The steel industry is responsible for 5% of total energy consumption and contributes 6% of CO₂ emissions worldwide [1]. Brazil produces around 30% of the world's charcoal and a large part of this is used to produce pig iron, ferroalloys and silicon metal. There is a large proportion of artisanal production in the country and pressure for sustainable production systems has led to the development of new clean technologies with higher yields [2]. There are a total of 21 types of carbonization furnaces, of which there are 172 patents with various improvements to the carbonization process [3].

Residues from rice, maize, soy, wheat and other crops such as bambo have high energy potential, and these sources can contribute to increasing electricity generation [4]. The carbonization process has evolved, as has furnace productivity, and making full use of the energy contained in biomass has reached technological limits [5]. With finite natural resources and an industry that is intensive for the development of society, it is necessary to develop alternatives in the direction of the circular economy [6].

This article carries out an analysis of the availability of maize waste and bamboo biomass in Brazil, as well as a review of the optimized carbonization process, where there is use of the gases generated and co-products from the pyrolysis process. The article also evaluates a charcoal generation process that can be adapted to the conditions of biomass availability in the regions of Brazil.

Mineral exploration generates a significant amount of waste, whose improper disposal can cause adverse environmental impacts. This work investigates the use of mining waste processed by gravimetric separation methods, aiming at the production of sustainable construction materials and the elimination of dams, pits, and dry stacks. The waste was subjected to separation processes using a shaking table and a Humphrey spiral, with the objective of separating the clay, sand, and iron contained in the residual material. 

Gravimetric methods are based on the difference in density between minerals to promote separation. The shaking table uses vibratory movements combined with a water flow to separate particles according to their density and size. In this process, heavier particles, such as iron, are directed to one end, while lighter particles, such as sand and clay, are collected at the other end. The Humphrey spiral, in turn, uses the centrifugal force generated by the spiral flow to separate particles of different densities, collecting the sand in the outer parts of the spiral and the clay in the intermediate areas. 

After separation, the resulting sand was analyzed for its granulometry through sieving. This process involves passing the sand through a series of sieves with different openings, classifying the particles according to their size. Adequate granulometry is crucial to ensure the quality of interlocking blocks, directly influencing their strength and durability. 

The processed sand was then used in the production of interlocking paving blocks, employing a vibratory press. This equipment compacts the mixture of sand, cement, and water, forming high-density and high-strength blocks. Interlocking blocks are a sustainable and efficient alternative for paving, offering ease of installation and maintenance, as well as allowing rainwater drainage. 

To evaluate the quality of the produced blocks, standard compressive strength tests were carried out. These tests consist of subjecting the blocks to compressive forces until rupture occurs, measuring the maximum strength supported. The interlocking blocks manufactured with the processed waste sand achieved a compressive strength of 14,87 MPa, meeting the normative requirements for paving.

In addition to using sand, the separated clay was used in the manufacture of soil-cement blocks for building construction. The clay was mixed with soil and cement, compacted in specific molds, and cured to achieve adequate strength for civil construction. These soilcement blocks offer advantages in terms of sustainability and cost-benefit, contributing to more ecological constructions. 

The iron separated from the waste was pelletized to supply the metallurgical industry. Pelletization involves agglomerating iron fines into pellets, which are then used as raw material in steel production. This process not only adds value to mining waste but also reduces the need for virgin iron ore extraction, promoting sustainability in the metallurgical industry. 

The results of this study demonstrate the feasibility of using processed mining waste in the production of sustainable construction materials and supplying the metallurgical industry. The application of gravimetric separation methods proved effective in obtaining materials of adequate quality, and the manufactured products showed satisfactory performance in strength tests. This study reinforces the importance of innovative solutions for mining waste management, promoting material recycling and the circular economy, eliminating the need for dams, pits, and dry stacks.

The present work aims to analyze the characteristics of macauba (Acrocomia aculeata), as well as its occurrence in Brazil and its energy properties that differentiate it from other biomasses due to its extreme importance for the generation of clean energy, from sources extracted from the environment and for sustainable development. The energy potential of macaúba biomass provides the strengthening of the Brazilian domestic market, since the oil extracted from this palm tree may have differentiated applications, including in industries. Compared to other biomasses, it is noted that macauba oil is produced in greater quantity and has high agricultural profitability. In the steel mill, the use of macaúba contributes to mitigate the emission of polluting gases resulting from the burning of fuels in blast-ovens, besides having several other advantages, as well as the low amount of ash generated.

The Ni-Ti alloy exhibits exceptional properties that enhance its compatibility with the human body, notably its low density, mechanical strength, corrosion and wear resistance, shape memory effect, and superelasticity. The shape memory effect involves a thermal hysteresis due to phase transitions from martensite to austenite when the alloy is cooled and then heated above its transformation threshold, enabling it to revert to its original shape. The superelasticity effect allows the material to return to its original shape after deformation of up to 10% under applied load. In this study, three samples containing 49.5% Ti and 50.5% Ni were produced using the powder metallurgy technique. The chemical composition of these samples was analyzed. The Ni and Ti metal powder mixture was sintered in a controlled atmosphere furnace at 1118°C in the presence of an inert atmosphere with analytical argon 2.0. Following analysis under an optical microscope and scanning electron microscope (SEM), Vickers microhardness, corrosion, and wear tests were conducted to evaluate the alloy's suitability for prosthetics and orthopedic implants.

According to the International Energy Agency (IEA) [1], the steel sector, among heavy industries, ranks first in CO2 emissions and second in energy consumption. Iron and steel are directly responsible for 2.6 gigatons of carbon dioxide (GT CO2) emissions annually, accounting for 7% of the total global energy system. The Sixth Assessment Report (AR6) of the IPCC (United Nations Intergovernmental Panel on Climate Change) of 2023 [2], containing a comprehensive study on the climate situation of the planet, has shown in a worrying way that the goals established on December 12, 2015, in the Paris Agreement, which aims to limit global warming to less than 2, preferably 1.5 degrees Celsius, are increasingly out of reach. Brazil is the largest steel producer in Latin America and the ninth largest in the world, according to the Instituto Aço Brasil [3]. Brazil's energy park has large renewable energy sources (hydroelectric, wind, solar and biomass plants), reaching 93.1% of electricity generation in 2023, E3G [4].In this way, with the decarbonization process of steel production, combined with the use of Biochar, green hydrogen, will make Brazil a major player in the production of green steel.This study aims to evaluate the ways and processes in which Brazil has been planning its decarbonization, thus contributing to achieving the goals of the Paris agreement.

The steelmaking industry is of fundamental importance in the energy context of Brazil, being characterized as one of the major consumers of electricity in the country. To be competitive in the global market, the steelmaking industry needs to show an excellent strategic plan. This plan includes efficient energy planning, seeking to make better use of resources, low environmental impacts and operating costs [1]. The thermoelectric power plants of coke integrated steelmaking industry demonstrate great economic potential, since they make use of the waste gases from the process [2]. The aim of this work is to analyze, from the environomic viewpoint, the thermoelectric power plant, observing the influence of hydrogen addition. The generation of hydrogen is by water electrolysis, driven by photovoltaic power. The methodology comprises of using a computational model created with Scilab [3]. For model validation, the actual data from the thermal power plant is used. Thermoeconomic modeling aims to obtain a system of cost equations that mathematically represents the cost formation process in the plant [4]. The computer simulations use seven scenarios of possible fuel mixtures, using the BFG, LDG, COG, and H2. The results indicate that up to 30% of hydrogen with BFG is possible to obtain energy and exergy efficiency equivalent to scenario zero that most represents the operation of the thermoelectric plant and still reduce the fuel cost [5]. The importance of energy management in an organization is highlighted in terms of potential financial gains and cost reductions. Scenario 0 based the real operating model showed lower exergetic efficiency 23.87%.

The objective is to inform, with a broad vision, the possibilities of acquiring, registering, legalizing and exploring a mining enterprise in Brazil. Bringing national or foreign investors legal and economic security, with the minimum necessary support, to reassure the investor in a correct and legal way, mining exploration as an excellent and profitable business to be invested in. This paper does not exhaust the topic addressed, since the Brazilian legislation on Mining Law, which is currently under the control of the National Mining Agency – ANM – as provided for in Law No. 13,575/2017, which should undergo some changes, as already under analysis in the Chamber of Deputies, Bill 957/24, which aims to bring several innovations and regulations into the legislation of the Brazilian Mining Law framework.

Currently, Brazil is the second largest producer of iron ore in the world, behind only China, which holds 21% of production, while Brazil contributes to 19%. This production plays a crucial role in the country's trade balance.

However, the extraction and processing activities of this natural resource also cause significant environmental impacts, mainly due to the generation and disposal of large quantities of waste.

Furthermore, iron ore tailings, a by-product of mining, are often deposited in dams, posing known risks to the population, as evidenced by the disasters in Mariana and Brumadinho in the State of Minas Gerais, which occurred in 2015 and 2019 respectively.

Given the need to minimize these impacts and risks, researchers and mining companies have been committed to developing studies to optimize processing, aiming to reduce the amount of waste generated and/or its use as raw material in other sectors, such as in the civil construction field.

In this sense, iron ore waste has been transformed, through technological innovation processes, into materials in order to create pavements and residential houses that can be used for the population of municipalities affected by the environmental impacts arising from mining. The paper aims to demonstrate the tax benefits that mining companies can obtain through the “Lei do Bem” (Law 11,196/2005), which grants tax benefits to companies that contribute to RD&I projects aiming at technological innovation, providing companies the benefits of the reduction in the Income Tax rate and the Social Contribution on Net Profits (CSL) to be applied to Actual Profit Method (“Lucro Real”) in total balance with environmental, social and governance (ESG) aspects.