前言降低铁水含硅量不仅对炼铁有利，对炼钢同样有较大的效益。根据多个企业

前言
降低铁水含硅量不仅对炼铁有利，对炼钢同样有较大的效益。根据多个企业统计，硅素每降低0.1%，燃料比降低4kg/t，产量提高5—7%，且有利于炉况稳定顺行。对炼钢而言，降低硅素可大量减少脱硅反应消耗的石灰及渣量，提高炼钢过程的精炼效果；同时随着渣量减少，炼钢冶炼时间缩短，生产率提高。因此，低硅冶炼对钢铁企业来说势在必行，是一个企业的重要效益增长点。
推进低硅冶炼是整个炼铁厂所有高炉同步进行的，各高炉都有不同特点，情况也不一样，有的高炉自身条件好一点，有的高炉自身装备差一点。通过各高炉相互学习、相互对标找差距，各高炉都有不同程度的进步。
我们永钢高炉自5月份实行低硅冶炼以来，经济效益明显，整个炼铁厂日产量由4月份平均19673吨上升到5月份的20277吨，6月份基本稳定在20700吨以上，硅素由0.5%以上下降到0.413%，6月份基本稳定在0.38%左右，在入炉品位下降的情况下实现了产量指标的进步，经济效益明显。炼钢自铁水产量上升后逐步减少了加入废钢的用量，每月仅此一项就降低成本1000万元，加上燃料比下降带来的效益，每月降低成本接近1500万，实行低硅冶炼以来，炉况基本保持了稳定顺行，随着炉况的进一步好转，各项指标均有进步的空间。
1.2低硅冶炼的原则：降硅不降热、亏热不降硅。要想实现低硅冶炼，必须有充足的炉缸物理热做保证，炉缸亏热会破坏气流的正常分布，造成炉缸工作失常，燃料比大幅升高，炉况顺行被打破。炉凉是大部分炉况失常的原因，炉凉给高炉带来的危害是巨大的。因此，低硅冶炼时必须重视炉缸热量，只有炉缸热量充沛，才能有降硅的空间，才能对高炉产生效益。
1.3低硅冶炼的好处：降低铁水含硅量不仅对炼铁有利，对炼钢同样有较大的效益。根据多个企业统计，硅素每降低0.1%，燃料比降低4kg/t，产量提高0.5—0.7%，且有利于炉况稳定顺行。对炼钢而言，降低硅素可大量减少脱硅反应消耗的石灰及渣量，提高炼钢过程的精炼效果；同时随着渣量减少，炼钢冶炼时间缩短，生产率提高。因此，低硅冶炼对钢铁企业来说势在必行，是一个企业的重要效益增长点。
1.4低硅冶炼的措施
低硅冶炼的措施：
加强原燃料入炉管理，精料是高炉不变的话题，也是高炉取得良好经济技术指标的必要条件。这里所讲的精料不一定非要入炉品位如何如何高，焦炭质量多么多么好，非要达到一定的标准才算精料，因为就目前来说，钢铁企业大多处于微利或亏损运营，上游原材料价格降幅低于钢铁产品降幅，因此，当前钢铁企业已不过分追求过高的入炉品位和过好的焦炭质量，低成本战略已成为当前钢企的追求方向，怎样在原燃料条件变差的情况下实现高炉稳定顺行，怎样使综合效益达到最大化成为企业努力的目标。就高炉来说，加强原燃料管理主要是三方面：一是稳定炉料结构，高炉操作稳定与变化是相对的，变化是绝对的，但稳定是我们追求的目标。原料稳定一是要求炉料结构相对稳定，不要频繁调整，因为任何一种原料的变化都会影响到软融带的变化，尤其是料种变化或同种料比例大幅度变化时影响较大，5月下旬三厂高炉失常就与当时烧结矿比例大幅度下降球团比例大幅上升有关。就焦炭来说，永钢采购的焦炭厂家多、品种杂，料场堆取料方面还存在诸多问题，加上永钢地处南方，雨水频繁，大气湿度波动大，造成焦炭实际水分波动较大，高炉燃料比波动较大，现在焦炭逐渐实现平铺直取，成分稳定性有所加强。二是强化筛分管理，减少粉末入炉。高炉原料要求高、熟、净、稳、小、匀，其中净就是强调筛净粉末，通过加强槽下筛分，减少粉末入炉，对永钢来说，块矿品种变化多，筛分困难，通过加大振筛振幅，延长振料时间，及时更换检查筛网等最大限度的保证筛分效果。三是原燃料成分要相对稳定。目前，烧结矿成分碱度波动仍然较大，尤其是碱度波动，给炉渣碱度平衡带来很大问题，致使炉料结构调整频繁，高炉稳定性得不到保证；二是料场在堆取焦炭方面还存在问题，虽然实现了对进场焦炭进行平铺，减少了不同厂家焦炭带来的成分和水分波动，但料场在给高炉料仓上料方面并没有真正实现直取，而是换堆频繁，造成高炉燃料比波动较大，炉温难以控制。以后应加强料场堆取料方面的学习和监管，真正为高炉提供相对稳定的原料。
提高热风温度，降低焦比。热风是最廉价的能源，实践证明，风温每提高100℃，焦比下降10—20kg/t，产量提高，此外，高风温可以使炉内高温区下移，降低了硅还原的高度，因而有利于冶炼低硅生铁。使用高风温还可以与喷吹燃料相结合，高风温可以补偿喷吹燃料所需要的热量，有利于炉况顺行，同时，还可以避免风口区理论燃烧温度过高导致SiO过多形成，并且缓解炉缸水平与垂直方向的温度梯度，有利于炉况稳定顺行。永钢高炉目前风温偏低，7座小高炉风温水平只有1050-1130℃左右，其中1高炉风温仅有950℃，7高炉风温虽有1050℃，但初末温差高达150℃，给高炉操作带来较大困难。高炉风温大大低于国内同类型高炉先进水平，造成焦比偏高，给降硅带来一定困难。通过优化烧炉方式，改进操作，稳定煤气用量，适当增加富氧等将风温提高20—30℃，相当于降低焦比5kg/t。
制定合理的上下部操作制度，提高煤气利用率。高炉操作讲究上稳下活，下部用高风速吹透中心，上部适当疏松边缘。对于高炉来说，要保证稳定顺行取得较好的经济技术指标，需要中心和边缘两道煤气流，要达到中心气流充沛，边缘稳定均匀。过分强调中心或边缘都是片面的，特别是小高炉，外围原料条件波动大，一定要在保证中心气流的基础上适当疏松边缘，否则边缘过重容易造成崩料甚至悬料，边缘过轻又容易造成炉况波动大，燃料比升高。经过对几座高炉的料制调整，目前几座高炉基本实现了稳定顺行，指标也有一定的改善。送风制度上尽量要求风口等长等径，风口长度应不小于炉缸直径的5%，边缘气流不均匀时首先调整风口直径，其次调整风口长度，从目前来看，一厂高炉风口调整幅度不大，二厂高炉风口长度明显偏短，有休风机会适当调整。
适当提高炉渣碱度，保证一定的镁铝比。采用合理的造渣制度是降硅的必要条件，维持较高的炉渣碱度对低硅冶炼有利。因为随着碱度的提高，渣中CaO与SiO2容易生成3CaO.SiO2和2 CaO.SiO2等化合物，降低了滴落带中中间渣的活度，抑制了硅的还原。此外，随着碱度提高，铁水物理热升高，有利于炉渣脱硫和降低硅素。考虑到永钢外围条件波动频繁，对炉况稳定带来的不利影响，二元碱度不宜过高，因为较高的碱度需要较高的热量，高炉降硅过程中不可避免的会出现亏热现象，而热量降低带来的最大危害在炉渣流动性和脱硫效果变差，一旦外围条件大幅度变化调剂不及时，容易造成炉缸工作变差，给高炉稳定顺行带来不利影响。而适当提高渣中MgO含量，保证一定的镁铝比，既可以保证炉渣脱硫效果，提高炉渣流动性，保证生铁质量。从当前的冶炼实践看，镁铝比应保持在0.65以上，上限不高于0.8%，以避免过高的MgO造成烧结矿成本上升和质量下降。
提高炉顶压力。顶压提高后，煤气流速降低，煤气在炉内停留时间延长，有利于提高煤气利用率。同时顶压提高后，可抑制SiO2的直接还原反应（C+SiO2---SiO+CO2）、减少SiO气体的生成，在一定程度上有利于降低铁水含硅。永钢小高炉以前顶压偏低，只有140Kpa左右，现在已提高到145—150KPa，既解决了高炉在入炉品位降低后透气性变差的问题，保证了入炉风量稳定，也在一定程度上对降硅起了推动作用。但目前在顶压使用方面，二厂几座高炉遇到了一定的问题，4高炉受气密箱影响顶压偏低，只有115Kpa，较一厂三座同类型高炉低30KPa以上，这就使高炉被迫采用长风口降低压差，对高炉边缘气流的控制造成了一定影响。5—7高炉炉役到了后期，热风系统存在隐患，风压限制在280KPa以内，也对高炉用风造成了一定影响。
推行炉温趋势管理。炉温趋势管理是高炉操作的难点。所谓趋势管理就是把影响炉温的各类因素(包括原因和作用时间)、风口的状况变化、炉温的现状和发展趋势、动作量的方向和作用效果等等，进行综合分析和判断，依照炉温变化趋势，预先调整热量水平。而不是以炉温现状(现在的[Si]水平)调炉温,这样可以减少炉温的波动，达到早动少动的效果。如果不是按炉温趋势进行管理，只靠看现时的[Si]或铁水温度来调炉温，就会发生滞后于炉温变化而加热过头引起炉温大热或连续减热造成炉温急剧向凉，使炉温大起大落地波动。
1.5实际生产中的问题
现时的[Si]或铁水温度是反映了以前冶炼过程热平衡的结果，虽有对炉温判断的参考价值，但不能做调炉温的依据。因为高炉操作具有热惯性，炉温正在随着各种因素的变化正在演变之中,现时炉温凉的炉子可能正在向热，也可能继续向凉，现时炉温热的炉子可能已在向凉，也可能继续向热，如果只是依照现时炉温调炉温，就可能滞后于炉温的发展趋势，且方向不明地在调炉温,往往只会加剧炉温的波动。而对于永钢高炉来说，风温水平低，原燃料波动大，加之南方天气变化湿分变化大，工长操作水平受限，车间管理不十分到位等情况，造成炉温波动较大，出现过山车式的波动，炉温低时，工长减风随意且幅度偏大，炉温上行趋势时工长加风不及时，而是根据出铁时实际炉温情况进行调整，操作滞后造成炉温大幅上行；炉温高时，减煤时间长，炉温趋势已经下行时调剂不到位，也是根据实际出铁炉温情况进行调剂，造成调剂滞后，炉温下降较多，如此反复，造成炉温呈过山车式波动，给炉内气流稳定造成极大困难，也给指标进步带来不利影响。工长应摒弃使用风量进行炉温调剂的思想，全风全氧操作，减少减风次数，一旦炉温过低或者物理热低于下限时可视情况控风，勤看风口，有上行趋势时及时加风，尽量减少损失。
影响炉温的因素很多，比如原燃料条件、风温水平、入炉品位、雨雪天气、操作调剂、炉况顺行情况等等。对于大的原燃料变化，比如烧结矿比例降低、大量配吃落地矿、生矿比例增加等，易引起焦比升高，此时要及时减轻负荷；对于雨雪天气，焦炭水分的变化要及时进行调整，此外由于空气湿度增大，造成实际入炉风量增加，料速加快，此时也应根据跑料情况及时控制氧量，防止超冶强造成炉温降低。工长要有冶强观念，8小时跑料三班要基本稳定，超冶强的危害很大，极易造成炉温下降，控制不好会造成炉凉，因此，工长在操作时要时刻关注小时料速，连续超过正常料速时要及时减轻负荷，必要时通过控氧减慢料速保证冶强稳定。
提高工长操作水平，实行精细化操作。要想取得比较好的经济技术指标，一定要加强精细化操作，对能够量化的东西尽量量化，减少随意性操作。长期以来，永钢高炉工长把减风操作当成日常控制炉温的手段，炉温低时随意减风，且减风数量很随意，没有具体量化标准，
加强设备点检维护，减少无计划休风和慢风。

結果 (英文) 1:

ObjectiveReducing Silicon content in molten iron is not only good for iron, also has greater benefits for steelmaking. According to multiple enterprise statistics, Silicon 0.1%, fuel ratio 4kg/t, production increased five and makes stable furnace conditions along the line. For steel-making, reduction of Silicon can greatly reduce the consumption of desiliconization reaction of lime and slag, improve the refining effect of steelmaking process; and with the reduced slag and steelmaking smelting time and productivity. Therefore, low Silicon smelting of iron and steel enterprises is necessary, is the important benefits of enterprise growth.Push all the blast furnace ironmaking plant of low Silicon smelting is the synchronized, each has different characteristics for blast furnace, the situation is not the same, some conditions of blast furnace itself well, blast furnace equipment itself is poor. Through mutual learning and mutual differences of blast furnace, blast furnaces with different degrees of progress.We blast since its May low Silicon smelting have obvious economic benefits, iron works as a whole average 19673 increased daily output from April to May of 20277 tons, basically stable in June at 20700 tons, of Silicon by more than 0.5% down to 0.413%, in June essentially stable at around 0.38%, furnace-grade decline in yield under the condition of progress, have obvious economic benefits. Steel-making molten iron production gradually reduced after the inclusion of the amount of scrap, alone will cost 10 million Yuan a month, plus benefits of fuel ratio, lower cost nearly 15 million a month, since the introduction of low Silicon smelting furnace condition remained stable, with the further improvement of furnace, the indicators are there is room for improvement.1.2 principles of low Silicon smelting: silicon heat, losing hot Silicon does not drop. To achieve low Silicon smelting, the hearth must have sufficient physical heat guarantee, hearth heat will damage the normal distribution of air flow, causing hearth disorders, fuel rate soared furnace along the line was broken. Furnace cooling is most causes of abnormal furnace condition, furnace cool to blast furnace brought harm is enormous. Therefore, low Silicon smelting hearth must pay attention to the heat only furnace heat energy, Silicon space, can blast furnaces to produce benefits.1.3 the benefits of low Silicon smelting: reducing Silicon content in molten iron is not only good for iron, also has greater benefits for steelmaking. According to multiple enterprise statistics, Silicon 0.1%, fuel ratio 4kg/t, production 0.5-0.7%, and conducive to stable furnace conditions along the line. For steel-making, reduction of Silicon can greatly reduce the consumption of desiliconization reaction of lime and slag, improve the refining effect of steelmaking process; and with the reduced slag and steelmaking smelting time and productivity. Therefore, low Silicon smelting of iron and steel enterprises is necessary, is the important benefits of enterprise growth.1.4 measures for low Silicon smeltingMeasures of low Silicon smelting:Strengthening the management of raw fuel into the furnace, blast furnace concentrate is the same topic, it is also necessary for blast furnace made good economic and technical indicators. Here by told of concentrate does not necessarily non-to into furnace grade how how high, coke quality how how good, non-to reached must of standard only is concentrate, because on currently for, steel enterprise most in profit or losses operation, upstream raw materials price drop below steel products drop, so, current steel enterprise has not too pursuit high of into furnace grade and had good of Coke quality, low cost strategy has became current steel enterprises of pursuit direction, how in original fuel conditions variable poor of situation Xia achieved BF stable Shun line, How to maximize benefits to be achieved in the enterprise. Blast furnace, strengthen raw material and fuel management is mainly in three aspects: a stable burden structure, stability and change in blast furnace operation is relative, change is absolute, but stability is our goal. Stability of raw materials is to ask the charging structure is relatively stable, not to frequent adjustments, because any changes in the raw material will affect the change of cohesive zone, particularly when material changes or significant changes in the same proportion greater impact, blast three disorders in late May and was a significant decline in the proportion of sinter pellets ratio increased significantly. Coke, coke factory steel procurement, miscellaneous, Stacker, there are still many problems, plus wing located in the South, frequent rain, humidity fluctuations, resulting in actual moisture of Coke fluctuates, blast-furnace fuel ratio fluctuates, coke now gradually plain and direct, and stability has been enhanced. Second is to strengthen screening management, reduce the powder into the furnace. High blast furnace raw material requirements, ripe, clean, stable, small, uniform, with net is the emphasis on screen powder, by strengthening under the screen, reduce the powder into the furnace, steel, lump ore, sieving difficult by increasing amplitude of vibration sieve, extended vibration time, timely replacement of check screen ensure maximum screening effect. Three is the raw material components are relatively stable. Currently, sintering mine components alkalinity fluctuations still larger, especially alkalinity fluctuations, to slag alkalinity balance brings is big problem, led charge structure adjustment frequently, BF stability have not to guarantee; II is material field in heap take Coke aspects also exists problem, although achieved has on entry Coke for tile, reduced has different manufacturers Coke brings of components and water fluctuations, but material field in to BF material warehouse Shang material aspects and no real achieved straight take, but for heap frequently, caused BF fuel than fluctuations larger, temperature to control. Material should be strengthened after heaping and taking the material aspects of learning and supervision actually provide relatively stable raw materials for blast furnace.Increased air temperature, reduce Coke consumption. Hot air is the cheapest source of energy, practice has proved that the air temperature each increased 100 ℃, the focal ratio decreased 10-20kg/t, production increased and, in addition, high temperature furnace high temperature area down, reduce the height reduction of silicon, which makes smelting low Silicon pig iron. Using high-temperature can be combined with fuel injection, high temperature to compensate for Jet fuel needed to heat and furnace along the line, at the same time, you can avoid air inlet area the theoretical combustion temperature is too high leads to formation of SiO, and ease the hearth temperature gradient in horizontal and vertical direction, conducive to stable furnace conditions along the line. Steel blast furnaces at present low air temperature, 7 small blast temperature level only about 1050-1130, of which 1 blast temperature of only 950 ° c, 7 blast temperature of 1050 ° c, but early temperature differences of up to 150 ℃, bring greater difficulties to blast furnace operation. Blast temperature significantly lower than the domestic advanced level of similar-type blast furnace, causing focal ratio is too high, bring some difficulties to Silicon. By optimizing furnace, improve operations, and stable gas consumption, increasing oxygen enriched air temperature increase, such as 20-30, equivalent to decreasing Coke ratio of 5kg/t.Set reasonable upper and lower parts of the operation system, improve gas utilization. On the blast furnace operation pay attention to live under stable, lower with high winds blew through the Center, loose upper right edge. For blast furnace, to ensure stability along the line to obtain better economic and technical indicators, needs two gas flow and edge away from the Center, to reach the Center air is plentiful, margins steady uniform. Overemphasize the Center or edges are one-sided, especially in small blast furnace, external conditions and volatile must ensure airflow on the basis of the loose edges of the Centre, otherwise the edge overweight easily slip even hanging, edge light and easy to create the conditions and volatile fuel rate rise. After making adjustments for several blast furnaces and several blast furnaces now basically stable, also has some improvements. Try to keep air in the ventilation systems such as length, diameter, outlet length should be not less than 5% of the hearth diameter edge uneven airflow first adjust air outlet diameter, then adjust the outlet length, for now, a factory blast furnace Tuyere modest adjustments, plant blast furnace Tuyere is obviously too short in length, damping down a chance to adjust.Increasing slag basicity, guarantees a certain amount of mg-Al ratio. Using reasonable slag is necessary for Silicon, maintenance of slag basicity on the low Silicon smelting with high advantage. Because with the increase of alkalinity, slag of CaO and SiO2 easily generate 3CaO.SiO2 and 2 CaO.SiO2 compounds, reduces the activity of slag in the dropping zone, inhibited the reduction of Silicon. In addition, as the alkalinity increases, increased physical heat of molten iron and slag desulfurization and reduced Silicon. Consider to Yong steel peripheral conditions fluctuations frequently, on furnace condition stable brings of adverse effect, II Yuan alkalinity should not be high, because high of alkalinity need high of heat, BF drop silicon process in the inevitable of will appeared lost hot phenomenon, and heat reduced brings of maximum against in slag liquidity and desulfurization effect variable poor, once peripheral conditions significantly changes transfers not timely, easy caused furnace cylinder work variable poor, to BF stable Shun line brings adverse effect. And appropriate improving MgO content in the slag, guarantee a certain amount of magnesium-aluminum, which can keep the slag desulfurization effect, improving slag fluidity, guarantee the quality of pig iron. From the perspective of current practice, mg-Al ratio should be maintained above 0.65, the ceiling not higher than 0.8% in order to avoid excessive caused rising costs and declining quality of the sinter MgO.Improving furnace top pressure. Top pressure increases, the gas velocity decreased, extended gas residence time in the furnace to improve gas utilization. While top pressure is raised, then it can inhibit the direct reduction of SiO2 (C+SiO2---SiO+CO2), reduction of SiO gas generation, to some extent, lower hot metal silicon. Steel before the small blast furnace top pressure is low, only about 140Kpa has now increased to 145-150KPa, can solve the low permeability of blast furnace grade variation problems, ensures stable into the furnace air flow, in part on Silicon reduction played a role. But in terms of top pressure uses, plant several blast furnaces ran into some problems, effects 4 blast furnace gas tightness box for low pressure, only 115Kpa, low over the same type of blast furnace plant three 30KPa above, this blast was forced to use longer air inlet reduce pressure, has had a certain impact on the edge of the blast furnace gas control. 5-7 service towards the end of a blast furnace, hot air system problems, the wind pressure limit less than 280KPa also had a certain influence on blast furnace with wind.Implementation of temperature trends in management. Temperature trend of blast furnace operation management is difficult. So-called trend of management are various factors that affect temperature (including the cause and effect of time), air condition, temperature changes of status and development direction of trends, movements and effects, comprehensive analysis and judgment, in accordance with the trend of temperature, adjust the heat levels in advance. Instead of taking the situation of temperature (now [Si] level) variable temperature, thus reducing the temperature fluctuations, less to early results. If it is not managed according to the temperature trend, just look at [Si] or hot metal temperature to adjust temperature, lags behind temperature changes will occur due to heating overdo temperature hot or sharp to cool in temperature caused by continuous reduction of heat, temperature fluctuations and volatility.1.5 practical problems in productionThe current [Si] or hot metal temperature reflects the results of heat balance the lead before, notwithstanding the judgment of temperature reference value, but you cannot adjust temperature according to. Because BF operation has hot inertia, temperature is with various factors of changes is evolution among, now temperature cool of stove may is to hot, also may continues to to cool, now furnace warm of stove may has in to cool, also may continues to to hot, if just in accordance with now temperature adjustable temperature, on may lag Yu temperature of development trend, and direction unknown to in adjustable temperature, often only will increased temperature of fluctuations. And on Yu Yonggang BF for, wind temperature level low, original fuel fluctuations big, coupled with South weather changes wet points changes big, foreman operation level by limited, workshop management not is in place, situation, caused temperature fluctuations larger, appeared had mountain car type of fluctuations, temperature low Shi, foreman reduction wind free and range partial big, temperature uplink trend Shi foreman added wind not timely, but according to out iron Shi actual temperature situation for adjustment, operation lag caused temperature sharply uplink; temperature high Shi, reduction coal time long, temperature trend has down Shi transfers not in place Is based on actual transfers the iron furnace, resulting in transfer delay, temperature drop more, and so forth, causing roller-coaster temperature fluctuations, created great difficulties for airflow stability in furnace, also bring adverse effects to indicators of progress. Foreman might be revised to abandon air temperature, wind all oxygen, reduce reduce air, once the temperature is too low or physical heat below the limit under Visual control of wind, air, there is an upward trend in time increases, to minimize the loss.Many factors affect the temperature, for example, into the furnace of raw material conditions, the air temperature grade, rain and snow, dispensing operation, furnace conditions along the line, and so on. For big of original fuel changes, like sintering mine proportion reduced, and large distribution eat landing mine, and health mine proportion increased,, easy caused Coke than increased, at to timely reduce load; for snow weather, coke water of changes to timely for adjustment, also due to air humidity increases, caused actual into furnace air increased, material speed speed up, at also should according to run material situation timely control oxygen volume, prevent Super ye strong caused temperature reduced. Foreman be ye strong ideas, running three shifts to stable for 8 hours, super great harm ye strong, easily caused a decline in temperature, cool in furnace caused by poorly controlled, so foreman speed to always pay attention when hours of operation, more than normal speed time to lighten the load and, if necessary, by controlling oxygen ye strong slow speed to ensure stability.Improve the level of foremen actions, fine operation. In order to achieve better economic and technical indicators, must be strengthened and refined action to quantify quantifiable things, reduce arbitrary actions. For a long time, steel foreman wind operation reduction as a means of controlling temperature, when temperature is low free to wind reduction, and reduced number of wind at will, there is no specific quantitative criteria,Strengthening equipment maintenance, reducing unplanned break wind and slow wind.

結果 (英文) 3:

It is not only beneficial for iron smelting to reduce silicon content in hot metal, it also has good benefit for steelmaking.. According to the statistics of many enterprises, the silicon element per 0.1% reduction, fuel ratio of 4kg/t, yield increase 5 - 7%, and are good for the stability of the furnace.. For steelmaking, to reduce the silicon element can reduce the amount of desilication reaction consumption of lime and slag quantity and improve the process of steelmaking refining effect; at the same time with the reduction of the amount of slag, smelting time is shortened and improve the productivity. Therefore, the low silicon smelting for iron and steel enterprise is imperative, is an enterprise important benefit growth point. Advancing low silicon smelting is carried out synchronously with all the blast furnace of the whole iron smelting plant.,Each blast furnace has different characteristics, the situation is not the same, some of the blast furnace itself is better, some of the blast furnace itself is equipped with a little bit. Through the mutual learning, mutual benchmarking for the gap of blast furnace, blast furnace has a different degree of progress.
we Yonggang blast furnace since may implement low silicon smelting has obvious economic benefit and the ironmaking plant daily output from the April average 19673 tons rise to 20277 tons in May, June is basically stable in more than 20700 tons, silicon by more than 0.5% dropped to 0.413%, June is basically stable at about 0.38%, grade into the furnace decreased the realized yield indicators of progress and economic benefits obvious.Steelmaking since the hot metal output increased and then gradually reduce the amount of scrap to join the monthly only reduced the cost of 10 million yuan, plus fuel to bring down the efficiency ratio of per month to reduce the cost of nearly 15 million, since the implementation of the low silicon smelting, furnace remained the smooth and stable, with a further improvement in the furnace, the indicators have progress of space.
1.2 principle of low silicon smelting: the silicon does not drop the heat, the heat loss is not reduced silicon. To achieve low silicon smelting, must do to ensure adequate hearth thermal physics, heat would undermine the airflow of the normal distribution hearth deficit, resulting in hearth disorders, fuel ratio significantly increased, operation of BF is broken.The cooling of the furnace is the cause of most of the furnace conditions, the harm caused by the furnace cooling to the blast furnace is enormous.. Therefore, low silicon smelting, you must pay attention to the hearth heat, only hearth heat abundant, in order to have a drop of silicon space to the blast furnace produce benefits.
1.3 low silicon smelting benefits: the reduction of silicon content in hot metal is not only beneficial for iron smelting, and also has a greater benefit for steelmaking. According to the statistics of many enterprises, the silicon element per 0.1% reduction, fuel ratio of 4kg/t, yield increase 0.5 - 0.7%, and are good for the stability of the furnace.. In the case of steel smelting, it can reduce the amount of lime and slag, and improve the refining effect of the process.;At the same time, with the reduction of slag amount, smelting time and productivity increase. Therefore, the low silicon smelting for iron and steel enterprise is imperative, is an enterprise important benefit growth point.
1.4 low silicon smelting measures
low silicon smelting measures:
strengthen the original fuel into the furnace management, fine material is the same topic, but also blast furnace to obtain good economic and technical indicators of the necessary conditions. What tell here concentrate not necessarily to grade into the furnace how high, coke quality how good, to reach a certain standard to concentrate, because for now, iron and steel enterprises mostly in profit or loss in operation,Upstream raw materials prices decline below the decline of steel products. Therefore, the iron and steel enterprises has not excessive pursuit of high grade into the furnace and coke quality, low cost strategy has become the pursuit direction of current steel prices, how to realize stability of BF, in case of deterioration of raw material and fuel condition, how to make comprehensive benefits maximized become enterprises in their efforts to the goal. Blast furnace, to strengthen the management of raw materials and fuel is mainly in three aspects: one is the stability of the furnace charge structure, blast furnace operation stability and change is relative, change is absolute, but stability is our pursuit of the goal. Is a stable raw material requirements of burden structure is relatively stable, not frequent adjustment,Because any kind of raw material changes will affect the soft melting zone changes, especially changes or the same proportion of the material greatly change material impact larger, late May factory blast furnace abnormal is and then sintering ore proportion greatly decreased the proportion of pellet rose sharply on. Coke, Yonggang procurement coke manufacturers, mixed breed, stockyard stacker and Reclaimer aspects still exist many problems, plus Yonggang, located in the south, frequent rain, large fluctuations in atmospheric humidity, resulting in coke actual moisture fluctuations larger, blast furnace fuel ratio greater volatility, now coke gradually realize tile straight, ingredient stability has been strengthened. Two is to strengthen the screening management,Reduce powder into the furnace. Requirements of blast furnace raw material to high, cooked, net, stability, small and uniform, the net is to emphasize the sieve net powder, by strengthening the slot sieve to reduce powder into the furnace, to Yonggang, lump ore varieties varied, sieving difficult, by increasing the vibration amplitude of the sieve, prolonged vibration feeding time, timely replacement of check the screen and to maximize the screening effect is ensured. Three is the original fuel ingredients to be relatively stable. At present, sinter composition alkalinity fluctuation is still large, especially alkalinity fluctuation, to slag basicity balance brings a big problem, resulting in frequent burden structure adjustment and stability of blast furnace can not be guaranteed.The second is material field in reactor coke problems still exist, although the realization of the tile on the approach of coke, reduce the coke from different manufacturers to bring the composition and moisture fluctuations, but the material field in to blast furnace bunker feeding did not realize direct, but stack changing frequently, resulting in high furnace fuel ratio fluctuations, temperature is difficult to control. We should strengthen the material field study and the supervision of the stacker, really provide a relatively stable raw material for blast furnace.
improve hot blast temperature, reducing coke. The wind is the most cheap energy, practice, air temperature increase for each 100 DEG C, coke rate decreased by 10 20kg/t, the yield increase, in addition,High temperature can lower the high temperature zone and decrease the height of the silicon reduction, so it is advantageous for smelting low silicon iron.. Using high temperature air can also and fuel injection combined, high blast temperature can compensation injection fuel to heat, it is beneficial to the operation of BF. At the same time, can also avoid tuyere theoretical combustion temperature is too high cause SiO formation of excessive, and ease of horizontal and vertical direction of the hearth temperature gradient, is conducive to the steady operation of furnace condition. Yonggang blast furnace air temperature is low, seven small BF air temperature only 1050-1130 DEG C, among them 1 blast furnace air temperature only 950 DEG C, 7 blast furnace air temperature although there are 1050 DEG C, but at the end of the beginning temperature up to 150 DEG C,To bring the blast furnace operation more difficult. Blast furnace air temperature is much lower than the domestic advanced level of the same type of blast furnace, resulting in high coke rate, bring some difficulties to the silicon reduction. Through optimizing the burning furnace and improve the operation, stable gas consumption, appropriate increase enriched oxygen will air temperature increase 20 - 30 DEG C, which is equivalent to reducing coke 5kg/t. Formulate reasonable upper and lower operating system, improve coal gas utilization. The operation of the blast furnace is about the stability of the furnace, the lower part is with high wind speed and the center, and the upper appropriate loose edge.. For the blast furnace, to ensure the stable operation of the economic and technical indicators, the need to center and edge of the two gas flow, to achieve the central air flow,Edge stability uniform. Too much emphasis on center or the edge is one-sided, especially small blast furnace, peripheral big fluctuations in raw material condition, must be to ensure the air flow center based on appropriate loose edge, otherwise the edge overweight easily lead to collapse even suspended material, edge of the light and easy to cause fluctuations in furnace conditions, fuel ratio increased. After several blast furnace material adjustment, at present, several blast furnace basic achieved stable, the index also has some improvement. Send wind system as far as possible the request tuyere equal length and diameter, tuyeres length should not be less than 5% of the diameter of hearth, edge airflow uneven first when adjusting tuyere diameter, secondly adjusting tuyere length.From the present situation, a factory blast furnace outlet adjustment is not much, the length of the two plant blast furnace is obviously shorter, there is a chance to adjust the wind opportunity.
increasing slag basicity, guarantee the mg / Al ratio. Reasonable slagging system is a necessary condition for reducing silicon, maintain high basicity of slag for low silicon smelting favorable. Because with the increase of basicity, slag of Cao and SiO2 is easy to generate 3CaO.SiO2 and 2 CaO.SiO2 and other compounds that reduce the dropping zone of middle slag activity, inhibit the reduction of silicon. In addition, with the increase of alkalinity, the physical heat of hot metal is increased, which is beneficial to slag desulfurization and the reduction of silicon.. Considering the conditions surrounding the frequent fluctuations of steel,To stabilize the furnace condition brings adverse effect, binary alkalinity should not be too high, will be inevitable because of the higher alkalinity needs a higher heat, blast furnace and silicon reduction process appear to lose heat and heat to reduce the greatest harm in slag fluidity and desulfurization effect becomes worse, once the external conditions change on a large scale relief is not timely, easy to cause the condition of hearth, to the stability of BF brings adverse effects. And appropriate to increase the MgO content in slag, ensure that the mg / Al ratio, not only can ensure the effect of slag desulfurization, improve the fluidity of the slag, ensure the quality of pig iron. From the current practice of smelting, mg / Al ratio should be maintained at more than 0.65,The upper limit is not higher than 0.8%, in order to avoid the high MgO caused the sintering ore cost rise and the quality fall.
enhancing top pressure. The gas flow rate is decreased, gas flow rate of gas is prolonged, and the gas utilization rate can be improved when the pressure is raised.. At the same time, the can inhibit the direct reduction of SiO2 (SiO2---SiO CO2 C), and reduce the generation of SiO gas, which can be decreased to some extent.. Before Yonggang small blast furnace top pressure is low, about only 140Kpa. Now, has been increased to 145 - 150kPa, not only to solve the blast furnace in the lower grade into the furnace permeability of the problem of poor, to ensure the incoming heat flow stability,And to some extent, it also plays a role in promoting the silicon.. But the top pressure use, plant a few blast furnaces met some problems. 4 blast furnace bullied secret compartment influence top pressure is low, only 115Kpa, plant a three seat above of the same type of blast furnace low 30KPa, which makes the blast furnace was forced to adopt tuyere drop low dropout, edge of air blast furnace control caused a certain influence. 5 - 7 blast furnace furnace service to the late, the hot air system has hidden trouble, the wind pressure within the limits of 280KPa, but also to blast furnace with wind caused a certain impact. The implementation of temperature trend management
. The temperature trend of management is a difficult problem in blast furnace operation.The so-called trend of management is to the current situation and development trend of the temperature effect of all kinds of factors, including the cause and effect of time, tuyere status changes, temperature, amount of motion direction and effect and so on, comprehensive analysis and judgement, according to temperature changes in trends, pre adjustment heat levels. Rather than on the current situation of furnace temperature (now the Si level) regulating temperature, which can reduce the temperature fluctuations, to early less dynamic effect. If not according to the temperature trend of management, only by the current Si or the temperature of the molten iron to adjust the temperature occurs behind the temperature change and overhead heating or hot temperature caused by continuous reduction of heat caused by temperature sharply to cool.The temperature of big wave landing.
1.5 in the actual production of
the current Si or the temperature of molten iron is reflected in the result of previous smelting process of thermal equilibrium, although the reference value of judgment on the temperature, but can not do basis for regulating temperature. Because the blast furnace operation has a thermal inertia, furnace temperature is along with the changes of various factors are evolving, the current temperature cool stove may is to heat, may also continue to cool, the current furnace heat stove may has to cool, may also continue to heat, if only in accordance with the current temperature regulating temperature, it may lag behind the development trend of temperature, and the direction is unknown in regulating temperature.Often will only aggravate the temperature fluctuation. And for Yonggang blast furnace, blast temperature low, large fluctuations of raw materials and fuel, coupled with the southern weather changes moisture changes, foreman operation level is limited, workshop management is not in place and other conditions, resulting in temperature fluctuation is large, and the emergence of the fluctuation of the roller coaster, low temperature, foreman to reduce wind freely and the magnitude is too large, upward trend in the temperature when foreman and the wind not promptly, but adjusted according to the actual temperature of the furnace tapping and operation delay caused by temperature sharply upward; at high temperature, reducing coal for a long time, temperature trend has been downward adjustment is not in place, is also the root according to actual tapping temperature transfers,Caused by the adjustment lag, temperature decreased a lot, so repeatedly, resulting in temperature a roller coaster fluctuations, airflow in furnace stability caused great difficulties to, or to adversely affect the progress indicator. Foreman should abandon the use of air temperature adjustment, the wind full oxygen operation, reduce wind reduction times, once the temperature is too low or physical heat below the lower limit of visual control of the wind, often see tuyere, the upward trend in a timely manner with the wind to minimize losses.
effect of temperature of many factors, such as raw material and fuel condition, air temperature, furnace grade, rain and snow weather, swap operations, the smooth operation of furnace condition and so on. For large raw fuel changes,Such as sintering ore proportion reduced, together with a great deal to eat ground ore, raw ore ratio increased and, easy to cause the coke ratio increased, this time to in a timely manner to reduce the load; for rain and snow weather, the coke moisture changes to timely adjustment. In addition due to the air humidity increases, resulting in actual furnace volume increased, feed speed, this time also should be according to the running situation timely control of oxygen, prevent super smelting caused by lowering temperature. Foreman must be ye strong notions and 8 hours to run three classes are basically stable, the super smelting of great harm, extremely easy to cause temperature drops, the control is not good will cause cooling of the furnace. Therefore, the foreman in operation to always pay attention to the hour of feeding speeds,It is necessary to reduce the load when the material is continuous and exceed the normal speed. It is necessary to ensure the stability of the smelting and smelting by controlling the oxygen reduction material speed..
improve the foreman level of operation, the implementation of sophisticated operation. To achieve a better economic and technical indicators, we must strengthen the fine operation, the quantification of things to quantify as much as possible, to reduce random operation. For a long time, Yonggang of blast furnace foreman to minus the wind operation as a means of daily temperature control, low temperature reduced in random wind, and reduced number of wind is free, no specific quantitative criteria,
strengthen equipment spot inspection maintenance, reduce unplanned downtime and slow wind.