2nd Global GypSupply Conference & Exhibition on gypsum supply trends and technology
22 - 23 February 2023, Brussels, Belgium
The second real-world edition of the Global GypSupply Conference and Exhibition on rock, synthetic and recycled gypsum has successfully taken place in Brussels, Belgium, with 65 delegates in attendance from 23 countries. The event was organised in cooperation with Eurogypsum, the European gypsum association.
Jörg Ertle of Etex and Eurogypsum (pictured above) gave a welcome and introduction. An elderly building stock in Europe means continued demand for gypsum based products. The EU intends to be carbon neutral by 2050, with the EU’s Green Deal includes a strong push towards energy-efficient buildings, with 35 million buildings to be renovated by the deadline. Gypsum is a building material of choice for several reasons: it is infinitely recyclable; it is much faster than wet construction methods; it is affordable; it has a relatively low embedded carbon footprint; and it can help to reduce carbon emissions during use. Jörg pointed out that gypsum is a strategic material, which is crucial to a number of industries. 17.5Mt of natural gypsum was used in the European industry in 2021, 7Mt of FGD gypsum and 1.4Mt of recovered gypsum. No coal-based power generation will take place in the EU by 2050, so that new FGD gypsum supply will reduce to zero by the same time. Natural gypsum will inevitably take the place of synthetic gypsum supply, but opportunities are limited, since around 35% of the EU will be protected for nature under the Natura 2000 plan. Mining and quarrying of gypsum will need to show careful consideration for biodiversity and nature in order to retain their ‘license to operate.’ Other industrial sources of synthetic gypsum will become more important, including gypsum from water treatment. Jörg concluded that recycling has had a good start in the EU, but that it has a long way to go.
Vincent Basuyau of DG Grow, part of the European Commission, spoke about the strategic issue of raw materials in the EU. Raw materials in the EU represent well-developed value chains, including plenty of jobs. Global demand for raw materials is likely to double by 2060, and global demand is set to outstrip global supply. The European Raw Materials initiative of 2008 had three ‘pillars’; the first was to diversify global supply at the same time as promoting global sustainable extraction; secondly to improve investment procedures to promote EU resources; and finally to promote circularity and efficient use of resources. Gypsum is not yet on the list of EU critical raw materials, meaning that its supply is not currently in doubt. The supply (and recycling) of lithium for EV batteries will need to be increased by 50x by 2050 in the EU, and there is a possibility that gypsum might be generated during this process. The European Action Plan for Critical Raw Materials, launched in 2020, reiterates the importance of robust supply chains for raw materials, as well as the elimination of distortions in international trade and full compliance with EU international obligations. The Critical Raw Material Act of 2023 will further all of these aims, as well as stockpiling to form strategic reserves of certain raw materials. A ‘Critical Raw Materials Club’ will bring together raw materials consumers and resource-rich countries to foster cooperation.
Joe Harder of OneStone Consulting next gave an outlook for the European plasterboard industry to 2030. Production is expected to continue to grow at a compound annual growth rate (CAGR) of 1.5 - 2.5% to 2030. Joe took issue with the suggestion that reusing factory-produced waste is recycling, and in the same way that offcuts at the construction site, never actually used, might be considered as recycling, and instead insisted that they should only be considered as ‘recovered’ materials. The Federal Association of the Germany Gypsum Industry suggests that FGD gypsum production in the EU will cease by 2038. However, Joe pointed out that the rise of renewable power has not displaced coal, but has displaced nuclear and gas instead. In Germany and Poland, coal has increased its share of power generation in the last few years, and FGD gypsum production has not slowed down in the last two years, compared to pre-Covid. Joe forecast that recycled gypsum supply will increase by 2.6x by 2030 to a total of 6Mt in the EU.
Tristan Suffys of Eurogypsum spoke about best practice in gypsum mining in Europe. He first pointed out that nature is in a state of crisis, and is facing a biodiversity emergency. Europe now has a strategy to protect 30% of both land and sea areas by 2030, as well as having a new ‘pollinators strategy.’ Of course, quarrying operations have a huge opportunity to manage biodiversity during mining and after activities have ceased. Temporary ponds can be created during quarrying, as well as leaving areas to provide continuity, and even shifting topsoil and biotas to areas close by, and all can help to preserve biodiversity. Quarry restoration, in order to promote biodiversity, is now essential in quarrying plans in the EU. Tristan suggested that quarrying can actually increase the biodiversity of an area, through the creation of new and varied habitats that were not previously present. Eurogypsum was a partner in the publication of the ‘Extractive Sector Species Protection Code of Conduct.’
Scott Coley of Atritor Ltd next spoke about the company’s dryer-pulveriser machine for milling, drying and classifying rock gypsum. The company’s turbo-separator equipment can alternatively be used to separate gypsum from the facing paper of gypsum board. The solution provides a 99.5% separation efficiency, and Scott mentioned that the key to the process is to not grind the material too finely, or it will be difficult to separate the constituents. The less moisture that the plasterboard has, the better will be the separation efficiency, although up to 10% moisture is not a problem.
At the end of the first day of the event, delegates enjoyed a lively dinner and quiz at the conference hotel, followed by a social at a local brasserie.
Second day
Jean-Luc Marchand, mineral resources director for Saint-Gobain, but speaking at the conference in his role as the chair of Eurogypsum’s Raw Material Committee, was the first speaker on the second day of the conference, on the subject of gypsum recycling in Europe. According to Eurogypsum, 26Mt of gypsum was used in the EU in 2022: 67% was natural rock, 27% was FDG gypsum, 3% was internal recovery and 3% was recycling gypsum. Around 700,000t of construction and demolition waste, CDW, was used as a gypsum source. Jean-Luc suggested that one plant in the EU uses up to 40% recycled gypsum in its raw material supply. He gave details of a French study which suggested that only up to 20% of gypsum supply could be derived from recycling in the future, and he suggested that Germany would have the same situation. He pointed out that to improve these numbers, gypsum companies will need to establish systems for plasterboard collection and logistics, and for processing. “Who pays for that?” He asked. It all depends on the cost of landfilling. When the cost of recycling is higher than the cost of landfilling and the cost of other sources of gypsum, then it becomes uneconomic for the recycler to recycle. He concluded that ‘high quality gypsum waste is crucial for closed loop recycling.’
Maarten Hendriks of New West Gypsum Recycling next gave an overview on European and North American gypsum recycling markets. Maarten pointed out that working with the plasterboard manufacturer is a crucial step towards establishment of successful recycling scheme. For interest’s sake, Maarten had asked ChatGPT to write a section of his presentation. The AI made a few good points, as well as making a number of incorrect or spurious claims, so Maarten switched back to his human-written presentation. He pointed out that when recycled gypsum is used in the cement industry, it is ‘downcycled,’ in that it reduces in value and it never comes back: it is no longer available to the circular economy. The cement industry is also more tolerant of a lower-quality gypsum, which does not tend to encourage higher quality waste recovery. Sweden stipulates that all boards sold on the market must contain at least 17% recycled gypsum, and this has strongly promoted the recycling industry in Scandinavia. France is also ramping up recycling, while the UK already has a major recycling sector, due to the dearth of availability of FGD gypsum. In Spain, Portugal, Italy and Greece, gypsum is hardly recycled, if at all. Eastern Europe has shown interest in recycling, but actual activity has so far been low. Canada’s recycling sector is relatively well-developed, but the main competitor to recycling is the possibility of cheap landfilling in the US. He pointed out that many US plasterboard plants are not actively recovering board, but instead are stockpiling it in stacks close to the plant. Total volume recycled and recovered for the whole of the US is only 100,000t per year, although shortages of FGD gypsum will eventually be the trigger for higher recycling rates in the US in the coming years. Maarten suggested that recycling of wallboard in the rest of the world is practically non-existent, although there is early interest. He concluded that the most successful areas for recycling are where raw materials prices are going up, where legislation forces recycling rates (and bans or makes landfilling expensive) and where recyclers can work hand in hand with board producers.
Christian Pritzel of the University of Siegen gave the penultimate presentation on the chemical barriers to gypsum recycling. He pointed out that recycling a gypsum crystal, with an intermediate heating stage to 150°C to simulate a plasterboard dryer, leads to a roughening of the crystal surface and more nucleation sites, more branching crystals and smaller new crystals. This leads to different properties, porosity and strength of gypsum-based building materials. The addition of citric acid to the stucco mix will result in shorter crystals with a larger diameter, and lower strength. Retarders and polycarboxylate ethers (PCEs) have different effects, while the combination of different additives can have complex and difficult-to-predict effects on crystal morphologies.
In the final presentation of the conference, Marcus Levermore of Enowa-Neom gave details of a new seawater desalination project that is likely to create significant quantities of synthetic gypsum. Neon is a region in northwest Saudi Arabia, on the Red Sea, consisting of a number of significant urban and industrial developments, including the Line, the Oxagon, Trojina, and the Southern Cluster. The desalination plant will produce 1Mm3 of water each day, enough for around nine million homes. The plant is designed for zero liquid discharge, and instead of discharging brine will valourise the brine into new products instead, including salts, soda ash, potassium, bromine, lithium and rubidium, magnesium and gypsum. The plant is expected to produce up to 1.8Mt of synthetic gypsum each year, at a purity of >95%, with low Na And Cl, and at less than 10% moisture. First gypsum production is slated for 2027.
Delegates voted for their three favourite presentations on the conference survey: Christian Pritzel was third for his talk on the effects of additives on crystal morphology; Jean-Luc Marchand speaking for Eurogypsum was second with his presentation on the status of recycling in Europe, while Maarten Hendriks of New West Gypsum Recycling was the winner for his global overview of gypsum recycling trends.
Attendees very strongly praised the event for its excellent networking opportunities, the lively discussions (seen below) and the useful knowledge gained.
• Well organized • Congratulations for the good job. • Thank you so much for your kind cooperation • Thank you for authenticity and structured organization with also some appreciated fun • You are making a good job • Good conference • Thank you for great work
20th Global Gypsum Conference, Exhibition & Awards 2 - 3 November 2022, Lisbon, Portugal
The 20th Global Gypsum Conference, Exhibition and Awards took place 2 - 3 November at the Estoril Congress Centre near Lisbon, Portugal, alongside the 15th Global Insulation Conference, and attracted around 370 delegates in total with around 50 exhibition stands. The conference will next take place in Chicago in 2023.
Joerg Ertle - president Eurogypsum and executive in charge of the central Corporate Social Responsibility activities of Etex - opened the 20th Global Gypsum conference, and mentioned that Eurogypsum has just celebrated its 60 birthday. He went on to describe the working of Eurogypsum, which is based on a number of working groups staffed by participants in the industry. Main groups are raw materials, environment and sustainability and the technical and scientific committee. Joerg pointed out that gypsum is a readily-recyclable mineral, which lends itself to the still-developing circular economy. Joerg pointed out that energy costs have risen by 30 - 40% in the last few months, and prices are expected to stay high for an extended period. Volumes are already being hit by production and product cost hikes. Joerg reminded delegates of the many benefits of gypsum and of insulation, and of lightweight construction in general.
Tristan Suffys, secretary general of Eurogypsum, was the second speaker at the joint event, and he spoke eloquently about the ‘vibes’ of gypsum: that it is versatile, integral (to construction), beautiful, economical and sustainable. The European Green Deal was first proposed in 2019 but has had to be rethought in light of Putin’s illegal war in Ukraine. However, the ultimate aim of the Green Deal is to ensure that Europe as a whole is climate neutral by 2050. At the moment, the EU is not on course to achieve its aim. Minimum energy performance standards will strongly promote renovation of the worst-performing buildings, boosting wallboard and insulation consumption in the long term. Byproduct gypsum may become available from lithium production in the future. The Saint-Gobain’s plant at Fredrikstad in Norway should become fully electrified by early 2023.
Joe Harder from OneStone Consulting then stepped up to present the findings of his company’s forthcoming report ‘Plasterboard Industry Focus 2030’ (PIF 2030). The PIF 2030, which covers 72 wallboard-producing nations, forecasts that the sector will grow from a value of US$17.3bn in 2021 to as much as US$21.3bn in 2025 and then US$27.1bn in 2030, with a compound annual growth rate (CAGR) of 1.7% expected. China will see moderate growth to 2030, with North America expected to see a slight decline and Europe to remain constant. The bulk of the growth over the next eight years will come from the rest of the world, with market value expected to increase by 4.2%. Regarding wallboard production, the PIF 2030 forecasts a CAGR of 1.6% between 2021 and 2025, rising to a CAGR of 1.7% between 2025 and 2030. This will lead to the production of 13.5Bnm2 in that year if realised. As for capacity, Joe expects capacity utilisation to rise more moderately than capacity utilisation factor, which will increase from 70.9% in 2018 to 76.9% in 2030. In the second part of his presentation Joe focussed on the the EU27+UK market, where production volumes are expected to hit nearly 2Bnm2 by 2030 from around 1.7Bnm2 at present. Wallboard capacity will rise very slightly over the next decade following an absence of new facilities between 2019 and 2022. The presentation then highlighted local examples of gypsum supply, including the effects of new international crude sources in Oman, the effects of coal-fired power plant closures across the EU on synthetic gypsum supplies, as well as the complexity of extracting crude gypsum in this sustainability-conscious market. Joe decried the imminent closure of Germany’s most efficient coal-fired power plant, which exhibits ‘phenomenal’ efficiency compared to others that use coal.
Rob Crangle from the United States Geological Survey spoke next, providing the audience with the view from the North American market, specifically the US. Rob outlined that crude gypsum volumes have fallen from the 21.7Mt extracted in 2019 to 21.2Mt in 2020 and 2021, with a drop to 20.8Mt expected for 2022. The decline since 2019 can be attributed to lower numbers of workers available (in part due to Covid-19 effects), consolidation of existing operations and the absence of new quarries. At the same time, crude gypsum prices have risen, from around US$8.60/t in 2019 to an expected US$12.00/t by the close of 2022. The increase in price partly reflects lower volumes being extracted, coupled to rising demand from cement and wallboard producers, as well as rising inflation. Falling crude volumes have been partly off-set by gradual increases in the supply of synthetic gypsum from flue gas desulphurisation, which is expected to hit 15Mt in 2022. US wallboard volumes, meanwhile, reached 2.53Bm2 in 2021, a rise of 4.1% year-on-year from 2020 (2.43Bm2). For the first two quarters of 2022, Robert reported that US wallboard manufacturers produced 1.32Bm2 of wallboard. As seen with raw gypsum prices, wallboard sales prices have risen such that the sector’s sales will reach US$4.1bn in 2022, a 2.5% rise compared to US$4.0bn in 2021. Looking to the future, Robert also looked to new home starts, which hit a 15 year high at 1.6 million in 2021. A total of 1.44 million home starts are expected for 2022, a drop of around 10%, while renovations have now clearly passed their peak.
Jeff Warren of GypTech next spoke on advances in technology for wallboard production. Using cleaner energy in the form of green electricity for drying is one step, while improving dryer efficiency with heat exchangers and co-generation, and putting in less water in the first place by using smart additives, all reduce the embodied energy of the board. Greater efficiency in calcination and grinding is crucial, but Jeff pointed out that wallboard is already very energy efficient. Having a sustainable workforce is also crucial, part of which is ‘being a company that people want to work for,’ while more mundane jobs can often be automated. All aspects of gypsum production, from the design of the equipment to the production of the products, is now digitised, allowing sophisticated modelling and optimisation. New instrumentation is required to control the process and Gyptech has approximately 30 new instruments in development. Jeff concluded that AI is coming to gypsum production.
Peer Hanneke of Claudius Peters Projects GmbH then spoke about alternative thermal energy generation and energetic optimisation of the calcination system. Peer suggested that the use of natural gas in burners for calcination could be avoided by using either electrical heaters or with the use of hydrogen. Electrical heating is already possible, but higher powers and higher temperatures are more challenging, while hardware costs are higher than for natural gas heaters, perhaps two to three times higher, whereas currently electrical prices are significantly lower than for natural gas. Hydrogen burners are already available on the market, at only slightly higher prices than natural gas, although price per hydrogen megajoule is much higher (but is progressively decreasing). Hydrogen’s energy density is three times lower than for natural gas. Hydrogen can be stored at high pressure for long periods, and requires less space than for natural gas, but is expensive. Ammonia has been mooted as an energy carrier or ‘crude oil-like’ precursor for hydrogen production, which would make transportation and storage easier, although conversion losses make this form of energy even more expensive than direct use of hydrogen. Some combination of these technologies is likely, with local variations.
The final presentation of the first day was given by Andreas Schieler of Gebr. pfeiffer, who spoke about grinding, drying and calcining in a single vertical roller mill. The Pfeiffer MPS mill is capable of grinding natural, synthetic and recycled gypsum, in a variety of ratios. Process gases are recirculated, along with a hot gas generator, to maximise thermal efficiency. Plant oil, biogas or hydrogen can all be used as fuels. Capacities of over 200t/hr are possible.
After the first day’s programme, delegates boarded buses to attend the Awards Dinner at Arriba, Guincho, a venue perched on a cliff-top overlooking the Atlantic, arriving just in time to see the sunset. The Global Gypsum Awards 2022 were presented at the event.
Second day
On the second day of the conference, Sebastian Scholl of Lutze International spoke about his company’s natural rubber setting/forming belts for gypsum-boards. He said that the belts have to be perfectly flat, with equal thickness along their length, in order to help to form perfect products. After every belt has been produced, Lutze does a pre-inspection and effects any required hot repairs, as well as checking thickness, and friction values on the top surface of the belt. If an endless belt has been ordered, then full documentation about the splicing method and expected lifetime is also provided.
Philipp Kunkel of Fagus-GreCon next spoke about x-ray scanning of both insulation and gypsum-boards. An x-ray source shines through the moving material bed, and is detected by a series of detectors under the belt. A resolution down to 1.6mm allows the detection of foreign bodies, but also enables the detection of both high and low densities in the material. This allows great control of the production process, and means that the process can be driven much closer to set points, either to increase production or quality, or to decrease product costs. The instrument can be used at different points in the process, allowing measurement of a variety of parameters and process variables.
Niklas Johansson of Gyptech Europe subsequently gave his presentation, “how to save the planet, one gypsum-board dryer at a time.” Dryers historically used coal-heated steam to dry the boards with no recovery of energy from exhaust gases, with an energy requirement of over 1000kCal/kg of water evaporated from the board. Recovery/reuse of the exhaust gas brought down the energy requirement to around 750kCal/kg, while air-to-air heat exchangers brought the requirement down to 650kCal/kg. Adding pre-heating or pre-drying zones, meaning a drying time of up to 80 minutes, would bring the energy consumption down to perhaps 550kCal/kg, but would mean a very large and long dryer. Alternative means need to be sought. Alternative fuels may be used, such as hydrogen, bark and other wood waste, rice husks or other biomass, using indirect heating for fuels that are not suitable for use in the dryer. The use of electricity for drying is a developing field, and if powered by renewables is fully carbon zero. Niklas announced a new patent-pending high-temperature heat pump using Sterling motors and super-heated water at 200°C to reduce energy requirements to around 360-450kCal/kg. The system can be retrofitted onto practically any dryer. A new system based entirely on heat pumps would have an energy requirement of only around 260kCal/kg,with a drying time of only 35 minutes.
Another Johansson, this time Bo, from Limab AB of Sweden, then spoke about non-contact laser measurement of gypsum-boards, for quality, process and environmental improvements. The system can accurately measure all aspects of boards, including edge tapers, and can also be used to measure shrinkage of boards through the dryer. More precise control of board thickness can be used to reduce wasted material, with knock-on reductions in CO2 emissions.
Dennis Schattauer of Grenzebach next spoke about ‘megatrend greening.’ He pointed out that the environmental impact of industry will need to reduce to net zero by 2050, and said that “the environmental ambition of the Green Deal will not be achieved by acting alone.” Dennis reminded the audience that in a supply squeeze, natural gas supply will be prioritised for households rather for industry - a huge threat that points towards industry becoming more independent from fossil fuels. A conventional dryer has a high demand of thermal energy, typically in the order of 13MW, combined with a high temperature. Grenzebach’s new Ultra-High-Efficiency (UHE) dryer offers a reduction in specific energy consumption of 30%, down to 400 - 450kCal/kg H2O. A 3D scan of existing factories will ensure proper integration of new equipment. SERICY is Grenzebach’s name for its digitalisation solutions, while the company also offers a full service option round the clock.
Mark Degroote of JBTC next sleyed some myths about automated guided vehicles (AGVs): that a plant has to be technically advanced; that a business is too unique for AGVs; that a plant’s existing systems will not interface with that of the AGVs; or that the plant would be obliged to completely change the way that it operates - all these myths are false. JBT has already automated 20 gypsum wallboard sites, with over one million journeys completed. An average of 11 AVGs are used per site, while each vehicle is capable of lifting up to 4.5t to a height of 7.5m. The laser-guided AGVs are equipped with extensive safety devices and these mobile robots have an excellent track record. Having robots look after the stacking means that there is built-in inventory tracking and ability to quickly and efficiently pick a variety of products for dispatch onwards to customers.
Rosy Scodro and Pierro Rizzi of Comec SRL next gave details of a continuous moulding line for gypsum panels, for which they won the award for Global Gypsum innovation of the year at the preceding night’s awards dinner. The company started in the Italian shoe industry, but has evolved into production of equipment for building materials. The new line can produce up to 5000 gypsum panels each day. The mixer used is similar to that used on a normal wallboard line, disgorging gypsum onto a forming line with continuous edge moulding. The panels are cut and air-dried on racks to avoid any thermal shocks. Edges are milled prior to packing and wrapping on pallets for dispatch.
Dany De Kock of Johns Manville (winner of a ‘Personality of the Year’ award the previous night) next spoke about DuraCore 303 fibreglass fibres, which are able to increase fire-ratings to higher levels than previously, or to the same level with less glass volume, while reducing shrinkage and avoiding problems with slurry viscosity at higher fibre concentrations.
Tomás Vivot from paper manufacturer Alier outlined his company’s aim to become the market leader of recycled paper and plastic and how it was aiming to supply a carbon neutral paper by 2024. He then introduced the company’s Value Added Paper from Alier (VAPA) concept, where it offers a consultation service to help its customers optimise production and reduce costs. He then ran through the company’s portfolio for the gypsum wallboard sector including High Performance products with reduced weight for the same strength as comparable papers, as well as products with water proofing, anti-fungal-, and anti-bacterial properties. In an example of a customer using the company’s High Performance paper he demonstrated that the lower weight allowed for a transport cost saving of Euro60,000/yr. A Hydro Performance product reported a water absorption or Cobb value of below 20g/m2. However, when asked, Vivot would not reveal what process is used to make Alier’s paper repel fungus, comparing the secret to that of the recipe for Coca Cola! He concluded his presentation by describing the company’s progress towards Sustainable Product Purchase Agreements, where it aims to encourage the uptake of sustainable products and practises.
Robert McCaffrey of Global Gypsum Magazine gave a late addition to the programme in the form of his presentation on how the cement industry is changing. His argument was that major cement companies have previously comprised combinations of adjacent production processes centred upon the key steps of cement, aggregate and concrete manufacture because this is where the best earnings reside. However, a mounting list of risks including increasing global carbon and fuel prices and recession fears may be encouraging the larger multinational cement companies to diversify away from cement, aggregate and concrete into connected sectors such as insulation, gypsum wallboard, construction chemicals, roofing and more. Rob McCaffrey gave examples from Holcim, Cemex, CRH, Heidelberg Materials and Votorantim Cimentos and also noted a trend from some of them to divest away from markets in some developing areas. He ended by pointing out that Lafarge’s decision to sell its wallboard business in the early 2010s might come to be viewed with hindsight as a mistake. The first audience question asked which wallboard and/or insulation company might be acquired by a cement company, leading McCaffrey to suggest that an answer “can be best discussed over several beers.”
David Appelfeld and Lucie Fraichard of Owens Corning (a company involved in manufacturing insulation, roofing and composites) pointed out that “we cannot build tomorrow with yesterday’s materials.” David pointed out that construction is moving from the massive and heavy to the light: from concrete and bricks to lightweight, high-performance materials and systems, including the use of glass-fibre-mat faced gypsum exterior sheathing boards. Lucie then showed how producers can reduce bleed-through of gypsum through facing glass mat by reducing pre-wetting of paper and by using multiple slurry spreader heads, but also by finely tuning the performance of the glass mat by changing its design and composition. OC is a world-leader in glass technology, and Lucie pointed out that glass-faced mats can be combined with glass fibre reinforcement to improve board performance.
Markus Mueller of Sika Services AG spoke about polycarboxylate ether (PCE) superplasticiser concepts that allow the reduction of water input into gypsum slurries. PCEs are compatible with FGD gypsum and natural gypsum, and new formulations are more compatible with swelling clays.
The final presentation at the conference was given by Christian Pritzel of the University of Siegen who asked what happens to the various additives when plasterboard is recycled, potentially more than once? Do they influence and interact with each other? Clays in recycling are known from natural gypsum, and producers cope well enough, so that is not the largest problem. Christian pointed out that when pure gypsum crystals are subjected to temperatures of 140°C, typical of a dyer, the crystal faces become flakey, giving the crystal a much higher surface area. When that crystal is then rehydrated and crystals are allowed to grow (akin to a recycling step, the flakes form nucleation sites, leading many smaller crystals to grow. More cycles lead to more surface defects and many more but smaller crystals. Additives strongly affect crystal morphology, but their effects reduce with more heating/rehydration cycles. Dehydrate seeds can act as a ‘catcher’ for some additives. Christian finally concluded that the industry may need to move in the direction of only using additives that can be easily recycled, perhaps additives based just on gypsum.
Farewells and prizes
The awards for best presentation were presented at the Farewell Party at the spectacular Estoril Congress Centre. In third place was Dennis Schattauer of Grenzebach, with Niklas Johansson of Gyptech Europe in second place. However, proving that being last in the programme is sometimes not a disadvantage, the best presentation prize went to Christian Pritzel of the University of Siegen.
The conference was strongly praised by attendees, with 91% being satisfied with the event’s Covid testing regime, and others lauding the networking opportunities, gala dinner and technical programme.
The 21st Global Gypsum Conference will take place in November 2023 in Chicago.
Purchase the Global Gypsum & Insulation Conference Pack 2022
The conference pack is available for purchase (use the link below) for GBP£695 (includes the video, presentations and proceedings from the event).
