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.

Disclosed are a hydraulic binder composition using rapidly-cooled steelmaking reduced slag powder and a method of preparing the same. More particularly, the rapidly-cooled steelmaking reduced slag (RC-LFS) powder is obtained by spraying and scattering gas at a high pressure and high speed onto electric furnace smelting reduction slag, which is one of the by-products generated during iron smelting performed in an ironworks, and quickly cooling and pulverizing the slag. The initial high hydration heat reaction and initial setting of the rapidly-cooled steelmaking reduced slag (RC-LFS) powder are delayed to ensure workability. A retardant and gypsum are mixed into the rapidly-cooled steelmaking reduced slag (RC-LFS) powder so as to activate the generation of needle-shaped ettringite and to thus develop the initial and long-term strength, and therefore the rapidly-cooled steelmaking reduced slag (RC-LFS) powder of the present invention can be used as a substitute for ordinary Portland cement.

The liquid steel slag (2) is poured in at least four successive layers (6-8), comprising a lowermost layer (6), an uppermost layer (7) and at least two intermediate layers (8), in a reservoir (3) and the layers of liquid steel slag are allowed to solidify. After having applied the uppermost layer (7), the solidified steel slag is cooled down more quickly by means of water. The average temperature of each of the intermediate layers (8) is kept at least until the start of the water cooling step, and this for at least one hour, above a minimum temperature which is equal to or higher than the temperature at which -dicalcium silicate is formed. In this way, more crystalline phases different from dicalcium silicates are formed so that the formation of fines by the transition of into -dicalcium silicates can be considerably reduced. A glassy material and/or a phosphorus containing compound is preferably added to the liquid slag to further reduce the formation of fines.

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.

Pig iron and spherical silica-based proppant are extracted and produced through the use of formers, fluxes, reductants, and stabilizers, at predetermined specified weight ratios. The base material utilized in this process is slag, typically derived from the mining industry. The slag is delivered and utilized in a manner that allows the adding and mixing of the various materials such as, but not limited to, carbon, calcium oxide, sodium oxide, aluminum oxide, magnesium oxide, and potassium oxide. The formulated mixture is then heated for a predetermined period of time, based upon weight to a liquid state, wherein the molten pig iron is separated from the molten silica glass. The molten pig iron is then poured into molds, and the molten silica glass is atomized into spherical proppant. The process is particularly well suited to slags produced from copper smelting, but can be extended to slags from other commodities and industries.

A method of ironmaking using full-oxygen hydrogen-rich gas which includes hot transferring and hot charging the high-temperature coke, sinter and pellet into the ironmaking furnace through transferring and charging device, and injecting oxygen and hydrogen-rich combustible gas at a predetermined temperature into the ironmaking furnace through the oxygen tuyere and the gas tuyere disposed at the ironmaking furnace, respectively. It also provides an apparatus for ironmaking using full-oxygen hydrogen-rich gas which includes a raw material system, a furnace roof gas system, a coke oven gas injecting system, a dust injecting system, a slag dry-granulation and residual heat recovering system and an oxygen system. Additionally an apparatus and method for hot transferring and hot charging of ironmaking raw material is disclosed.

A method for the granulation of a metallurgical slag includes blowing, from a blower or air nozzle, heated air onto liquid slag to atomize the liquid slag and subsequently form granulated slag as the atomized slag cools. The granulated slag is blown into and collected by a working chamber. In order to ensure a high quality of the granulated slag and operate in an energy-efficient manner, the atomization is provided by blowing a heated air jet free from the addition of water onto the liquid slag. The granulated slag particles are collected in the floor region of the working chamber. Air that is released from the working chamber is either supplied to a heat exchanger, which further heats the air jet blown onto the liquid slag, or the released air is directly recirculated to the blower or air nozzle in order to atomize the supply of liquid slag.

A process for the granulation of slag deriving from iron and steel production, in particular a process for the granulation of slag in air, and an apparatus configured to perform this process, provide for the production of granulates with different characteristics depending on the intended use, thus making this process and apparatus particularly versatile. More specifically, a process according to the present invention includes a step of controlling and modifying the time and/or the cooling rate of the slag granules so as to obtain slag granules having desired morphological features.