Environment

In 2005 AngloGold Ashanti became a signatory to the International Cyanide Management Code, a voluntary initiative for the gold mining industry that focuses on the safe management of cyanide being produced, transported and used for the recovery of gold. It is compulsory for all of AngloGold Ashanti’s operations to be in compliance with this code.

One of these operations is Navachab mine in Namibia which has been in existence since 1989. Although most of the technical aspects of complying with the code were initiated, they were not fully applied at Navachab as the mine was scheduled to close at the end of 2005. When Navachab’s life as a producing mine was extended, compliance with the code became a priority. Navachab’s leadership quickly allocated the resources required to achieve compliance in the stipulated time frame. The mine began developing operating procedures in response to the requirements of the code, conducting risk assessments and using hazard identification techniques.

Some of the interventions carried out were:

• The upgrade to briquette cyanide from flake cyanide. Briquette cyanide is the superior choice with 98% concentration whereas flake cyanide is the weaker of the two with a 33% and 55% concentration.
• The conversion of lime tanks to modern cyanide make-up and dosing tanks; this is where briquette cyanide is mixed with water to form a 10% solution after which it is used in the leaching system.
• The switch from lined steel piping to high density plastic piping for cyanide dosing.

A review of operational standards, extensive engineering, and new risk assessments were carried out to optimise the process plant. Technologically advanced gas monitoring equipment was purchased and the cyanide dosing system was automated with state of the art instrumentation. Environmental specialists were contracted to ensure that the environment was protected from possible cyanide contamination. To keep the local residents informed of the developments at Navachab, the mine held regular meetings with the community and interested parties.

Diagrams which indicate instrumentation and the respective electrical stream designs were updated, and expertise from professional engineering companies was brought in to assist in achieving compliance. An intensive training schedule was adopted to enable staff to work safely with cyanide.

The mine also employed a full time cyanide champion in 2007, to ensure continuity in the cyanide programme. The PRAGMA maintenance system; a data based system that helps to control and maintain systems; was implemented to help keep projects and maintenance operating optimally.

A code initial gap audit was done during February 2008 in which the mine achieved a score of 56% which was followed by the accreditation audit conducted in November 2008 where Navachab achieved 99.42%. According to the auditors, Navachab had two examples of best practice in the group: the newly built Detox Area (for the destruction of cyanide before the slurry is pumped to the tailings facility) and the burning area (for the disposal of used cyanide crates and packing material).

Navachab currently has partial compliance status, because the external component of the transportation of cyanide has not yet been audited. This will take place in 2009.