JSE-listed African Oxygen (Afrox), part of The Linde Group, is developing a technology that aims to significantly improve the efficiency of using the cyanide destruction process at gold mines.
Afrox supplies oxygen to a significant portion of gold mines in South Africa, increasing the feasibility of converting oxygen to ozone for cyanide destruction. Afrox technical solutions engineer Rob de Zoeten says that ozone can be generated on site, by using ozone generators and using the existing oxygen supply at gold mines. Oxygen is used in the Afrox Goldox process, which provides many advantages for the gold extraction process.
As a first step in commercialising the use of ozball drive valve seat cutter chinaone in cyanide destruction, Afrox started a trial at an operating gold mine in Mpumalanga province, which currently uses the Afrox Goldox application. The mine expressed interest in the trial as cyanide destruction in their tailings is a long-term environmental requirement of their mining licence.
The trial was undertaken on the gold plant’s tailings, before its deposition on the maicommonly used mill in coal grindingn tailings dam. The ozone was generated using oxygen from the existing supply and a portable ozone generator. The ozone was injected using a specially developed contacting system to ensure that optimal reaction efficiency took place before the water was pumped into the tailings dam.
De Zoeten reports that samples taken at the pump to determine the effectiveness of the cyanide destruction indicamarble crusher for salete that cyanide oxidation occurs quickly, with free cyanide being reduced by more than 85%. The ozone consumption during the trial was about 2 g of ozone for every gram of cyanide. “The results were encouraging, suggesting that using ozone in cyanide destruction could prove to be a viable process route for gold plants wanting to reduce cyanide levels in their tailings,” he says.
The need for cyanide destrubirtley engineering coal washingction has increased over the years and Afrox is well positioned to develop tailor-made ozone-based solutions to meet the ever-changing industry’s needs. De Zoeten says that the growing demand for sustainable solutions to neutralise destructive cyanide in tailings dams could possibly be attributed to the fact that an increasing number of local mining companies are voluntarily subscribing to the United Nationtypes of mechanical crushers’s International Cyanide Management Code (ICMC).
De Zoeten explains that the fundamental aim of the code is to manage the use of cyanide throughout the gold beneficiation process, which limits the release of solutions containing cyanide into the environment from spillages and tailings disposal.
Although compliance with the code is voluntary, it has been implemented by the world’s major gold producers.
While there are a number of proven pro- cesses to destroy or eliminate harmful cyanide in gold processing solutions, each method has its own benefits and drawbacks. Afrox reports that cyanide destruction through the use of ozone is a technically proven, environment-friendly process, yet ozone has not been popular, owing to comparatively high capital and operating costs.
The advantages of using the ozone-based process for cyanide destruction should, however, be a huge driver for mines when considering a cyanide destruction process. The advantages associated with using this system include the fact that no adjustment to the tailings stream is required when installing ozone equipment and the reaction is rapid, complete, irreversible and by-product free.