Key challenges

Vanadium

A small percentage of the population is susceptible to developing a reversible form of occupational asthma from prolonged exposure to vanadium pentoxide dust. Xstrata produces vanadium pentoxide and ferrovanadium from one integrated plant, Rhovan, in South Africa. All potential employees and contractors undergo pre-employment allergy tests to determine any general sensitivity before employment. All employees are regularly tested in line with Rhovan's biological and gravimetric air sampling strategy which requires employees working in high risk areas to be sampled every three months and artisans and loader drivers in high risk areas to be sampled every two months to identify elevated vanadium levels in urine.

Xstrata has made a number of investments at Rhovan specifically to minimise dust in working areas over the past three years.

In 2005, the Rhovan plant achieved a reduction in high vanadium levels among its employees due to ongoing training and education to ensure employees minimise the risk of exposure through proper use of PPE and personal hygiene and capital investment in improvements to the plant. Some examples of the initiatives undertaken at Rhovan are as follows:

  • dust levels were reduced in the kiln off-gas area through replacing the total fines system at a cost of ZAR2.6 million;
  • a dust suppression fogging system was installed in the concentrate plant to eliminate fugitive dust and the mine and access routes were sprayed to create a tar-like road, eliminating dust from vehicles moving through the area;
  • a Vac-Air industrial vacuum cleaner was installed at a cost of ZAR500,000 to remove dust from the fusion building;
  • a highly efficient venturi scrubber was installed to remove vanadium pentoxide particles and ammonia gas from the off-gas stream and three stacks were combined into one extended stack with a booster fan at a total cost of ZAR2.6 million; and
  • baghouses have been installed or extended throughout the plant to significantly reduce vanadium dust in the workplace.

As a result of these initiatives, vanadium levels detected through workplace air sampling has decreased by 50%-55% compared to average 2004 levels. This, in addition to behavioural improvements, has led to a 64% reduction in the number of employees with elevated levels of vanadium at the Rhovan plant in 2005 compared to 2004.