17th Global Gypsum Conference, Exhibition and Awards
25 - 26 October 2017, Kraków, Poland
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Photos of participants by Johns Manville
The 17th Global Gypsum Conference and Exhibition successfully took place in Kraków in October 2017. The event attracted 300 delegates from 41 different countries and included 46 exhibiting companies and 16 presentations. Delegates agreed that this was the best Global Gypsum Conference ever staged, giving it top marks in a number of areas. The 18th Global Gypsum Conference will take place on 22-23 October 2018 in Vancouver, Canada.
The 17th Global Gypsum Conference started off with a Welcome Party in the Exhibition area, which was well-attended by delegates from 41 countries. The exhibition area was given its highest-ever rating by delegates and served as a central hub for business, making contacts and networking.
In 2017 at the request of delegates, the event included a number of innovations to increase delegate interactions, including internet-based questions (using Slido.com), the ‘Global Gypsum Power Summit Lunch’ and more information on the larger delegate badges, along with the popular ‘meet the delegates’ and ‘speed dating’ networking sessions.
On the first morning of the conference, Christine Marlet, Secretary General of Eurogypsum, the European gypsum association, pointed out that the EU wishes to create a circular economy, driving the building materials sector away from extraction and towards recycling, never demolishing and always only transforming materials, avoiding waste and transforming pre-used materials into new resources. “Think circular and act circular,” Christine exhorted the delegates. Of course, gypsum has a distinct advantage over some other building materials, in that it is infinitely recyclable. Christine hinted that a trend toward lightweight wallboard gives the industry a fantastic opportunity to add to the housing stock by building additional stories on top of pre-existing buildings without having to strengthen foundations and weight-bearing walls and at the same time avoiding additional urban sprawl.
Robert Morrow of Innogyps, a well-known Canadian gypsum consultancy, next gave a ‘blue skies’ presentation on the economic impact of a gypsum wallboard factory. A single large wallboard factory in the developed world has an impact in the billions of dollars over multiple years and while smaller factories in less developed countries have less of an impact, they are still a major economic ‘motor’ that can power local economies.
Rob Crangle of the USGS National Minerals Information Center next gave an overview of the price trends of gypsum in the US over the last 120 years. The information is based on a series of surveys that are anonymously completed by gypsum industry participants, including the US Gypsum Association and the American Coal Ash Association. Amazingly, using 2017-inflation adjusted dollars, the price of gypsum has fallen from an average of around $40/t from 1880 - 1970, to around $10/t in more recent years. This is partly due to the arrival on the market of FGD gypsum. This FGD gypsum costs only a few dollars per tonne (and in some instances the gypsum users have been paid to take it away). The current price of synthetic gypsum ranges from $3 - 8/t, depending on the region. This has tended to underpin the possible price for natural gypsum, although transport costs are the largest factor and final arbiter of gypsum cost at the factory gate. Hearsay at the conference suggests that the reduction of coal-fired generation in the US is leading to a severe shortage of FGD gypsum and increasing efforts to find alternative sources.
Oliver Pralle of Haver Niagara next started a session on gypsum processing with a presentation on gypsum crushing. Oliver underlined the point that only the minimum number of crushing steps possible must be undertaken to crush gypsum efficiently, while avoiding the production of fines and dust and also producing the most valuable size fractions.
Steve Becker of Schenck Process next spoke on the differences that have to be taken into account when pneumatically conveying both synthetic and natural gypsum. Steve pointed out that synthetic gypsum typically has a much narrower range of particle sizes than natural gypsum, which might lead to some problems with discharge. For both natural and synthetic gypsum, hopper cones should be at high angles and should have a wide discharge outlet. Synthetic gypsum presents particular problems with pneumatic conveying and Steve concluded that the dense phase pump should include a vessel discharge flow regulator. An ‘auto-flow’ pneumatic conveying pipe includes an inner bypass line that allows conveying air to break up plugs by causing turbulence locally to the ‘flutes’ in the bypass line. If material does eventually form a long plug, the inner pipe automatically pressure-balances across plugs to prevent blockages.
Jeff Warren of Gyptech next spoke on stucco conditioning. Jeff suggested that the best way to optimise stucco conditioning is to have a uniform feedstock, to maximise the amount of hydratable material and to minimise the amount of raw gypsum that remains in the calcined stucco. After the stucco has been calcined, it must be cooled effectively: if done too early, then the stucco can be ‘frozen’ in a less-than-perfect state, while ineffective cooling can lead to undesirable condensation. Stucco ageing comes with exposure to humidity, which heals some fractures in the stucco particles and means that they are less likely to break apart when mixed with water. This means that the surface area is reduced and water demand is kept low. Different stuccos can be blended to create a mix that is optimal for the process. Jeff spoke about the now-Gyptech-owned NuGyp enhanced accelerated ageing system, which treats plaster with high pressure steam to optimise stucco properties.
Peer Hanneke of Claudius Peters next spoke on a two-step calcination process, which aims to increase capacity for existing plants if they are limited due to their hot gas generator or main fan. Stucco quality is optimised by a combination of fast and slow calcination and by using steam from the second calcining step to improve the quality of the stucco coming from the first calcination step. This makes additional steam generation unnecessary and reduces waste gases and energy requirements. In the second process step, the calcination is completed by exposing the material in a fluidised bed to a lower calcination temperature for a longer retention time, with a humid process gas and under pressurisation in the fluidised bed reactor. In practice on an experimental rig, various levels of pressurisation are possible from ambient to 2barg, with semi-continuous operation via material air locks.
Michael Chen of Arvos Raymond Bartlett Snow LLC next spoke about the use of the Raymond planetary roller mill for grinding, drying and calcining of FGD gypsum and natural gypsum in one step and in one piece of equipment. A direct air-swept grinding zone improves drying and calcining efficiency and the integral classifier gives a narrow particle size distribution to optimise the gypsum flash calcining process and to ensure stucco homogeneity.
The final presentation on the first day of the conference was given by Viktor Zerr, on Gebr. Pfeiffer’s comprehensive solutions for gypsum grinding and calcining. Viktor spoke specifically about a case study at Trevo Drywall, a 4Mm2 drywall producer in Juazeiro Do Norte, Brazil. The MPS 10 GC mill supplied to the plant has a finished-product production rate of 7.3-13.5t/hr, with an installed power of 84kW, with a product surface moisture of less than 1%. The finished product has an initial setting time of less than 8 minutes and a water/plaster ratio of 22/78. Viktor suggested that Gebr. Pfeiffer’s modular vertical roller mill solution, previously used in the cement industry, should be widely applicable for the production of plaster and stucco for plasterboard.
Gala dinner and Global Gypsum Awards 2017
The Global Gypsum Awards took place during a gala dinner at the UNESCO-listed Wieliczka Salt Mines. The Global Gypsum company of the year was Winstone Wallboards of New Zealand, while the supplier of the year was Gyptech. The prize for plant of the year was shared between two National Gypsum factories: Indiana Shoals and Mount Holly, both in the US, after a dead-heat in the online voting. Siniat’s Weather Defence Board was named product of the year, while innovation of the year was Johns Manville’s DuraCore M300 glass fibre product. The award for outstanding contribution to the global gypsum industry was awarded to Knauf Gips KG. Finally, the ‘Global Gypsum ‘personality of the year’ was awarded to Colin Hanson of Sensortech Systems, Inc. After the dinner, networking continued late into the night.
Second day
At the start of the second day, Dany De Kock of Johns Manville explained why delegates might like to use DuraCore in their wallboard products. DuraCore is a wet chopped glass fibre, supplied with 7% moisture, which allows for consistent dosing and excellent fibre dispersion. The fibres are dosed into wallboard to increase the fire performance of board and Dany explained that testing had shown that 16µm fibres were found to be the most effective diameter for performance improvement for its cost. Testing also showed that at dosages up to 1% for 16µm and quarter inch length that there was no significant influence on the slurry viscosity, which is crucial to avoid impacts on the wet-end of wallboard production.
Rachel Marcon of Owens Corning next focused on how lightweight construction can be used to expand the housing stock through vertical expansion of buildings. Rachel suggested that there will be a marked trend away from ‘massive’ (concrete) construction and towards lightweight and drywall-based construction, by reducing the overall load on pre-existing foundations. Rachel also pointed out that modular construction methods can reduce costs and building time by up to 50%. Glass non-wovens, such as those manufactured by Owens Corning, are now widely used throughout the building materials industry. These materials can improve impact resistance, reduce wind uplift, improve dimensional stability, reduce weathering and increase mould resistance and fire performance. This means that gypsum-based products can be moved outside, becoming much more weather-resistant. Indeed, these types of products are already widely used in the North American exterior sheathing sector.
Next up was Ivan Sigfrid of Gyptech, who spoke about air heating systems for wallboard dryers. Gas, oil or even solid fuels can be used for air heating, but when using solid fuels an indirect heating system will be used to avoid staining the boards. In-duct gas heaters can be used for oil and gas firing in direct systems. Mixers may be needed to ensure an even temperature profile through the dryer. Burners must be carefully designed to avoid excess production of NOx and CO and this generally means operation in the range 1700 - 1900°C. Temperature stratification in the dryer must be avoided, in order to avoid the production of burned and/or wet boards. Dynamic instability can be caused by feedback loops, involving flow and mixture perturbations, heat oscillations and acoustic oscillations. Steam or thermal oil can be used with a heat exchanger when using indirect heating and this can lead to a very even temperature profile in the dryer. Steam has some drawbacks when it comes to maximum achievable temperatures at reasonable pressures. Solar-collection systems can also be used to heat thermal oil as part of an indirect system and molten salt reservoirs can be used to store heat for use overnight.
Bernd Luebbert of Claudius Peters Projects GmbH next spoke about the new PacPal palletiser, which is typically used in the gypsum industry for palletising 25kg bags of gypsum plaster. Bernd mentioned that the rate-limiting step is usually the lift that removes the full pallet. New models (and retrofitted machines) now have a unique upper pallet feed, so that as the full pallet is removed, an empty pallet clamping device enables the creation of up to two layers of bags of up to 500kg weight, before the pallet lift returns, allowing an uninterrupted process: this can mean an increase in palletising speed of up to 10%. The PacPal automatic truck loader is a new state-of-the-art solution for truck loading, without having to use fork-lift trucks or other human operators and without the use of pallets.
Matthias Schellhorn and co-authors from Stephan Schmidt KG spoke about the reduction of the fire shrinkage behaviour of glass-reinforced plaster boards using special clays. The company excavates up to 350 different types of crude clays from different quarries in Germany. The clays are processed, blended and homogenised into more than 400 standard recipes. Custom-tailored recipes are possible for batches of more than 25t. A dilatometer is used to determine the degree of expansion of product specimens during heating, with different amounts and types of additives. A ‘good’ product would have less than 3.5% shrinkage at temperatures above 850°C. Gypsum board without additives cannot achieve this low level of shrinkage, but the addition of the Capsil® special clay blend can reduce the amount of shrinkage to below 3% above 850°C.
Christian Pritzel of the University of Siegen gave the penultimate presentation, on the influence of additives on the morphology and technical properties of gypsum. Many properties are affected by the morphology of crystals, including porosity, expansion during hydration, casting accuracy and compressive and bending tensile strength. Critically, calcium sulphates are less soluble as temperature rises. At higher ionic concentrations in solution, smaller crystals are created and more branches are formed in the resultant final crystals. Christian showed how citric acid added to the crystallising solution inhibits growth on the fastest-growing crystal surface (the end of needle-like forms) and hence leads to shorter crystals with larger diameters. Potassium sulphate, on the other hand, leads to longer crystal needles with fewer branches. Small amounts of dihydrate crystals added to the mix increase the reaction speed and increase the strength of the final gypsum.
Mike Maretich of Stepan Company ended the speaker programme with his enthusiastic delivery of a presentation on ‘How to communicate effectively,’ which was a distillation of his knowledge from more-than three decades of communication and selling. Critically, his most important slide was one which - in order to communicate more effectively - beseeched his audience to listen.
Farewell and conference awards
Before delegates dispersed to the four corners of the world for another year, a number of prizes were handed out at the jolly Farewell Party, while being serenaded by Kraków’s Leliwa Jazz Band.
Rachel Marcon was third in the best presentation awards, for her paper on improving market penetration with glass non-wovens. Christian Pritzel of the University of Siegen was second for his paper on crystal growth modifiers. However, the winner of the ‘best presentation award’ was Dany De Kock of Johns Manville, for his talk on the use of wet chopped glass fibres for the improvement of fire-resistance of gypsum wallboard.
The best exhibition stand award went to five companies that tied for first place: Grenzebach, Gyptech, Hamburger Containerboard, Jürgens Maschinenbau and Sauerländer Spanplatten GmbH.
The conference in Kraków was highly-rated by delegates - indeed, overall, it was the highest-rated ever.
The 18th Global Gypsum Conference, Exhibition and Awards will next take place on 22 - 23 October 2018 at the Sheraton Wall Centre in Vancouver, Canada.
