Method of operating a blast furnace installation comprising a top gas recycle blast furnace and hot stones, whereby a hydrocarbon containing fuel is transformed into a transformed gas stream consisting mainly of CO and H.sub.2 and substantially devoid of hydrocarbon, whereby a low-heating-value gaseous fuel is generated comprising a mixture of the transformed gas with a portion of the CO.sub.2-rich tail gas obtained by decarbonatation of the blast furnace gas, and whereby the low-heating-value fuel is used to heat the hot furnace gas is heated before being injected into the blast-furnace.

Processes that generate syngas or reformed gas that have the desired H2/CO ratio, such that they can be used directly for producing higher value liquids, such as using a FT GTL process. The systems and methods of the present invention are simpler and more cost effective than conventional systems and methods. The systems and methods of the present invention generate the required CO2 in a reforming furnace by combusting natural gas with a mixture of O2 from an external source and CO2 that is recirculated from a reforming furnace. A second application of the natural gas combustion with external O2 mixed with recirculated CO2 in the reformer burners can be utilized in a DR process. The reformed gas or syngas containing H2 and CO is used to reduce iron oxide to metallic iron in a shaft furnace, for example.

Systems and methods for processing slag produced by iron and steel making processes are disclosed. The slag is treated produce a series of valued industrial products, such as metal oxides, metal carbonates, rare-earth metals, and water glass. The systems and methods also integrate slag processing with CO.sub.2 sequestration and flue gas desulphurization. Processing slag minimizes the land use for stockpiling or landfilling wastes produced from iron and steel making processes and protects the ground water underneath. Overall, the solid and gaseous emissions of an energy-intensive and highly polluted industrial process have been largely reduced, recycled and valorized in order to achieve a near zero-emission goal.

Blast furnace installation having top gas recycling and process for operating same, in which the oxygen concentration of the oxidizing gas injected into the blast furnace is regulated as a function of the flow rate of the recycled top gas.

The present disclosure relates to a corrosion resistant duplex stainless steel (ferritic austenitic alloy), which is suitable for use in a plant for the production of urea and uses thereof. The disclosure also relates to objects made of the duplex stainless steel Furthermore, the present disclosure relates to a method for the production of urea and to a plant for the production of urea having one or more parts made from the duplex stainless steel, and to a method of modifying an existing plant for the production of urea.

In a process and apparatus for the reduction of metal oxides (3) to form metalized material by contact with hot reducing gas, which is produced at least partially by catalytic reformation of a mixture of a gas containing carbon dioxide (CO.sub.2) and/or steam (H.sub.2O) with gaseous hydrocarbons,
the heat for the endothermal reformation processes which take place during the reformation is provided at least partially by the combustion of a fuel gas.

The present disclosure relates to a corrosion resistant duplex stainless steel (ferritic austenitic alloy) which is suitable for use in a plant for the production of urea; and uses thereof. The disclosure also relates to objects made of said duplex stainless steel. Furthermore, the present disclosure also relates to a method for the production of urea and to a plant for the production of urea comprising one or more parts made from said duplex stainless steel, and to a method of modifying an existing plant for the production of urea.

The present invention provides a method for reducing iron oxide to metallic iron using coke oven gas, including: dividing coke oven gas from a coke oven gas source into a plurality of coke oven gas streams; providing a first coke oven gas stream to a hydrogen enrichment unit to form a hydrogen-rich product stream that is delivered to a reduction shaft furnace as part of a reducing gas stream; and providing a tail gas stream from the hydrogen enrichment unit to a reforming reactor to form a reformed gas stream that is delivered to a reduction shaft furnace as part of the reducing gas stream. Optionally, a spent top gas stream from the reduction shaft furnace is cleansed of CO.sub.2 and recycled back to the reducing gas stream.

A method of forming an earth-boring tool includes introducing metal into a die, rotating the die to generate centrifugal forces on the metal, and cooling the metal in the rotating die. A rotary drill bit may include a unitary, centrifugally cast bit body including an integral shank, at least one blade, and at least one cutting element on the blade. A rotary drill bit or a roller cone may include a first centrifugally cast material and a second centrifugally cast material. Another rotary drill bit includes a bit body comprising a maraging steel alloy. A method of forming a rotary drill bit may include disposing cutting elements on a rotary drill bit comprising maraging steel and aging the rotary drill bit to form at least one intermetallic precipitate phase. Methods of repairing a rotary drill bit include annealing and aging at least a portion of a rotary drill bit.

A method and apparatus for producing direct reduced iron (DRI), including: generating a reducing gas in a coal gasifier using coal, oxygen, steam, and a first coke oven gas (COG) stream as inputs to the coal gasifier; and delivering the reducing gas to a shaft furnace and exposing iron ore agglomerates to the reducing gas to form metallic iron agglomerates. The method further includes delivering a second COG stream directly to the shaft furnace.