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Commercial debut for a process that makes ‘green’ pig iron

| By Gerald Ondrey

Last month, Vale S.A. (Rio de Janeiro, Brazil; began construction on the first commercial plant to use its Tecnored process, which produces pig iron with biomass instead of metallurgical coal (coke). Located in Marabá, in the southeast of Pará, Brazil, the new unit will have an initial capacity to produce 250,000 ton/yr of “green” pig iron, with the possibility of reaching 500,000 ton/yrin the future. The start-up is scheduled for 2025 with an estimated investment of approximately BRL1.6 billion ($341 million).

Developed over 35 years by Tecnored Desenvolvimento Tecnológico S.A. (Pindamonhangaba, SP, Brazil;, which Vale acquired in 2014, the Tecnored process eliminates the need for coke ovens and sintering, which are process steps used by traditional blast furnaces. As a result, investment and operating costs are reduced by about 15%. By replacing metallurgical coke by biomass, the net CO2 emissions are reduced by up to 100%, which is said to be an important step in contributing to the decarbonization of the steel industry.

The Tecnored furnace is much smaller in size than a traditional steel blast furnace and is quite flexible in the use of its raw materials, which can range from iron ore fines and steel residues to dam sludge. For fuel, the furnace can be fed by carbonized biomass, such as sugarcane bagasse and eucalyptus. Both are first transformed into briquettes (small compact blocks) and then deposited into the furnace, generating green pig iron.

Initially, fossil fuel will be used to evaluate the performance of the plant, as this will be the first large-scale operation of the technology. “Gradually, we are going to replace coal with carbonized biomass until we reach the goal of 100% biomass”, explains Leonardo Caputo, Tecnored’s CEO.

Currently, Vale maintains a 75,000-ton/yr demonstration plant that started up in 2011 in Pindamonhangaba, where tests were carried out to develop the technology and its technical and economic feasibility.