Tag Archives: Vargem Grande

Vale adapts iron ore processing route to make sand product for construction sector

After seven years of research and investment of about BRL50 million ($8.9 million), Vale says it has developed a process for producing sand from its production processes with applications in the construction market.

After adaptation in the state of Minas Gerais’ iron ore operations, the sandy material, previously disposed in piles and dams, is now being processed and transformed into a product, following the same quality controls used in the production of iron ore. This year, around 250,000 t of sand has been processed and destined for sale or donation to be used in concrete, mortar, cement and road pavement.

According to Marcello Spinelli, Vale’s Executive Vice President for Iron Ore, the development of this product is the result of more sustainable operating practices.

“This action promotes a circular economy within our units and reduces the impact of tailings disposal for the environment and the society, in addition to being a reliable alternative for the construction industry, where the demand for sand is high,” he said.

Sustainable sand stock yard at Brucutu

Vale’s Sustainable Sand is considered a co-product of the iron ore production process. The material extracted in the form of rocks undergoes several physical processes in the plant, such as crushing, classification, grinding and concentration, until iron ore is obtained.

The innovation introduced by Vale lies in the concentration stage where the by-product of the iron ore processing is once more processed until it reaches the necessary quality to become sand for commercial use. In the traditional method, this material would become tailings and be destined to dams or piles. Every tonne of sand produced represents one less tonne of tailings being generated.

The sand resulting from the iron ore treatment is a 100% certified product, with high silica content and very low iron content, in addition to high chemical and granulometric uniformity.

According to Jefferson Corraide, Executive Manager of the Brucutu and Água Limpa Complex, the sand does not have hazardous characteristics in its composition.

“The mineral processing to obtain the sand is essentially physical, not altering the composition of the materials, so the product is not toxic,” Corraide said.

Recently, Vale’s sand had its application in concrete and mortar certified by three specialised laboratories in Brazil: Instituto de Pesquisas Tecnológicas, Falcão Bauer and ConsultareLabCon.

The properties of Vale sand are also being analysed by an independent study conducted by researchers from the University of Queensland’s Sustainable Minerals Institute (Australia) and the University of Geneva (Switzerland), who are investigating whether alternative construction materials produced from mineral ores could become a sustainable source of sand while significantly reducing the volume of waste produced by mining. These researchers introduced the term “ore sand” to refer to this type of processed sand sourced as a co-product or by-product of mineral ores.

Precast concrete produced with Vale’s Sustainable Sand

Production scale

Vale has already committed to allocating more than 1 Mt of sand for sale or donation in 2022. Buyers are companies operating in four different regions in Brazil: Minas Gerais, Espírito Santo, São Paulo and Brasília. It is estimated that, in 2023, production will reach 2 Mt.

Rogério Nogueira, Director of Ferrous Marketing, explained: “We are getting ready to scale up the sand destination even more from 2023. For this purpose, we have a team of professionals dedicated to this new business and adapting our operations to meet the market needs.”

Currently, Vale is producing sand for sale and donation at the Brucutu Mine, in São Gonçalo do Rio Abaixo (Minas Gerais).

Other mines of the company, also located in Minas Gerais, are in the process of obtaining environmental and mining approvals for sand production.

André Vilhena, Manager of New Businesses at Vale, said: “Our mines provide a sandy material that is rich in silica, which can be used in different industries. We are working with several institutions, including universities, research centres and Brazilian and foreign companies, to develop new solutions to give new destinations to iron ore tailings.”

In addition to using the existing infrastructure in the iron ore mines, Vale also has a railway and road network to transport the sand to markets in several Brazilian states. “With this activity, our main focus is on the sustainability of our iron ore operations, minimising the environmental liabilities, in addition to seeking to promote employment and income by means of new businesses,” Vilhena said.

Eco products

Vale has been carrying out tailings application studies since 2014. Last year, the company inaugurated the Pico Block Factory, the first pilot plant for construction products whose main raw material is tailings from mining activity. Installed at the Pico Mine, in the municipality of Itabirito (Minas Gerais), the factory promotes a circular economy in iron ore processing operation.

The Federal Center for Technological Education of Minas Gerais (CEFET-MG) provides technical cooperation with the Block Factory. Ten researchers from the institution are working on site during this period, including professors, laboratory technicians and graduates, undergraduates and technical course students. During the R&D period, the products will not be sold.

Another research initiative aims to develop the use of sand in pavement solutions in partnership with Itabira’s campus of the Federal University of Itajubá (Unifei). The focus is on the donation of sand for the pavement of local roads.

More sustainable mining

In addition to the Eco products line, Vale has other initiatives to make its mining more sustainable and reduce the generation of tailings. The company has been developing technology to increase the dry processing of its ores, which does not require the use of water. Currently, around 70% of Vale’s production is dry processed and this shall remain at this level when the production capacity of 400 Mt/y is reached and after the start-up of new projects. In 2015, this figure was 40%.

In Carajás, as the iron content is already high (above 65% Fe), the material is only crushed and screened to be classified by size (granulometry).

In Minas Gerais, in some mines, the average content is 40% Fe. By the conventional method, the ore is concentrated by means of processing with water to increase the iron content, with most of the tailings deposited in dams or pits. This is where another technology under implementation at Vale stands out: FDMS (Fines Dry Magnetic Separation). This technology sees the magnetic concentration of ores of low iron grade with no use of water, and therefore, with no need for dams.

Developed in Brazil by New Steel, a company acquired by Vale in 2018, this technology is already in use in a pilot plant in Minas Gerais. In 2023, the first commercial plant will start up in Vargem Grande, with a production capacity of 1.5 Mt/y and investment of up to $150 million.

Another technology which reduces the need of dams is tailings filtration and subsequent dry piling. Once the capacity of 400 Mt/y is reached, more than 60 Mt/y (or 15% of this total) will be processed in plants, where most of the tailings will be filtered and piled this way.

Vale has already opened a filtration plant in Vargem Grande and three more will be commissioned in the March quarter of 2022: one in Brucutu and two in Itabira. Only 15% of the production will continue to be processed by the conventional method, with wet concentration and disposal in dams or deactivated mine pits.

Vale’s Vargem Grande iron ore complex slowly coming back to life

Vale says Brazil’s National Mining Agency (Agência Nacional de Mineração – ANM) has authorised the partial resumption of dry processing operations at the Vargem Grande Complex in Minas Gerais.

The Vargem complex is comprised of three operating mines — Capitão do Mato, Tamanduá and Abóboras — and produces a mixture of fines, lump and concentrate products for the seaborne export market and the Vargem Grande pellet plant.

Vale said all operations of the complex were suspended by ANM on February 20, to prevent “occasional triggers” that could affect tailings dam stability as a result of ongoing activities at the complex.

Vargem was one of several operations that were suspended after one of Vale’s tailings dams ruptured at its Córrego do Feijão mine (Paraopeba complex) on January 25, 2019.

The decision will enable the partial resumption of dry processing operations at the complex within 24 hours, totalling about 5 Mt of additional production in 2019, thus increasing the supply of Brazilian Blend Fines, Vale said.

The Brazil-based miner reaffirmed its 2019 iron ore and pellets sales guidance of 307-332 Mt, as per previous announcements.

Vale looks to decommission upstream tailings dams following Brumadinho breach

Vale says it has presented to the Brazilian authorities a plan to decommission all its dams built by the upstream method.

The plan aims to “de-characterise” these structures as tailings dams in order to reintegrate them into the environment, the miner said.

The move by the miner comes less than a week after reporting a breach to the tailings dam at the Feijão mine in Brumadinho, Brazil, which saw water dispersed more than 63 km from the point of breach. As at 18:00 (Brazil time) on January 27, Vale said 361 displaced people had been found, 305 people were missing and 16 fatalities were confirmed by the Instituto Médico Legal.

Vale currently has 10 dams built by the upstream method, all of which are currently inactive. All of Vale’s dams present stability reports issued by external, independent and internationally respected companies, the company said.

The miner estimates investments of around BRL5 billion ($1.3 billion) will be necessary to decommission its upstream dams and the decommissioning process will occur over the next three years.

In order to carry out the decommissioning of the upstream dams safely and quickly, Vale will temporarily halt the production of the units where the structures are located, namely: Abóboras, Vargem Grande, Capitão do Mato and Tamanduá operations, in the Vargem Grande complex; and the Jangada, Fábrica, Segredo, João Pereira and Alto Bandeira operations, in the Paraopeba complex, also including the stoppage of the Fábrica and Vargem Grande pelletising plants.

“The operation of the halted units will be resumed as the decommissioning works are completed,” it said.

The estimated impact of the production stoppage is about 40 Mt/y of iron ore. Included in this figure is the pellet feed needed for the production of 11 Mt of pellets, an impact that will be offset by the increase in production of other systems of the company, Vale said.

Vale’s 2018 iron ore production is expected to come in at 390-400 Mt, alongside 55 Mt of iron ore pellets.

The miner added that it expected to reallocate all its collaborators currently located in the operations that will be halted.

Photo caption: Vale CEO Fabio Schvartsman flies over the Brumadinho site