Having completed the cold commis-sioning of two 33 MVA ferro- and silicomanganese furnaces for India-based Sarda Metals and Alloys (Smal) in January, high-capacity electric smelting furnace designer and supplier Tenova Pyromet believes it has entrenched its position in India and is currently the preferred furnace supplier on the Indian subcontinent, owing to its experience in the Indian ferroalloys market.

The contract from Smal, originally awarded in 2010, involved the supply of full electrode columns, automatic furnace control (Auto-Furn) and full process plant basic engineering and design, which were completed in ten months, according to Tenova Pyromet con-tinuous development manager Sachin Arjun.

This greenfields development near Vishakhapatnam – a port city on the southeast coast of India – includes its own 80 MW cap-tive power plant, which will generate capacity that will be distributed among the two furnaces and the local power grid.

Additional plans for the plant include an extensive greenery project and a rainwater-harvesting dam, which will reduce the plant’s overall carbon footprint, making it one of the most environment-friendly plants in India.

Arjun tells Mining Weekly that Tenova Pyromet will continue to assist its client in optimising the furnaces.

In carrying out the project, Tenova Pyromet drew on its operational plant experience and software tools, including the latest three-dimensional computer-aided design, finite element analysis and computational fluid dynamics software to take full account of the characteristics of its client’s raw material in the development of the critical furnace dimensions.

Further, proprietary in-house developed mass and energy balance models enabled Tenova Pyromet to study the effects that input changes, such as different raw materials, would have on the process. The process design was complicated by the need to blend the lower manganese-content Indian ores with other higher-grade manganese ore from South Africa or Australia in a two-step process route required to produce 78% high-carbon ferro- and silicomanganese with a manganese content of 65%.

“This ensures that a high grade of product is produced for the export market,” explains Arjun.

Tenova Pyromet claims that its understand-ing of the different mineralogies of South Africa, Australia and India’s ores enabled it to design an optimised process that will be used in conjunction with its submerged arc furnaces and furnace controllers.

Optimisation included not only the process but also the project net-present values, internal return rates and break-even and cash flows, in conjunction with changes in input costs, input raw materials and process parameters, as the mass and energy balance models are directly linked to financial models.

These models were used in real time, enabling Tenova Pyromet to find the best solution for Smal.

Meanwhile, the electrode columns designed and supplied to the ferroalloys manufacturer offer exceptional operational availability and power efficiency, with features such as a robust lower electrode system, with protection for key equipment, and a modular arrangement for easy maintenance.

The slipping device has a clamping shoe configuration that can exert adequate pressure on the electrode casings, reducing the risk of damage.

Tenova Pyromet’s AutoFurn automatic fur-nace control controls the electrode movement and the transformer. Prioritising the alarming convention has enabled Smal to operate these large plants with a smaller workforce.

“The advantage of Tenova Pyromet’s extensive capability and wealth of operational plant experience is clearly demonstrated by our furnace designs exceeding contracted performance guarantees, normally in daily operation and without the need for extensive tests, and complying with all safety and environmental aspects,” maintains Arjun.

Tenova Pyromet has been working with private- and State-sector ferroalloy firms in India since 2004, when it was contracted by Nava Bharat Ferro Alloys to design and supply the electrode column and electrode seals for its 24 MVA silicomanganese furnace.