until you’ve found the cause.” Photos of disintegrating monolithics, cap-spalled refractory, hot-pressed dust in expansion joints and parted welds were interspersed with hints and tips on avoiding such problems. |
The fifth paper in this session was delivered by RHI AG’s Roland Krischanitz. Results of RHI’s ‘Impregnated alumina bricks with superior alkali resistance,’ as used in a number of cement rotary kilns, were presented. The impregnated bricks, Mr Krischanitz said, “have surpassed expectations.” In kilns with an excessively alkaline atmosphere, “impregnated bricks proved extremely resilient against chemical attack and infiltration processes, more than doubling their lifetime in critical areas.” This claim was backed up by some impressive photographs of silica-impregnated bricks in good condition while surrounding magnesia spinel bricks showed clear degeneration. Mr Krischanitz described the chemical processes and wear mechanisms – noting the increased input of wear-relevant elements from alternative fuels – and explained that a refractory producer normally has to compromise between refractoriness and alkali resistance. In these impregnated bricks, however, the whole microstructure is filled with silica solution to achieve both high refractoriness and high alkali resistance. In the paper that followed, Alexander Koshi, works manager at the Arabian Gulf Cement Company and a cement industry veteran with 25Mt of cement under his belt, gave a detailed history of refractory use at his plant from 1981 to 2000, with his paper entitled ‘A case study of refractory consumption in the first precalciner cement plant in the Middle East: achieving a world-class benchmark.’ The relevance of the plant’s history was that “no plant has used so many fuels,” he said, “We are constantly reinventing ourselves.” Besides providing a wealth of information about the plant and its refractory history, Mr Koshi stressed the importance of the total quality management principal: “If you document every single problem, it is fully traceable.” Mr Koshi also noted the emergence of the Middle East as an area of growth in cement production. The area, he said, will produce 140Mt/year by 2010 and the UAE is set to produce 40.5Mt in 2009. For this reason, he said, “all refractory suppliers should focus on the Middle East.” |
 Above: Alexander Koshi, works manager at the Arabian Gulf Cement Company, gave a detailed history of refractory use at his plant from 1981 to 2000. |
 Above: Discussion at York Linings' exhibition stand during a coffee break. |
After lunch, the next presentation – ‘Sandwich ready shapes for grate cooler roofs’ – was given by Michael Louen of Calderys. Mr Louen first went through the costs of using monolithics for a grate cooler roof in terms of time and quality, then suggested tempered sandwich ready shapes as a solution. The ready shapes allow quick assembly as the anchorage is factory-welded and all insulation is factory-installed. The products’ advantages were explained with the help of two case studies: a horizontal cooler roof and a sloping cooler roof. Mr Louen described step-by-step the installation of the 498kg/piece ready shapes, from their positioning through their hanging from suspension bails, to the closing of joints; he then went on to report on their durability: both cooler roofs have been failure-free since 2005. Dave Richardson of vhi UK Ltd followed with ‘Refractory anchors for cement and lime.’ The choice of refractory anchor is often left to a third party – cement plants “should take ownership of that decision,” he said. Mr Richardson went on to give overviews of material selection for refractory anchors (recommending 310H above 310/314), sigma phase formation and feedstock options (vhi favours DIN671). The traditional method of producing corrugated anchors (using stamps or moulds) causes local thinning and differential stress levels along the anchor. vhi's 3D bending process results in a low and consistent stress level, according to Mr Richardson. Round steel sections should be used instead of flat steel and slotted pins, and welding should always be done according to the approved pattern via an accredited route, he added. |
Nigel Longshaw of CERAM presented the conference’s second paper on refractory anchors, describing the initial results from a series of experiments designed to form the basis of a test procedure suitable for grading the resistance of refractory anchor materials in a variety of service environments. Mr Longshaw implicated anchors in the failure of 0.5Mt of monolithic around the world annually, amounting to 70% of cases. CERAM’s aim is to develop a corrosion test for end users and manufacturers, in order to improve confidence in anchors, better estimate their service life, better inform material choice and to examine the effectiveness of the various protective coatings. Details of the simulative tests and their initial results were presented. The tests produce reacted structures similar to those exhibited by samples returned from service environments. Vesuvius’ Steve Woodcock gave the penultimate presentation: ‘Saving
time on turnaround maintenance – recent advances in monolithic
refractories technology and installation methods.’ Mr Woodcock
noted that monolithic refractory lining solutions have become widely
accepted due to increasing time pressure on maintenance shut-downs – good
news for Vesuvius, with over half of the company’s turnover coming
from monolithics. The paper chronicled the evolution of monolithics,
described installation techniques (including shotcreting, dry-gunning
or ‘drycreting’) and the dry-out process and gave examples
of typical applications. Details of research undertaken at Vesuvius UK’s
R&D department at Barlborough were also given. In this research,
a range of techniques were employed in an attempt to characterise factors
affecting dehydration and dry-out, with particular emphasis on thermogravimetric
study and strength development. The main findings of the study included:
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 Above: Castle Cement's Peter Parkes presents his award-winning paper ‘What a cement producer expects of a refractories supplier.’ |
 Above: Best Presentation award-winners (from left) Stephen Woodcock and Steven Wilkinson (Vesuvius), David Jarvis (Wahl Refractory Solutions) and Peter Parkes (Castle Cement UK). |
The final presentation of the conference was given by Peter Parkes of Castle Cement UK (part of the HeidelbergCement group). ‘What a cement producer expects of a refractories supplier’ gave the refractory producers present an insight into the enigma that is the mind of a cement producer. Mr Parkes noted the importance of low prices in the global cement industry, but admitted that the cheapest refractory is not necessarily the best choice (“a brick which lasts forever and costs less than 30 bob,” he conceded, was unattainable). He went on to list the wide range of concerns cement producers have with regards to refractory bricks, monolithics, wrecking and installation. Awards and farewell drinks The event was rounded off with farewell drinks after the second day’s presentations, and awards were presented for the best exhibition stand (Calderys), and for the best presentations. David Jarvis of Wahl Refractory Solutions was awarded the third prize, with his paper ‘Refractories engineering in practice.’ Second place went to Stephen Woodcock of Vesuvius for his presentation ‘Saving time on turnaround maintenance – recent advances in monolithic refractories technology and installation methods.’ Peter Parkes, process improvement manager at Castle Cement, came top of the ‘best presentation’ poll, with his paper entitled ‘What a cement producer expects of a refractories supplier’ – the final paper presented at the conference. 2nd Global Refractories Conference for Cement and Lime, 2008 After the success of the first Global Refractories Conference and Exhibition for Cement and Lime, the second will take place in Cologne, Germany, 8-9 December 2008. See you there..! |