The 800,000 L of sulfuric acid was bought by Incitec Pivot Limited (IPL) to be used in the production of ammonium phosphate fertiliser at its plant at Phosphate Hill (south of Mount Isa).
Glencore Plc has an agreement with Incitec Pivot Ltd to provide sulfur dioxide from the copper smelter to the Mount Isa acid plant. Sulfuric acid is produced by collecting and cleaning sulfur dioxide before converting it, first to sulfur trioxide, and then to sulfuric acid. The acid plant has the capacity to take up to 80% of the sulfur dioxide emissions from the copper smelter, significantly reducing the emissions of sulfur dioxide into the atmosphere. The sulfuric acid is then taken by train to Phosphate Hill, more than 100 km away.
Phosphate Hill combines a large open-cut phosphate mine with a plant for the production of fertiliser. The proved reserve is 29 Mt at 24.6% P2O5. The phosphate ore is first crushed and washed before being dissolved in sulfuric acid to produce phosphoric acid. Gypsum, CaSO4.2H2O, a by-product of the process, is stockpiled. The phosphoric acid is converted into ammonium phosphate fertiliser using ammonia gas:
NH3 + H3PO4 → NH4H2PO4 (known as MAP)
2NH3 + H3PO4 → (NH4)2HPO4 (known as DAP)
The ammonium phosphate is then sent by train to the port at Townsville about 900 km away for shipment.
Wet weather hampered access to the disaster site for several days, but testing of the waters 8 km downstream in Horse Creek revealed changes in acidity. Locally sourced limestone is being used to treat the water.
Sulfuric Acid Production
pH Calculations for Acids
Suggested Study Questions:
- Convert 800 000 L of sulfuric to a volume in:
- megalitires (ML)
- kilolitres (KL)
- millilitres (mL)
- Assume the density of this sulfuric acid is 1.84 g mL-1. What is the mass of 800,000 L of sulfuric acid?
- Assuming all the sulfuric acid was distributed equally between the 26 carriages, what volume of sulfuric acid was contained in each carriage?
- Write the chemical formula for each of the following:
- sulfur dioxide
- sulfur trioxide
- sulfuric acid
- sulfurous acid
- tonnes (t)
- kilotonnes (kt)
- kilograms (kg)
- grams (g)
- What mass of P2O5 is present in 1 tonne of the ore?
- What mass of the element phosphorus is present?
- What mass of the element oxygen is present?