The proportion of alternative raw materials used in Brazilian cement is one of the best in the world, country's leading cement producer reports, citing domestic construction industry association SNIC.
“Brazil has one of the highest clinker substitution rates in the world and this is due to industry research and the development of technologies to incorporate natural substitutes and even steel industry dejects into cement manufacture”, says Edvaldo Rabelo, executive director of energy, sustainability and safety of Votorantim Cimentos. In 2013, 91 per cent of all the cement sold in Brazil had some additive in addition to the clinker derived from limestone used in cement production.
As a particular example, Votorantim Cimentos' R&D manager Silvia Vieira, highlights the company's in Porto Velho plant in Rondônia which is considered a model in climate change initiatives. In operation since 2009, the unit also saw alternative raw materials as a means of reducing operational costs.
The plant is located in the North of Brazil, where there is a lack of limestone for clinker production and the high cost of transporting it from other mines is prohibitive. “This led us to think about producing calcined clay pozzolan at the plant and increasing the proportion of substitutes. After research, the involvement of scientists to establish technical specifications and diverse tests, we developed our own furnace for producing the material”, states Silvia.
The construction of the Porto Velho unit involved an investment of BRL$176m. “The investment was very similar to what would be spent on a regular plant, but this unit is superior in ecoefficiency. Our emissions are half those of a regular plant, we spend 35 per cent less energy and consume 40 per cent less water than a conventional factory that produces cement without additives”, Silvia concludes.
Votorantim Cimentos presented the Porto Velho case study and its sustainable initiatives at the 2015 CBI Brazil & Latin America Congress, last week at the Hotel InterContinental in São Paulo. During the event, Mr Rabelo talked about the company's sustainability policies while Ms Vieira focussed on the addition of sustainable materials in cement production.
At the congress, the Porto Velho plant also received the second annual Dr Clemente Greco Award for the best project within the cement and lime sector, due to its high ecoefficiency ratings.