Storage and Heating Guide

Stored correctly, bitumen and sulphur hold their properties for a long time; stored badly, they lose value before they are ever used. This guide covers how to protect the product once you have taken delivery.

Temperature management for bitumen

The fundamental rule with bitumen is this: hold it at the lowest temperature that still allows safe pumping. Every extra degree accelerates oxidation and ages the binder.

For long-term storage

• Do not hold product at high temperature for extended periods; where possible lower the temperature and reheat before use.
• Do not measure tank temperature at a single point. Place thermometers at bottom, middle and top levels; local overheating can occur near the heater.
• Overheating at the heater surface (hot spots) carbonises the bitumen. The heating surface load must stay within the manufacturer's limits.
• Adding fresh product on top of a tank that has not been fully emptied can mix grades. Different grades should be kept in separate tanks.

Safety

• Hot bitumen causes severe burns. Heat-resistant gloves, a face shield and long-sleeved protective clothing are mandatory.
• Keep it away from water. Water collected at the bottom of a tank flashes to steam on contact with hot bitumen, causing foaming and overflow. This is one of the most frequent causes of serious accidents in the industry.
• Pressure and vapour must be released before opening tank hatches.
• Use long-handled equipment when sampling; never lean over the tank opening.

Storage in drums and bags

Packaged bitumen should be kept in a closed, dry area out of direct sunlight. Drums are stacked upright, no more than two rows high. Drums left outdoors for long periods develop rust and internal surface degradation.

Sulphur storage and safety

With sulphur the risk is not temperature but dust and static electricity. Sulphur dust mixed with air in certain proportions can form an explosive atmosphere.

• Closed-system handling: Particularly for the powder form, dust collection and ventilation should be used at transfer points.
• Earthing: Discharge and transfer equipment must be earthed to prevent static build-up.
• Keep away from ignition sources: Welding, cutting and open flame work should be prohibited in the storage area.
• Moisture control: Moisture oxidises sulphur into an acidic environment that corrodes metal surfaces. Big bags should be kept in a closed, dry area.
• Personal protective equipment: Dust mask, goggles and anti-static work clothing.

Preventing caking

Granular and prilled sulphur are free-flowing products, but they cake if they take on moisture. Keeping big bags on pallets, off the floor, in an area with limited temperature swing largely removes this risk.