Refractory minerals are used to improve the performance of refractories products by imparting properties such as strength, protection from chemical and physical attack, and slag resistance. Refractories products can be broadly divided into basic, neutral and acidic groups, which relate to the type of refractory environment the product has been designed for (e.g., basic oxygen steelmaking) and hence the minerals used in its manufacture.
Minerals commonly used for refractories include (but are not limited to) alumina, bauxite, graphite, kaolin, magnesia and zirconium. These minerals are produced globally but, in some cases, not always of grades suitable for refractory applications (e.g., alumina and bauxite). Owing to its favorable mineral resources, China is a leading producer of numerous refractory minerals, but is also a huge consumer of these raw materials for its own domestic refractories industry.
In 2012 and 2013, global production of refractory raw materials fell across most mineral groups. This was the result of lower demand from the refractories sector, which faced falling consumption from a range of end markets, including glass, cement, ceramics, and non-ferrous metals, but especially iron and crude steel output (the largest consuming sector).
Alumina may be consumed in either metallurgical (e.g., Bayer alumina for aluminum production) or non-metallurgical (e.g. ceramics, refractories) applications. Alumina grades that are commonly used in refractories are those categorized as specialty calcined products, such as calcined, white fused and tabular alumina. Brown fused alumina (BFA) is also a type of specialty calcined alumina used in refractories. However, it is produced by fusing abrasive-grade calcined bauxite and is influenced more by demand for bauxite.
In general, refractory aluminas are produced from Bayer alumina feedstock. Bayer alumina production is reported by the International Aluminum Institute (IAI) as either metallurgical or “chemical” (non-metallurgical). In 2012, the IAI placed total alumina production at 100.5 million tons. Of this total, production of all non-metallurgical aluminas amounted to 5.5 Mt. The largest producing region was Western Europe at 1,680 kt, followed by Africa and Asia at 1,063 kt, and China with 978 kt (see Figure 1).
Estimated production of specialty calcined alumina was just over 40% out of the 5.5 Mt total. Around 60% was specifically consumed for refractories, a fall of 7% compared to refractory alumina use the previous year.
Global capacity for refractory alumina is fairly balanced between Asia, Europe and North America. Germany-headquartered Almatis is one of the largest calcined alumina producers worldwide, with 700 ktpy of tabular alumina capacity in six countries. The Treibacher Schleifmittal business of Imerys Fused Minerals is a leading producer of brown and white fused alumina from 10 plants throughout the world, including those in Europe, North America and the Middle East. Washington Mills of Canada and the U.S. can produce around 130 ktpy of fused alumina. Chinese producers have the capacity to manufacture more than 3.5 Mt of fused alumina, including white and brown grades, but much of this capacity is not used.
Around 600 kt per year of additional production capacity for non-metallurgical alumina could be brought online over the next few years. Hindalco Industries of India looks to add 316 ktpy of specialty calcined alumina through the conversion of its Belgaum plant, which previously produced metallurgical alumina. In Indonesia, PT Antam is jointly developing a 300 ktpy non-metallurgical alumina project in West Kalimantan with Japanese producer Showa Denko. Commissioning of the new plant began in October 2013, and Antam expects commercial production to start in mid-2014. The company will sell 100 ktpy to the domestic market, while Showa Denko will use 200 ktpy.
World production of bauxite is estimated to have totaled around 265 Mt in 2012. A large proportion of output is metallurgical grade and used for the production of alumina—itself consumed for aluminum production. There is also a significant market for non-metallurgical bauxite, used for applications such as Portland cement, slag conditioning, and calcined/fused grades for refractories. Non-metallurgical bauxite production is estimated to have been
10 Mt in 2012.
Production of refractories-grade bauxite is estimated at 2.5 Mt in 2012, a fall of 7% compared to 2011. This figure includes calcined refractories-grade bauxite and calcined abrasive-grade bauxite for BFA production. It does not include the proportion of BFA for non-refractory (e.g., abrasives) uses.
World supply of refractory-grade bauxite is fairly limited, particularly for the export market. The main producers of refractory bauxite are based in China, and the country accounts for over 85% of production. Leading companies include Bosai Minerals, Shanxi Fangxing, CMP, and Shanxi Yangquan. Other important global producers include Ashapura Minechem of India, Orient Abrasives of India, Severo-Onezhsky Bauxite Mine of Russia, Timan Bauxite/Rusal of Russia, and Bosai Minerals’ operation in Guyana.
Canadian company First Bauxite is developing a new non-metallurgical bauxite source in Guyana for the production of refractory bauxite. The company intends to mine almost 300 ktpy of bauxite to produce 100 ktpy of sintered material, significantly expanding world capacity outside China.
Graphite is used in refractories as a source of carbon. The mineral can be produced from either natural or synthetic sources. Naturally occurring graphite is mined in the form of amorphous, flake or vein graphite, with the former two being the most common. Synthetic graphite is predominantly produced in the form of electrodes from calcined petroleum needle coke, which is crushed, shaped and carbonized over a six-month period into a high-purity, high-cost product. Only natural graphite is used in refractories production; it is lower cost than synthetic graphite and is able to meet the requirements of refractories producers.
World production of graphite in 2012 is estimated to have reached 2.2 Mt, of which around 710 kt was natural graphite. The main producer is China, with Asia as a whole accounting for almost 540 kt of output in 2012. South America is the next-largest producer at 100 kt in the same year. Refractories consumed an estimated 70% of natural graphite output.
The main producer in China is South Graphite. The company accounts for all of the country’s amorphous graphite production, with a capacity of over 225 ktpy. Other important Chinese graphite producers are China Graphite, Heilongjiang Aoyu Graphite, and Jixi Liumao Graphite Resources. The largest non-Chinese producer is Brazilian company Nacional de Grafite, with a capacity in excess of 75 ktpy.
Graphite exploration has seen somewhat of a resurgence in the last five years, and numerous greenfield and mine reactivation projects are currently under development. Most exploration activity is focused in Canada; other notable projects are located in the U.S., Australia, Brazil, Sweden, Madagascar and Mozambique. Up to 200 kt per year of natural graphite capacity could be added over the next few years.
Magnesia is produced in three forms: caustic calcined (CCM), dead burned (DBM) and fused (FM). The latter two are largely used in the production of refractories. DBM and FM grades are typically used in basic refractories in combination with graphite, dolomite, alumina, or chrome.
Magnesia is generally derived from the calcination of magnesite, although higher-purity synthetic magnesias can be produced from seawater or brine sources. Synthetic magnesia is made in a handful of countries and is largely accounted for by production in Ireland, Mexico, Norway, Russia, South Korea, and the U.S.
World refractory magnesia production totaled 9.5 Mt in 2012, split between 7.7 Mt of DBM and 1.8 Mt of FM. Similarly to graphite, magnesia was one of the few refractory minerals to post an increase in consumption between 2011 and 2012. Asia was the largest producer (principally from China), accounting for 6.2 Mt of output. Europe also accounted for a significant amount of refractory magnesia production, estimated at 2.6 Mt in 2012. Almost all DBM and FM produced was consumed for refractories, although some output of FM is used in electrical-grade magnesia (EGM) for heating elements.
China is by far the largest producer of DBM and FM worldwide, with over 100 companies involved in magnesite mining or magnesia production. The industry is centered in the province of Liaoning; leading producers are Jiachen Group (> 800 ktpy total magnesia capacity), Huayin Group (> 1 Mtpy), and Fengchi Group (> 570 ktpy).
Outside of China, the largest refractory magnesia producer is Magnezit of Russia, which has an estimated DBM/FM capacity of over 1.8 Mtpy. The company is an integrated refractories producer and consumes much of its magnesia output in-house. Other integrated producers with significant refractory magnesia capacity include Austria-headquartered RHI AG, Brazilian group Magnesita Refratários, and Turkey’s Kumas Manyezit.
Kaolin is typically used in neutral or acid refractories as an aluminosilicate source, where alumina levels of 30-70% are required (low-high alumina). When an alumina content of above 70% is desired, bauxite and specialty calcined aluminas are more suitable.
The U.S. is the world’s largest kaolin producer, accounting for 5.9 Mt out of a global production of almost 26.7 Mt in 2012. Kaolin output grew by 200 kt between 2011 and 2012, although the amount used for refractories remained similar in both years.
On a regional basis, Europe accounted for the largest proportion of kaolin production at 9.1 Mt in 2012, with significant output from Germany (4.8 Mt), the UK (1 Mt) and Italy (650 kt). China is also a leading contributor to world kaolin production, with output estimated at almost 4 Mt in the same year.
Imerys is the largest U.S. processor of kaolin, with a total estimated capacity of nearly 3 Mtpy. The group, which is headquartered in France, built up its kaolin business over more than 20 years with a series of acquisitions, the most recent being PyraMax Ceramics in 2013. Imerys’ C-E Minerals subsidiary has a plant at Andersonville, Ga., that is reported to be the world’s largest producer of calcined kaolin for refractory applications. Elsewhere in the U.S., BASF holds an estimated 2.3 Mtpy of capacity at four plants, while KaMin controls 1.1 Mtpy of capacity in Georgia.
In addition to its North American operations, Imerys has kaolin processing subsidiaries in Australia, Brazil, France, New Zealand, Thailand, Ukraine and the UK. Quarzwerke is also a dominant European producer, with capacity split between seven subsidiaries in Bulgaria, Germany, Poland and Ukraine. Guangdong Highsun is China’s largest producer, and capacity is split between two subsidiaries. Meanwhile, Belgium-headquartered Sibelco has nine subsidiaries in Asia, Europe, North America and Oceania.
Zirconium can be used in a variety of refractory products, mainly in the form of zircon, zirconia or alumina-zirconia-silica. Zircon is generally used in acidic refractory environments, while zirconia-based refractories are considered to be basic.
Zircon is usually extracted as a co-product of heavy mineral sand operations in conjunction with the titanium minerals ilmenite and rutile. Most zirconia production is based on zircon sand feedstock, with the exception of Russian company Kodvorsky DOK, a subsidiary of EuroChem, which processes zirconia from a naturally occurring zirconium dioxide ore called baddeleyite.
World production of zircon sand is estimated to have totaled just over 1.2 Mt in 2012, with 49% of this coming from Australia and 31% from South Africa. Other important producers of zircon include the U.S., Indonesia and Mozambique. Production in 2012 fell by 250 kt compared to the prior year, largely due to lower demand for zircon in ceramics following high substitution rates.
Australia-headquartered Iluka, which also mines zircon in the U.S., is the world’s largest zircon producer with around 500 ktpy of capacity. Rio Tinto (South Africa and Madagascar) has around 325 ktpy of capacity, followed by Tronox (Australia and South Africa) with around 260 ktpy. Other important producers include Cristal Mining of Australia and Ireland-headquartered Kenmare Resources, which mines zircon in Mozambique.
Global refractories production is estimated to have totaled 40.4 Mt in 2012, a fall of 2.2 Mt compared to 2011. As discussed earlier, the downturn in demand for refractories in 2012 had a subsequent impact on the production of refractory raw materials. Current estimates for 2013 also indicate that refractories production may have fallen by an additional 2 Mt. This would place output at similar rates to those seen in 2008.
Future refractories demand will be largely determined by growth in crude steel and iron production. As shown in Figure 3, this sector accounted for an estimated 73% of refractories consumption in 2012, followed by cement and lime (13%), and non-ferrous metals (4.5%).
Between 2012 and 2020, world crude steel output is forecast to grow at an average of 3.5% per year (see Figure 4). The Middle East is expected to show the highest growth in crude steel output at 5.5% per year, although this will be starting from a low production base. Asian output of crude steel will account for the majority of growth at an average rate of 4.1% per year, growing to 1,383 Mt by 2020.
This rise in refractories demand will be offset slightly by an overall reduction in consumption of refractories per ton of steel produced, as steel production methods and refractory product quality improve. This is a trend that will affect rapidly industrializing nations such as China and India. Overall refractories demand is therefore forecast to grow at a slightly lower rate of just under 3% per year, with similar growth rates expected for refractory raw material demand.
Market-specific factors and trends will affect demand for individual minerals, such as the phase-out of chrome to the benefit of spinel. The growth of monolithics relative to shaped refractories will also benefit certain minerals, such as low-grade dead-burned magnesia.
Increased energy costs will be a key issue for future refractory mineral production. These costs will make it more expensive to produce fused minerals, thereby increasing prices for grades such as white and brown fused alumina, fused zirconia and fused magnesia. Higher prices may well encourage the use of alternative minerals, such as high-grade dead-burned magnesia over fused magnesia.