Recently, a reporter from China Metallurgical News learned from Vale that after 7 years of research and investment of about 50 million reais (approximately US$878,900), the company has successfully developed a high-quality ore production process that is conducive to sustainable development. Vale has applied this production process to the company’s iron ore operation area in Minas Gerais, Brazil, and converts the tailings processing that originally required the use of dams or stacking methods into high-quality ore products. The ore products produced by this process can be used in the construction industry.
It is understood that up to now, Vale has processed and produced about 250,000 tons of such high-quality mineral sand products, which have high silicon content, extremely low iron content, and high chemical uniformity and particle size uniformity. Vale plans to sell or donate the product to produce concrete, mortar, cement or to pave roads.
Marcello Spinelli, Executive Vice President of Vale’s Iron Ore Business, said: “There is a huge demand for sand in the construction industry. Our ore products provide a reliable choice for the construction industry, while reducing the environmental impact of tailings treatment. The negative impact caused.”
According to United Nations statistics, the global annual demand for sand is between 40 billion tons and 50 billion tons. Sand has become the natural resource with the largest amount of man-made extraction after water. This mineral sand product of Vale is derived from a by-product of iron ore. Raw ore can become iron ore after several processes such as crushing, screening, grinding and beneficiation in the factory. In the traditional beneficiation process, by-products will become tailings, which must be disposed of through dams or in stacks. The company reprocesses the by-products of iron ore in the beneficiation stage until it meets the quality requirements and becomes a high-quality mineral sand product. Vale said that using the process of converting tailings into high-quality ore, every ton of ore products produced can reduce 1 ton of tailings. It is reported that researchers from the Institute of Sustainable Minerals at the University of Queensland in Australia and the University of Geneva in Switzerland are currently conducting an independent study to analyze the characteristics of Vale’s mineral sand products to understand whether they can truly become a sustainable alternative to sand. And significantly reduce the amount of waste generated by mining activities.
Jefferson Corraide, Executive Manager of Vale’s Brucutu and Agualimpa integrated operations area, said: “This kind of ore products are truly green products. All ore products are processed by physical methods. The chemical composition of the raw materials has not been changed during the processing, and the product is non-toxic and harmless.”
Vale stated that it plans to sell or donate more than 1 million tons of such ore products by 2022, and increase the output of ore products to 2 million tons by 2023. It is reported that buyers of this product are expected to come from four regions in Brazil, Minas Gerais, Espirito Santo, Sao Paulo and Brasilia.
“We are ready to further expand the application market of mineral sand products from 2023, and for this we have set up a dedicated team to operate this new business.” said Rogério Nogueira, director of Vale’s iron ore market.
“At present, other mining areas in Minas Gerais are also preparing a series of preparations for adopting this production process. In addition, we are cooperating with a number of research institutions to develop new solutions and are committed to the rational treatment of iron. Ore tailings provide new ideas.” said André Vilhena, business manager of Vale. In addition to using the existing infrastructure in the iron ore mining area, Vale has also specially established a huge transportation network to efficiently and conveniently transport sustainable mineral sand products to multiple states in Brazil. “Our focus is to ensure the sustainability of the iron ore business, and we hope to minimize the environmental footprint of the company’s operations through this new business.” Villiena added.
Vale has been conducting research on tailings treatment applications since 2014. In 2020, the company opened the first pilot plant that uses tailings as the main raw material to produce construction products-the Pico brick factory. The plant is located in the Pico mining area in Itabilito, Minas Gerais. Currently, the Federal Technical Education Center of Minas Gerais is actively developing technical cooperation with the Pico Brick Factory. The center sent more than 10 researchers, including professors, graduate students, undergraduates and technical course students, to the Pico Brick Factory to conduct research in person.
In addition to research and development of ecological products, Vale has also taken a variety of measures to reduce the number of tailings, making mining activities more sustainable. The company has been committed to developing dry processing technology that does not require water. Currently, about 70% of Vale’s iron ore products are produced through dry processing technology. The company said that the use of dry processing technology is closely related to the quality of iron ore. The iron ore in the Carajás mining area has a high iron content (over 65%), and the processing only needs to be crushed and sieved according to particle size.
The Vale subsidiary has developed a dry magnetic separation technology for fine ore, which has been applied in a pilot plant in Minas Gerais. Vale applies this technology to the beneficiation process of low-grade iron ore. The first commercial plant will be put into use in the Davarren operating area in 2023. Vale said that the plant will have an annual production capacity of 1.5 million tons, and the total investment is expected to be US$150 million. In addition, Vale has opened one tailings filtration plant in the Great Varjin mining area, and plans to open three more tailings filtration plants in the first quarter of 2022, of which one is located in the Brucutu mining area and two are located in Iraq. Tagbila mining area.