An agglomerated ore is reduced while being subjected to a predetermined load at 1000? C. to 1200? C., both inclusive, to produce a reduced aggregate; a tumble treatment is performed on the reduced aggregate using a tumble tester; cluster strength CS of the reduced aggregate calculated by Formula (1) below is measured; and a clustering property of the agglomerated ore is assessed using the cluster strength CS: CS=(W/W)?100 . . . (1), where CS is cluster strength (mass %); W is the mass (g) of a reduced aggregate that is equal to or larger than a maximum particle diameter of the agglomerated ore; and W is the mass (g) of a reduced aggregate after a tumble treatment in the tumble tester that is equal to or larger than the maximum particle diameter of the agglomerated ore.

Provided is an ore crushing method capable of efficiently crushing iron ores that are difficult to finely crush. The ore crushing method includes coarsely crushing the iron ores to reduce the proportion of particles with a particle size of greater than or equal to 1 mm, and then finely crushing the iron ores to increase the proportion of particles with a particle size of less than 63 ?m. The average pore size of the iron ores is preferably less than or equal to 10 ?m, the proportion of the particles with a particle size of greater than or equal to 1 mm in the iron ores is preferably greater than or equal to 30 mass %, the iron ores are preferably coarsely crushed so that the proportion of the particles with a particle size of greater than or equal to 1 mm becomes less than or equal to 20 mass %, the iron ores are preferably finely crushed so that the proportion of the particles with a particle size of less than 63 ?m becomes greater than or equal to 70 mass %, and the iron ores are preferably finely crushed with a wet ball mill. A pellet production method is also provided that includes granulating a raw material, which includes the iron ores crushed with the ore crushing method, into pellets.

Provided is a device for producing partially reduced iron, with which partially reduced iron having a prescribed reduction ratio can be produced efficiently. The present invention is equipped with: CO sensors that detect the carbon monoxide concentration in an exhaust gas; an O.sub.2 sensor that detects the oxygen concentration in an exhaust gas; an exhaust gas circulation device that adjusts the circulating amount of the exhaust gas supplied to a reduction furnace main body, and an air feed device that adjusts the amount of air that being fed; and a control device that controls these devices. The control devices on the basis of the carbon monoxide concentration in the exhaust gas as detected by the CO sensor and the oxygen concentration in the exhaust gas as detected by the O.sub.2 sensor.

Provided is a device for producing partially reduced iron, with which partially reduced iron having a prescribed reduction ratio can be produced efficiently. The present invention is equipped with: CO sensors that detect the carbon monoxide concentration in an exhaust gas; an O.sub.2 sensor that detects the oxygen concentration in an exhaust gas; an exhaust gas circulation device that adjusts the circulating amount of the exhaust gas supplied to a reduction furnace main body, and an air feed device that adjusts the amount of air that being fed; and a control device that controls these devices. The control devices on the basis of the carbon monoxide concentration in the exhaust gas as detected by the CO sensor and the oxygen concentration in the exhaust gas as detected by the O.sub.2 sensor.

A method and a device for producing granulates (1) which are obtained by the method steps: intensively mixing raw materials (2) and optionally additives (6) by adding water (3) to form a mixture (4); introducing the mixture (4) and optional additives (6) into a granulator (11); granulating the mixture (4) by adding water (3) to form raw granulates (12); introducing the raw granulates (12), water (3) and optional additives (6) into a rolling drum (17) and rolling the raw granulates (12) to form the granulates (1).

A method and a device for producing granulates (1) which are obtained by the method steps: intensively mixing raw materials (2) and optionally additives (6) by adding water (3) to form a mixture (4); introducing the mixture (4) and optional additives (6) into a granulator (11); granulating the mixture (4) by adding water (3) to form raw granulates (12); introducing the raw granulates (12), water (3) and optional additives (6) into a rolling drum (17) and rolling the raw granulates (12) to form the granulates (1).

There is provided a method for producing (high purity) hematite for ironmaking, in a process where a mineral acid and an oxidizing agent are added to an ore containing iron and a valuable metal and then the valuable metal is leached under high temperatures and high pressures, comprises the steps of: (1) a high pressure leach step; (2) a preliminary neutralization step; (3) a solid-liquid separation step 1; (4) a neutralization step 1; (5) a neutralization step 2; (6) a solid-liquid separation step 3; (7) seed crystal addition treatment; (8) a solid-liquid separation step 2; and (9) a firing step.

There is provided a method for producing (high purity) hematite for ironmaking, in a process where a mineral acid and an oxidizing agent are added to an ore containing iron and a valuable metal and then the valuable metal is leached under high temperatures and high pressures, comprises the steps of: (1) a high pressure leach step; (2) a preliminary neutralization step; (3) a solid-liquid separation step 1; (4) a neutralization step 1; (5) a neutralization step 2; (6) a solid-liquid separation step 3; (7) seed crystal addition treatment; (8) a solid-liquid separation step 2; and (9) a firing step.

Examples herein generally relate to sinter blend compositions for use in a sintering process that do not contain coke breeze (0.0% coke breeze), or contain only very small amounts of coke breeze. In particular, these sinter blend compositions are capable of repurposing mixture of iron-making reverts, having high total and metallic iron levels that re-oxidize so as to become a replacement fuel source for the coke breeze typically used in sinter blend compositions for use. in a sintering process, while still managing to produce a sinter with sufficient ISO tumble strengths.

Examples herein generally relate to sinter blend compositions for use in a sintering process that do not contain coke breeze (0.0% coke breeze), or contain only very small amounts of coke breeze. In particular, these sinter blend compositions are capable of repurposing mixture of iron-making reverts, having high total and metallic iron levels that re-oxidize so as to become a replacement fuel source for the coke breeze typically used in sinter blend compositions for use. in a sintering process, while still managing to produce a sinter with sufficient ISO tumble strengths.