Refractory clays stuck in the mud

Four years ago, the refractory clay market was robust owing to the strong performance of the steel market. But during the third quarter of 2008, the industry saw a dramatic U-turn when the market started to crash. Steel production, a good indicator of refractories demand, declined worldwide, dropping 51% in the first seven months of 2009 in the USA compared to the previous year.

As US Geological Survey (USGS)’s clay analyst Robert Virta confirmed to IM, the “current world market for refractory clays continues to be affected by the downturn in the world economies.” The US and European markets started to slow down, followed by China some time later.

However, even though the refractory clay market seems to have been less impacted compared to the overall family of refractory raw materials, it has nevertheless suffered since then and is still picking up the pieces.

Vatutinski Kombinat Vognetryviv (VKV), AGS
Mineraux’s 86%-owned subsidiary, has a production
capacity of 200,000 tpa of refractory clays in Ukraine.
Courtesy Imerys

The uncertainty is now about when the market will recover. The refractory clay industry has certainly decreased at a lower speed with more stable prices than refractory minerals but the recovery is expected to be a slow process.

Decline in the USA

The USA, which is a major supplier of refractory clays products, mainly kaolin/kaolinitic and ball clays, could not escape the effects of the crisis and the US refractory clay market has inevitably been affected by the economical downturn.

“The chief markets for refractory products, including refractory clays have declined with curtailments at many of those [end uses] plants in the past year,” explained to IM Robert Virta.

According to the USGS, the country produced an estimated 508,000 tonnes of fireclay and 964,000 tonnes of ball clay in 2008, down from 1.2m. tonnes in 2004.

In general, the use of refractory clay products has been in decline. “This is particularly true for refractory clay shapes, which have shown a decline for at least the past 10 years,” noticed Virta who believes that “the percentage of unshaped refractory clay applications will continue to increase over time”.

Based on USGS survey data, the decline in sales of fire clays has slowed. From 2004 to 2007, the market appears to have reached some stage of stability with sales hovering just below 200,000 tonnes. “That is probably where sales will remain for the near future once the economy recovers,” forecasted Virta. However, the USGS’ analyst does not “anticipate any return to the markets of the 1970s”.

For refractory grades of kaolin, the same trend as fire clay is considered, with declines in uses through 2005. After that, the sales seem to have flattened out. “That probably will be the general trend for the near future,” estimated Virta.

The USA hosts important deposits of refractory grade kaolin, which are located in Georgia, Alabama and California; fire clay or flint clay is produced mainly from Missouri but also in Ohio, South Carolina, California, and Alabama while refractory grade ball is sourced from Kentucky and Tennessee.

“Levels are well below 2008”

Christy Minerals LLC produces raw and calcined flint clay in addition to raw plastic fire clay. Christy’s deposits are located in central Missouri, USA, with refractory clay ranging from 35% to 65% Al₂O₃ and graded according to alumina content, flux content, and plasticity.

The company, which operates a rotary calcining kiln with capacity of 100,000 tpa at High Hill in Missouri, markets raw clays both as mine run and processed (ground and packaged) and calcined clays.

Christy supplies the markets of refractory, investment casting, ceramic tile, pottery, cement, sanitary ware, and concrete additive (Pozzalon) into The North American Free Trade Agreement (NAFTA) countries along with South America and Europe.

A small percentage of the company’s volume is exported outside of NAFTA countries.

Shane Bower, Christy’s vice-president sales and marketing, saw the slowdown in the economy starting in the early fourth quarter of 2008. “The current market is difficult with refractories consumption down on the order of 40%-50% in North America,” he told IM.

According to Bower, steel pour rates in North America have had a direct impact on refractory consumption. “Although there are reports of slight increases in pour rates, the levels are well below 2008,” he explained.

Low demand

Harbison-Walker Refractories Co. has mothballed its plant in Birmingham, Alabama, owing to declining demand from steel and aluminium makers (IM 10 September ’09: US refractories plant mothballed).

The company, a subsidiary of ANH Refractories Co. which produces fireclay, mullite and andalusite brick, laid off 75 workers beginning of September 2009 and plans to keep the plant idled until demand increases.

ANH does not expect to reopen the plant before November but said it was committed to operating the plant in the long term. The Pennsylvania-based company said that problems stemming from low demand had affected more than a dozen of its plants.

Stronger conditions

Imerys SA’s subsidiary C-E Minerals Inc., which supplies calcined clay to the refractory industry, is the world leader in the production of sintered mullite with high alumina content marketed under the trademark Mulcoa^¨.

C-E Minerals has the capacity to produce 625,000 tpa of Mulcoa at Andersonville, Georgia. The company has different grades M45, M47, M50, M60, M70, the number corresponding to the Al₂O₃ content of the product.

In early 2009, C-E Minerals constructed a new kiln to increase its production by 75,000 tpa and improve efficiency and flexibility.

For Mike Pierce, vice president of sales at C-E Minerals, the market which had previously been quite robust until the end of 2008 is “down with a slow recovery foreseen”.

“The worldwide recession and specifically the downturn in steel production in North America and Europe have most impacted the market,” Pierce told IM.

Therefore, Pierce forecasts a “slow, but steady increase in consumption of refractory clays for the future”. “We are just beginning to see the signs of stronger conditions in both the US and in Europe,” he added.

Europe more affected

US and European refractory clays have similarly been affected by the financial crisis. However, it seems that Europe has suffered a bit more. Therefore, Europe is expected to lately follow the USA, which is said to be “six months ahead of us”, in the recovery process (see Outlook).

New chamotte unit at Imerys

“As up to 70% of refractory products are used in the steel industry, it does not come as a surprise that the refractory industry has been affected by the crisis,” Philippe Bourg, Imerys’ commercial and marketing manager for Minerals for Refractories Division in Europe and Asia, explained to IM.

However, Bourg believes that “the refractory market has a trend to consolidate” and demand will be evolving towards products with increasingly stringent technical requirements”.

That is why the mining giant decided in January 2008 to consolidate its subsidiaries AGS MinŽraux (France), Vatutinsky Kombinat Vognetryviv (VKV, Ukraine) and the Molochite^TM activity (UK) in a new business unit, European Chamottes.

“This new structure helps to improve efficiency and cost effectiveness by pooling various entities’ expertise in terms of production, logistic and commercial issues,” reported the company.

Imerys has several high quality aluminosilicate deposits in Europe and the USA, including kaolins in Cornwall (UK), Alabama and Georgia, USA (see Stronger Conditions); clays, metakaolin and chamottes in ClŽrac, France; and chamottes in Ukraine through its subsidiary Vatutinsky.

The French group also produces chamottes and ceramic clays in South Africa, through its subsidiary Ecca Holdings (Pty) Ltd. These products are sold to the local South African market, chiefly for floor tiles. All Imerys’ products are sold to major refractory companies such as Vesuvius, RHI, Calderys and Magnesita.

According to Imerys, the Minerals for Refractories division of the mining giant represented about 8% off all the activities of the group in 2008, with a turnover of about Û270m. for refractory clays from its total turnover of Û3,400m.

AGS Mineraux

AGS Mineraux, part of Imerys’ new European Chamottes business unit, mines high purity kaolinitic clays in the Charentes basin, Clerac, France, for the refractories industry.

With more than fifty grades, AGS operates two major product lines: clays and chamottes, mainly for the refractory, sanitaryware, tile and investment casting industries; clay and metakaolin-based specialities for the chemical industry, the building materials industry, cattle feed, fertilisers. Typically, the alumina content varies from 35% to 47%. Global production capacity of AGS in France is about 150,000 tpa of clays and 200,000 tpa of chamottes and metakaolin.

The company has a production capacity of 200,000 tpa of chamottes and metakaolin in the centre of Ukraine, on the kaolin province of Ukrainian Shield, through its 86%-owned-subsidiary VKV , acquired in July 2007. AGS believes that VKV will “extend the portofolio of products, production capacity and enters also some new markets from a logistics point of view”, as VKV targets east European markets, mainly Ukraine and Russia.

In terms of sales, nearly half of the volume of AGS is sold for refractory applications, mainly for the European market.

Olivier Joubert AGS’ sales, marketing and development manager, told IM that the market for AGS and VKV raw materials is “depressed, following the trend of the recession affecting industrial minerals, and more specifically the trend of the refractory end usage market.”

UK: “Enquires have been drying up”

DSF Refractories & Minerals Ltd produces a wide range of aluminosilicate and high fired mullites. It is one of the largest producers of shaped refractories with a range of high alumina, spinel and other special refractories.

The UK-based refratories manufacturer supplies the major refractory using industries of glass, steel and cement. It is also a supplier into some of the more specialist refractory users such as incineration, carbon black, kiln and kiln car construction, aluminium and other non-ferrous metal production, carbon calcination and many others.

The UK plant, based in the Peak District of Derbyshire, in the centre of England, has a capacity of about 50,000 tpa, with an annual turnover of about £21m. DSF supplies refractory products worlwide.

DSF has extended its mullite producing capacity by 50% at its Friden plant in Derbyshire, UK (IM March 2009: DSF ups mullite capacity by 50%).

The £850,000 ($1.17m.) investment in a new fuel efficient high temperature kiln, is also aimed at reducing delivery times for customer orders. Neale Parkin, managing director of DSF, recently told IM: “We have been losing orders because of the long lead times recently.” Parkin also accepts that the new mullite capacity - produced from firing andalusite and alumina - would probably not be fully utilised in the near term, but expects business to grow in the longer term. “Enquires have been drying up, but we still have a number of orders to fulfil,” said Parkin.

DSF’s new Bricesco high temperature kiln became operational in June, firing DSF mullite products. However, the company reported that this new kiln is “unfortunately coming on line at a time when our order book is not quite so full, so the extra capacity will not instantly transfer into extra sales But this new facility will allow a faster reaction time and reduce standard lead times for some of the DSF flagship products including DSF Frisil H.”

DSF’s mullite refractories are mainly used in glass manufacture, and mullite’s popularity has grown in popularity over other refractory materials, such as magnesite.

Sibelco UK, another refractory clay producer in the UK, has been producing world-renowned ball clays from the deposits of the Bovey Basin in South Devon and the Petrockstowe Basin in North Devon, UK, for over 300 years.

Spain: 20% decrease

Spain produces chamottes in Oviedo, Asturias, in the north-west of the country, which is also the headquarter of Arcillas Refractorias SA (Arciresa).The company has five deposits in the center of Asturias, including a new one called Nueva Perdiz with reserves of 500,000 tonnes. Arciresa supplies a full range of clays and kaolins for ceramic and refractory applications, including calcined clays and chamottes (42%-44% Al₂O₃, low alkalis < 0,5% and low iron < 0,7%).

In 2008, Arciresa produced 35,000 tonnes of chamotte and expects to produce 40,000 tonnes for this year. The company exports 25% of its sales to Spain, France, Italy, Portugal, the Netherlands, the UK and Magreb.

Like its neighbours, the Spanish refractory clay market has suffered from the effects of the financial crisis, which has particularly stricken the building industry and therefore, the cement, steel and ceramic industries.

As explained to IM Fernando Lopez, Arciresa’s managing director, after a fall down of 35% during the first half of 2008, the market is recovering by 15%. “So we estimate a global decrease of 20% for this year and a 10%-increase for next year,” he forecasted.

Lopez also underlined that an increase of demand in metakaolin is expected for new applications, such as agriculture, mortars and precast materials.

Arcillas y Chamotas Asturias SL (Arcichamotas) manufatures chamotte at its facility in Silvota, Asturias, using flint clay mined by its subsidiaries Caolinas de Merilles and Carolines de las Espinas SL. In 2004, Caolinas de Merilles mined about 26,000 tonnes of flint clay while Caolines de las Espinas exploited 20,000 tonnes of flint clay.

China doing better

The Chinese refractory clay industry is said to have suffered from the present economic downturn but not as much as Europe and the USA. As the economy of China increased in 2008 and 2009, although at a slower growth rate than in the previous five to seven years, “the refractory clay market is probably doing better than in the USA and Europe”, analyses Robert Virta for IM.

About 15 leading producers produce more than 1m. of refractory clays in China. Among them, China Mineral Processing Ltd (CMP) is a European company formed by a group of independent investors to develop the processing of Chinese minerals in China for export into the world market. The Tianjin-based company produces a range of products for the refractories market, including clay products such as flint clay, chamotte and the sintered mullite products Reframul 45, 47, 60 and 70.

Based in Qingdao, Shandong Refractories Corp. supplies fire clay chamotte and sintered mullite.

DSF, under its subsidiary DSF Refractories (Tianjin) Ltd, has also started producing refractory products at its plant in Tianjin, east China. The first stage of production started in August 2008, while a new kiln was installed last November. Presently, DSF is inviting customers to look at its Chinese plant products before ramping up output. Refractory products are expected to be made from chamotte, flint clay, and alumina, amongst other minerals.

Jungar Mengsheng New Materials Co. Ltd (JMNM) is a joint venture that was established in 2003. The company is located at Xuejiawan, Jungar, Erdos about 120km south-west of Hohhot, Inner Mongolia. The plant is adjacent to the coal strip mine of Shenzhua Group Zhunger Energy Co. Ltd and just 1km from National Highway 109. The reserves of JMNM’s deposit amount to 88m. tonnes of “super high quality kaolin” and 20m. tonnes of “high alumina” bauxite. The kaolin deposit typically contains 39.5% Al₂O₃, 42.43% SiO₂, and is very low in iron, <0.5% Fe₂O₃, <1.2% TiO₂, and alkalies.

The main market target is the domestic refractory sector, although JMNM claims some 15,000 tonnes has been sold to Europe and Japan.

Elsewhere

Germany, Poland and Czech Republic are also important producers of refractory clays.

In the Czech Republic, P-D Refractories CZ a.s. produces about 100,000 tpa of fireclays in Velke Opatovice. P-D Refractories also has a plant in Březina, located about 10km from VelkŽ Opatovice. Over 50 % of the mining capacity of raw and fired clays is used in the production process in Velke Opatovice.

Lasselsberger AS, the Czech minerals Division of Austria-based Lasselsberger group, produces a range of kaolinitic clay products for refractories includes B1, B2, B3, and B4, which are used as the binding and fireproof component of refractory bricks and pots, furnace stones, chimney pieces, and ceramics, which require a high level of compactness and strength. Most of its output is consumed domestically, with some 10% being exported to Germany, Austria and Poland.

In Germany, WBB Central Europe, part of Sibelco, is one of the major suppliers of high alumina blue clays and light-firing clays and kaolins for refractories (up to 38% Al₂O₃) through its subsidiaries WBB Fuchs GmbH & Co. KG (Germany), Kaolin- und Tonwerke Seilitz-Lšthain GmbH in Saxony, Kaolin Hlubany AS (Czech Republic) and Pornon &Cie SARL (France). Also in Germany, Rohstoffgesellschaft GmbH Ponholz mines kaolinitic clays at MaxhŸtte-Haidhof and Auhofweither in the southern of the country.

In Poland, Jaro SA is the leading producer of refractory clay products. Based in Jaroszow in the south-west of the country, the company produces a range of raw refractory clays branded G1, G2, G3 and G4, in addition to burned refratory clays PGM, and porous refractory materials such as the light-weight chamotte.

Clay versus bauxite

“We expect to see an increase in the uses of mullites instead of bauxites or andalusites for some applications,” forecasts Michel Vaucquelin, managing director of Victory Minerals SL, a Rotterdam-based trading company specialising in refractory and ceramic minerals (IM April ’09, p.70: Victory Minerals).

Bauxite is a key refractory mineral, produced in China and Guyana. But owing to the uncertainty of bauxite supply and pricing, refractory manufacturers have started to use various refractory clays and mullites to substitute (or blend) with bauxite. “Like any recipe you can use different ingredients to come up with a somewhat similar result,” commented Mike Pierce, C-E Minerals.

Higher alumina raw materials prices for the refractories market have lately increased, specifically bauxite or bauxite derivatives and particularly in China.

As reported by IM, prices for non-metallurgical grades of bauxite sourced from China are set to rise further despite the dire market conditions, as export authorities in China continue to tighten restrictions on exports of the material. In recent years, China has indeed steadily reduced the amount of bauxite that can be exported and has introduced taxes to further increase the cost of exports.

Renewed interest

It comes as no surprise that refractory manufacturers have started to eye alternatives such as refractory clays. “With the price and long term availability of Chinese bauxite being a question, refractory producers are returning to raw materials used prior to the introduction of Chinese bauxite to the refractory industry. These include clays and other alumina materials,” underlined Pierce.

Shane Bower, from Christy Minerals, confirmed that “there has been renewed interest in calcined clay refractories in certain applications.”

According to Vaucquelin, the quantities of available Chinese bauxite will decrease in the next few years, but only for refractory applications. Philippe Bourg from Imerys estimates that, at present, just considering licences differential between 2008 and what is likely to be allocated for 2010, there could be up to 500,000 tonnes shortage of refractory bauxite supplied out of China. “Therefore, as soon as demand will be back to 2007/2008 levels, we are likely to see some positive impact on many refractory minerals supplies, including the one Imerys is offering (Mulcoa, Chamottes, Andalusite),” he explained.

Vaucquelin also believes that in the future, mullites will come in larger quantities from China, India and Brazil where there are good reserves of high alumina clays and a lower cost of calcination and labour. “They have good reserves in these areas and some facilities. You have a lot of producers in China but also in Brazil and India with nice material but up to now not well introduced in the market,” he declared to IM.

When comparing Chinese bauxite and refractory clays price, substituting refractory clays for bauxite appears as a win-win operation. But it also raises concerns in the industry about the performance. As underlined by Bourg, in the short term, performance of refractory products is not seen as a priority. At present, prices are more a concern for the buyers”, he explained to IM. However, Bourg believes that “mid-term, once capacity utilisation of steel plants will be back to the one observed in 2007 and 2008, performance will become again the most important factor. Then, the ability to supply consistent high quality minerals will be valued again”.

“If the performance of the clays versus bauxite was equivalent or greater, it is likely that a noticeable substitution trend would be seen for clays and bauxite given the price differences,” estimated Virta.

Stable prices

Even though prices for refractory clays and mullites (ranging from $105/tonne FOB for clay, European calcined kaolinitic clay, 43% Al₂O₃ to $479/s. ton FOB USA for clay, Mulcoa 70% (sized in bulk bags), for ceramic milled material) have risen in the past two years, they remain “remarkably stable” compared to the fluctuations seen for bauxite, magnesite and other refractory raw materials.

“Prices are stable at present and will keep stable until mid-2010. After that, we will see,” confirmed Fernando Lopez from Arciresa to IM.

At that time, a slight increase is expected for refractory clay products but not at a high rate, owing to the competition from other materials. “Price increases have been instituted but they are probably more related to increases in production costs than to demand exceeding supply,” said USGS’ Robert Virta. “Consumers may resist high price increases for the next couple of years after suffering loses themselves due to the downturn in industries that use clay-based refractories,” he added.

Mike Pierce, from C-E Minerals, believes that the costs to locate, analyse, extract and transport clay deposits will continue to increase. “But hopefully costs can be sufficiently contained to moderate future increases,” he commented to IM.

Lopez goes further, forecasting an increase of 5%-10%. “As soon as the market will recover, prices will increase, also following the increase of the prices of the oil, gas and electricity,” he declared.

Slow recovery

The refractory clay industry apparently is starting to show a cautious optimism for the future. “For the end of 2009/beginning of 2010, we are still a bit cautious,” Philippe Bourg from Imerys told IM.

“In terms of global demand and more specifically on the West European market, we do not see a strong recovery at the moment,” he explained, blaming “a lack of projects”.

“There is still some uncertainty about Chinese ability and willingness to export significant volumes. And that would affect the market,” underlined Bourg.

However, the commercial and marketing manager for Imerys’ Minerals for Refractories Division in Europe and Asia remains confident on the long term. “If we forecast on the next five years, we see favourable perspectives, owing to the rarity and the cost of raw material from China.”

One of the favourable factors would certainly be the major increases in higher alumina raw materials prices for the refractories market, specifically bauxite or bauxite derivatives. That would certainly help cheaper refratory clays to become more attractive. “There has been renewed interest in calcined clay refractories in certain applications,” confirmed Shane Bower from Christy Minerals.

Outlook

A mid-to-long term recovery is expected but which market will lead the way to lighter days: China, the USA or Europe? One fact seems to be certain: Europe lags behind. Therefore, China and the USA are the two main favourites. But on that matter, the industry is in different minds.

Robert Virta bids on China for first place, believing that “since its economy did not decline as much as did those of the USA and Europe, [it] probably will lead the way in terms of increases in tonnage sales.”

For the USGS’s analysts, the US and European markets will probably recover “at about the same pace since some signs of a slight economic recovery have been reported in both regions”. However, as improvements seem to be more in the financial sector rather than the manufacturing sectors, Virta warns that the recovery of refractory clay markets may take a while.

Mike Pierce from C-E Minerals also anticipates that the USA and Europe “will come back together” but with perhaps the USA “rebounding just slightly quicker.”

Bourg is more categorical. “The USA seems to be six months ahead of us in Western Europe” he explained to IM. “The US market will recover before Europe.”

Refractory clays at a glance*

Refractory clay products can take many forms but the essential qualities required are a composition of >38% alumina (usually 42-47%) with a low iron (<1wt% each) and alkali (Na, K) content. They can be either uncalcined or calcined, and include high performance calcined grades such as mullite.

Formula Al₂O₃.2SiO₂.2H₂O (ie. 39.5% alumina, 46.5% silica and 14% water)

Within this group, kaolinite is most abundant.

Other names Fireclay, flint clay (or hard clay), ball clay (or plastic clay), and kaolins. Their common feature is that they all contain kaolinite as the main mineral phase, and their composition is 20-45% Al₂O₃, <3% Fe₂O₃, <3% Na₂O+K₂O.

Mullite Another ‘refractory clay’ product, (3Al₂O₃. 2SiO₂), which can be manufactured by calcining high alumina kaolin and bauxitic kaolin to temperatures of 1,200-1,500¡C. At these temperatures, the main mineral phases of the clay are transformed to mullite, cristobalite and a glassy phase.

Fireclay A siliceous clay rich in hydrous aluminium silicates, capable of withstanding high temperatures without deforming, disintegrating, or becoming soft and pasty. The better grades contain at least 35% Al₂O₃ when fired.

Chamotte Fired kaolinitic clay at (1,300-1,450¡C) containingÊmullite, glass and amorphous phase, cristoballite. Mixtures ofÊrefractory clays and chamotte (~50-50%) are used for manufacturingÊrefractory bricks.

Chinese clays

• Mild clay (includes ball clay), fireclay and kaolin: <45% Al₂O₃
• Flint clay, kaolin, and high alumina ore: >45% Al₂O₃
• High alumina chamotte: 75-90% Al₂O₃

Sources: Philippe Blanchart, professor, Ecole Nationale Superieure de Ceramique Industrielle, Limoges, France; and Dictionary of Mining Terms, American Geological Society