Boral Cement manufactures and supplies a wide range of cementitious products used by the building and construction industries of Australia. These products include both ‘bulk’ and ‘bagged’ cements, cement blends, and dry mixes with a variety of applications.
The business additionally specialises in the sourcing and delivery of a range of dry and other ‘powder’-based products such as oxides, grouts, ‘sands’, repair products and demolition agents. Boral Cement also incorporates De Martin & Gasparini (DMG), expert concrete ‘placement’ service providers.
What is cement?
Cement has been in use as far back as the time of the ancient Egyptians, Greeks and Romans. Variations of cement have been used by humans to ‘glue together’ stone and other building materials for centuries. Cement is a term used today to refer to the fine powdery material left after ‘clinker’ has been ‘milled’. When mixed with water, cement can be used to bind or join (as mortar for example) or, when combined with aggregates and sand, create strong and hard surfaces and structures (concrete).
How is cement made?
Boral produces ‘Portland cement’, a variant first manufactured in the 1820s. Crushed limestone, mainly from Boral Cement’s mine at Marulan South in New South Wales, is conveyed to a cement works where it is blended along with elements such as shale, iron ore and sometimes sand. The resulting ‘meal’ travels to the top of a ‘pre-heater’ where it falls under gravity through several cyclonic hot gas systems. This pushes the temperature of the meal to about 1000 degrees Celsius. Once at the bottom, the meal enters a rotating kiln and is further heated to 1450 degrees Celsius. After the mixture has travelled through the kiln, it fuses to become ‘clinker’. Clinker takes the form of small pellets, with a colour and texture similar to the pumice you might find in some bathrooms. The clinker is then transferred to a mill where it is crushed down to the fine powder with which most people are familiar. Depending on the type of cement to be made, this ‘powder’ is combined with items such as gypsum before being ‘bagged’ (packaged) or distributed to the market in bulk.
What are the uses of cement?
Cement is primarily used for concrete, the world’s second most consumed material after water. Concrete’s applications are boundless, meaning the cement must be flexible to a range of tasks. Boral’s cement can therefore found in buildings of all types, roads, bridges, tunnels, pathways, public spaces such as parks and plazas, walls and barriers and art installations. In Australia, the use of the terms ‘cement’ and ‘concrete’ are often incorrectly exchanged. Cement refers to the dry powdered product resulting from milling clinker. Concrete is the result of adding water, aggregates (crushed rock) and sand to cement and mixing (‘agitating’) it.
Where does the cement go after it is made?
Boral’s cement is distributed throughout the country by both rail and road transport. In both cases, the dry cement ‘powder’ is pumped into tankers under air pressure to ensure the maximum volume can be shipped, and that the chance for any product to escape is greatly reduced. Once it reaches its destination, the cement is then pumped (again under air pressure) into storage silos where it is held until required. In regional areas, this can occur several times as the product moves from rail to road tankers, then to individual locations like concrete plants.
How is the cement works kiln heated?
Boral has only one kiln in operation, located at the Berrima Cement Works in New South Wales. This kiln currently relies upon coal for its heat energy. Between 1929 and 2013, the coal was supplied from a mine at nearby Medway, however the coal is now sourced from the Illawarra region. Coal is traditionally used as a kiln fuel because of its high and consistent ‘calorific’ (heat) value. It is therefore able to reach the required temperatures of up to 1450 degrees Celsius. Consistency of heat is essential to the quality and quantity of the clinker produced. More recently, Boral has started to integrate ‘solid waste derived fuels’ (SWDFs) into production. SWDFs are made from recovered and processed wastes such as wood, combustible refuse and used tyres – items which would otherwise be destined for landfills. SWDFs are used in place of a portion of the coal used to heat the kiln. This provides both an economic and environmental advantage to Boral and the wider community.
Does the cement production process generate any air emissions?
As with most industrial processes, there are some air emissions associated with cement manufacturing. However, the extremely high temperatures used in the process mean elements normally considered to pose the most risk are reduced to minimal levels. Strict limits, set by local environmental authorities, are in place to ensure these emissions are kept well below levels which may interfere with surrounding residents and properties. Ongoing monitoring of emissions, and reporting of the results to the relevant authorities, occurs year-round. Individual items monitored include solid particulates, nitrous oxides, heavy metals and deposited dust. Boral’s Berrima Cement Operation has a strong track record of being well within compliance with the respective limits. Monitoring results are shared with the public through community meetings. Click here to find out more.
Who works at a Cement Plant/Operation?
A wide variety of roles are undertaken at a cement works, ranging from operators to tradespeople, logistics workers, scientists, management and administration.
The cement works is operated from a central control room via an array of computers and monitors showing live images from parts of the plant. Operators work in shifts to manage and monitor the flow of product through the kiln continuously. The facilities also employ technicians and tradespeople, such as electricians and fitters, to ensure the plant and equipment is maintained to the appropriate standard.
In the site laboratory, scientists such as chemists are on hand for product testing and quality purposes, as well as to monitor manufacturing. The movement of raw materials and finished cement means there is a large number of employees involved in logistics.
In addition to the bagging and packaging teams, a cement works will have both truck drivers and rail crews to support these movements.
To view the current job opportunities at Boral Cement, or to find out more about the career possibilities, visit Boral Careers
What’s the noise like near a cement works?
The noise associated with cement manufacturing is very similar to most other industrial premises. Similarly to them, noise is regulated through a series of local and state obligations including maximum limits. When noticed from off-site, the majority of noise at a cement works can be traced back to transport (heavy vehicles and rail), and the site’s exhaust fans, used to both cool the clinker after it has been produced, and the general kiln system. Several re-designs of exhaust fans have been undertaken over the years in an effort to reduce their noise effects. This has included reducing the amount of fan blades, and altering their angles, retaining the desired cooling effect but with less disturbance to the air.
Simple practices such as ensuring doors to work and storage sheds are kept closed also assist with keeping noise levels low. Measures implemented in other Boral businesses around transport, such as routing away from residential areas and spacing out loads, are also in place for Cement.
How do you protect against dust emissions at the cement works?
Dust at a cement works can be generated from the raw materials used in production (limestone, shale, coal and so on), or can occur as ‘fugitive’ dust on the hard surfaces and roads of the site.
Several measures are in place to reduce the possibility of dust emissions escaping from raw materials during their loading, unloading and storage. Incoming and outgoing loads on trains are kept covered during transit, while material stockpiles are also either covered or kept watered during hot, dry times. Truck loading areas are usually enclosed, and a special loading ‘sock’ which fits around the portals of tankers and trucks to prevent dust escaping during materials transfer is used. Cement is loaded into tankers under air pressure, sealing off the chance for dust to escape. The cement works itself features an ‘electrostatic precipitator’ which effectively ‘scrubs’ dust particles out of the air during clinker production. The number of ‘trips’ (dust escapes) the precipitator is allowed to have is closely regulated.
Other buildings are also fitted with filtration to capture any escaping dust. Regular sweeping of roads and ‘hard stand’ areas is conducted to reduce the ‘fugitive’ dust falling from vehicles or generated from other sources. The Berrima Cement Operation also has a landscaping plan through which trees and vegetation has been planted to ‘screen’ dust from the surrounds.
Why can I see emissions out of the top of your tower?
On occasion, a milky white short air stream may be seen emitting from the cement works’ stack. This is water vapour (steam) being given off as the result of the water used for several purposes within the plant, as well as from the interaction of the various elements under heat. Water is used to keep components of the cement works plant cool, enabling their proper function and prolonging their life. It is also used for dust control within the electrostatic precipitator. Water is also created as a result of the chemical reactions which take place in the ‘meal’ as it falls through the cyclonic hot gas systems.
Can cement production be made any ‘greener’?
Yes. Boral has invested a substantial amount of resources into producing cement with a lower carbon ‘footprint’. There are two opportunities which have had our focus – the source of heat energy for production, and substitution of raw materials.
The traditional source of heat energy for Boral’s cement kilns is coal. Over time, Boral has investigated ways to reduce reliance on coal by incorporating ‘solid waste derived fuels’ (SWDFs) into the heat energy ‘mix’ of sites. SWDFs make use of recovered and processed items from waste streams which would otherwise be sent to landfill. These include wood wastes, combustible refuse and shredded used tyre ‘chips’. They replace a portion of the coal, reducing not only environmental outputs, but costs as well.
Boral has also been replacing portions of the raw limestone and shale used in manufacturing with various forms of ‘slag’. Slag, specifically steel slag and granulated blast furnace slag (GBFS), is a waste by-product of the steel manufacturing process. The slag has similar qualities to, and contains the necessary components of, the raw materials it replaces. This reduces the need to use new natural resources while allowing re-use of a waste which would otherwise end up in landfills.
Innovations such as these have led to the introduction of award winning products such as Boral’s Envisia Concrete.
What are Boral oxides?
Boral produces a range of iron ore oxide-based pigments in a variety of colours which can be used to colour concrete, mortar, cement rendering and similar applications.
What is ‘Manufactured Sand’?
Boral Cement produces ‘manufactured sand’ at its limestone mine in Marulan South, New South Wales. Manufactured sand is produced by crushing limestone down to the finest possible point, creating a sand-like material which can be substituted for ‘natural’ sand in many applications. The importance of manufactured sand has increased due to the depletion and non-availability of permitted natural sand resources in key locations around Australia. Sand is a major ingredient of concrete, among other items, so manufactured sand has been developed to bridge this gap.
What is concrete ‘placement’?
Concrete placement services are offered through De Martin & Gasparini (DMG), a subsidiary of Boral Cement. Placement can involve making pre-fabricated concrete beams/panels and ‘placing’ them into position at work sites, or pumping concrete into specific positions before ‘finishing’ the surface. DMG works with all types of concrete in their placement work. They have helped to create landmark public structures, coloured and polished concrete surfaces, and large scale industrial, commercial, residential and retail complexes through their involvement with projects.
Boral Cement operates production from locations in New South Wales and Victoria, but distributes right across Australia. Click here to view where we are.