A method and system for recovering a high yield of low carbon ferrochrome from chromite and low carbon ferrochrome produced by the method. A stoichiometric mixture of feed materials including scrap aluminum granules, lime, silica sand, and chromite ore are provided into a plasma arc furnace. The scrap aluminum granules are produced from used aluminum beverage containers. The feed materials are heated, whereupon the aluminum in the aluminum granules produces an exothermic reaction reducing the chromium oxide and iron oxide in the chromite to produce molten low carbon ferrochrome with molten slag floating thereon. The molten low carbon ferrochrome is extracted, solidified and granulated into granules of low carbon ferrochrome. The molten slag is extracted, solidified and granulated into granules of slag.

A method for the treatment of black slag, which contains lime (CaO) or lime-based compounds, and which is generated in an electric furnace that produces steel from scrap, includes indirectly cooling the black slag immediately after the black slag exits from the electric furnace or after collection of the black slag in a cauldron, for a period of time between about 10 minutes and about 45 minutes.

A reduced iron production method includes: a reduction-step of producing reduced iron by heating an agglomerate containing iron oxide and carbonaceous reducing agent to reduce the iron oxide and solidifying a product produced by melting the reduced iron; a first-magnetic-separation-step of separating, among granular metallic iron, first slag, and second slag containing more fine-granular metallic iron than the first slag that are contained in the product, at least the granular metallic iron from the first slag by use of a first magnetic separator to separate first slag containing substance and a granular metallic iron containing substance from each other; a second-magnetic-separation-step of separating the second slag from the first slag containing substance or the granular metallic iron containing substance by use of a second magnetic separator having attraction force different from attraction force of the first magnetic separator; and a crushing-step of crushing the second slag.

A method and system for recovering a high yield of low carbon ferroalloy, e.g., low carbon ferrochrome, from chromite and low carbon ferrochrome produced by the method. A stoichiometric mixture of feed materials including scrap aluminum granules, lime, silica sand, and chromite ore are provided into a plasma arc furnace. The scrap aluminum granules are produced from used aluminum beverage containers. The feed materials are heated, whereupon the aluminum in the aluminum granules produces an exothermic reaction reducing the chromium oxide and iron oxide in the chromite to produce molten low carbon ferrochrome with molten slag floating thereon. The molten low carbon ferrochrome is extracted, solidified and granulated into granules of low carbon ferrochrome. The molten slag is extracted, solidified and granulated into granules of slag.

A method for the treatment of black slag, which contains lime (CaO) or lime-based compounds, and which is generated in an electric furnace that produces steel from scrap, includes indirectly cooling the black slag immediately after the black slag exits from the electric furnace or after collection of the black slag in a cauldron, for a period of time between about 10 minutes and about 45 minutes.

A liquid slag granulating system includes a granulator (1), a granulator connecting part and a granulator drive part. The granulator (1) is disc-shaped or cup-shaped, and a diversion cone is arranged at a center of the granulator (1). The granulator drive part drives the granulator to rotate, thus granulating liquid slag. The system further includes an air supply part.

An apparatus for cooling a material includes: at least one reactor, substantially tubular, which is rotatable and which includes a rotating tubular structure defining inside it a chamber for receiving and passing through the material to be cooled; and means for indirectly cooling the material passing through said chamber by means of a cooling fluid, the means for indirect cooling comprise at least one dispensing device for the cooling fluid. The at least one dispensing device includes at least two dispensing mouths defined by respective slots, with substantially longitudinal development, for the escape of the refrigerant fluid, the device being arranged with respect to the tubular structure in so that the flow outgoing from said two slits affects and laps two respective areas, distinct from each other, of the external surface of the tubular structure.

A system and method deliver fluidized powder based on flue gas carrying waste slag and instant cooling steel slag. A first flue gas pipeline receives pressurized CO.sub.2-rich flue gas and in fluid communication with a fluidization air pipeline, a pressurization air pipeline and a supplementary air pipeline respectively and through them enters an upper discharge bin; a second flue gas pipeline receives the pressurized CO.sub.2-rich flue gas and in fluid communication with a gas-gas mixer, a dense phase discharge guide pipe first end extends into the upper discharge bin and receives high-pressure dense phase gas-powder flow of CO.sub.2-rich flue gas, and a dense phase discharge guide pipe second end is connected to the gas-gas mixer; a variable-pitch twin screw sealed conveyor discharge end extends into an upper discharge bin internal space, and is provided with an upwardly inclined gas-blocking segment.

The present invention provides a method of simultaneously recycling plastics and detoxifying chromite ore processing residue with residual heat from a steel slag. By heating and gasifying plastics with steel slag, followed by catalytically split-decomposing the plastics with catalysts such as chromite ore processing residue, the plastics are thoroughly converted into a energy gas under water vapor gasification. The surface coking of Chromite Ore Processing Residue is avoided. Meanwhile, the energy gas reduces Cr.sup.6+ in Chromite Ore Processing Residue into Cr.sup.3+, and the energy gas is cooled, and CO.sub.2 and Cl in the energy gas are adsorbed by alkaline substances in Chromite Ore Processing Residue. With this method, chromite ore processing residue is detoxified, and steel slag is cooled, furthermore, energy is saved and a energy gas is obtained.

Some methods for making a granular material comprise crushing demetallized slag particles with one or more crushers and screening the crushed demetallized slag particles with one or more screens to separate the demetallized slag particles into two or more fractions, the granular material comprising at least one of the fractions of the demetallized slag particles. Prior to the crushing, ones of the demetallized slag particles having a size that is less than or equal to 2 inches can account for at least 90% of the demetallized slag particles. An iron-compound content of the demetallized slag particles, by weight, can be less than or equal to 10%. Crushing and screening can be performed such that ones of the demetallized slag particles of the granular material having a size that is less than or equal to 1.25 mm account for at least 90% of the demetallized slag particles of the granular material.