This study aims to quantify the amount of iron recoverable from iron ore tailings through physical separation methods applied both individually and in combined sequences. The separation techniques employed include the Humphrey spiral concentrator, magnetic drum separator, and shaking table, all widely used for fine mineral processing. The experiments were designed to evaluate the iron content recovered using each method separately and all six possible combinations of the three techniques in different sequences. For each configuration, tailings samples were processed, and the resulting concentrate was analyzed to determine iron recovery efficiency, yield, and grade. The results showed that while individual methods such as the shaking table or magnetic separation yielded moderate iron recoveries, sequential processing— particularly combinations starting with gravity concentration (Humphrey spiral) followed by magnetic separation—produced significantly higher iron recovery rates. The study demonstrates that proper sequencing of physical separation techniques can substantially enhance the beneficiation potential of iron ore tailings, contributing to resource recovery and environmental demage mitigation.

This study investigates the effects of incorporating iron ore tailings in their raw (as-received) state as a partial substitute for natural sand and stone powder in the production of interlocking concrete blocks. The research aims to evaluate the technical viability and environmental benefits of utilizing this mining residue as an alternative fine aggregate. Granulometric analyses were conducted to determine the compatibility of the tailings with standard grading curves recommended by Brazilian technical norms. Experimental concrete mixes were formulated with varying replacement percentages (6%, 13%, and 20%) of the tailings, and corresponding curves were compared to reference limits for block production. The results demonstrated that the inclusion of iron ore tailings from 6% up to 20% maintained the granulometric conformity necessary for non-structural concrete block fabrication and testing the bloc's compression resistence for 30 days as brazilian normatives indicate . This approach offers a sustainable and cost-effective solution by valorizing mining waste and reducing the demand for virgin raw materials.

The exhaustion of natural resources (quantity and quality) and CO₂ emission controls are becoming increasingly important in steel industry.  A lot of steel engineers studied various means to decrease reducing agent at blast furnace for reduction of CO₂ emissions.  For example, injection of waste plastics and carbon neutral materials such as biomass into blast furnace is better alternative. Especially, biomass has novel advantage, namely, no CO₂ emissions, because of carbon neutral.  Production of carbon composite iron ore agglomerates having good reducibility and strength is becoming one of the most important subjects. 

   Carbon composite iron oxide pellets using semi-char or semi-charcoal were proposed in order to enhance the reduction rate of iron oxide at lower temperatures.  The carbonization was done under a rising temperature condition until arriving at a maximum carbonization temperature Tc,max to release some part of the volatile matter included (V.M.).  Starting point of reduction of carbon composite pellet using semi-charcoal produced at Tc,max = 823 K under the rising reduction- temperature condition was observed at the reduction temperature T_R = 833 K, only a little higher than Tc,max (823 K), which was the aimed phenomena.  As Tc,max increases, the emitted carbonization gas volume increases, while the residual V.M. decreases, and, as a whole, the total heat value of the carbonization gas emitted tends to increase monotonically.

According to the International Energy Agency (IEA)[1]  , the steel sector, among heavy industries, ranks first in CO2 emissions and second in energy consumption. Brazil is the largest steel producer in Latin America and the ninth largest in the world, according to the Instituto Aço Brasil[2] . This work aims to analyze existing standards and definitions for greener steel in Brazil and Europe in order to contribute to achieving the goals of the Paris Agreement [3].The steel industry faces major challenges to become more sustainable. Steel production is very carbon-intensive. This contributes significantly to greenhouse gas emissions.The industry is under pressure to reduce its carbon footprint. It needs to adopt more sustainable practices. A recent report emphasizes the importance of a low-carbon economy. [Green steel seeks to reduce carbon emissions. This is done by using renewable energy and sustainable materials. Green steel is a cleaner option than traditional steel. It is made with technologies that reduce gas emissions. Our goal is to make steel without much impact on the environment.4]

The steel industry is vital to the Brazilian economy, contributing to socio-economic development and job creation. Brazil is one of the largest steel producers in the world, but faces significant environmental challenges, such as greenhouse gas emissions and excessive consumption of natural resources. Adopting sustainable practices is essential to mitigate these impacts and ensure the sector's competitiveness. The need for sustainable practices in the steel industry is driven by the environmental impacts of steel production, which include CO2 emissions, natural resource degradation and waste generation. Inadequate solid waste management also represents a challenge. The implementation of advanced technologies and energy efficiency are key to the sustainability of the sector. The industry needs to balance economic growth with environmental protection. The aim of the article is to discuss sustainable practices that reconcile economic development and environmental protection in the steel industry, demonstrating how it is possible to reduce environmental impacts without compromising the sector's growth. The article highlights that the Brazilian steel industry has advanced in technologies that promote sustainability, but still faces challenges compared to other countries. The recommendations include adopting sustainable technologies, implementing circular economy practices, promoting transparency and social responsibility, and educating and training employees. The government should develop public policies that encourage sustainable practices, while civil society should adopt conscious consumption habits and actively participate in sustainability initiatives.

The steel industry is responsible for 5% of total energy consumption and contributes 6% of CO₂ emissions worldwide [1]. Brazil produced 31,869 million tons of steel in 2023. The industrial park has 31 plants, 15 of which are integrated, 7 of which are coking plants, meaning that they consume around 74% of all the coal imported by the country [2].

Mineral coal is the main source of energy still in use in modern society. This input is exported by several countries around the world, such as Australia and the USA, of which Japan, India and China are major importers of the main input for reducing iron ore. A reactor is used to make steel and is called a blast furnace [3].

In the steel chain, 40 to 50% of the cost of steel is in the coal to be used in the coking plant and the constant search to optimize this commodity directly reflects on the competitiveness of the business, which is why various parameters are evaluated in the composition of the coal and subsequently the properties of the coke [4-5].

The main objective of this work is to present a proposed predictive model using combinatorial mathematical analysis and probability, where particles from different coals interact within the coke oven. The model shows promise for the proposed mixtures and could be used as a tool to improve the quality of the coke produced.

The text addresses the environmental impact of the automobile industry, highlighting the increase in pollutant emissions with the mass production of combustion vehicles. As a more sustainable alternative, electric vehicles have gained prominence because they do not emit pollutants and are more efficient. However, their batteries present technological challenges, such as high cost, limited useful life and environmental risks due to improper disposal. Batteries operate based on oxidation-reduction reactions, especially lithium-ion batteries, due to their high energy density. Studies suggest that battery performance can be improved with a higher carbon content in the electrodes. In this context, the use of sugarcane bagasse biochar in the anode is proposed, as it is abundant in Brazil, has good electrical conductivity, porosity and mechanical stability. Furthermore, the development of lithium-sodium (Li-Na) hybrid batteries is considered as a promising alternative, using sodium oxyhydroxide in the cathode, aiming at greater durability, lower cost and less environmental impact. The combination of organic materials and alternative elements can favor the circular economy, sustainability and commercial viability in different technological applications.