关于水泥的中英文对照文章

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  International best practice values of energy consumption for cement production
  
  For the international best practices at each stage of production, data were gathered from public literature sources, plants, and vendors of equipment. These data and calculations are described below.
  
  --Raw materials and fuel preparation
  
  Energy used in preparing the raw material consists of preblending (prehomogenization and proportioning), crushing, grinding and drying (if necessary) the raw meal which is mostly limestone. All materials are then homogenized before entering the kiln. Solid fuels input to the kiln must also be crushed, ground, and dried. Best practice for raw materials preparation is based on the use of a longitudinal preblending store with either bridge scraper or bucket wheel reclaimer or a circular preblending store with bridge scraper reclaimer for preblending (prehomogenization and proportioning) at 0.5 kWh/t raw meal, a gyratory crusher at 0.38 kWh/t raw meal, an integrated vertical roller mill system with four grinding rollers and a high-efficiency separator at 11.45 kWh/t raw meal for grinding, and a gravity (multi-outlet silo) dry system at 0.10 kWh/t raw meal for homogenization. Based on the above values, the overall best practice value for raw materials preparation is 12.05 kWh/t raw material. Ideally this value should take into account the differences in moisture content of the raw materials as well as the hardness of the limestone. Higher moisture content requires more energy for drying and harder limestone requires more crushing and grinding energy. If drying is required, best practice is to install a preheater to dry the raw materials, which decreases the efficiency of the kiln. For BEST Cement, it is assumed that pre-heating of wet raw materials is negligible and does not decrease the efficiency of the kiln.
  
  Solid fuel preparation also depends on the moisture content of the fuel. It is assumed that only coal needs to be dried and ground and that the energy required for drying or grinding of other materials is insignificant or unnecessary. Best practice is to use the waste heat from the kiln system, for example, the clinker cooler (if available) to dry the coal. Best practice using an MPS vertical roller mill is 10-36 kWh/t anthracite, 6-12 kWh/t pit coal, 8-19 kWh/t lignite, and 7-17 kWh/t petcoke or using a bowl mill is 10-18 kWh/t product. Based on the above, it is assumed that best practice for solid fuel preparation is 10 kWh/t product.
  
  --Additives preparation
  
  In addition to clinker, some plants use additives in the final cement product. While this reduces the most energy intensive stage of production (clinker making), as well as the carbonation process which produces additional CO2 as a product of the reaction, some additives require additional electricity for blending and grinding (such as fly ash, slags and pozzolans) and/or additional fuel for drying (such as blast furnace and other slags).
  
  Additional requirements from use of additives are based on the differences ween blending and grinding Portland cement (5% additives) and other types of cement (up to 65% additives). Portland Cement typically requires about 55 kWh/t for clinker grinding, while fly ash cement (with 25% fly ash) typically requires 60 kWh/t and blast furnace slag cement (with 65% slag) 80 kWh/t (these are typical grinding numbers only used to determine the additional grinding energy required by additives, not best practice; for best practice refer to data below in cement grinding section). It is assumed that only fly ash, blast furnace and other slags and natural pozzolans need additional energy. Based on the data above, fly ash will require an additional 20 kWh/t of fly ash and slags will require an additional 38 kWh/t of slag. It is assumed that natural pozzolans have requirements similar to fly ash. These data are used to calculate cement grinding requirements. For additives which are dried, best practice requires 0.75 GJ/t (26 kgce/t) of additive. Generally, only blast furnace and other slags are dried. Those additives that need to be dried (the default is all slags, although the user can enter this data as well in the production input sheet) best practice requires an additional 0.75 GJ/t (26 kgce/t) of additive.
  
  --Kiln
  
  Clinker production can be split into the electricity required to run the machinery, including the fans, the kiln drive, the cooler and the transport of materials to the top of the preheater tower (“kiln preheaters” and “cooler system”), and the fuel needed to dry, to calcine and to clinkerize the raw materials (“precalcination”, if applicable, and the “kiln”). Best practice for clinker making mechanical requirements is estimated to be 22.5 kWh/t clinker, while fuel use has been reported as low as 2.85 GJ/t (97.3 kgce/t) clinker.
  Final grinding
  
  Best practice for cement grinding depends on the cement being produced, measured as fineness or Blaine (cm2/g). In 1997, it was reported that the Horomill required 25 kWh/tonne of cement for 3200 Blaine and 30 kWh/tonne cement for 4000 Blaine. We make the following assumptions regarding Chinese cement types: 325 = a Blaine of less than or equal to 3200; 425 = a Blaine of approximately 3500; 525 = a Blaine of about 4000; and, 625 = a Blaine of approximately 4200. More recent estimates of Horomill energy consumption range ween 16 and 19 kWh/tonne. We used best practice values for the Horomill for 3200 and 4000 Blaine and interpolated and extrapolated values based on an assumed linear distribution for 3500 and 4200 Blaine. We estimated lowest quality cement requires 16 kWh/tonne and that 3500 Blaine is 8% more than 3200 Blaine (17.3 kWh/tonne), 4000 Blaine is 20% more than 3200 Blaine (19.2 kWh/tonne), and 4200 Blaine is 24% more than 3200 Blaine (19.8 kWh/tonne). We then used these values to estimate the values of other types of cement, based on more or less grinding that would be needed for any additives. We assumed common Portland cement grinding required similar energy as pure Portland cement, that blended slag and fly ash cements were on average, 65% slag and 35% fly ash, that grinding pozzolans required similar energy as grinding slags (at a similar ratio of 65%) and that limestone cement contained 5% extra limestone with grinding requirements similar to grinding slag.
  
  --Other production energy uses
  
  Some cement facilities have quarries on-site, and those generally use both trucks and conveyors to move raw materials. If applicable to the cement facility, quarrying is estimated to use about 1% of the total electricity at the facility.
  
  Other production energy includes power for auxiliaries and conveyors within the facility. (We have excluded packaging from our analysis). Total power use for auxiliaries is estimated to require about 10 kWh/t of clinker at a cement facility. Power use for conveyors is estimated to require about 1 to 2 kWh/t of cement. Lighting, office equipment, and other miscellaneous electricity uses are estimated to use about 1.2% of the total electricity at the facility.
  
  国际上水泥生产能耗的最佳实践值
  
  各个生产过程的国际最佳实践值是根据公开发表的各种文献，以及水泥企业和设备商的确定的。下面来介绍这些及其计算过程。
  
  --生料和
  
  生料的能耗包括生料（主要是石灰石）的预混合（预均化和配料）、破碎、粉磨和烘干（如果需要的话）。所有物料在入窑之前都要经过充分的均化。入窑的固体也要先经过破碎、粉磨和烘干。生料的最佳实践值计算依据如下：预混合采用带桥式刮板式取料机或斗式取料机的纵向预均化堆场，或者带桥式刮板式取料机的环形预均化堆场（电耗0.5kWh/t生料）；破碎采用转子破碎机（电耗0.38kWh/t生料）；生料粉磨采用带高效选粉机和四个辊子的立磨系统（电耗11.45kWh/t生料）；均化采用重力式（多出口筒仓）烘干系统（电耗0.10kWh/t生料）。综合以上能耗数值，生料的最佳总能耗为12.05kWh/t生料。理论上，该能耗值还应考虑生料水分和石灰石硬度的影响。水分越大则烘干能耗越多，石灰石硬度越高则破碎和粉磨能耗越多。如果原料需要烘干，则最佳的措施是安装一个预热器，虽然它会降低窑的热效率。“BEST Cement”假设烘干湿原料的能耗可以忽略不计，因此没有降低窑系统的热效率。
  固体的能耗也与的水分有关。“BEST Cement”假设只有煤需要烘干和粉磨，其他物料的烘干和粉磨能耗可忽略不计。烘干煤粉的最佳措施是利用窑系统（如熟料冷却机）的废热做烘干热源。煤粉磨的最佳措施是采用MPS立磨（电耗为10-36kWh/t无烟煤，6-12kWh/t烟煤，8-19kWh/t褐煤，7-17kWh/t石油焦），或碗磨（电耗为10-18kWh/t产品）。综合以上能耗数值，的最佳总能耗为10kWh/t产品。
  
  --混合材
  
  除了熟料以外，一些水泥企业还在水泥终产品中混合材。该措施在减少熟料生产能耗以及CO2排放量的同时，需要增加混合材的混合与粉磨电耗（如粉煤灰、矿渣和火山灰）以及烘干用的消耗（如高炉矿渣和其他矿渣）。
  根据硅盐水泥（5％混合材）和其他类型水泥（混合材配比最高达65％）在混合和粉磨方面的差别，混合材会增加额外的电耗。硅盐水泥的熟料粉磨电耗一般为55kWh/t，而粉煤灰水泥（含25％粉煤灰）的粉磨电耗一般为60 kWh/t，高炉矿渣水泥（含65％矿渣）的粉磨电耗一般为80 kWh/t（这些能耗数值是掺加混合材的一般能耗水平，不是最佳能耗水平；最佳能耗水平可参考下文的水泥粉磨部分）。“BEST Cement”假设只有粉煤灰、高炉矿渣、其它矿渣和天然火山灰需要额外的能耗。综合以上能耗数值可知，粉煤灰需要的额外电耗为20 kWh/t粉煤灰，矿渣需要的额外电耗为38kWh/t矿渣。天然火山灰的额外电耗假设与粉煤灰相同。这些可用于计算水泥粉磨电耗。混合材烘干热耗的最佳水平是0.75GJ/t（26kgce/t）混合材。一般情况下，只有高炉矿渣和其他矿渣需要烘干。那些需要烘干的混合材（默认情况是所有矿渣，虽然用户可以在生产信息输入表中输入该）的最佳烘干热耗为0.75GJ/t（26kgce/t）混合材。
  
  窑系统
  
  熟料生产过程的能耗可分为驱动机械设备（如风机、窑的驱动装置、冷却机和预热器喂料提升机等）的电耗和烘干物料、煅烧生料的消耗。熟料生产的最佳电耗水平是22.5 kWh/t熟料，最佳消耗水平可低至2.85 GJ/t（97.3kgce/t）熟料。
  
  水泥粉磨
  
  水泥粉磨的最佳电耗水平取决于水泥的细度或比表面积（cm2/g）。1997年，有文献指出用筒辊磨将水泥粉磨到3200 cm2/g的电耗为25 kWh/t水泥，粉磨到4000 cm2/g的电耗为30 kWh/t水泥 。对于中国的水泥，我们做如下假设：标号为325的水泥的比表面积小于等于3200 cm2/g；标号为425的水泥的比表面积约3500 cm2/g；标号为525的水泥的比表面积约4000m2/g；标号为625的水泥的比表面积约4200 cm2/g。最新的研究认为筒辊磨的能耗范围是16-19 kWh/t水泥。我们以用筒辊磨将水泥粉磨到比表面积为3200 cm2/g和4000 cm2/g的电耗水平作为相应细度的最佳电耗水平，并根据线性分布假设通过内插和外插计算出比表面积为3500 cm2/g和4200 cm2/g的最佳电耗水平。我们估算得出比表面积为3200 cm2/g的水泥最佳粉磨电耗为16 kWh/t水泥，比表面积为3500 cm2/g的水泥的最佳粉磨电耗要比3200 cm2/g的水泥高出8％（17.3 kWh/t水泥），4000 cm2/g的水泥的最佳粉磨电耗比3200 cm2/g的水泥高20％（19.2 kWh/t水泥），4200 cm2/g的水泥的最佳粉磨电耗比3200 cm2/g的水泥高24％（19.8 kWh/t水泥）。我们用这些值又估算了其他类型水泥的最佳粉磨电耗，估算过程中考虑了混合材的粉磨电耗。我们假设普通硅盐水泥的粉磨能耗与硅盐水泥相当，矿渣水泥的矿渣含量平均为65％，粉煤灰水泥的粉煤灰含量平均为35％，火山灰的粉磨能耗与矿渣的粉磨能耗相当（掺加量都是65％），并假设含5％额外石灰石的石灰石水泥的粉磨能耗与矿渣粉磨能耗相当。
  
  --其他生产能耗
  
  一些水泥企业就建在矿山旁，它们一般采用卡车或皮带来运送原料。如果是这样，则矿山开采的能耗约占全厂总能耗的1％。
  其他生产能耗还包括厂区内所有辅助设备和输送设备的动力消耗（我们已经将水泥包装过程的能耗排除在外）。一个水泥企业辅助设备的总能耗约为10kWh/t熟料。所有输送设备的总能耗约为1－2kWh/t水泥。照明、办公设备和其他各种各样的电耗约为全厂总电耗的1.2％。

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