Specialised corrosion-resistance and surface-protection company Industrial Acid Proofing (IAP) last month secured the sole distributorship for China-based Hebei Ancor Tecmin KNT Polymer Concrete’s Supertank electrolytic cells in Africa.
IAP MD Michael Wende tells Mining Weekly that the Supertank’s monolithic impermeable internal tank is ideally suited to electrowinning applications in copper, zinc, cobalt, lead and nickel mining, owing to its ability to resist the highly acidic solutions used in the leaching process, which extracts the precious metals from their orebodies.
The internal tank has an effective operating life of at least 20 years, a significant improvement on other tanks currently being supplied to the African mining industry, which last five to eight years, he notes.
The internal tank is manufactured using multiple layers of fibre-reinforced plastic (FRP), which complies with international chemical barrier norms, thereby ensuring the long-term corrosion resistance of the Supertank.
The structural core of the Supertank is constructed using Hebei Ancor Tecmin KNT Polymer Concrete’s patented Hyperbonded polymer concrete formulation, which achieves a low-coefficient thermal expansion rate, providing long-term structural integrity with low thermally induced stresses to the Supertank.
Its external layer is sealed with FRP, protecting the structural core from exposure to the leaching solutions.
Wende highlights that being the sole distributor for Supertanks will help create an additional revenue stream for IAP, which is particularly important in the current difficult economic climate. “The sales volumes for electrolytic cell tanks are very high and would certainly generate [an additional] income stream for IAP. Although it is not our core business, it certainly complements our business.”
Meanwhile, South African refractory manufacturer Vereeniging Refractory’s (Verref’s) Verref Shaped business supplied its last batch of acid-resistant bricks last month, following the business being placed under business rescue earlier this year.
Acid-resistant bricks are used in aggressive and oxidising environments, such as sulphuric, hydrochloric and nitric acid applications.
Wende notes that Verref Shaped was the only acid-resistant brick manufacturer in Africa and, since its closure, suppliers and consumers have to resort to imports, resulting in longer lead times and increased costs.
Acid spillages are not unusual in mining operations and, when the acid mixes with water, an exothermic reaction takes place, reaching up to 140 °C, he explains.
“While epoxy flooring solutions can withstand the acids, they are unable to deal with the combination of the heat and the acids,” Wende states, highlighting the importance of acid-resistant bricks.
He laments that, previously, IAP had a lead time of about three weeks for acid-resistant bricks, which has now increased to as long as 12 weeks because they are imported from various countries abroad.
The search for a cost-effective high-quality product was difficult, as “there is often a premium attached to quality”, he says.
Wende highlights that he personally inspected various brick manufacturing plants, as quality control is of utmost importance.