摘要:
A cement production plant may include a preheater for preheating raw meal, a calciner for calcining the preheated raw meal, and a furnace with a furnace burner for firing the raw meal to form cement clinker. The furnace has a combustion gas inlet for admitting a combustion gas with an oxygen content of 30% to 75% into the furnace. The cement production plant may also include a cooler for cooling the cement clinker. The calciner and the furnace each have at least one respective fuel inlet for admitting at least one fuel into the calciner and the furnace. The calciner and the furnace each have at least one respective inert gas inlet for respectively admitting inert gas into the calciner and the furnace.
摘要:
Processes and plants for producing cement clinker, in which an oxygen-containing gas having a proportion of 15% by volume or less of nitrogen and a proportion of 50% by volume or more of oxygen is conveyed from a first section of the cooler directly adjoining the top of the furnace into the rotary furnace and is optionally additionally conveyed to the calciner, and where the total gas streams fed in to the combustion processes consist to an extent of more than 50% by volume (preferably more than 85% by volume) of oxygen.
摘要:
Oxygen is lanced into the main combustion reaction of a cement kiln to increase heat transfer to the clinker bed and to increase clinker production. Oxygen is separately lanced along the floor, i.e. the lowest wall of the kiln, to delay mixing with the flame to provide deep staging. The deeply staged oxygen flow is adjusted frequently to control emissions and stabilize the burning zone while the primary oxygen flow is maintained constant.
摘要:
Disclosed is a method for manufacturing calcium aluminates in an industrial furnace, according to which, continuously, into a tank made of refractory material containing a molten pool that is constantly heated, fine particles are introduced of a raw material source of alumina and/or of aluminium and of a raw material source of calcium oxide and/or of calcium having a median diameter d50 less than or equal to 6,000 μm in order to melt the fine particles of raw material, and, continuously, at the outlet of the tank a mass of liquid calcium aluminates is recovered.
摘要:
A process for preparing dicalcium silicate includes providing a starting material comprising calcium carbonate (CaCO3) and silicon dioxide (SiO2), wherein a molar ratio of calcium:silicon (C:S) is from 1.5:1 to 2.5:1. At least one of an inorganic alkali metal salt and an alkaline earth metal salt is added as a mineralizing agent to the starting material in an amount of from 0.5 wt.-% to 20 wt.-%, based on a total weight of the starting material. The starting material is reacted with the mineralizing agent in a gas atmosphere having a CO2 partial pressure of from 0.05 MPa to 0.2 MPa at a temperature of from 900° C. to 1100° C. so as to obtain a dicalcium silicate product. The dicalcium silicate product comprises a content of an unreacted starting material of
摘要:
The invention relates to a method for manufacturing a sulfoaluminous or belitic sulfoaluminous clinker from a raw mix formed from a mixture including minerals containing calcium, aluminum, silica, iron, and sulfur, preferably in sulfate form, and is characterized in that the method comprises the steps including: at least partially dehydrating and decarbonating the mixture through placement in a vertical kiln (1) comprising a substantially vertical chamber (2) wherein the mixture is heated, the chamber (2) of the vertical kiln (1) being supplied with hot gases the temperature of which is between 900 and 1150° C; extracting the dehydrated and decarbonated mixture from the vertical kiln (1) and conveying the same in a continuous kiln (4) comprising a furnace (5) and a transporting means (6) for transporting the mixture across the furnace (5); heating the mixture from the vertical kiln (1) by passing the mixture through the furnace (5) via the transporting means (6) such that a clinkerization of the mixture is obtained, the average passage time in the furnace being greater than 15 minutes.
摘要:
The present invention relates to apparatus for thermal treatment of a mineral starting material, wherein the apparatus comprises a calciner, wherein the calciner comprises at least a first calciner section and a second calciner section, wherein the first calciner section is arranged vertically, wherein the second calciner section is arranged at an incline, wherein the second calciner section has an angle α between the horizontal and the flow direction of the second calciner section, wherein the angle α is between 20° and 80°, wherein the first calciner section has a first hydraulic diameter dh,1, wherein the second calciner section has a second hydraulic diameter dh,2, wherein the second hydraulic diameter dh,2 is less than or equal to the first hydraulic diameter dh,1 multiplied by the sine of the angle α.
摘要:
A method for the thermal treatment of clays by: preheating the clay, which is suspended in a carrier gas, in a heat exchanger; thermally treating the clay in a calcination stage operated under chemically oxidizing conditions; subsequently thermally treating the clay in a calcination stage operated under chemically reducing conditions; cooling the clay in a cooling stage operated under chemically reducing conditions; cooling the clay in a cooling stage operating under chemically oxidizing conditions.
摘要:
A process for preparing dicalcium silicate includes providing a starting material comprising calcium carbonate (CaCO3) and silicon dioxide (SiO2), wherein a molar ratio of calcium:silicon (C:S) is from 1.5:1 to 2.5:1. At least one of an inorganic alkali metal salt and an alkaline earth metal salt is added as a mineralizing agent to the starting material in an amount of from 0.5 wt.-% to 20 wt.-%, based on a total weight of the starting material. The starting material is reacted with the mineralizing agent in a gas atmosphere having a CO2 partial pressure of from 0.05 MPa to 0.2 MPa at a temperature of from 900° C. to 1100° C. so as to obtain a dicalcium silicate product. The dicalcium silicate product comprises a content of an unreacted starting material of
摘要:
In the method according to the invention for operating a cement plant, the raw meal is preheated in a preheating zone, the preheated material is precalcined in a calcining zone and the precalcined material is finally sintered in a sintering zone. The cement plant is operated in such a manner that the precalcined material which is supplied to the sintering zone has an SO3 concentration of at least 5.5% by mass and a CaSO4 proportion of at least 75%, preferably 90%, of the total salt content.