Review of the Loesche Symposium 2017 that took place on 6 - 7 September 2017 Düsseldorf, Germany.
Above: Matthias Mersmann of Loesche and aixergee acted as 'master of ceremonies' for the duration of the symposium.
Click here to view the photo gallery for the Loesche Symposium 2017.
The Loesche Technical Symposium celebrating the company's 111th anniversary was started off by Dr Thomas Loesche, owner and managing director of the company, who gave a welcome to all of the 528 registered delegates from 55 countries around the world. Rüdiger Zerbe, managing director of Loesche GmbH, outlined how the company hopes to 'evolve the future,' not only through advances in technology, but also through decreasing the capex of plants and through the optimisation of spare parts management. Sustainability will be addressed through lowering the clinker factor, through the use of alternative clinkers and through increasing the use of alternative fuels - to 90% thermal substitution rate (TSR) and beyond.
Jacques Glémarec, senior Vice President of LafargeHolcim, next spoke about LafargeHolcim's aims for the future. Increased use of AFR, new products and low or zero impacts on water were perhaps expected promises, but Jacques also announced a target of zero fatalities, and zero injuries, from the building of and operation of its facilities - including those workers delivering its products on the roads. The company also aims for 100% reporting of 'near misses.' These are bold and laudable ambitions, but as Jacques later confirmed to Global Cement, "No other target is permissible." In addition, Jacques Glémarec confirmed that a lower capex environment is coming down the road for LafargeHolcim, supported by digital information networks.
Dr Jörg Krämer of Commerzbank next gave an overview of global economic trends. He started by saying that highly indebted state-owned companies are likely to weigh on growth in China. These represent 50% of investment, but only 20% of 'valued-added,' and Dr Krämer suggested that state-funded companies will progressively cut investment. Alongside an end to a Chinese house price boom, lower investment will hit the construction sector and cement demand. The US is in an economic 'sweet spot,' with full employment, low inflation and low interest rates. However, rate hikes are coming and the Fed is likely to start to effectively reverse its programme of QE later in 2017. He suggested that future 'deepening' of the EU will include the appointment of a finance minister for the Eurozone (with the authority to be able to borrow on behalf of the EU), European debt mutualisation, a common deposit insurance scheme and common Eurozone unemployment insurance. However, in the meantime, the ECB will start to taper its QE efforts starting from the end of 2017, with the first rate hikes forecast for mid-2019 (from -0.4% to -0.3%). Italy remains a worry, in that it is 'too big to (be allowed to) fail.'
Asif Boda, managing director of HSBC, London, gave an outlook of cement trends worldwide. He pointed out that the cement multiplier has reduced from before the crisis to now, reflecting changes in construction methods and hence the cement-intensity of construction. In nearly every region worldwide, cement production capacity utilisation has dropped since 2000, with only the US seeing a strong and sustained increase in utilisation in the post-crisis period. Boda suggested that at least one third of the cement production capacity of Europe is now 'not needed.' Greenfield capacity is now uneconomic in many parts of the world (although brownfield and milling capacity may still be profitable additions). Cement prices worldwide have dropped from 2010 to 2015. Capacity additions have slowed and will continue to slow. Urbanisation is continuing, with an additional 1.1 billion people expected to live in cities by 2030, with the majority of these people expected to move into cities in the developing world. Growing global megacities will require large amounts of infrastructure to correctly function, and investment will take off again. Capacity utilisation rates should thus improve and prices and margins will improve. Asif Boda forecast slow growth in cement demand in Europe to 2020, stronger rates of 5% CAGR for the US but slower growth in South America (and contraction in Brazil), patchy (from low to high) cement demand growth in the countries of sub-Saharan Africa, 6-8% CAGR for India, but -2% to +2% CAGR for China on the basis of a 'managed decline.'
Shen Jun, chairman of Sinoma/Nanjing Design Institute, spoke about his organisation's capabilities in cement plant construction around the world.
Dr Regina Krammer of Loesche - former editor of Global Cement magazine - next explained the Barcamp discussion group concept to the collected audience.
Prof. Dr. Horst-Michael Ludwig of the Bauhaus University of Weimar next spoke about product trends in the global cement industry. Approximately 60% of the CO2 emitted during clinker production comes from decomposition of limestone, while the rest is emitted from fuels and electrical consumption. The greatest potential reductions in CO2 emissions are likely to come from alternative fuels with high biomass content, presuming that carbon capture and storage is economically impractical. Improvements in energy efficiency could cut CO2 emissions by a further 10%, while the reduction of the clinker factor could reduce specific CO2 emissions by another 10% at least. Alternative raw materials such as slag and flyash bring challenges, however, including reductions in early strength - although additives and/or ultra-fine grinding of supplementary cementitious materials (SCMs) can be used to mitigate this effect. The availability of SCMs is an issue, with only 300Mt of blast furnace slag (BFS), and around 900Mt of suitable flyash available, compared to a global cement production of around 6Bt. Calcined clays may be used in the future as SCMs, with large amounts available, and no cyclical or seasonal variations in supply. However, to create a cementitious material, the clays must be calcined at 500 - 1000°C. Metakaolin is too expensive for use in cement, but cheaper 'dirty' clays such as illite and montmorrilonite can be used instead, albeit with higher calcination temperatures. Prof. Ludwig briefly mentioned the LC3 cement concept, which combines high proportions of limestone, calcined clay and gypsum (and only 50% clinker) to produce a low clinker factor cement. He also mentioned Loesche's work on the thermal transformation of steel slag into clinker-like materials. Ultra-fine grinding of steel slag to 'uncover' ferrous-covered belite phases can accomplish much the same effect. In the case of x-ray-amorphous unreactive belite, reactivation by ultra fine grinding is not possible, so that the creation of this phase during slag solidification should be avoided through carefully-designed cooling trajectories. Work on alternative binders is ongoing, including on Novacem, Ternesite, Solidia, Calera and Celitement. A new type of binder, LTBB, based on the calcium and silicon system of minerals, is currently being developed. Ultra-high strength concretes can be made with lower water content, high cement content and high silica fume contents of above 200kg/t concrete (or by using ultra-finely ground blast furnace slag). Carbon-fibre-based reinforcements in concrete - instead of metal reinforcement - will require cement and concrete mixes with a lower pH value.
Dr. Daniel Strohmeyer of Loesche reminded delegates that the industry's ultimate product is not clinker, is not even cement, but is in fact concrete. Setting time and strength development, workability and durability are the prime quality parameters of cement in its final use in concrete, all of which are influenced by and influence the water demand. Particle size distribution and particle shapes critically influence water demand, and can be controlled and modified by changing a number of operational factors in a Vertical Roller mill (VRM), including changing the grinding pressure, changing the height of the dam ring, varying the mill air flow or changing the classifier speed. Gypsum is a source of SO3 ions, the availability of which in solution is important for cement crystallisation. Daniel pointed out the critical influence of gypsum dehydration to anhydrite on cement performance: low mill exit temperatures and short retention time will reduce dehydration to anhydrite, which may mean that an increased amount of gypsum is required in the final cement blend, or additional anhydrite. At the same time, clinker pre-hydration should be avoided, through reduction of water injection into the clinker mill and by reducing the dew point in the mill. Process stability is crucial to being able to control all other operational parameters. Daniel suggested that three new Loesche developments will help: a fourth-generation support roller; grit cone water injection onto the grinding bed, and flow optimisation in the already-advanced third-generation LDC classifier. He concluded with the astonishing statistic that in 2010, Loesche mills ground around 45% blended cements, whereas in 2017 Loesche mills create 58% blended cements - a clear trend towards greater sustainability and a lower clinker factor.
Dr Mathis Reichert of Loesche next spoke about the market demand for ever-larger grinding capacities, which has been driven by increasing kiln sizes, the use of SCMs such as slag and flyash (and fillers) and economies of scale (one bigger mill rather than two smaller mills). Dr Reichert explained how scale-up factors are based on mathematical models that originated in the 1960s and 70s, but which have been shown to still be valid even at the current very large scale of mills (which now include VRMs with table diameters of 7m (such as the recently-commissioned LM 70.4+4 CS at Mfamosing) and beyond (such as the 7.2m table diameter mill at Hub in Pakistan which is currently being built). Dr Reichert outlined the COPE gearbox, co-developed with RENK, which incorporates 'active redundancy,' high efficiency, avoidance of critical parts and compact design and which he suggested is a perfect drive partner for the very largest mills. Mathis pointed out the advantages of using the same design and size of mill (the 'unification concept') for raw meal grinding and for clinker/slag grinding at the same plant, in terms of spare parts and maintenance expertise.
Dr Arif Bashir of D.G. Khan Cement Co. Ltd, Pakistan, next gave details of a project to build the most modern cement in the world, with the largest COPE drive, which will be commissioned in December 2017. The new plant has been built on the basis of anticipated future infrastructure investments, including the China-Pakistan Investment Corridor, and China's 'One belt, One Road' policy. Capacity utilisation in the country is around 87% and this is anticipated to increase to 90% in 2018. Exports have been dropping for the last five years as domestic demand has increased. Several new players are ready to enter into the cement market including Gharibwal Cement, the Sapphire Group and the Fatima Group. D.G. Khan Cement Co. Ltd is now nearly ready to commission its new greenfield plant at Hub in Baluchistan, with a single line with 9000t/day. The pyroprocess is a six-stage FLS system, with three Loesche raw, coal and clinker mills, a Rotoseal packing plant from Haver & Boecker, ring silos from IBAU, civil construction from local company Izhar and mechanical and electrical work from Zealcon/Izhar. The grinding table of the new mill is 7.2m in diameter and weighs 160t: only two workshops in Germany could cast this piece, with no others in the whole of Europe or in the US. The installed power of the clinker mill is 10,000kW, with a capacity of 450t/hr.
Thomas Fahrland, sales director at Loesche, compared the improved performance of the Porsche 911 Carrera from 1994 to 2017, to the performance data of Loesche mills over a much shorter time span, from 2012 to 2017. In this case, newer mills have been improved in many ways compared to older designs, including a vortex rectifier for the mill (leading to a lower pressure drop), improved comminution efficiency, greater mill stability, higher classifier efficiency and reduced plant footprint. For the same power input, a greater output can now be achieved, or the same tonnage of cement with a higher Blaine.
Ibnaan Shamir Pasha, director of the Shun Shing Group, spoke next on the major capacity expansions of the group in its native Bangladesh and in Dubai in the UAE. Its Seven Rings cement brand in Bangladesh is made at its plant in Dhaka, which will be enlarged with the introduction of a new 400t/hr VRM. Capacity in Bangladesh will be expanded from its current level of 3.5Mt/yr to 7Mt/yr by 2019 with the addition of a new grinding plant in Chittagong with a new VRM with a capacity of 180t/hr, as well as with a new slag grinding plant in Dubai. Other future projects in Vietnam, Cambodia, the Philippines and India are envisioned.
Pierre Wlodarzyk of Loesche explained that cement is often not made where it is needed, for example, it is often made on the coast of Africa, but rather is needed in the interior. When cement transport in Africa costs around $0.09/km/t, it is crucial to have production as close to the consumer as possible. Pierre suggested that instead of transporting a tonne of cement inland, with the possibility of some of that cement 'going missing' in transit, clinker should be transported instead, being milled with fillers, SCMs and additives, using a Loesche Compact Cement Grinding (CCG) plant. The plants can produce 30-45t/hour, using less than 1.5MW, and with a supply and construction period of less than one year. The plants can subsequently be disassembled and re-constructed in a different location, as market conditions dictate. Pierre underlined that Loesche can help with project financing, in partnership with one (or more) of the several financial institutions that exhibited at the Loesche Symposium.
Dr Omar Bekri, general director of Cemos Ciment in Morocco, bookended the day by speaking about the use of bituminous shale as a raw material for cement production. The first phase of the project involves the installation of a 180,000t/yr Loesche CCG unit at Tarfaya Port in southern Morocco using imported clinker as a market entry enabler, with a later phase aimed at using the Tarfaya Shale as both raw material and calorific fuel source for clinker production. In the first phase of the project, the low capex level and high residual value of the CCG plant makes financing of the project easier.
Celebration dinner
At a celebration dinner at the end of the first day of the conference, Dr Thomas Loesche welcomed guests and gave a fascinating history of his company, without shying away from its very difficult time during and after the Second World War. He gave an account of the varying successes and some false-starts of the company over the last 50 - 60 years, and pointed to the foundations that have been built to allow future growth for the company.
Second day
On the second day of the conference, the programme commenced with a presentation from Olivier Thomas, managing director of Loesche Group company Primetec, who spoke about operations and maintenance (O&M) services. Olivier suggested that, after the assets have been created, they need to be managed over the longer-term through maintenance (corrective, preventive and predictive), through process improvement (increased energy savings, performance improvements) and through continuous improvements to preserve value and strategically position the assets for the future. Full O&M would include guarantees on production, energy consumption, annual production, product quality, production rate index, overall equipment efficiency, mean time between failures, net availability and, potentially, management of spare parts inventory and supply.
Dorival Tecco of Loesche next spoke on maintenance of modern grinding plants. With his strong background in welding technology, Dorival explained how mill tyres should best be maintained, through in-situ welding. He pointed out that non-experienced welders can apply a hard-faced welding profile to tyres that tends to create vibrations, and which can also lead to the mill tyre cracking due to thermal stresses. He suggested that with the correct procedures, the tyres can be resurfaced with heat de-stressing that avoids vibration and crack propogation. Loesche is now also introducing a ductile 'base' tyre, which can then have a Loesche hard-facing applied to the grinding surface, at the factory site.
Ralph Viebrock, the director of customer service at Loesche GmbH, next gave details of the new Loesche browser-based online spare part catalogue and service: MySpares. Easy part identification now makes quote production much easier and faster, while practically any Loesche spare part can be identified and ordered online. You won't find that on Amazon.
Matthias Mersmann, managing director of aixergee GmbH - a Loesche group company - next gave his listeners some tips on how they could progress, step-by-step, towards 'total' thermal substitution with alternative fuels. Alternative fuels can bring fuel costs down to below zero, even at a TRS of 30 - 40%. However, the right equipment must be used and process adaptations must be made to allow higher TSR. The first stage in using AF might be addition of lightweight 'fluff' into the riser duct of a preheater kiln, although users must watch out for insufficient burn-out. The next step would be to make alterations to the existing burner, or perhaps invest in a new burner, in order to avoid brown clinker due to fuel drop-out and reducing conditions on the clinker bed. Sulphides and chlorides may become a problem with the use of higher levels of AF, so that a bypass system may be required, along with removal of high alkali dust. To get to even higher AF TSR levels, it may be required to build a tertiary air duct and a calciner extension (or add a combustion chamber or turbulent mixing chamber at the top of the existing calciner), while at the same time optimising injection ports and process conditions. Another option, instead of extending the calciner length, would be to reduce the size of the fuel particles (and/or to optimise their shape/surface texture), perhaps using the Loesche - A Tec 'Rocket Mill,' to ensure full fuel burn-out. Matthias pointed out that his company can aid cement producers to increase their AF usage rates through the application of sophisticated computational fluid dynamics modeling. Matthias Mersmann briefly mentioned a new approach to SOx reduction which is just undergoing its first full-scale installation, involving on-site lime production and mixture with process dust.
Dr Stefan Kern of A TEC next gave an overview of new methods for processing alternative fuels. He divided solid AF into two categories: high quality RDF (<30mm, <20% moisture, <5% ash and >20,000kJ/kg) which is mostly fired in the kiln, and low quality RDF which is mostly used in the calciner. Stefan detailed the operation of the A TEC post-combustion chamber which is installed at the top of the calciner: the cross sectional area of the duct leading into the chamber is increased so that there is a reduction in gas and particle velocity. Larger particles then remain in the first part of the chamber and burn out until they are small enough to leave the chamber with the gas flow. The downstream gas outlet subsequently imparts turbulence into the process stream which also promotes higher burnout rates. Stefan Kern next described the operation of the A TEC Rocket Mill, which comprises two grinding chambers which contain horizontally rotating chains, surrounded by perforated screens. The final product of the mill is of fine particles, with 50% <5mm, which have a fluffy texture for improved burnability. Moisture reduction of around 10% is also achieved in the mill. Stefan Kern also announced a new 20-foot container-based single-chamber 'mobile' Rocket Mill.
Tais Mazza, senior process engineer at Loesche GmbH, delved into the potentially profitable interface between the waste industry and the cement industry, pointing out that the use of waste in the cement industry has a lower capex and higher profitability (through gate fees and coal substitution) compared to use in the waste-to-energy industry.
The final afternoon of the symposium was taken up with the so-called 'Barcamp' discussion forms, organised according to delegate topic suggestions. A variety of robust discussions took place on topics including financing options, alternative fuels, roller presses versus VRMs, grinding condition optimisation and how to encourage more women into working in the cement industry - including as engineers.
A final enjoyable evening was spent at the Classic Remise 'old-timer' car centre. The next day, many delegates boarded two specially-chartered planes to visit the new calciner and pre-combustion chamber built by A TEC at the Mannersdorf cement plant in Austria, and to see an A TEC Rocket Mill installed at the FCC Group's waste-processing plant at Wiener Neustadt in 2016.
