Glass production is a big consumer of countless industrial minerals, including soda ash, quartz and limestone. It is additionally used in a wide selection of industries, such as construction, manufacturing and home ware. However with the financial recession quiet leaving a follow of devastation in countless industries, exactly how will the glass it is provided chain fare in 2013?

Glass is an amorphous, non-crystalline solid product recognised because that its low-cost suitability for many everyday uses consisting of transparent panes and receptacles. While the adaptability that glass to many different products and also applications is recognisable, the use of commercial minerals in its development is by no means minimal - particularly considering the variations between glass kind and glass production process.

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Image: FEVE
The most familiar and also commonly produced form of glass is soda-lime glass. This glass is provided widely in two main species - flat glass, design for finish uses together as window panes and also in the automobile industry, and also container glass, used to do receptacles such as tablewear and bottles.

Soda lime glass is created using mineral such together soda ash, quartz (silica) and also lime.

Glass can additionally be identified in a much more comprehensive sense to include every solid that possesses a non-crystalline, amorphous framework that exhibits a glass transition when heated towards the fluid state.

In this broader sense, glasses can be made of various classes that materials consisting of metallic alloys, ionic melts, aqueous solutions, molecule liquids and polymers. For many applications, polymer glasses, such as acrylic glass, polycarbonate, polyethylene terephthalate, are a lighter alternate to traditional silica glasses.

Glass manufacturing is facility and includes an enormous selection of compositions and product types. Products for glassmaking deserve to be share in 3 groups: glass formers, fluxes and also stabilisers.

Soda-lime glass

Soda lime glass is composed of about 75% silica (SiO2), sodium oxide (Na2O) native soda ash, lime (CaO) and several various other minerals including stibnite (the key ore the antimony) and feldspar. The mix of minerals provided to do soda-lime glass is termed ‘batch’.

The glass is created by melting the batch in a glass heater at temperature of as much as 1,675¡C (3,047¡F). The temperature of the heater is restricted by the quality of the furnace superstructure material, that is even if it is it can withstand greater temperatures, and by the glass composition.

“In the process of melting a viscous liquid is formed and also the mass i do not care clear and also homogeneous at temperatures over 1,000 ¡C. Once removed from the reactor, the glass repurchase a shape allowing handling. By managing the temperature the cooling, avoids devitrification or crystallisation,” Felix Antonio Martinez Sendoya, Colombian Silica’s CEO the silica and business, told IM.

Image: FEVE
reasonably inexpensive minerals, such as soda ash, sand and also feldspar, are added to the batch as fluxing agents to mitigate the melt temperature that quartz and help to manage the viscosity that glass.

for minerals such as feldspar (p74), the alkali content acts as flux, lowering the glass-melting temperature and also thus reducing manufacturing costs. Coloured glass, such together that used to make green and also brown bottles, is developed from raw materials containing stole oxide (see pp.42-45).

A common batch because that clear glass containers might consist that 155kg soda ash, 172kg limestone, 145kg feldspar and 5kg sodium sulphate. Level glass batches require around 115kg the soda ash per 450kg of silica sand supplied <Industrial Minerals and Rocks, 7th Edition>.

“Importantly, the manufacturing procedure is virtually the same for all types; alters from one specimen to another is the material. Every one of them have a better or lesser ratio of silicon atoms,” Sendoya told IM.

if the materials used to do flat and also container glass come native the exact same mineral batch, the physical procedure used to create the perfect glass differs slightly.

For level glass, the float procedure is administered, while for containers, glass punch is performed. Float glass has actually a greater magnesium oxide and sodium oxide content contrasted with container glass, and lower silica, calcium oxide and aluminium oxide content. This means that the high quality of container glass is higher, mainly due to the truth that it is compelled to be safe for usage as homeware receptacles (for chemistry durability versus water).

Quartz (silica)

commercial sand and gravel, often referred to as silica, silica sand or quartz sand, has sands and also gravels v high silicon dioxide (SiO2) content. Silica is the major ingredient in practically all types of glass including containers, level glass, light glass, tableware, TV tubes and also screens, decorative glass, fibreglass, optical glass and also vacuum flasks. The commercial uses of glass (containers, windows, car glazing) contain between 70 - 74% silica, the ultimate resource of i beg your pardon is silica sand.

Glass manufacturers room principally involved with the chemical composition of silica sands, specifically iron, chromite and other refractory mineral contents, according to the brother Geological inspection (BGS).

Quality demands depend ~ above the type of glass being manufactured - whether it will be coloured or clean - and to some degree on the demands of the separation, personal, instance glass manufacturer. Silica sand for colourless glass containers typically has one iron content of 2O3 (ferric stole oxide), for flat glass in the range 0.040 come 0.1% Fe2O3 and for coloured glass containers 0.25% come 0.3% Fe2O3.

global sand resources are large and widespread and somewhat unquantifiable. However, in terms of production, 140m tonnes silica sand was created in 2012, follow to the us Geological survey (USGS). Some 49m tonnes the this sand were developed in the US, with around 17% the this being offered to do glass.

while resources and also production are on a big scale, several constraints surrounding silica sand exist global including geographical circulation - which can regularly be a costly and also uneconomic exercise - eco-friendly restrictions - pertained to potential wellness risks linked with the use of silica sand - and also quality demands for use, as outlined above.

Soda ash

The glass sector is the largest consumer of soda ash, an especially the glass-container sector. Soda ash has actually been offered in glass production for more than 5,500 year <Industrial Minerals and Rocks, 7th Edition> and continues to be provided in the market today.

Soda ash is a resource of sodium oxide the is offered as a fluxing agent in container, fibre, and speciality glass manufacturing to reduce the temperature in ~ which the life materials, such together silica sand, melt. Soda ash additionally decomposes into sodium oxide and also carbon dioxide, which rises with the glass melt and also helps mix the ingredients.

In terms of supply, China ongoing to overcome last year, creating 23m tonnes in 2011, follow to recent USGS data. The us followed, developing 14.5m tonnes in 2011, v a complete value of approximately $1.3bn.

“China proceeds to it is in the largest and fastest-growing market for soda ash. As result of its size and the persistent over-capacity in the Chinese industry, it likewise has a strong impact on essential markets because that soda ash profession - Asia, and also to a lesser extent, Latin America,” FMC Corp., the Wyoming, US-based producer, said IM.

However, while the usual players are continuing to create within expectations, there are brand-new entrants come the market, consisting of some from developing countries.

“In emerging countries, the soda ash is cultivation by 5%; in the US and Europe demand is stable. Full growth is 2m tpa - 1m tpa in China 1m in the remainder of the world,” Novacarb, the France-based soda ash producer, called IM.

Turkey is a country that arised as a key soda ash producer in 2012, with an ext than 2m tonnes of volume logged in 2011.

“China continues to lead the way for new capacity coming on-stream, and also Turkey has emerged as a brand-new player with good access to European and also Middle east markets,” Dennis Kostick at the USGS called IM.


The recycling that glass has lugged the expense of residential container glass manufacturing down by far-reaching amounts together cullet, the mixture of supplied glass broken down to it is in recycled, is used to replace part of the silica requirements in a glass batch. Cullet likewise has a much reduced melting temperature - roughly 20-25% listed below a conventional batch - additional reducing the cost by lowering the amount of flux required.

Image: FEVE
“Glass recycling is an increasingly important input into container glass production. <É> an ext than 68% <2010 data> that glass bottles and also jars placed on the industry are collected for recycling and also most of lock are recycled in a bottle-to-bottle, closed-loop recycling system,” the europe Container Glass Federation (Feve) told IM.

that, once produced, glass can be provided over and over again without down-cycling and also by reducing use of brand-new minerals and raw materials and preventing garbage generation. Glass is mono-material and also does not need any additional barriers to maintain food and also drinks, do its recycling specifically easy. This is a good illustration of just how a circular economic situation for packaging have the right to work,” Feve added.

because that every tonne of recycled glass, 1.2m tonnes the virgin raw products are saved in the melt process, follow to the federation. This is extremely essential for the container glass industry because by using recycled glass also reduces the amount of energy used and CO2 emitted.

“It has a big contribution to the sustainability the the industry. That is why some of the mineral providers (for instance Sibelco) room investing in recycling infrastructure (for example Pate),” Feve told IM.

if this is confident news because that container glass manufactures, that is no so good for soda ash producers, which have seen lessened demand since the worldwide push come recycle gained underway in earnest.


Feldspar acts as a fluxing certified dealer in glass making and also is used to lug the melting temperature of silica down. The is also a stabiliser. Stabilisers impart to the glass a high degree of resistance come physical and chemical attacks. Fluxes space oxides, including potassium oxide (K2O) and also sodium oxide (Na2O) and also stabilisers have the right to be oxides such together alumina (Al2O3) <Industrial Minerals and Rocks, 7th Edition>.

throughout glass manufacture, feldspar has two functions, acting as a flux by giving alkaline oxides (K2O and also Na2O) and also as a stabiliser by giving alumina and calcium oxide. A usual batch for container glass contains around 8% feldspar, according to Roskill info Services.

Feldspar is the most abundant group of mineral in the Earth’s crust, forming about 60% the terrestrial rocks. Feldspar make reservation are found in assorted countries, consisting of India, Czech Republic, Portugal and Poland among others. Turkey and also Italy are the height two creating countries, accounting for about 50% the the human being production with virtually 10m tpa in 2012, follow to USGS estimates.

Identified and hypothetical sources of feldspar are an ext than sufficient to accomplish anticipated world demand, the USGS added, which claims that quantitative data on sources of feldspar present in feldspathic sands, granites, and pegmatites usually have not been compiled.

“Ample geologic proof indicates that resources are large, back not constantly conveniently accessible to the major centres that consumption,” it said in its most recent feldspar report.

Other products that have the right to be supplied for glassmaking incorporate fluorspar, lime, chromite, olivine, staurolite and also zircon sands, follow to the USGS.

Glass markets: manage with treatment

Soda-lime glass, when the many abundantly manufactured kind of glass, has actually experienced experimentation times throughout the past few years as the an international economic crisis substantially slowed the quantity of new building and the amount of production worldwide.

Glass to be hit difficult by a crash in the global housing market during the period 2008-2012. This collapse, in turn, caused the price for some minerals supplied to develop glass - such together soda ash - to dip to the suggest where prices for the mineral were together low as they can feasibly go.

various other glass-using industries, together as vehicle manufacturing, also took a knock, which again filtered down to the life materials need level.

despite this, global chemicals agency Solvay, the world’s number one man-made soda ash producer, claimed that a autumn in need for flat glass in the construction and also automotive sectors was rescue ring by solid performance in the container glass sector.

Feve agreed through this statement, telling IM: “The container glass industry produces some 20m tpa glass. In regards to tonnage, the greatest markets because that the container glass market is the beverage sector. Beer, spirits and wines account for the biggest share. Overall, glass packaging to represent one-third of the european beverage sector in units.”

“While the beverage market is important, the food sector is progressively offering crucial growth possibility for glass packaging. This is certainly linked to brand-new market patterns orientated by consumers demand for high-quality, natural, essential food. More than any kind of other material, glass can best communicate to consumer these product characteristics. Glass is a packaging reference for brands and for consumers,” the federation added.

While part glass markets dipped in 2012, this year has currently begun to show some promise. In the real estate sector, for example, 23 markets have demonstrated much better year-on-year statistics in Q3 2012 compared with Q3 2011, according to a report through Global residential or commercial property Guide. Recovery of the US real estate market has been particularly evident, with growth in Q3 2012 being the highest because Q2 2006, according to the Federal real estate Finance Agency (FHFA), the guide reported.

“Certainly ours sector saw a dip throughout the crisis years, however we view that us are currently almost earlier to the pre-crisis levels in terms of tonnage. Follow to latest obtainable figures

, glass packaging production volumes in Europe grew by 1.9%. The development is in solution to the increasing demand on the domestic and also outside EU markets. This builds on the positive trend videotaped in 2011,” Feve called IM.

“Despite the turbulent economic and also financial crisis that negative affects the totality European production sector, these records shed a positive light on the stability and also future prosperity the the europe container glass sector. This is definitely due come the fact that consumers proceed to have actually a solid preference for glass - 74% of consumers would recommend glass as a packaging material ,” the federation added.

regardless of these encouraging results, the influence of the worldwide economic crisis is tho evident across the glass industry.

increased production costs, unilateral CO2 costs, fluctuating and unfavourable exchange rates, and also high labour prices hamper the expense competitiveness at global level of the container glass sector, Feve said,

“Combined, this challenges hold-up long-term investment decisions and, rather, end up being incentives because that delocalisation of production sites and R&D investments exterior EU to more industry friendly atmospheres with lower costs,” the added.

Glass fibre

Glass fibre is made up of bulk, chopped fibres or strands that glass and also durable plastic resin. It is provided in reinforcing plastics and also composites and other specialised electrical and thermal applications.

Minerals provided in the development of glass fibre are similar to those work in the creation of other develops of glass. These include silica sand, limestone, soda ash, borates, kaolin, lithium minerals, potash, feldspar, fluorspar and also sodium sulphate.

The most common glass fibre is a calcium-alumina borosilicate through an alkali content of less than 1%. The is generally known as e-type glass, due to the fact that it was originally arisen for use in electric insulation systems.

E-type glass was produced in the 1950s to insulate electronics. Today, uses for glass fibre incorporate mats, heat insulation, electrical insulation, sound insulation, combine of assorted materials, tent poles, sound absorption, heat- and corrosion-resistant fabrics and also automobile bodies.

Glass fibre is offered in customer goods together as warm tubs, bath tubs and boats. That is additionally used in water storage tanks, because that pipes in the oil and gas industry, as well as in households and also offices, in roofing and cladding.

Glass fibre manufacturing

Glass fibres are developed by to run molten glass indigenous a direct-melt heating system into a platinum alloy bushing comprise a large number of small holes, from every of i beg your pardon a glass filament is drawn.

Filaments for commercial use space normally in between nine and 15 microns in diameter. The filaments space layered v an emulsion prior to being gathered into fibres.

The fibres are solid and they have excellent electrical properties. Castle are also resistant to most chemicals and also moisture wear. They are non-combustible, v a melting point around 1,500ºC.

Glass fibre industry

The fastest-growing industry sector for glass fibre is in insulation, as populations become more concerned with power conservation. The european Union’s press to enhance energy usage by 20% by 2020 has seen countless governments offer complimentary or subsidised insulation and also this is welcome news because that glass fibre mineral such together kaolin and borates.

outside of the EU, Russia is aiming to reduce energy intake by 40% in 2020 and also China has actually invested greatly in rebuilding ‘energy poor’ housing and has pledged $23bn because that energy reliable projects.

The Obama management in the US has launched ambitious energy-saving initiatives, including a $2,000 taxation credit because that residential homeowners who insulate properly and also make your existing properties much more energy efficient.

In Australia, the government pledged in 2009 come install free ceiling insulation in approximately 2.7m dwellings under the energy Efficient houses Package. However, the home Insulation Programme was later shelved in favour of a brand-new scheme and also then exit in April 2010. The system was controversial, due to worker fatalities while installing the insulation, and costly, as result of compensation payment.


The truth that glass is challenged with economic difficulties is regarded as a boy hurdle for many working in the industry, even at the industrial minerals level, as glass remains the number-one option industrial minerals producer of borates, silica sand and soda ash. This is since it is used for numerous industries consisting of automobile, tableware, cosmetics and construction.

This ongoing market need will, in turn, rise the contact for commercial minerals such together soda ash, silica, limestone and fluxes consisting of feldspar.

Glass is also classed together a product of the future as it is recyclable, re-usable and refillable.

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“This makes it certainly a referral for the circular economic situation - where there is a big change from the linear economic situation model come the one model. This is based upon recycling, which close the door the loop,” Feve said.