摘要:
The present application relates to a process for the purification of waste materials or industrial by-products, the process comprising the steps of: a) Preparing a composition (C) by blending or mixing waste materials or industrial by-products comprising chlorine (B) with one or more materials comprising heavy metals (HM) b) Reacting (B) and (HM) by thermal treatment of (C) c) Separating evaporated heavy metal chloride compounds (HMCC) d) Obtaining a solid material after the thermal treatment step.
摘要:
A method for treating and utilizing bypass dusts from a cement production process involves a) contacting the bypass dust with an aqueous phase and mixing the same to obtain a suspension, wherein water-soluble components of the bypass dust are dissolved in the aqueous phase; b) performing a solid/liquid separation, in particular a vacuum filtration or a filter press filtration, to separate the solids contained in the suspension, wherein a brine remains; c) precipitating a partial amount of the heavy metals present in the brine, and optionally Ca, and separating the precipitate from the brine; and d) subjecting the brine to an electrocoagulation, wherein a flocculate containing the heavy metals remaining in the brine is separated.
摘要:
A method for cleaning bypass gases of the cement or mineral industry includes cooling down a removed bypass gas from a cement or mineral processing plant to a temperature of between 500° C. and 150° C., and coarsely dedusting the bypass gas, the dust burden being reduced by 30 to 95%. After the dedusting step, the gaseous constituents contained in the partly dedusted bypass gas are reduced in a reducing step. The partly dedusted bypass gas is further finely dedusted. The gaseous constituents reducing step includes at least a catalytic reduction of one or more of nitrogen oxides, hydrocarbons, and carbon monoxide.
摘要:
The method according to the invention for producing cement clinker comprises substantially the following method steps: raw cement material is preheated in a preheater, the preheated material is heated further in a calcining zone while admitting combustion air, and the material heated in this manner is fired in a kiln to form cement clinker, wherein a part of the waste gases developing in the kiln is used to preheat the raw cement material in the preheater, and another part is diverted, and is used in a heat exchanger to preheat the combustion air used in the calcining zone.
摘要:
Process for the purification of a residue containing solids and mother liquor and having a chloride ion content greater than 5000 ppm by weight relative to the weight of the residue which comprises (a) piston washing said residue with a washing fluid and (b) recovering a purified residue.
摘要:
An object of the present invention is to separate CO2 gas generated in a cement-manufacturing facility in a high concentration and recover the CO2 gas. The present invention includes: feeding a cement material before calcination and a heat medium which has a particle diameter larger than that of the cement material and has been heated to the calcination temperature or higher in a medium-heating furnace (14), to a mixing calciner (12); and recovering the CO2 gas generated by the calcination of the cement material. The heat medium circulates between the medium-heating furnace and the mixing calciner. Another aspect of the present invention includes: feeding a cement material before calcination to a regenerative calciner (112) which has been heated to the calcination temperature or higher and has stored heat therein; and recovering the CO2 gas generated by the calcination of the cement material.
摘要:
A method and an apparatus for manufacturing of cement includes cement raw meal being preheated in a preheater, calcined in a calciner by contact with hot gases which are introduced into the calciner via a gas inlet and being diverted from the calciner via a gas outlet, and where calcined cement raw meal is diverted from the calciner, burned into cement clinker in a kiln and subsequently cooled in a clinker cooler. At least a portion of the calcined cement raw meal diverted from the calciner is heated further in a separate system to a temperature which exceeds the calcination temperature and is subsequently recirculated to the calciner. That at least a portion of the gases which are diverted via the gas outlet of the calciner is removed from the plant with a view to storage underground or other additional treatment.
摘要:
Manufacturing methods and plants for carrying out methods of manufacturing cement clinker including diverting gases from a separation cyclone for a calcined cement material. The diverted gases are cooled to a temperature of 850° C. or less by introducing raw cement materials into the diverted gas stream.
摘要:
Described is a method as well as a plant for preheating particulate or pulverulent material such as cement raw meal or similar material in a cyclone preheater (1), comprising at least two cyclone stages, each comprising a riser duct (2a, 2b, 2c, 2d) and a cyclone (1a, 1b, 1c, 1d). The method is peculiar in that a portion of the material which is fed to at least one cyclone stage is introduced to the first part of the riser duct, viewed in the direction of travel of the exhaust gases, and is heated from a temperature of maximum 450° C. to a temperature of at least 550° C., and in that the remaining material which is fed to the same cyclone stage is introduced into the last part of the said riser duct. As a result, there will be a reduction in the amount of SO2 which is discharged from the cement plant preheater as emission, without a simultaneous increase in energy consumption.
摘要:
For a decrease of NO.sub.x content in the exhaust gases from cement-burning kilns by an addition of ammonia and/or ammonia-containing substances to hot exhaust gases, the exhaust gases are desulfurized at a temperature from 50.degree. to 100.degree. C. in a dry or semidry process by a mixture of raw cement powder and calcium hydroxide, and the mixed solids which have been removed the exhaust gas in a dry state in the desulfurizing stage are returned to the exhaust gas stream when it is at a temperature from 850.degree. to 1,000.degree. C.