炼钢课程设计讲稿-第二章

,*,炼钢厂设计原理,第2章 氧气转炉物料平衡与热平衡计算,1,收入项：开吹前首先要向炉内加入钢铁料：铁水和废钢，然后降枪吹氧，同时加入造渣料：石灰、萤石、白云石、铁皮或矿石等，以及吹炼过程中炉衬要受到侵蚀而剥落下来进入炉内。,支出项：开吹后首先从炉口冒出炉气，炉气中夹带着烟尘，吹炼过程中要产生一些喷溅，并且要产生炉渣，炉渣中夹带着铁珠，最后得到钢水。还有其它一些支出物。,2,通过以上分析，可以给转炉物料平衡和热平衡下个定义：所谓物料平衡就是计算在炼钢过程中加入炉内并参与炼钢过程的全部物料和炼钢过程产生物之间的平衡关系。它是物质不灭定律在炼钢过程中的具体应用。,所谓热平衡就是计算在炼钢过程中热量的收入与支出之间的平衡关系。它是能量守恒定律在炼钢过程中的具体应用。,进行物料平衡与热平衡计算有什么意义呢？在进行炼钢设计和组织炼钢生产过程中，经常向我们提出一些“量”的问题需要我们来回答：,3,C,Si、Mn、P、,S,、,Fe,炉气,炉渣,钢水,铁 水,矿 石,CO,90,%,CO,2 10%,炉气,炉渣,炉渣,炉渣,炉气,H,2,O,SiO,2,等,Fe,2,O,3,钢水,莹 石,炉气,炉渣,H,2,O,CaF 等,炉 衬,炉气,C,CaO 等,炉渣,白云石,炉气,烧减,CaO 等,炉渣,石灰,炉气,烧减,CaO 等,计算渣中FeO 10%Fe,2,O,3,5%,总炉渣,烟尘含铁量,自由氧,、,N,2,总炉气,总钢水,氧气,氧气,氧气,氧气,氧气,氧气,渣中铁珠量,喷溅铁量,氧气,100 kg,1 kg,0.5 kg,0.5 kg,3 kg,根据碱度计算,1.6 kg,1 kg,渣量 8%,4,2.1,原始数据,表21 铁水成分及温度,成分,C,Si,Mn,P,S,温度，,%,4.250,0.850,0.580,0.150,0.037,1250,表23 冶炼钢种Q235成分,成分,C,Si,Mn,P,S,%,0.17,0.30,0.350.80,0.035,0.035,5,种,类,成,分,表22 原材料成分,石灰,矿石,萤石,白云石,炉衬,CaO,91.08,1.00,30.84,54.00,SiO,2,1.66,5.61,6.00,0.46,2.05,MgO,1.54,0.52,0.58,20.16,37.75,Al,2,O,3,1.22,1.10,0.78,0.74,1.00,S,0.06,0.07,0.09,P,0.55,CaF,2,90.00,FeO,29.40,Fe,2,O,3,61.80,烧减,4.44,47.80,H,2,O,0.50,2.00,C,5.00,100.00,100.00,100.00,100.00,100.00,6,项目,固态平均比热,KJ/kg度,熔化潜热,KJ/kg,液态或气态平均比热,KJ/kg度,生铁,0.745,218,0.837,钢,0.699,272,0.837,炉渣,209,1.248,炉气,1.137,烟尘,0.996,209,矿石,1.046,209,表24 平均比热,7,反应,元素氧化放热,KJ/Kmol,KJ/kg元素,元素,C+1/2O,2,=CO,131365.0,10949.1,C,C+O,2,=CO,2,414481.7,34521.0,C,Si+O,2,SiO,2,795023.6,28314.0,Si,2P+5/2O,2,=P,2,O,5,1172078.6,18922.6,P,Mn+1/2O,2,MnO,384959.0,7020.3,Mn,Fe+1/2O,2,FeO,266635.0,5021.2,Fe,2Fe+3/2O,2,Fe,2,O,3,822156.0,7340.7,Fe,2CaO+SiO,2,=2CaOSiO,2,124600.4,2071.1,SiO,2,4CaO+P,2,O,5,=4CaOP,2,O,5,690414.9,5020.8,P,2,O,5,表25 铁水中元素氧化放热,（6）反应热效应（25）,8,1)渣中铁珠量为渣量的8；,2)金属中碳的氧化，其中90的碳氧化成CO，10的碳氧化成CO,2,；,3)喷溅铁损为铁水量的1；,4)炉气和烟尘量，取炉气平均温度1450。炉气中自由氧含量为0.5。烟尘量为铁水量的1.6，其中FeO=77%,Fe,2,O,3,=20%;,5)炉衬侵蚀量为铁水量的0.5；,6)氧气成分，98.5O,2,、1.5N2。,（7）根据国内同类转炉的实测数据选取；,9,根据铁水成分、原材料质量以及冶炼钢种，采用单渣不留渣操作。为了简化计算，以100kg铁水为计算基础。,2.2 物料平衡计算,（1）炉渣量及成分计算,炉渣来自金属中元素的氧化产物、造渣剂及炉衬侵蚀等。,10,1)铁水中各元素氧化量,表26 铁水中各元素氧化量,成,分,项,目,C,Si,Mn,P,S,铁水,4.250,0.850,0.580,0.150,0.037,终点钢水,0.150,痕迹,0.170,0.015,0.025,氧化量,4.100,0.850,0.410,0.135,0.012,*终点钢水成分是根据国内同类转炉冶炼Q235钢种的实际数据选取，其中：Si：在碱性氧气转炉炼钢法中，铁水中的硅几乎全部被氧化，随同加入的其它材料而带入的SiO2一起进入炉渣中，所以终点钢水硅的含量为痕迹。,P：采用低磷铁水操作，炉料中磷约8595%进入炉渣，本计算采用低磷铁水操作，取铁水中磷的90%进入炉渣，10%留在钢中。,Mn：终点钢水余锰含量，一般为铁水中锰的含量3040，取30。,S：去硫率，一般为3050的范围，取33。,C：终点钢水含碳量，根据冶炼钢种的含碳量和预估计脱氧剂等增碳量之差，则为终点含碳量。本计算取0.15%。,11,元素,反应极其产物,元素氧化量kg,耗氧量kg,氧化产物量kg,备注,C,C+1/2O2=CO,4.100,90%=3.690,3.690,16/12,=4.920,3.690,28/12,=8.610,C,C+O,2,=CO,2,4.100,10%=0.410,0.410,32/12,=1.095,0.410,44/12,=1.503,Si,Si+O,2,=(SiO,2,),0.850,0.850,32/28,=0.971,0.850,60/28,=1.821,Mn,Mn+1/2O,2,=(MnO),0.410,0.41,16/55,=0.119,0.41,71/55,=0.529,P,2P+5/2O,2,=(P,2,O,5,),0.135,0.135,80/62,=0.174,0.135,142/62,=0.309,S,S+O,2,=SO,2,0.012,1/3,=0.004,0.004,32/32,=0.004,0.004,64/32,=0.008,S,S+(CaO)=(CaS)+O,0.012,2/3,=0.008,0.008,(-16/32),=-0.004,产生氧量,0.008,72/32,=0.018,产生(CaS),-0.004表示还原出氧量。,耗CaO量,000856/32=,0.014,Fe,Fe,+1/2,O,2,=(FeO),1.055,(Fe量后面才能计算),1.055,16/55,=0.307,1.356,由渣量计算10%,见表2-13,Fe,2Fe,+3/2,O,2,=(Fe,2,O,3,),0.475 (同上）,0475,48/112,=0.203,0.678,由渣量计算5%,见表2-13,共计,7.037,7.787,表27 铁水中各元素氧化产物量,12,矿石加入量为1.00/100Kg铁水，其成分及重量见表28。,2）矿石加入量及成分,成分,重量 kg,备注,Fe,2,O,3,1.0061.800.618,不进入渣中,FeO,1.0029.400.294,不进入渣中,SiO,2,1.005.610.056,Al,2,O,3,1.001.100.011,CaO,1.001.000.010,MgO,1.000.500.005,S,*,1.000.070.0007,S以S+CaO=CaS+O的形式反应,其中生成CaS量为0.001 72/320.002,消耗CaO量为0.001,56/32,0.002kg,H,2,O,1.000.500.005,进入烟气,共 计,1.000,表28 矿石加入量及其成分,13,萤石加入量为0.5/100kg铁水，其成分及重量,3）萤石加入量及成分,成分,重量，kg,成分,重量，kg,CaF,2,0.590.000.45,P,*,0.5,0.550.0028,SiO,2,0.5,6.000.030,S,*,0.5,0.090.0004,Al,2,O,3,0.5,1.780.0089,H,2,O,0.5,2.000.010,MgO,0.5,0.580.0029,共计,0.500,*P以 2P+5/2 O2=(P2O5)的形式进行反应，,其中生成 P2O5 量为 0.0028,142/62,=0.007 kg。,消耗氧气量为,0.0028,80/62,0.004kg,*S微量，忽略之。,表29 萤石加入量及成分,14,炉衬被侵蚀量为0.50kg/100kg铁水，其成分及重量见表2-9,4）炉衬被侵蚀重量及成分,成分,重量 kg,成分,重量 kg,CaO,0.50,54.00,0.270,Al,2,O,3,0.50,1.000.005,MgO,0.50,37.950.190,C,*,0.50,5.00,0.025,SiO,2,0.50 2.05,0.010,共计,0.500,*被侵蚀的炉衬中碳的氧化，同金属中碳氧化成CO、CO,2,的比例数相同，即：,CCO,0.025,90%28/120.053kg,CCO2,0.025,10%42/120.009kg,其氧气消耗量：0.053,42/12,0.030kg,0.053 16/28,0.007kg,共消耗氧气量为 0.030+0.0070.037kg,表210 炉衬被侵蚀重量及成分,15,为了提高转炉炉衬寿命，采用白云石造渣剂，其主要目的是提高炉渣中的MgO含量，降低炉渣对炉衬的侵蚀能力。若使渣中MgO含量在6.008.00的范围之内，其效果显著。经试算后取生白云石加入量为3.00Kg/100Kg铁水，其成分及重量,5）生白云石加入量及成分,成分,重量 kg,成分,重量 kg,CaO,3.0030.840.925,SiO,2,3.00,0.460.014,MgO,3.0020.160.605,烧减,*,3.00,47.801.434,Al,2,O,3,3.000.740.022,共计,3.000,*烧减是指生白云石（MgCO3CaCO3）分解后而产生的气体。,16,6）石灰加入量,取转炉终渣碱度,17,量铁水中Si氧化成SiO,2,量 1.821,+炉衬带入的SiO,2,量 0.010,+矿石带入的SiO,2,量 0.056,+萤石带入的SiO,2,量 0.030,+白云石带入的SiO,2,量 0.014,1.821+0.010+0.056+0.030+0.0141.931kg,量白云石带入的,CaO,量 0.925,+炉衬带入的,CaO,量 0.270,+矿石带入的,CaO,量 0.010,-铁水中S成渣耗CaO量 0.014,-矿石中S成渣耗CaO量 0.002,0.925+0.270+0.010-0.014-0.0021.189kg,18,成分,重量 kg,成分,重量kg,CaO,6.5291.085.940,S,*,6.52,0.060.004,SiO,2,6.521.660.108,烧减,*,6.52,4.440.289,MgO,6.521.540.100,共计,6.520,Al,2,O,3,6.521.220.0795,表212 石灰成分及重量,*,S以S+(CaO)=(CaS)+O的形式反应，其中,生成（CaS）量为 0.00472/32=0.009(kg),生成氧量为 0.00416/32=0.00