Resource industries solutions provider Tenova Takraf Africa is installing the largest air environmental plant that the company has received to date at platinum producer Impala Platinum’s (Implats’) Impala Platinum refineries, in Gauteng. The first phase is complete and is in the process of optimisation.
The project was awarded in July 2013 and is scheduled for completion in 2017. It involves the installation of a boiler emissions abatement (BEA) plant to enable Implats to exceed the requirements of new air-emissions regulations. The plant has to efficiently and effectively remove pollutants, such as fly ash particulate, sulphur dioxide and nitrogen oxides, from the boiler flue gas.
Tenova Takraf air environ-mental manager Jimmy Tomlin explains that Implats – whose refineries are situated in Springs, on the East Rand – uses steam-driven processes across its base metals refinery and precious metals refinery for matte conversion and purification into marketable products.
An electrostatic precipitator was used to reduce particulate content of the flue gases being discharged from the six-boiler steam plant; however, the plant configuration was no longer sufficient to comply with the requirements of the National Environment Management: Air Quality Act No 39 of 2004, which will come into effect in 2020.
Tomlin says the Act aims to bring emissions standards in South Africa well within global limits, and focuses on ambient control rather than emissions control to secure an environment that is not harmful to the wellbeing of people.
“As a result, the Act presents new challenges to industries, as it imposes far stricter regulations and heftier penalties for noncompliant companies than ever before.”
He explains that complying with the new legislation requires holistic air-pollution control mechanisms; this starts with the collection of emissions at source to ensure a healthy working environment. Companies are increasingly seeking low-cost systems that use reliable technology to manage dust and fume collection with energy efficiency.
“The South African air environmental market is going through a dynamic phase as it starts to feel the impact of [this] new legislation,” Tomlin notes, adding that “despite the current economic hardships faced by emissions-generating industries, with the increased stringency of national air-quality regulations in South Africa, we have definitely seen an upswing in demand”.
Owing to this, Tenova Takraf notes that the BEA plant at Impala Platinum refineries was designed to provide the most economical solution, while maintaining a low degree of technical risk and using scarce resources optimally.
The plant reduces sulphur particulate matter from the boiler flue gas to less than 25 mg/Nm3, sulphur dioxide to less than 200 mg/Nm3 and nitrogen oxides to less than 150 mg/Nm3. It will further improve existing boiler heat recovery and boiler feed water systems and produce a minimal amount of waste residual, reducing the environmental impact from waste handling or disposal.
Meanwhile, Tenova Takraf has been awarded a number of Tenova Dynamic Wet Scrubber contracts in the past 18 months, most recently from independent diamond mining group Petra Diamonds for its Finsch and Koffiefontein mines, in the Northern Cape and Free State respectively.
The projects, which are scheduled for completion this year, entail the replacement of the existing Tenova scrubbers at the mines with new upgraded systems. Tomlin says these projects will demonstrate the durability of Tenova Takraf’s dust control technology and the company’s ability to fully support its installations over the long term.
Tenova Takraf has also been contracted to supply scrubbers to uranium miner Swakop Uranium’s seven-million-ton-a-year uranium metallurgical plant, in Namibia, and at diamond miner Debswana’s Letlhakane mine, in Botswana. The scrubbers are used for general dust collection of medium to heavy dust loads, and allow for low dust emissions to be achieved with relatively low capital and operational costs.