WINDHOEK: Dundee Precious Metals (DPM) Inc. has announced on Wednesday the completion of a feasibility study by Johannesburg-based SNC-Lavalin on the installation of a sulphuric acid plant at its copper smelter in Tsumeb. The smelter is owned and operated by Namibia Custom Smelters (Pty) Ltd, a wholly-owned subsidiary of DPM.
The proposed construction of an acid plant is the currently preferred option to capture sulphur from emissions at the smelter.
Towards the end of last year, the Tsumeb Smelter made headlines in local newspapers for excessive arsenic at the smelter, which represents a serious health risk to a substantial number of workers.
It was stated that the NCS emits about 60 000 tonnes of sulphur a year into the environment in the form of sulphur dioxide.
This can cause acid rain, which kills plants over a wide area and causes breathing problems for people. As a result, the smelter had to reduce its monthly production from 17 000 tonnes to 7 000 tonnes of copper concentrate, resulting in losses of more than N.dollars 30 million per month.
According to a media statement issued by the the company on Monday, DPM’s board of directors gave its approval to proceed with the project, subject to final cost estimates and commercial arrangements that provide for acceptable economics and the long-term marketing of the acid produced.
The first phase of the project, comprising basic engineering, site preparation, final costing and detailed scheduling, has been awarded to Outotec, the global leader in sulphuric acid plant design and delivery.
The capital cost estimate for the project, based on the Outotec tender, is USD167 million, (approximately N.dollars 1,4 billion), which includes a 30 percent contingency and excludes offsite infrastructure costs, which NCS is working to mitigate through various third parties, the statement said.
Based on an expected annual smelter production capacity of 240,000-310,000 tons of concentrate, the acid plant will produce in the range of 270,000-340,000 tons of sulphuric acid, it said.
The project is consistent with the directives issued to NCS by the Namibian government in April 2012 aimed at improving off-gas capture and workplace conditions at the smelter. The sulphuric acid plant will process off- gas from the smelter and the acid produced will be sold into the market through off-take agreements.
NCS has entered into a memorandum of understanding with Protea Chemicals Namibia (Pty) Limited, a subsidiary of Omnia Group (Pty) Limited and a leading industrial chemicals company with significant presence in Sub- Saharan Africa, to assist with the marketing and sale of the acid.
‘The construction of an acid plant is the final step in converting our smelter in Namibia to a facility that will operate at international environmental standards’, said Jonathan Goodman, President and CEO of DPM. ‘We look forward to working with Outotec and utilizing their vast experience in acid plant design and construction,” he added.