Abstract: A reverse osmosis desalination system for treating feed water, the feed water containing minerals, the system comprising a reverse osmosis unit comprising a first reverse osmosis stage (21) and a second reverse osmosis stage (22), each of the reverse osmosis stages (21, 22) having a feed water input, a product water outlet and a brine outlet, and a fluidized bed crystallizer (30), configured to remove minerals from the water, wherein the fluidized bed crystallizer (30) receives brine from the first reverse osmosis stage (21) and passes treated water to the feed water input of the second reverse osmosis stage (22).

Abstract: A process for producing pig iron or liquid primary steel products in a smelting unit (1), in particular a melter gasifier. Iron-ore-containing charge materials, and possibly additions, are at least partially reduced in at least one reduction unit (R1, R2, R3, R4) by means of a reducing gas. A first fraction of the at least partially reduced charge materials is melted down in the smelting unit (1), while carbon carriers and oxygen-containing gas are supplied, with the simultaneous formation of the reducing gas. The reducing gas is fed to the reduction unit (R1, R2, R3, R4) and, after the reducing gas has passed through the reduction unit, it is drawn off as top gas. A second fraction of the at least partially reduced charge materials is fed to a smelting reduction unit for reducing and smelting.

Abstract: A direct reduction process for a metalliferous material includes supplying the metalliferous material, a solid carbonaceous material, an oxygen-containing gas, and a fluidizing gas into a fluidized bed in a vessel and maintaining the fluidized bed in the vessel, at least partially reducing metalliferous material in the vessel, and discharging a product stream that includes the partially reduced metalliferous material from the vessel. The process comprises (a) reducing the metalliferous material in a solid state in a metal-rich zone in the vessel; (b) injecting the oxygen-containing gas into a carbon-rich zone in the vessel with a downward flow in a range of ±40° to the vertical and generating heat by reactions between oxygen and the metalliferous material (including metallized material), the solid carbonaceous material and other oxidizable solids and gases in the fluidized bed, and (c) transferring heat from the carbon-rich zone to the metal-rich zone by movement of solids within the vessel.

Abstract: In a process for reducing iron-ore-containing particulate material in at least a two-stage process, reducing gas is conducted through at least two reaction zones consecutively arranged in series and formed by a moving particulate material and the particulate material passes through the reaction zones in reverse order to the reducing gas, with the particulate material being heated in the reaction zone arranged first for the particulate material and being reduced in the further reaction zone.

Abstract: The present invention relates to method, which helps to reduce and remove the build-up forming on the grate of a fluidized-bed furnace in the roasting of fine-grained material such as concentrate. The concentrate is fed into the roaster from the wall of the furnace, and oxygen-containing gas is fed via gas nozzles under the grate in the bottom of the furnace in order to fluidize the concentrate and oxidize it during fluidization. Below the concentrate feed point, or feed grate, the oxygen content of the gas to be fed is raised compared with the oxygen content of the gas fed elsewhere.

Abstract: Methods and apparatus for the reduction into metallic iron of iron-oxides-containing particles having a broad range of sizes. Particles, typically within a broad range of sizes of about 0.1 mm to about 50 mm, are reduced by contact with a hot reducing gas, preferably from a horizontal gas distributor which defines the bottom of the reduction zone by supplying a uniform upflow of gas mainly composed of hydrogen (and/or carbon monoxide) within a temperature range of 650° C. to 1050° C. and at a velocity of about 0.5-0.7 m/s to fluidize at least some of the particles of a size of about 1.0 mm or less (when present).

Abstract: A fluidized bed reduction method in which powder raw material, including powder ore or partially pre-reduced powder ore, forms a fluidized bed with, and is sequentially reduced by reducing gas while being moved between a plurality of fluidized bed chambers; and to a fluidized bed reduction reactor which can be used in the same method. The movement of the powder ore between the fluidized bed chambers is carried out giving priority to relatively larger powder particles with the aim of improving the stability of the fluidized bed in the fluidized bed chambers. The adjustment of the reducing power of each fluidized bed chamber is made possible by introducing the reducing gas into the fluidized bed chambers in parallel, whereby an increase in the degree of reduction of the raw material can be realised.

Abstract: A method and device are provided for direct reduction of ore fines in a wide range of particle size, the reducing agent being hydrogen placed in a fluidized bed gutter with a plurality of sequentially arranged chambers. The fluidization rate in the supply base is set so that a defined class of particle size remains in the chamber concerned where it will be submitted to a reduction process and that the finest particle size fraction is discharged from the chamber, then precipitated in a hot gas cyclone to solid material (or fines) and gas. The ore fines precipitated in the cyclone then reaches the following chamber. The gas from all the hot gas cyclones is fed by a collector to the pre-heater. After reduction in the chambers, the ore fines are conveyed in pressure vessels for submission to further processes.

Abstract: The present invention describes a method and apparatus for the reduction into metallic iron of iron-oxides-containing particles having a broad range of sizes. Particles, preferably within a broad range of sizes smaller than about 3.2 mm, are reduced by contact with a hot reducing gas, preferably mainly composed of hydrogen and within a temperature range of 700 to 750.degree. C. The reducing gas flows through a descending moving bed of coarser particles and forms an ascending fluidized bed of fines, all in a single reduction reactor, where the particles charged to the reactor are fed into the lower portion of the fluidized bed and the reduced fines are withdrawn from the reactor from the upper portion of the fluidized bed.

Abstract: In a process for the reduction of fine ore by reducing gas in the fluidized bed method, the following characteristic features are realized in order to achieve a uniform and even degree of metallization at optimum utilization of the reducing gas and while minimizing the amount of reducing gas employed, that the fine ore is fractionated by aid of the reducing gas into at least two fractions having different grain size distributions, that each fraction is reduced by the reducing gas in a separate fluidized bed, wherein the reducing gas maintains a first fluidized bed containing the coarse-grain fraction and separates the fine-grain fraction from the same, is accelerated together with the fine-grain fraction, subsequently under pressure release forms a further fluidized bed, into which it is continuously injected in a radially symmetrical manner and from below, and wherein, furthermore, secondary reducing gas additionally is directly injected into the further fluidized bed in a radially symmetrical manner, and th

Abstract: A process for controlling the conversion of reactor feed to iron carbide is disclosed. The reactor feed is subjected to a process gas in a fluidized bed reactor (10), and the off-gas from this reaction is analyzed (56) to determine its composition and the temperature (64) and pressure (66). A stability phase diagram is generated based on the temperature. Different regions of the stability phase diagram are representative of different products being formed by the conversion of the reactor feed. Based on relative concentrations of the individual gases in the off-gas and the total pressure, a point is plotted on the stability phase diagram indicative of the favored reaction product. The process parameters can then be adjusted to insure that iron carbide can be produced from the reactor feed based on the stability phase diagram. In one embodiment, the rate of conversion of the reactor feed into iron carbide is controlled.

Abstract: A process for the direct reduction of metal oxides containing iron to obtain a DRI metallized iron product comprises feeding heavy hydrocarbon oil under controlled conditions to a cracking zone upstream of the reduction reactor so as to form a cracked product rich in CH.sub.4 and thereafter feeding said cracked product directly to the reaction zone wherein a reformed reducing gas rich in H.sub.2 and CO is formed and contacted with said iron oxide material thereby effecting reduction of said iron oxide material in the reaction zone.

Abstract: The present invention relates to a process for the production of liquid steel from iron containing metal oxides and, more particularly, a process for the direct production of iron-containing metal oxides wherein the hot discharge of direct reduced iron (DRI or sponge iron) is fed to a melting furnace with the process gases from the direct production furnace for refining the DRI to liquid steel.

Abstract: A process for the direct reduction of iron-containing metal oxides to obtain iron is disclosed in which a reformed reduction gas rich in H.sub.2 and CO and having an oxidation degree in the range of from about 0.30 to about 0.35 is formed and reduction is carried out simultaneously in a single reaction zone of a reduction reactor. The reformed reduction gas is formed using a highly endothermic reaction during which a mixture of heated natural gas, recycled top gas and air, preferably oxygen enriched air, is placed into contact with heated surfaces of DRI metallized iron in the reaction zone. The resulting reformed reducing gas consists essentially of from about 45% to about 48% hydrogen, from about 32% to about 34% carbon monoxide, from about 2% to about 4% carbon dioxide, from about 1% to about 3% methane, from about 14% to about 16% nitrogen and from about 1% to about 3% water vapor.