Global materials handling company Clyde Bergemann is focusing on the injection of fine solids into plasma furnaces and triple electrode furnaces, specifically used for high-end smelting functions in the nonferrous metals and ferrous metals mining industry, to improve operating efficiencies and reduce harmful emissions, says Clyde Bergemann Africa (CBZ) business development executive director Jeremy Kirsch.

CBZ provides its services in the materials handling field, particularly in the dense-phase pneumatic conveying of powdered and granular materials in the mining sector.

Its most recent projects included the replacement of a greenfield furnace feed mechanism at several platinum processing plants, in South Africa, and at a copper smelting facility, in Zambia.

With the pneumatic conveying technologies, products can be continuously injected into process environments at easily controlled rates, with accuracies of 0.5% and against back pressures of 20 bar, thus, allowing injection below molten metal.

Kirsch states that the materials can be injected either continuously or in a batch process to multiple points.

He adds that, wherever there is a need to inject powdered or granular materials into a process environment, there is a potential application for CBZ’s injection technologies.

The company typically uses its Rotofeed or Rotoscrew technologies, which are used in applications such as blast furnace coal injection, granular coal injection, deep ladle injection, flux feed, oxyfuel burners, slag furnaces, blast and flash furnaces, bath and flash smelters, and Catalytic and Noranda converters.

CBZ can also assist with the thermal control of furnaces. In conjunction with its feed cannon, the company can feed the materials with its injection technologies at a specific rate, to a specific location, within the thermal process, thus enabling the operator to maintain consistent operating conditions across the furnace.

Meanwhile, Kirsch says that the company’s offering is prevalent in the power industry, where it develops systems for the injection of pulverised activated carbon and other absorbents into high-temperature flue gas flowing out of a boiler furnace.

“This allows for the abatement of emissions such as mercury, acid gases, sulphur dioxide and sulphur trioxide components,” Kirsch explains.

Further, he notes that these solids injection technologies are both upgrades of existing systems, which have been designed specifically for industrial and mining type applications. “The upgrades include sizing smaller pneumatic injection systems, which have historically possessed larger capacities,” he adds.

CBZ’s North America-based associate company, Clyde Bergemann Americas, Injection Systems website states that its pneumatic injection systems meet all the mining industry- and power production industry-related criteria necessary to achieve highly efficient stoichiometric ratios in a sorbent injection system, while providing the operating flexibility required to meet the modern- day operational requirements of both industries.

“The company’s field-proven design will accept a variety of dry sorbents, and premium stoichiometric ratios are achieved by uninterrupted phase flow to multiple injection points, with turndown ratios of up to 25:1,” it adds.

“In South Africa, these solids injection technologies have been used for many years in the industrial market. However, in the power market, we have yet to use these technologies, as the emissions to atmosphere legislation is not yet favourable to these systems, as companies are not yet forced to reduce their harmful emissions,” he adds.

However, Kirsch says that pneumatic injection systems in the industrial market are gaining momentum, owing to their environment-friendly operations.

He highlights that, in the power industry, in markets where legislation stipulates that smelters and furnaces have to comply with strict air pollution limits in terms of sulphur dioxide emissions – such as the US and the European Union – the uptake has been positive.

“South Africa has been slow to implement these technologies; however, I believe this undoubtedly will change, owing to growing industry concerns about environment- friendly practices,” he asserts.

System Features

The injection unit tests and demonstrates the emission control requirements specific to each plant.

It is a portable testing platform capable of injecting various sorbents such as powdered activated carbon and lime-based sorbents.

Kirsch enthuses that the company’s injection system offers con- tinuous and accurate injection rates without creating any pulses or surges. It also allows for a single feed to multiple injection points.

He adds that CBZ exhibited its injection system technology at Electra Mining 2010.