Jacketed rotary converter. The converter includes an inclined pot mounted for rotation about a longitudinal axis, a refractory lining for holding a molten alloy pool, an opening in a top of the pot for introducing feed, a lance for injecting oxygen-containing gas, a heat transfer jacket for the pot adjacent the refractory lining, and a coolant system to circulate a heat transfer medium through the jacket to remove heat from the alloy pool in thermal communication with the refractory lining. Also disclosed is a PGM converting process using the jacketed rotary converter. The process can also include low-or no-flux converting; refractory protectant addition; slag separation; partial feed pre-oxidation; staged slagging; and/or smelting the slag in a secondary furnace with primary furnace slag.

The invention relates to a plant complex for steel production comprising a blast furnace for producing pig iron, a converter steel mill for producing crude steel and a gas-conducting system for gases that occur in the production of pig iron and/or in the production of crude steel. According to the invention, the plant complex additionally has a chemical or biotechnological plant connected to the gas-conducting system and a plant for producing hydrogen. The plant for producing hydrogen is connected to the gas-conducting system by a hydrogen-carrying line. Also the subject of the invention is a method for operating the plant complex.

The invention relates to a plant complex for steel production comprising a blast furnace for producing pig iron, a converter steel mill for producing crude steel and a gas-conducting system for gases that occur in the production of pig iron and/or in the production of crude steel. According to the invention, the plant complex additionally has a chemical or biotechnological plant connected to the gas-conducting system and a plant for producing hydrogen. The plant for producing hydrogen is connected to the gas-conducting system by a hydrogen-carrying line. Also the subject of the invention is a method for operating the plant complex.

A process and system having a primary crusher to reduce the fragments according to their granulometry; a magnetic separator to remove metallic fragments bigger than a determined granulometry; a rotary dryer to dry slag; an impact mill to disaggregate and fragment slag particles; a classifier for aero-classification and drag of fine and superfine particles; a cooler for cooling slag by means of heat exchange and removal of the fine and superfine particles that were not collected by the impact mill a vibrating sieve provided with two or more decks with screens of predetermined sizes; low-intensity magnetic separators, with generation of non-magnetic slag fractions free from metallic iron and from iron monoxide, and of magnetic fractions composed by metallic iron and iron monoxide; and low-intensity magnetic separators to reprocess the magnetic fractions with generation of concentrate with high metallic iron contents and a product with high concentration of iron monoxide.

A slag volume evaluation method for a molten metal surface includes calculating an approximation curve indicating a correspondence between a thickness of slag and a density parameter in advance by measuring thicknesses of a plurality of pieces of the slag which float on a surface of a molten metal in a container and differ from each other in thickness, and calculating a value of the density parameter which is correlated to a density in a pixel region corresponding to the plurality of pieces of the slag in a captured image of a molten metal surface in the container; and calculating a volume of the slag by calculating and integrating the thickness of the slag for each of pixels constituting the captured image obtained by capturing an image of the molten metal surface which is an evaluation target, according to a value of the density parameter of each of the pixels and the approximation curve.

The present invention relates to a method and system for recovering carbonate from steel slag, in which it is possible to extract carbonate from steel slag and reuse the extracted carbonate, and to recycle steel slag and make use of CO.sub.2 gas without emission to the atmosphere. Since unreacted metal ions and an acidic solvent are reused in the method and system, it is possible to increase carbonate extraction efficiency and reduce an amount of waste.

The present invention relates to a method and system for recovering carbonate from steel slag, in which it is possible to extract carbonate from steel slag and reuse the extracted carbonate, and to recycle steel slag and make use of CO.sub.2 gas without emission to the atmosphere. Since unreacted metal ions and an acidic solvent are reused in the method and system, it is possible to increase carbonate extraction efficiency and reduce an amount of waste.

Integrated PGM converting process. The process includes smelting a catalyst material in a primary furnace, smelting the primary furnace slag in a secondary furnace, converting the collector alloys from the primary and secondary furnaces in a converter to recover PGM enriched alloy and converter slag, separating the recovered converter slag into first and second converter slag portions, and supplying the first converter slag portion to the secondary furnace for smelting with the primary furnace slag. The process can also include low- or no-flux converting; refractory protectant addition; magnetic slag separation; partial feed pre-oxidation; staged slagging; and/or jacketing the converter.

The process includes melting an initial collector alloy charge to start a converter cycle, introducing feed and injecting oxygen into the alloy pool, allowing ferrous slag to collect, terminating feed introduction and oxygen injection to tap the slag, repeating the feed introduction/oxygen injection/slag tapping sequence a plurality of times, and then tapping the alloy to end the cycle. A delay before non-final slag tappings allows any entrained alloy to settle back into the alloy pool, but the final slag tapping is commenced promptly and alloy is optionally entrained. Slag from the final tapping that may contain entrained alloy can be recycled to the converter, e.g., in a subsequent cycle. The process can also include low- or no-flux converting; refractory protectant addition; slag separation; partial feed pre-oxidation; smelting the slag in a secondary furnace with primary furnace slag; and/or jacketing the converter.

A method and an installation (10) for removing slag allows both slag removal and metal recovery from slag (60) to be performed quickly and easily. The risk of slag fires is reduced.