Abstract: A low infrared absorbing lithium glass includes FeO in the range of 0.0005-0.015 wt %, more preferably 0.001-0.010 wt %, and a redox ratio in the range of 0.005-0.15, more preferably in the range of 0.005-010. The glass can be chemically tempered and used to provide a ballistic viewing cover for night vision goggles or scope. A method is provided to change a glass making process from making a high infrared absorbing lithium glass having FeO in the range of 0.02 to 0.04 wt % and a redox ratio in the range of 0.2 to 0.4 to the low infrared absorbing lithium glass by adding additional oxidizers to the batch materials. A second method is provided to change a glass making process from making a low infrared absorbing lithium glass to the high infrared absorbing lithium glass by adding additional reducers to the batch material. In one embodiment of the invention the oxidizer is CeO2. An embodiment of the invention covers a glass made according to the method.

Abstract: A method is provided for leaching the metals while granulating molten matte, comprising the steps of feeding a molten matte as a falling stream into a granulation chamber, spraying a liquid jet on the stream of molten matte to atomize the matte, and cooling the matte particles thus formed. The liquid jet comprises an acid solution containing water and sulfuric acid so that the acid solution starts leaching metals from the molten matte when the liquid jet contacts the molten matte. Part of product solution from granulation can be circulated to liquid jets to increase the metal content in the solution and to reduce its acid con-tent.

Abstract: An electrorefiner system according to a non-limiting embodiment of the present invention may include a vessel configured to maintain a molten salt electrolyte and configured to receive a plurality of alternately arranged cathode and anode assemblies. The anode assemblies are configured to hold an impure nuclear feed material. Upon application of the power system, the impure nuclear feed material is anodically dissolved and a purified metal is deposited on the cathode rods of the cathode assemblies. A scraper is configured to dislodge the purified metal deposited on the cathode rods. A conveyor system is disposed at a bottom of the vessel and configured to remove the dislodged purified metal from the vessel.

Abstract: The invention relates to a raw material charge for a melt for producing continuous mineral fibers, containing 30% to 70% basalt and/or diabase, 8% to 40% quartz components, in particular quartz sand, and 5% to 30% slag, in particular blast furnace slag, the use thereof and a method of producing continuous mineral fibers from a melt, the melt being formed from raw material comprising 30% to 70% basalt and/or diabase, 8% to 40% quartz components, in particular quartz sand, and 5% to 30% slag, in particular blast furnace slag.

Abstract: In order to produce metallurgical grade silicon and solar cell grade polysilicon in batches, a method of the present invention comprises: a step of reduction in an arc furnace, consisting of removing C and CO in a silicon reduction atmosphere using silica stone and carbon black by an arc so as to produce metallurgical grade silicon; a step of refining by slag consisting of removing phosphorus (P) and boron (B) by slag; a step of refining by unidirectional solidification consisting of removing metal impurities (Fe, Al, Ti, Mn, etc.) by means of unidirectional solidification; and a step of steam plasma-electromagnetism continuous refining consisting of charging a furnace with the unidirectionally solidified silicon and removing boron (B) by a steam plasma torch.

Abstract: A method for manufacturing a plate inorganic nonmetal material by using a molten slag by introducing the molten slag into a pool for preserving heat and modifying, wherein a temperature of the molten slag is 1450° C.-1600° C., and modifying a viscosity and/or a color of the molten slag according to requirements of the product manufactured. The modified molten slag is introduced into a float process furnace using tin or tin alloy carrier forming a plate of inorganic nonmetal material which is discharged at 1000-1300° C. The plate is maintained at 600° C.-900° C. for 0.5-2 hours in a non-reducing atmosphere, and then cooled to a room temperature within 1-2 hours. An energy-saving and efficient method for comprehensively utilizing the blast furnace slag is provided. The produced plate inorganic nonmetal material has such characteristics as stable color quality, abrasion resistance, pressure resistance, strong adhesiveness, low coefficient of expansion and low shrinkage ratio.

Abstract: A device for recovering heat of molten slag, having a simple structure and high heat recovery efficiency. The device includes: a fluidized bed (3) formed of a fluidized bed material (32) composed of a crushed solidified slag; a slag pool (4) for feeding a molten slag to the fluidized bed; heat transfer tubes (7) for recovering heat from the fluidized bed; and a solidified slag withdrawing device (21) for recovering a solidified slag (34), such solidified slag (34) being formed in the fluidized bed as the molten slag is solidified therein. Molten slag droplets (31) are dripped into the fluidized bed (3) from the slag pool (4) and solidified in the corresponding fluidized bed. The heat released at that time is transferred to the heat transfer tubes (7) through the bed material (32).

Abstract: A method for the pyrometallurgical processing of sulphide material containing nickel using a fluxing composition that includes calcium. The fluxing composition forms a slag having an Fe/CaO ratio of between about 0.5 and 5.0 by weight and an SiO2/Fe ratio of less than 0.2 by weight.

Abstract: A method of desulfurizing steel including steps of forming a slag over a molten metal, drawing a vacuum to less than 5 torr over the slag and molten metal, stirring the molten metal and slag, and deoxidizing and desulfurizing the molten metal and slag to degas the steel reducing at least sulfur, nitrogen, oxygen, and hydrogen contents, and reducing activity of oxygen in the molten metal to less than 30 ppm. The method includes forming a slag composition after degassing the steel comprising CaO between about 50 and 70% by weight, SiO2 between about 20 and 28% by weight, CaF2 between about 5 and 15% by weight, MgO not more than 8% by weight, Al2O3 not more than 1% by weight, and a combination of FeO+MnO not more than 2% by weight, where the sum of CaO+CaF2+SiO2+MgO is at least 85% by weight.

Abstract: A steel production method in the steel and iron industry involves dividing a vertically falling solid slag stream which flows from a steelmaking furnace into individual streams, forcedly cooling the individual streams, dividing the individual streams into parts by cutting across the movement thereof, forcedly cooling the parts and transferring them to a belt conveyor on which the separate parts are forcedly cooled and transported away from the vessel. A shaped conveyor belt, on which the slag parts are crushed by means of a cylindrical roll, is used for additional crushing.

Abstract: An apparatus for the production of a mineral melt burns combustible material in the presence of inorganic particulate material to form a melt. The apparatus has a circulating combustion chamber having at least two inlets which receive fuel, pre-heated mineral material, and combustion gas. A heat exchange system for pre-heating the mineral material has a pre-heater cyclone, a conduit running from the circulating combustion chamber to the first pre-heater cyclone for transporting exhaust gases, a material inlet for injecting the material into the conduit, and a bottom cyclone outlet for feeding pre-heated mineral material to the combustion chamber. The outlet of the pre-heater cyclone stabilizes and splits the mineral material flow into two material flows for feeding combustion chamber inlets.

Abstract: A method for manufacturing a plate inorganic nonmetal material by using a molten slag by introducing the molten slag into a pool for preserving heat and modifying, wherein a temperature of the molten slag is 1450° C.-1600° C., and modifying a viscosity and/or a color of the molten slag according to requirements of the product manufactured. The modified molten slag is introduced into a float process furnace using tin or tin alloy carrier forming a plate of inorganic nonmetal material which is discharged at 1000-1300° C. The plate is maintained at 600° C.-900° C. for 0.5-2 hours in a non-reducing atmosphere, and then cooled to a room temperature within 1-2 hours. An energy-saving and efficient method for comprehensively utilizing the blast furnace slag is provided. The produced plate inorganic nonmetal material has such characteristics as stable color quality, abrasion resistance, pressure resistance, strong adhesiveness, low coefficient of expansion and low shrinkage ratio.

Abstract: A process for manufacturing a vitreous slag including rotating a cone about a vertical cone axis, the cone including an external shell having a lateral surface; cooling the lateral surface of the external shell; pouring molten slag onto the lateral surface of the cone to form a film of slag by gravity, which is solidified as it is entrained in rotation by the cone about the cone axis; and detaching pieces of the film from the lateral surface and removing solidified slag in the form of the pieces after the film has been entrained through between 0.6 and 0.9 revolutions of the cone, the molten slag being poured onto the lateral surface in a pouring zone and spreads to form a film over substantially the entire length of the lateral surface, preferably over between 75% and 95% of the length of the lateral surface.

Abstract: A method of smelting a nickel intermediate product in a smelter that contains a molten bath of metal and slag to produce a nickel product, the method comprising supplying the nickel intermediate product and a solid reductant to the smelter and smelting the nickel intermediate product to produce molten nickel, and controlling the chemistry of the slag so that the slag has (a) a high solubility for elements and compounds in the nickel intermediate product that are regarded as contaminants in the nickel product and (b) a liquidus temperature in the range of 1300-1700 C.

Abstract: A glass composition useful in preparing fiberglass comprises 12 to 25 weight % CaO; 12 to 16 weight % Al2O3; 52 to 62 weight % SiO2; 0.05 to 0.8 Fe2O3; and greater than 2 up to about 8 weight % alkali metal oxide.

Abstract: A method improves yield of an upgraded metallurgical-grade (UMG) silicon purification process. In the UMG silicon purification process, in a reaction chamber, purification is performed on a silicon melt therein by one, all or a plurality of the following techniques in the same apparatus at the same time. The techniques includes a crucible ratio approach, the addition of water-soluble substances, the control of power, the control of vacuum pressure, the upward venting of exhaust, isolation by high-pressure gas jet, and carbon removal by sandblasting, thereby reducing oxygen, carbon and other impurities in the silicon melt, meeting a high-purity silicon standard of solar cells, increasing yield while maintaining low cost, and avoiding EMF reduction over time. An exhaust venting device for the purification process allows exhaust to be vented from the top of the reactor chamber, thereby avoiding backflow of exhaust into the silicon melt and erosion of the reactor.

Abstract: In a process for granulating slag, from a blast furnace or a smelting reduction plant, in which a granule/water mixture formed during the granulation is fed to a granulation tank and then to a dewatering installation, in which the slag granules are dewatered. H2S-containing vapors and gases formed during the granulation are at least partially condensed by injection of water in a condensation space which is flow-connected to the granulation tank. H2S-containing residual gases are discharged from the compensation space below the water injection point, H2S is burnt.

Abstract: A method and apparatus for manufacturing ceramic microspheres from industrial slag. The microspheres have a particle size of about 38 microns to about 150 microns. The microspheres are used to create a cement slurry having a density of at least about 11 lbs/g. The resultant cement slurry may then be used to treat subterranean wells.

Abstract: A method of making a foamed glass composite, including crushing a vitreous precursor material, such as waste glass, frit, metallurgical slag or the like, sizing the crushed vitreous precursor to segregate an amount of crushed particles of a predetermined size and pelletizing the crushed particles. The pellets are preheated and passed through a high-temperature zone to foam the pellets. The foamed pellets are rapidly quenched to a temperature below their dilatometric softening point and then cooled to room temperature. The high temperature zone is at least about 1200° C. and the pellets are preheated to within no more than about 25° C. of their dilatometric softening point. The pellets are quenched to partially or completely avoid annealing and have increased hardness and compressive strength as a consequence, as well as a preferred failure mode under compression and torsional loads of crushing/shattering.

Abstract: A method for improving yield of an upgraded metallurgical-grade (UMG) silicon purification process is disclosed. In the UMG silicon (UMGSi) purification process, in a reaction chamber, purification is performed on a silicon melt therein by one, all or a plurality of the following techniques in the same apparatus at the same time, including: a crucible ratio approach, the addition of water-soluble substances, the control of power, the control of vacuum pressure, the upward venting of exhaust, isolation by high-pressure gas jet, and carbon removal by sandblasting, thereby reducing oxygen, carbon and other impurities in the silicon melt, meeting a high-purity silicon standard of solar cells, increasing yield while maintaining low cost, and avoiding EMF reduction over time. An exhaust venting device for purification processes is also disclosed, which allows exhaust to be vented from the top of the reactor chamber, thereby avoiding backflow of exhaust into the silicon melt and erosion of the reactor.

Abstract: A process of water-granulating copper smelting slag can readily suppress elution of As from the copper smelting slag. A process of water-granulating a copper smelting slag with granulation water in a circulating system, includes granulating the copper smelting slag with the granulation water; settling suspended solids from the granulation water circulating in the system in a settling tank followed by discharging part of the granulation water through the settling tank from the system; and feeding supplementary water having a concentration of As of 0.01 mg/L or less into the system in such an amount that the total amount of the granulation water circulating in the system is kept constant; wherein the amount of granulation water discharged through the settling tank is such that As eluted from the copper smelting slag after water granulation is 0.01 mg/L or less.

Abstract: A synthetic glass family in the quaternary phase field of CaO—SiO2-Al2O3-MgO (CSAM) with hydraulic and pozzolanic properties for use in differing applications in the gas and oil well cementing area. A method of making a mud-to-cement (MTC) slurry and a method for treating oil and gas wells with the MTC slurry containing a homogenous amorphous synthetic glass made from a mixture of inorganic materials selected from the group consisting of CSAM, wherein the cementing glasses with the mixture of inorganic materials are in a 100% amorphous phase with a degree of crystallization of zero.

Abstract: A method for the recovery of refractory debris materials and ladle slags as process slags in the iron metallurgy production in EAFs and the related metering to the furnace for the formation of the process slag comprises the following steps: grinding and screening of the refractory debris materials until powders of controlled granulometry are obtained, storage of the powders in storage sites, injection of the powders into an EAF furnace by means of automatic metering of the various components.

Abstract: A method and apparatus for manufacturing ceramic microspheres from industrial slag. The microspheres have a particle size of about 38 microns to about 150 microns. The microspheres are used to create a cement slurry having a density of at least about 11 lbs/g. The resultant cement slurry may then be used to treat subterranean wells.

Abstract: A synthetic glass family in the quaternary phase field of CaO—SiO2-Al2O3-MgO (CSAM) with hydraulic and pozzolanic properties for use in differing applications in the gas and oil well cementing area. A method of making a mud-to-cement (MTC) slurry and a method for treating oil and gas wells with the MTC slurry containing a homogenous amorphous synthetic glass made from a mixture of inorganic materials selected from the group consisting of CSAM, wherein the cementing glasses with the mixture of inorganic materials are in a 100% amorphous phase with a degree of crystallization of zero.

Abstract: A process for preparing a loose grain abrasive material comprising the steps of providing a mixture of electric arc furnace dust, sand and glass, and melting such mixture at a temperature of less than 1430 degrees Celsius.

Abstract: A method for supplying heat to a melting furnace for forming a molten product using ash-containing fuels. A fuel having an ash component is introduced into a slagging chamber of a slagging combustor and at least partially combusted with a first oxidant mixture and a second oxidant mixture within the slagging chamber. Ash component is collected as a layer of molten slag in the slagging chamber. Slagging combustor gas effluent is passed from the slagging chamber of the slagging combustor into the combustion space of the melting furnace at high temperature to supply heat to form the molten product. Molten slag is withdrawn from the slagging chamber of the slagging combustor and may be selectively introduced into the melting furnace or not introduced into the melting furnace.

Abstract: In a process for granulating slag, from a blast furnace or a smelting reduction plant, in which a granule/water mixture formed during the granulation is fed to a granulation tank and then to a dewatering installation, in which the slag granules are dewatered. H2S-containing vapors and gases formed during the granulation are at least partially condensed by injection of water in a condensation space which is flow-connected to the granulation tank. H2S-containing residual gases are discharged from the compensation space below the water injection point, H2S is burnt.

Abstract: The invention relates to a process for the separation and recovery of non-ferrous metals from zinc-bearing residues, in particular from residues produced by the zinc manufacturing industry. The process allows for the valorisation of metal values in a Zn-, Fe- and Pb-bearing residue, and comprises the steps of: subjecting the residue to a direct reduction step, thereby producing a metallic Fe-bearing phase and Zn- and Pb-bearing first fumes; extracting the Zn- and Pb-bearing first fumes and valorising Zn and Pb; subjecting the metallic Fe-bearing phase to an oxidising smelting step, thereby producing an Fe-bearing slag and second metals-bearing fumes; extracting the second metals-bearing fumes and valorising at least part of their metallic content. The main advantage of this process is that an environmentally acceptable output for Fe is obtained.

Abstract: Disclosed herein is a method for stabilizing slag, which is an oxide byproduct generated after completion of refining in a converter process for converting molten iron into molten steel via de-carbonization or in an electric arc furnace process for producing molten steel via melting of scrap iron, during iron/steel making processes, and a novel material produced thereby. More particularly, disclosed is a method for stabilizing and recycling slag, wherein converter slag or electric arc furnace slag, which is difficult to recycle because of free lime (i.e. free calcium oxide (CaO) referring to single-phase CaO) remaining therein after cooling, is subjected to appropriate treatments after completion of converter blowing, thereby restricting generation of free lime, and consequently, minimizing differentiation/expansion, environmental pollution and instability of slag.

Abstract: A method of making a material for use as a steel-making slag comprises mixing sufficient lime and/or magnesia containing materials with combustion ash until the so-formed composition has a basicity ratio appropriate for use in steel making.

Abstract: A method for supplying heat to a melting furnace for forming a molten product using ash-containing fuels. A fuel having an ash component is introduced into a slagging chamber of a slagging combustor and at least partially combusted with a first oxidant mixture and a second oxidant mixture within the slagging chamber. Ash component is collected as a layer of molten slag in the slagging chamber. Slagging combustor gas effluent is passed from the slagging chamber of the slagging combustor into the combustion space of the melting furnace at high temperature to supply heat to form the molten product. Molten slag is withdrawn from the slagging chamber of the slagging combustor and may be selectively introduced into the melting furnace or not introduced into the melting furnace.

Abstract: The invention relates to a method for treating wastes, in particular from the production of mineral fibres such as fibreglass wool or rock fibres associated with organic binders and optionally with water or other metal and/or organic matters consisting in fusing a waste mass (9) by supplying a pure oxygen or an oxygen-enriched air in order to obtain a mineral material usable in the form of a vitreous raw material for glass melting and in inputting energy by means of at least one burner submerged under the waste mass (9). A device for carrying out said method is also disclosed.

Abstract: In a process for pulverizing and granulating melts, especially oxidic slag, glass, or thermoplastic melts, in which the melts are heated with burner (6) in an antechamber (5) and ejected as a shroud surrounding a propellant stream into a granulating chamber (11), hot combustion gases from the antechamber (5) are mixed with the propellant stream.

Abstract: The invention relates to a method for producing mineral wool, whereby a cracking catalyst having an aluminum oxide content of at least 35% by weight is used as a base material or aggregate. Said catalyst materials produce waste products which are difficult to eliminate in the chemical industry and which can be reused in the production of mineral fibers and can be used in an economical and resource sparing manner.

Abstract: A method is presented for the treatment of slag from electric steel plants which comprises the following steps: (a) transference of the slag into a metallurgical receptacle; (b) defoaming of the slag in this metallurgical receptacle by adding a defoaming agent, preferably silica; (c) subsequent heating of the slag to make it fluid; and (d) forced cooling of the slag, for example by an aqueous granulation.

Abstract: The slag in a molten state formed at a step of refining stainless steel is adjusted such that the slag has a basicity in the range of 1.3-4.0, and the slag is mixed with a sulfur-containing material wherein the sulfur is zero or minus in valence, thereby setting the concentration of sulfur in the slag to be not less than 0.2% by weight. The slag is so modified that Cr6+ is substantially completely prevented from being eluted and can be effectively utilized as a roadbed material and a reclamation material for civil works. The slag is quenched at such a speed of cooling that the temperature of the slag is decreased from 1200° C. to 400° C. within 48 hours so that noticeable effects are attained.

Abstract: A simple and compact device for wet granulation of liquid slag, comprising a granulating basin with a water injection device and a decanting basin that is separate from the granulating basin. A distribution channel for the granulate-water mixture extends above the decanting basin and is provided with outflow means along the entire length and on the lower side thereof for the granulate-water mixture. A vertical inflow shaft that is open towards the bottom is arranged underneath the distribution channel. The outflow means for the granulate-water mixture discharges into said inflow shaft.

Abstract: A method is presented for the treatment of slag from electric steel plants which comprises the following steps: (a) transference of the slag into a metallurgical receptacle; (b) defoaming of the slag in this metallurgical receptacle by adding a defoaming agent, preferably silica; (c) subsequent heating of the slag to make it fluid; and (d) forced cooling of the slag, for example by an aqueous granulation.

Abstract: The method for converting harmful polychlorinated biphenyl (PCB) oil into a resource includes chemical decomposition treatment, pelletizing treatment and thermal decomposition treatment. The chemical decomposition treatment uses a decomposing agent including calcium oxide powder coated with a vegetable oil and quartz porphyry powder, causes a decomposing action of CaO and far-infrared rays emitted from quartz porphyry, to act onto polychlorinated biphenyl oil, and decomposes the polychlorinated biphenyl oil into powder including a metal salt. The pelletizing treatment hardens the powder into pellets. The thermal decomposition treatment melts the pellets and glass cullet at a temperature above the thermal decomposition temperature of the PCBs for molten integration of the pellets and glass cullet as slag. The slag is cooled and the solid substance can be widely used as various types of construction materials and agricultural materials.

Abstract: In a process for melting inorganic materials (7) in a rotary horizontal converter or a rotary kiln (1) by adding fuel (8), oxygen or oxygen-enriched gases (10) and the inorganic materials (7) to a liquid bath (5), solid fuel (8) is added in piece form. The oxygen or the oxygen-enriched gas (10) is blown at high velocity (v) onto the surface of the bath (5), reacts with the solid fuel (8) and releases heat in the course of this. By means of the process of the invention, high temperatures can be achieved with the use of inexpensive fuels.

Abstract: The present invention refers to a method for using electric steel plant slag, ground and/or in particles of less than 6 mm, in self-reducing agglomerates, in the form of pellets or briquettes, as a fluxing material and as a secondary source of iron, in sufficient amounts to adjust the binary basicity of the final slag (ratio of CaO/SiO2) of the reduction/melting process to values equal or greater than 1.1. This application enables a reject that is difficult to discard to be transformed into a secondary source of iron and a final slag having adequate characteristics to be used in the concrete and asphalt paving industries.

Abstract: The method for converting harmful polychlorinated biphenyl (PCB) oil into a resource according to the invention comprises chemical decomposition treatment, pelletizing treatment and thermal decomposition treatment. The chemical decomposition treatment uses a decomposing agent including calcium oxide powder whose surface is coated with a vegetable oil and quartz porphyry powder, causes a decomposing action of CaO and far-infrared rays, which are emitted from quartz porphyry, to act onto polychlorinated biphenyl oil, and decomposes the polychlorinated biphenyl oil into powder including a metal salt. The pelletizing treatment hardens the powder produced by the chemical decomposition treatment into pellets. The thermal decomposition treatment melts the pellets produced by the pelletizing treatment and glass cullet at a temperature above the thermal decomposition temperature of the PCBs for molten integration of the pellets and glass cullet as slag.

Abstract: The object of the present invention is to provide a safe, easy-to-manage, successive, and swift method and system for preventing granulated blast-furnace slag from solidifying. Carbonated water is generated by dissolving carbon dioxide in water. Granulated blast-furnace slag which has been cooled is immersed in the generated carbonated water.

Abstract: A method of solidifying a steel-making slag is performed by subjecting a mixture of a steel-making slag containing at least about 50% by weight of a powdery steel-making slag having a particle size not greater than about 5 mm and a substance containing at least about 30% by weight of SiO2 (e.g., a fly ash and/or the fine powder of a granulated blast furnace slag) to a hydration reaction. The resulting solidified material contains at least about 20% of a tobermorite phase, has high strength and is suitable as an inorganic material useful as a roadbed material, building and civil engineering materials, etc.

Abstract: It is an object of the invention to effectively absorb and remove CO2 in an exhaust gas generated during an industrial process for reducing an amount of exhausting CO2 into the atmospheric air. The exhaust gas containing CO2 is blown into the agglomerate of solid particles containing CaO and/or Ca(OH)2 to contact CO2 to the agglomerate for fixing CO2 in the exhaust gas as CaCO3, thereby to reduce the CO2 concentration in the exhaust gas. Preferably, the solid particles contain water, and more preferably, the solid particles contain surface adhesive water.

Abstract: The method for granulating liquid slag melts, in particular blast furnace slag, in which the melt (2) is ejected into a cooling chamber via a slag tundish (1) and in which fluid under pressure, in particular compressed gas, vapor or pressurized water, is injected in the direction of the slag exit (6) in order to eject said liquid slag, is characterized in that the pressure fluid jet discharges into a throttle pipe (3) which is immersed in the slag bath and whose lower edge is mounted so as to be adjustable in the height direction (4). The corresponding device comprises a lance (7) which is surrounded by a height-adjustable throttle pipe (3) whose lower edge (5) is immersed in the slag bath (2) contained in the tundish (1) and forms a throttling cross section between the slag exit (6) and the slag bath (2).

Abstract: The present invention relates to a process and apparatus to cast and form slag directly from the molten state into crystalline or amorphous products suitable for use as decorative and structural building and construction materials. Molten slag and additives are refined at high temperature in a treatment furnace for a period of hours. The eventual entrapped gas content is controlled using a variety of methods, such as vacuum pressures and bottom stirring with inert gas. The molten slag is cast directly into moulds, and these moulds form the slag into any shape desired. The formed products are immediately introduced into a heat treatment furnace at temperatures at or above the glass transition temperature (GTT) for the case of crystalline products, or just below the GTT for amorphous products. The product is thermally cycled over a period of hours to relieve thermal stresses during cooling to ambient temperatures.

Abstract: A material with high surface area can be obtained through the partial or total removal of CaO and MgO by acid leaching of blast furnace slag. This is accomplished by an improved process for selective leaching of blast furnace slag and other solid solution materials by control of temperature during leaching, rate of addition of acid, type of the acid, concentration of the acid, and concentration of the slag in the slurry. When these variables are controlled as disclosed a hierarchy of dissolution occurs. The hierarchy begins with MgO, progresses to CaO, and is followed by A12O3, and the rate of acid addition is slow and controlled so that alumina does not dissolve (thereby depriving the remaining silica has no acid sites or catalytic activity). By invoking the hierarchy one gains selectivity, and this can be used to convert blast furnace slag to a material with high surface area which may have applications as an absorbent could be economically feasible.

Abstract: In a process for dechroming, and/or depleting the MgO content of, steel slags, oxygen is introduced into the liquid steel slag to an extent sufficient for converting iron quantitatively to iron oxide and at least 5% by weight of the iron oxide contained in the slag to iron-III-oxide. The oxidized slag obtained solidifies and is disintegrated, whereupon the paramagnetic portions formed are magnetically isolated and separated from the dechromed slag.