Loading concentrate at Prominent Hill for transport to the Port of Darwin
Unloading Prominent Hill concentrate at the Port of Darwin storage shed

Transport of Products and Materials

At most of our operations, the products are mineral concentrates which leave the site via a combination of pipeline, road, rail and/or ship en route to our customers. In all cases, the concentrates are in the form of a moist powder.

After leaving our process plants, the most significant hazard is loss of containment of these concentrates, in the form of spillage or loss as dust.

For these reasons, every effort is made to ensure that road and rail transport is conducted by reliable and reputable carriers with appropriate track records and contingency plans are in place in case of spillage.

Unloading, stockpiling and shiploading operations are conducted so as to minimise the generation of dust, and clean up any unavoidable minor spillages.

During 2008, the Australian Dangerous Goods Code was revised and re-issued for implementation by 2010. Some of the changes have potential to change the Dangerous Goods classification of some OZ Minerals products. Some of our concentrates may become classified as Class 9 Environmentally Hazardous. This classification is determined using prescribed dissolution tests and protocols for predicting potential environmental impact.

We tested our concentrates from Golden Grove during 2008 and determined that the lead concentrate met the criteria for classification as a Class 9 Dangerous Good (Environmentally Hazardous). The zinc and copper concentrates did not qualify as Dangerous Goods.

The impact of this changed classification of lead concentrate has resulted in changes to trucking operations (driver training, spillage clean-up methods, placarding and signage, etc) and modifications to the stockpiling and handling operations at the port of Geraldton (improved dust containment and wash-down facilities). Required modifications to the kibbles used to carry the concentrates by truck will be implemented during 2009.

Similar testing of concentrates is underway at our other operations. Any changes arising from re-classification under the new Dangerous Goods Code are required to be in place as of 1 January 2010.

Part of the Prominent Hill project consisted of building a storage shed at the Port of Darwin. Custom-made kibbles will be used to transport the concentrate by rail to Darwin, where the concentrate will be stockpiled, ready for shipment to overseas customers. These kibbles are the same as those used over many years by our Golden Grove operation and ensure encapsulation of the concentrate from Prominent Hill to the Port of Darwin. Baseline environmental studies have been conducted at the Port of Darwin to provide a basis for assessing any potential impact from the shipments of Prominent Hill copper concentrate.

During 2008, risk assessments and community consultation was conducted along the rail transport route to Darwin to ensure that the export operation is conducted safely and with no environmental impact.

The smelter at BHP Billiton’s Olympic Dam operation is also a customer for Prominent Hill concentrate. Transport to Olympic Dam will be via road train and similar precautions have been taken.

Prominent Hill ore and concentrate contains background levels of uranium. Radiation levels are below regulatory limits and monitored under a radiation management plan that ensures there is no risk to the workforce or the public at any stage of the production or transport operations.

OZ Minerals operations reported there were no incidents of non-compliance with regulations and voluntary codes related to the safety and health impacts of our products, information and labelling, breaches of customer privacy, losses of customer data or marketing communications during the reporting period.

All sales contracts for OZ Minerals’ products contain agreed levels of chemical specifications including maximum limitations for any potential deleterious elements which may be contained or derived from the ore or production processes. Monitoring and testing regimes are maintained to ensure adherence to all of these contractual commitments. This process of consultation and contracting ensures there are no issues in downstream smelting or refining of OZ Minerals’ products.

In addition, all customers are provided with Material Safety Data Sheets which describe safety, health or environmental hazards associated with our products.

MV Wunma – Board of Inquiry follow up

On 7 February 2007 Century’s concentrate transfer vessel, MV Wunma, relayed a distress signal indicating that it had taken on water in severe seas caused by cyclone Nelson. The ten crew members were safely evacuated and the vessel eventually stabilised by the Emergency Response Team. After a full assessment, and minor remedial work, the vessel was returned to service on 23 February with no significant disruption to mine production.

On 15 March 2007, it was announced that a Marine Board of Inquiry (BOI) would be established to “investigate the circumstances surrounding a ship abandoned in the Gulf of Carpentaria during a tropical cyclone in February 2007.

After 10 months of hearings and deliberations, the BOI released its final report in December 2007. Although a large number of factors were found to have contributed to the incident, three key opportunities for improvement were identified in the report. These were:

  • Aspects of the Maritime Safety Queensland’s (MSQ) role as a regulator and the legislative framework it operated in
  • The water management system on board the MV Wunma
  • The company’s cyclone contingency plan and, more particularly, the need for a dedicated cyclone mooring

The company implemented the recommendations of the BOI as they were raised during the inquiry process and by the time the report was released, the majority of recommendations had been implemented.

As part of this process, the company worked closely with Maritime Safety Queensland to improve the Cyclone Contingency Plan which the Wunma has been operating under for the previous two cyclone seasons. Additional mooring facilities to increase the cyclone category rating of the Karumba wharf were fabricated and are currently being installed.

The Wunma operated under a Restricted Use Flag for the duration of the inquiry and while the recommendations were being implemented. The vessel’s full registration was re-instated on 1 December 2008.