Lime products play an important role across construction, water treatment, mining, manufacturing and agriculture. But before hydrated lime, quicklime and agricultural lime can be used in these applications, they begin with a naturally occurring raw material: limestone. Limestone extracted from Boral's Marulan South Limestone Mine supports the production of cement and lime products used across a wide range of Australian industries.
What is Limestone?
Limestone is a sedimentary rock primarily composed of calcium carbonate. It is one of the world's most abundant natural resources and is widely used in construction, manufacturing and industrial processes.
At Marulan South in New South Wales, limestone is extracted from a significant deposit that has supported Australian industry for generations. The majority of the limestone is supplied to Berrima Cement Works for cement manufacturing, while a portion is used in the production of lime products.
Step 1: Extracting Limestone
The lime manufacturing process begins with the extraction of limestone from a quarry or mine. At Marulan South, limestone is mined using modern open-cut drill-and-blast techniques before being transported to processing facilities.
Once extracted, the limestone is crushed and prepared for the next stage of the process.
Step 2: Producing Quicklime
Quicklime, also known as calcium oxide (CaO), is produced by heating limestone in a kiln at high temperatures.
During this process, known as calcination, carbon dioxide is released from the limestone, leaving calcium oxide behind. The resulting material is known as quicklime and is widely used in industrial applications including mining, water treatment and steel manufacture.
Quicklime is valued for its high reactivity and is commonly used in applications requiring rapid chemical reaction and process performance.
Step 3: Producing Hydrated Lime
Hydrated lime is produced by adding water to quicklime through a carefully controlled process known as hydration or slaking.
This process converts calcium oxide into calcium hydroxide (Ca(OH)₂), creating the fine powder commonly known as hydrated lime. Hydrated lime is easier to handle than quicklime and is widely used across soil stabilisation, water treatment and industrial applications.
Premium Hydrated Lime follows the same fundamental process but is manufactured to achieve specific performance characteristics for demanding treatment and industrial applications.
Different Types of Lime Products
Different applications require different lime products.
Quicklime
Quicklime is a highly reactive calcium oxide product commonly used in steel production, mining, industrial processing and water treatment.
Hydrated Lime
Hydrated Lime is a versatile calcium hydroxide product used for soil stabilisation, water treatment, mining, asphalt production and industrial applications.
Premium Hydrated Lime
Premium Hydrated Lime is manufactured for treatment applications where product consistency, reactivity and process performance are critical. Common applications include drinking water treatment and environmental treatment processes.
Agricultural Lime
Agricultural Lime differs from quicklime and hydrated lime because it is a finely ground limestone product used to help manage soil acidity and support productive farming systems.
How Lime is Used Across Industry
Lime products are used in a wide range of industries throughout Australia. Common applications include:
- Soil stabilisation and road construction
- Drinking water and wastewater treatment
- Mining and mineral processing
- Steel manufacturing
- Asphalt production
- Industrial processing
- Environmental treatment
- Agriculture and soil conditioning
The type of lime used depends on the application's performance requirements and operating conditions.
Learn More About Boral Lime Products
Boral produces a range of lime products to support industry, infrastructure and agriculture across Australia.
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Or learn more about the operations behind Boral's limestone supply at Marulan South Limestone Mine in the video below.