Disclosed herein are methods and compositions for producing composite pellets comprising a core comprising: iron ore and a carbonaceous reducing agent; and a shell comprising: iron ore; and having a core and shell transition in a manner such that no visible boundary exists between the core and the shell in a cross-section of the pellet. The methods can be used to produce composite pellets with improved productivity and quality, and the resulting composite pellets can be used to produce direct reduced iron (DRI).

A method of processing iron ore fines from various possible sources, with particle size up to 0.15 mm (through 100 mesh sieve) with no or limited comminution, directly into the intense mixer, with a set of binders in specific proportions, aiming to optimize physical and metallurgical properties of the pellets with minimal binder addition, thus not compromising the quality of steel products. The binders are starch, sodium silicate and sodium hydroxide, among others. The mixture with adjusted moisture content goes through conventional balling discs or drums and size screening. The green pellets then undergo drying with forced air at around 150° C. for a short time. The pellets obtained have excellent metallurgical properties, and compression resistance around 70 kgf/pellets, without the high and undesirable economic and environmental costs of the conventional indurating process. An alternative embodiment (FIG. 3) considers indurating the pellets at temperatures below 1,200° C. to obtain similar mechanical resistance than pellets made by the conventional induration process, with temperatures above 1,300° C.

The present invention concerns the use of a magnesium-including compound as binder for producing metallic ore fluxed pellets, in particular iron ore fluxed pellets, said magnesium-including compound comprising semi-hydrated dolime fitting the general formula aCa(OH).sub.2.Math.bMg(OH).sub.2.Math.cMgO, a, b, and c being weight fractions wherein the weight fraction b of Mg(OH).sub.2 is between 0.5 and 19.5 % by weight with respect to the total weight of said semi-hydrated dolime.

A method for producing briquettes from pellet fines, DRI sludge, DRI fines and dust from DRI dedusting systems and, in this way, reincorporating same into steel production processes, thereby contributing to the re-use of the by-products of these processes, as well as minimizing the stocks of these types of materials and, consequently, helping to improve the environment. The invention comprises: grinding and sieving the pellet fines and the DRI sludge; sieving the DRI fines; storing the dust from DRI dedusting systems; briquetting with roller presses, using liquid sodium silicate and bentonite or composite Portland cement as binders; sieving the briquettes; shredding the edges and waste of the fresh briquettes; and curing in order to improve the physical properties thereof, such as strength. Once cured, the fresh briquette can be stored or sent directly to direct-reduced iron production processes for use as part of the feedstock for reduction ovens or reactors.

Improved processes and systems are disclosed for producing renewable hydrogen suitable for reducing metal ores, as well as for producing activated carbon. Some variations provide a process comprising: pyrolyzing biomass to generate a biogenic reagent comprising carbon and a pyrolysis off-gas; converting the pyrolysis off-gas to additional reducing gas and/or heat; reacting at least some of the biogenic reagent with a reactant to generate a reducing gas; and chemically reducing a metal oxide in the presence of the reducing gas. Some variations provide a process for producing renewable hydrogen by biomass pyrolysis to generate a biogenic reagent, conversion of the biogenic reagent to a reducing gas, and separation and recovery of hydrogen from the reducing gas. A reducing-gas composition for reducing a metal oxide is provided, comprising renewable hydrogen according to a hydrogen-isotope analysis. Reacted biogenic reagent may also be recovered as an activated carbon product. Many variations are disclosed.

A method for supplying raw material to a sinter plant and facilitating a sinter process with reduced consumption of fossil fuels, provides that a mixed material is used to supply raw material, wherein the mixed material includes particulate iron-containing material and particulate pyrolised biomass in mixed form. The iron-containing material is preferably iron ore and/or the pyrolised biomass is preferably charcoal.

An induration machine includes a travelling grate for transporting bulk material along a transport direction from a heating zone for heating and/or drying the material to a cooling zone for cooling the material by cooling gas. The machine includes a hood disposed over the travelling grate having a first hood section in the heating zone and a second hood section in the cooling zone; and two recuperation ducts for guiding used cooling gas from the second hood section to the first hood section.

The recuperation ducts are disposed on opposite sides of the hood, are laterally offset with respect to the hood, and are connected to the second hood section by a V-shaped gas collector duct. Each recuperation duct is connected to the first hood section by at least one gas supply duct and has at least one dust purge opening disposed in the lowermost part of the recuperation duct for purging dust from the recuperation duct.

Improved processes and systems are disclosed for producing renewable hydrogen suitable for reducing metal ores, as well as for producing activated carbon. Some variations provide a process comprising: pyrolyzing biomass to generate a biogenic reagent comprising carbon and a pyrolysis off-gas; converting the pyrolysis off-gas to additional reducing gas and/or heat; reacting at least some of the biogenic reagent with a reactant to generate a reducing gas; and chemically reducing a metal oxide in the presence of the reducing gas. Some variations provide a process for producing renewable hydrogen by biomass pyrolysis to generate a biogenic reagent, conversion of the biogenic reagent to a reducing gas, and separation and recovery of hydrogen from the reducing gas. A reducing-gas composition for reducing a metal oxide is provided, comprising renewable hydrogen according to a hydrogen-isotope analysis. Reacted biogenic reagent may also be recovered as an activated carbon product. Many variations are disclosed.

Improved processes and systems are disclosed for producing renewable hydrogen suitable for reducing metal ores, as well as for producing activated carbon. Some variations provide a process comprising: pyrolyzing biomass to generate a biogenic reagent comprising carbon and a pyrolysis off-gas; converting the pyrolysis off-gas to additional reducing gas and/or heat; reacting at least some of the biogenic reagent with a reactant to generate a reducing gas; and chemically reducing a metal oxide in the presence of the reducing gas. Some variations provide a process for producing renewable hydrogen by biomass pyrolysis to generate a biogenic reagent, conversion of the biogenic reagent to a reducing gas, and separation and recovery of hydrogen from the reducing gas. A reducing-gas composition for reducing a metal oxide is provided, comprising renewable hydrogen according to a hydrogen-isotope analysis. Reacted biogenic reagent may also be recovered as an activated carbon product. Many variations are disclosed.

Improved processes and systems are disclosed for producing renewable hydrogen suitable for reducing metal ores, as well as for producing activated carbon. Some variations provide a process comprising: pyrolyzing biomass to generate a biogenic reagent comprising carbon and a pyrolysis off-gas; converting the pyrolysis off-gas to additional reducing gas and/or heat; reacting at least some of the biogenic reagent with a reactant to generate a reducing gas; and chemically reducing a metal oxide in the presence of the reducing gas. Some variations provide a process for producing renewable hydrogen by biomass pyrolysis to generate a biogenic reagent, conversion of the biogenic reagent to a reducing gas, and separation and recovery of hydrogen from the reducing gas. A reducing-gas composition for reducing a metal oxide is provided, comprising renewable hydrogen according to a hydrogen-isotope analysis. Reacted biogenic reagent may also be recovered as an activated carbon product. Many variations are disclosed.