Metal markets in flux

All metals are sourced from ores, and all ores contain impurities. For metal producers, unwanted minerals are an inherent part of the production process and impurities must be removed prior to the metal reaching its final form.

The simplest method of removing impurities from metallic ores is with the addition of a metallurgical flux during the smelting stage of metals production. The primary purpose of a flux is to react and combine with unwanted minerals in the metallic melt to form a slag that can be separated from the metal and removed from the furnace.

Fluxes are a key component of the metals production process and without them metallic products could not exist; yet few minerals meet the demanding criteria of this market. Considering their importance in metals production, it is somewhat ironic that flux minerals are considered to be a niche market by many industrial minerals producers.

Slab scarfing: the surface of the steel block is
treated prior to rolling. Courtesy ThyssenKrupp AG


The principal flux minerals are dolomite, fluorspar, lime and olivine, with smaller amounts of bauxite, silica and wollastonite also used (see panel).

Demand from the flux market for each of these minerals differs, with perhaps fluorspar, lime and olivine the most strongly tied to this particular aspect of metals production. Although other minerals (such as bauxite) are dependent on the metals market for a number of reasons (ie. ore, refractories) their use as a flux is estimated to be less than 1% of total production.

The metals market (particularly aluminium and steel) is well-known to be cyclical, and the most recent example of this has been the past 18 months in the industry. The market during the first half of 2008 was a bonanza for aluminium and steel; both metals reached record production highs and prices were hugely inflated.

Increased metals production required increased flux consumption, and for many flux minerals 2008 was a record year for production and prices. Yet towards the last few months of 2008 all that came crashing down.

Using aluminium as the example: between July 2008 and February 2009 the London Metal Exchange (LME) cash price for aluminium plummeted 62%. The all-time high of $3,291/tonne reached on 11 July 2008 had, by 24 February 2009, collapsed spectacularly to $1,253/tonne.

A dearth of demand for metallurgical fluxes, similar to refractory minerals, characterised the period from late 2008 through to mid-2009, and producers also had to contend with substantially lower prices for their products.

From July 2009 onwards the situation improved. The World Steel Association’s figures started to show a turnaround. Initially this was a shallower decline in global steel output, but it was followed in later months with year-on-year production increases.

In October 2009 global crude steel output was up 13% on 2008 levels, although this was mainly driven by a 42% jump in Chinese production ( IM 20 November 2009: October steel output rises 13%).

A market in flux: lime & dolime

This market U-turn was particularly difficult for lime and dolomite producers. Iron and steel are the two most widely produced metals in the world and their primary fluxing agents are lime and dolomite. Global production of these two minerals is vast and the flux market consumes almost half of all lime produced (around 130m. tpa - see Table 3).

Owing to its MgO content dolomite is an important refractory mineral, and dolomite fluxes (and their calcined counterparts) are primarily used to extend the life of refractory linings and bricks (see panel). Dolomite is also used to manufacture an array of primary refractory products.

Consequently, lime and dolomite producers rely heavily on metallurgical markets (and steel in particular) to drive consumption.

One USA-based lime and dolime producer told IM: “Obviously, the reduction in steel production has led to a corresponding reduction in lime and dolime consumption. As a result, there have been numerous kilns throughout North America which have been placed on idle. In general, these kilns can be brought back online easily and in tandem with increased steel production.”

All too often has the effect of reduced consumption been seen in the financial results of lime producers. The world’s second largest lime producer, Carmeuse Group of Belgium, reported a net turnover of €709.1m. in its Q3 2009 financial results, representing a fall of 30.4% on Q3 2008 levels. Carmeuse cited a “sharp deterioration of the economic environment” for the fall in revenue and said that crude and calcined products alike had been affected.

Following the publication of its Q3 2009 results, Carmeuse announced that it had undertaken a refinancing programme which had been approved by backers. The group also revealed that at the end of June 2009 Carmeuse had breached a portion of its agreed bank covenants for the first time in the group’s history.

“Due to the economic crisis and its significant impact on certain of its clients like the steel or construction sectors, the group is facing a significant reduction of volumes sold since October 2008,” Carmeuse explained.

United States Lime & Minerals Inc. reported decreased sales volumes for the first nine months of 2009 owing to reduced demand for lime in construction and steel markets. The company countered the sales fall with price rises for lime and limestone, which on average were increased by 9.4%

Mississippi Lime Co. also introduced price increases of 10% in September 2009 for its standard quicklime and hydrated lime products, in order to “recover ongoing cost increases, support continued investment in the business and maintain the quality and reliability of supply”.

But is the situation changing? In October 2009 Finland-based Nordkalk Corp. was given the go-ahead to develop a 2.5m. tpa limestone mine on the Swedish island of Gotland, with 60% of this material destined for the steel flux market.

Anders Mattsson, Nordkalk’s managing director, told IM that the company had been given a 25-year permit to mine 50-60m. tonnes of limestone, with the option to apply for an additional permit that would allow the mine to go deeper and extend to 80-90m. tonnes.

Fluorspar

Fluorspar’s role as a flux in both steel and aluminium production has seen it hit doubly hard by the reduction of the world’s metal output. Low grade metspar and high grade acidspar are consumed by these markets, with almost 70% of total fluorspar production destined for metals consumption (Table 3). As a result prices for all grades of the mineral closely followed the turbulence in the aluminium and steel prices over the past 12 months (Figure 1).

Several papers at IM’s Fluorspar 09 conference in Valencia, Spain in November 2009, addressed the issue of pricing and demand from metallurgical markets and gave estimates for short-term and long-term metals production ( IM December ’09, p.9: Metals fortify fluorspar).

UK-based economics consultant, James King, gave a comprehensive forecast indicating that AlF₃ markets could account for a 4% growth in acidspar demand in 2010, while figures for consumption in 2030 placed fluorspar demand at almost 50% higher (an additional 1.05m. tonnes) than present levels.

Meanwhile, a bullish growth figure of 10% was forecast by King for fluorspar demand from steel markets in 2010. Elsewhere, King’s long-term steel forecast indicated that an additional 1.77m. tonnes could be required in 2030 Ð that is, if EAF steel output reaches King’s estimate of 840.1m. tonnes, more than 50% higher than production in 2008.

These figures were debated by Michael Reynolds, director of MS Reynolds Srl, who suggested in his presentation that AlF₃ prices are likely to fall before they increase, owing to a possible surge in exports from Chinese producers.

Reynolds proposed that adoption of an “aggressive export policy” by China could bring world AlF₃ prices down to the range of the lower cost Chinese product and saturate the market leaving little room for western AlF₃ producers.

Fluorspar uncertainty

“There are a lot of uncertainties in the main metal markets nowadays, and the long recession has made people’s nerves brittle,” commented Dawei Mi, general manager of Chinese fluorspar producer Tianjin Steyuan Minerals Co., Ltd (Steyuan).

“[These uncertainties mean] we are unsure about the market trends. Concerning fluorspar, the Indian market was active in the first half of this year but it became quiet from July until now. Meanwhile, the European market recovered in the second half of 2009,” Mi told IM.

Steyuan, based in Tianjin, around 170km south-east of Beijing, is an international producer and exporter of a range of industrial minerals, including fluorspar, graphite, calcium aluminate and caustic calcined magnesite briquettes.

The company owns three subsidiaries F&C (HK) International Ltd, Jenny Mineral Resources International Ltd, and Steyuan (Mongolia) I/E Trading Co. Ltd. It supplies metallurgical grade fluorspar from Mongolia, with a capacity of 2,500-4,000 tpm.

Steyuan says demand for its high grade fluorspar has exceeded supply since the second half of 2008, while demand for its lower grade metspar has been “moderate”. The company expects demand to remain at these levels throughout 2010, so long as the market does not suffer “exceptional” circumstances.

Mi told IM: “Different from other industrial products, fluorspar is a natural ore and it is difficult to control its quality when processing. With a qualified supply and a perfected method of production, the quality control is guaranteed. Then, the product can be competitive.”

Regarding fluorspar’s use as a metallurgical flux, Steyuan believes it is still a crucial market: “Steyuan is promoting calcium aluminate to replace fluorspar in [steel] slagmaking, but fluorspar is indispensible in fluxing at present,” Mi commented.

“We hope industries reduce the usage of fluorspar and we look forward to new technological innovations to replace fluorspar in fluxing. In doing so, we wish to contribute to environmental protection and the sustainable development of society.”

Fluorspar alternatives?

Calcium aluminate is viewed as a potential substitute for fluorspar fluxes in steelmaking. The material itself can be sourced from slags formed from alumina-based fluxes used in a basic (lime-bearing) system; essentially calcium aluminate is a recycled material.

“Steyuan is making great efforts to promote the use of calcium aluminate while supplying fluorspar,” Mi told IM. “In this way, we not only meet customers’ demands for raw materials but also guide their demands in accordance with the trend of environmental protection.”

Steyuan sources calcium aluminate from plants in Henan and Liaoning provinces and has invested in one of the local plants to ensure the quality of the product is high. The company’s calcium aluminate capacity is around 2,000 tpm and the product has a typical chemical composition of 45-51% CaO, 35-45% Al₂O₃, 5% max. SiO₂, 2% max. Fe₂O₃, and 10% max. MgO.

Mi believes that calcium aluminate can “fully meet” the metallurgical requirements of a flux and that it has some benefits to using fluorspar, such as: consistent chemical composition; low melting point, short smelting time, low viscosity; and decreasing damage to refractory components.

Olivine

Olivine may be a small volume product but, thanks to its refractory properties, it has some major consumers. Around 65% of total production is estimated to be diverted to the flux market (Table 3), while the remaining amounts are used in markets for refractory bricks and castables, foundry sand, EBT taphole filler, CO₂ sequestration, and in abrasives, among many others.

Norway-based North Cape Minerals A/S (NCM), a wholly-owned subsidiary of Unimin Corp. (ultimately owned by SCR Sibelco NV), is the world’s largest producer of olivine. The company owns three olivine mines in Norway - Aheim, Bryggja, and Raubergvik - which produced 2.4m. tonnes in 2007.

The company’s olivine operations have been significantly affected by reduced demand and in summer 2009 NCM announced that it had temporarily suspended the plants at Bryggja and Raubergvik, leaving only Aheim unaffected ( IM 21 July 2009: NCM suspends olivine mines).

The temporary closure of Bryggja could last as long as five years, but NCM commented: “At the current low production volumes, [these steps] will allow a sustainable development of the resources and secure future competitive power and creation value.”

Meanwhile, in November 2009, NCM announced that its ownership of Turkish olivine producer Beykrom Mining Co. had been transferred to Turkish feldspar producer Cine Akmaden, now owned by parent Sibelco ( IM 4 December 2009: North Cape merges with Askania).

The future for NCM is also changing, as from 1 January 2010 NCM will be merged with industrial minerals producer Askania AS, which was bought by Sibelco in 1992. Askania supplies a range of minerals including bauxite, bentonite, olivine, and zircon flour.

Falling olivine consumption also contributed to the bankruptcy of Norwegian olivine producer, Steinsvik Olivin AS. Steinsvik began olivine extraction in 2004 from a deposit near Dalsfjord, west Norway, and operated with a 150,000 tpa capacity; but in September 2009 the company was declared bankrupt.

Svein Parr, managing director of Steinsvik, told IM at the time that bankruptcy had been the only solution for the company, largely owing to a lack of market volume for olivine and “financing of production in the original company”.

One olivine company bearing up well in the depressed economy is Swedish minerals producer Minelco AB, which celebrated 20 years’ service in September 2009. Minelco is the world’s second largest olivine producer, operating from the Seqi deposit in Fiskefjord, west Greenland, with a capacity of 1.1m. tpa.

A significant portion of Minelco’s olivine is believed to be captive; supplied to parent company, and leading iron ore producer, LKAB of Sweden. Industry sources estimate that prior to Minelco’s purchase of the Seqi deposit in 2005, LKAB sourced around 300,000 tpa of olivine from Minelco rival NCM ( IM November ’09, p.44: Olivine’s future in flux). The majority of the company’s olivine production is shipped to Norway, with smaller amounts transported to the Netherlands, the UK and the USA.

Pasek Espana SA is Spain’s only producer of dunite (a magnesium silicate mineral containing olivine). The company operates two dunite mines in Cabo Ortegal, Galicia, in the north-west of the country, with a capacity of around 1m. tpa. Pasek produces dunite for a range of markets, including as a slag conditioner for blast furnaces and taphole sand for eccentric bottom tapping.

Javier Martinez, Pasek’s managing director, told IM: “Pasek delivers dunite for steelmaking through the blast furnace route. In this market we have followed the downturn on production through 2009 and expect to follow the volume recuperation trend that will come in 2010, as blast furnaces are being started up all through Europe.”

Martinez explained that the company has seen a trend from its clients towards more detailed studies of fluxes as a small but very important part of the mix. “As a result there have been some developments in the way that MgO is added to the process of steelmaking,” Mart’nez commented.

The company believes that there is a clear movement to reduce the addition of MgO to sinter plants in favour of direct addition into the blast furnace.

“Under these operating conditions we see many of our customers’ predictions and test proposals for next year moving to our bigger grain products,” Martinez revealed. “We expect to benefit from this situation since coarse dunite is the best available flux to be handled directly into the blast furnace. It is also the most effective way to remove sulphur and evacuate alkalis from the pig iron together with a higher Fe content and a reduction of coke consumption.”

Table 2: Mineral fluxes and their applications

Wollastonite finds the majority of its market usage as a high performance filler in plastics, with other uses in coatings, ceramics and glass. A smaller, but significant market for the white mineral is as a powder for tundish and continuous casting moulds in steelmaking and a lubricant for molten ore, with around 10-15% of wollastonite used in this application (Table 3).

The global supply chain is heavily concentrated between a few major players such as Wolkem India Ltd, China’s Lishu Dadingshan Wollastonite Co. Ltd, and USA’s NYCO Minerals Inc.

One relative newcomer is Spain’s Crimidesa Group, owned by Compania Minera Ilustracion (CM), which produced 20,000 tonnes in 2008. The company has focused its wollastonite production on the ceramic and container glass markets but supplies some material to the metallic flux industry ( IM November ’09, p.44: Wollastonite’s pins and needles).

Jose Arribas, quality manager for CM, told IM: “The outlook for metal production (and flux consumption) in 2010 is not very positive as the metals demand is still weak and the prices are low. This is due in part to the Chinese pressure that reducing stocks to all cost are eroding the international market.”

Arribas explained: “Speaking more precisely about metallurgical fluxes, I see a bad outlook as some metal producing plants in Spain are closing and the production rate has been reduced in the rest, so all related products should suffer the same fortune.”

Table 3: World production of main flux minerals

** not including untreated, raw limestone products

^e estimated

Source: Industry estimates, US Geological Survey


Future trends

It is inevitable that the market for the three major metals will recover - indeed downturns are expected in this cyclical industry - but for now the focus of metals and flux producers is on when and where demand will recover first.

Aluminium demand appeared to rebound in Q2 2009 largely owing to the restart of Chinese smelters. At the time industry participants were concerned that the production restarts were a result of artificially high prices and not in response to true demand returning ( IM July ’09, p.40: China’s bauxite blockade).

More recently estimates of the aluminium market indicate that inventories which were at an all-time high in June 2009 have actually begun to dry up, creating uncommonly high prices in December 2009, particularly in North America, according to reports in Metal Bulletin.

“Aluminium demand recovered in the second half of 2009 after a sharp fall, with a particularly strong rebound in China. Producers in China responded to this by a sharp increase in smelter production, raising demand and creating a tightness in markets for raw materials,” James King, economics consultant, explained to IM.

“Metal stocks remain extremely high, but the market is ignoring those and aluminium prices are strong. Production may now be growing too fast for the underlying state of the market and western smelters need to be cautious about restarts,” King warned.

King anticipates that, in the short-term, there may be a correction to prices as stocks continue to rise, but by the second half of 2010 and into 2011 strongly rising demand should permit the industry to resume a normal level of capacity utilisation.

But what about iron and steel? Metal Bulletin reports that the US pig iron market is described as “lacklustre” at present, yet Brazilian pig iron producers exporting to the USA are refusing to compromise on prices setting the bar at $325/tonne FOB. It is a matter of who blinks first.

“Speaking on domestic [US] steel markets only, the outlook is entirely subject to the overall economic recovery,” one US lime producer told IM. “Predictions from industry insiders generally yield modest recovery estimates until 2012. Sustained improvements in the automotive, residential and commercial markets will drive steel production.”

Globally speaking, the world steel demand was seen to be recovering strongly from mid-2009 onwards. Producers in many countries began to restart some of the huge quantity of capacity that had been idled in late 2008, with China leading the way.

“Demand growth was strongest in China, but elsewhere was much more modest,” King commented. “Rising steel production created tightness in the market for steelmaking raw materials (iron ore, coal and scrap), raising the costs of steel production. By late 2009 steel production began to look excessive in relation to real demand and steel prices started to weaken.”

King explained: “Steel producers are therefore under pressure from rising costs and falling prices and the recovery of production may stall for some months. Underlying growth in demand across many markets, still led by China, is likely to require further restarts of idle steel capacity in 2010 and normal operation of the industry by 2011.”

So what does this mean for flux minerals? In the short-term China will continue to be the primary driver of metals production and thus the primary consumer of metallurgical fluxes.

The rest of the world, particularly Europe and North America, has been slower to show signs of recovery. Consequently, flux consumption in these areas is likely to remain low until there is any true demand for metals from end-user market segments and that will require recovery in the automobile and construction industries.

Figure 2: Crude Steel: World Production by Process


Source: James King, 2009


Metallurgical fluxes at a glance

A metallurgical flux is an additive for purifying and improving metallic ores. Its primary purpose is to combine with impurities in molten ore (such as phosphorous, silica, sulphur, zinc) to form a slag that can be separated from the metal. Other benefits of metallurgical fluxes include: decreasing viscosity and aiding lubrication, neutralising acidity of the metallic melt, preventing reaction of the melt with atmospheric gases, and slag conditioning.

In slag formation, using the correct flux will create a lower density slag that is immiscible with the molten metal and can be easily removed. The slag comprises the original flux mineral combined with impurities from the ore. As there are a number of different ores (which are destined for different end products), the type of impurity needed to be removed is variable (ie. ferrous versus non-ferrous metallurgy).

As a consequence, there are three main flux types, with several minerals falling into each category: acid, basic and neutral (Table 1). A “basic” system is that of steelmaking, because its primary fluxes are bases limestone and dolomite (and their calcined counterparts)  while non-ferrous metals (eg. aluminium, copper) are treated as “acid” systems.

Table 1: Mineral fluxes and their applications

Industrial minerals are used throughout all aspects of the iron and steel production process, from the initial preparation of iron ore pellets (that are bound with bentonite) through to continuous casting (where steel is lubricated with a wollastonite flux).

In sinter production, olivine and lime are typically supplied to sintering plants and as direct feed for blast furnaces. Magnesia silicates (ie. olivine) are commonly used as blast furnace fluxing additives, not only to adjust the slag MgO content, but also to promote potassium elimination with the slag, and limit the harmful accumulation of potassium in the stack.

In basic oxygen steelmaking, molten iron is charged from a blast furnace into a refractory-lined furnace, where it is injected with oxygen at high speeds resulting in oxidation of carbon and any impurities.

Quicklime is typically added to the BOF steel mixture after the beginning of oxygen injection, where it reacts with impurities (primarily silica and phosphorus) to form a slag which is later removed. The lime needed to manufacture one tonne of steel ingot is around 150lbs.

Steel plants tend to use a high calcium quicklime flux, yet most of the basic oxygen plants substitute or add 30-50% dolime, as the magnesia content of the dolomitic material helps to extend the life of the refractory lining in the furnace. Dolime for BOF is in the range of 10-40mm in size.

Fluorspar is a neutral flux (the reaction product of a base and an acid) which has traditionally enjoyed high rates of usage in steelmaking, where it is used to improve fluidity. Over the past decade its use as a flux in steel has declined, but higher grades of fluorspar (acidspar) are very much in demand for the production of aluminium.

Wollastonite’s main use is as a component of tundish and continuous casting mould powders. Wollastonite also prevents steel reacting with atmospheric gases, and lubricates the steel as it passes through the mould, preventing sticking

Electric Arc Furnace

Electric arc furnaces (EAFs) are used to produce steel from scrap. Scrap steel, plus iron ore and beneficiated iron ore, is placed in a furnace and melted by heat from an electric current.

A lime flux comprising quicklime or a blend of quicklime and dolime is added, with the total flux amount used varying between 50-120lbs/tonne of steel. Dolime may account for up to 50% of the flux, and is typically added in 5-20mm size fractions.

Non-ferrous fluxes

Although lime and dolime are also used in non-ferrous metallurgy, the principle fluxes in this area are alumina, fluorspar and silica.

The primary non-ferrous metal is aluminium, which consumes large volumes of acid grade fluorspar for its production.

Smelting and refining of copper and other non-ferrous ores can produce noxious SO₂ gas fumes; these can be neutralised in scrubbers by passing through a dilute hydrated lime mixture (milk-of-lime).

i) Basic Oxygen Furnace



ii) Electric Arc Furnace



iii) Hall-Heroult cell


The principle methods of metal production: i) Basic Oxygen
Furnace for iron and steel production; ii) Electric Arc Furnace
for producing steel from scrap; iii) Hall-Heroult cell for retrieving
aluminium from electrolysis. Note on each example a flux is used.
Source: Redrawn from Corus Group

Flux prices

Bauxite: Latest IM prices for welding grade bauxite (FOB China) are $470-480/tonne.

Fluorspar: One Chinese-based fluorspar producer quoted fluorspar (min. 90% CaF₂, FOB China) as $230-360/tonne over the past two years, with current prices ranging $250-270/tonne. The producer told IM that it expects prices in 2010 to move up to $250-300/tonne.

Latest IM prices for metallurgical fluorspar (Mexican, FOB Tampico) are $140-195/tonne, while acidspar filtercake (Mexican, FOB Tampico) are $260-290/tonne.

Lime: The average price for quicklime amounted to $89.20/tonne in 2008, while hydrated lime average price was $106.30/tonne.

Wollastonite: Latest IM prices for wollastonite (Chinese, FOB, tonne acicular minus) are $80-90/tonne for 200 mesh and $90-100/tonne for 325 mesh.

Figure 1: Flux prices, 2008-2009



Monthly IM prices for bauxite (welding grade, FOB China), fluorspar (acid filtercake, FOB Durban), and wollastonite (200 mesh, acicular, FOB China), between January 2008 and December 2009. More mineral prices can be found online at www.indmin.com