WO2022011693A1 - 高炉喷吹用兰炭的定向制备技术及高效使用的优化方法 - Google Patents

高炉喷吹用兰炭的定向制备技术及高效使用的优化方法 Download PDF

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WO2022011693A1
WO2022011693A1 PCT/CN2020/102745 CN2020102745W WO2022011693A1 WO 2022011693 A1 WO2022011693 A1 WO 2022011693A1 CN 2020102745 W CN2020102745 W CN 2020102745W WO 2022011693 A1 WO2022011693 A1 WO 2022011693A1
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coal
blue
blast furnace
low
carbonization
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PCT/CN2020/102745
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French (fr)
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张建良
刘征建
王广伟
徐润生
焦克新
李克江
王振阳
王翠
宁晓钧
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北京科技大学
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Priority to US17/631,426 priority Critical patent/US20220275280A1/en
Priority to PCT/CN2020/102745 priority patent/WO2022011693A1/zh
Publication of WO2022011693A1 publication Critical patent/WO2022011693A1/zh

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    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10B—DESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
    • C10B57/00—Other carbonising or coking processes; Features of destructive distillation processes in general
    • C10B57/02—Multi-step carbonising or coking processes
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10B—DESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
    • C10B53/00—Destructive distillation, specially adapted for particular solid raw materials or solid raw materials in special form
    • C10B53/04—Destructive distillation, specially adapted for particular solid raw materials or solid raw materials in special form of powdered coal
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10B—DESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
    • C10B57/00—Other carbonising or coking processes; Features of destructive distillation processes in general
    • C10B57/04—Other carbonising or coking processes; Features of destructive distillation processes in general using charges of special composition
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10B—DESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
    • C10B57/00—Other carbonising or coking processes; Features of destructive distillation processes in general
    • C10B57/14—Features of low-temperature carbonising processes
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B5/00—Making pig-iron in the blast furnace
    • C21B5/001—Injecting additional fuel or reducing agents
    • C21B5/003—Injection of pulverulent coal
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B5/00—Making pig-iron in the blast furnace
    • C21B5/007—Conditions of the cokes or characterised by the cokes used

Definitions

  • the invention belongs to the technical field of metallurgy, and in particular relates to a directional preparation technology of blue carbon for blast furnace injection and an optimization method for efficient use.
  • Blast furnace ironmaking is currently facing enormous pressure for energy conservation and emission reduction.
  • Blast furnace coal injection is an important technical means to reduce the consumption of coke in blast furnace ironmaking. meaning.
  • traditional blast furnace coal injection is mainly based on high-quality anthracite resources.
  • Anthracite is a non-renewable resource with very little reserves in China, and its scarcity is constantly highlighted. Therefore, the continuous expansion of the scope of blast furnace injection fuel is a constant effort of Chinese iron smelters. direction.
  • blue carbon has a price far lower than coke and has a large production capacity in China.
  • Chinese invention patent CN201810419081.7 discloses a method for preparing blast furnace injection pulverized coal by using blue carbon as blast furnace injection raw material.
  • blue charcoal is first made into prefabricated powder, which is then mixed with bituminous coal or anthracite, and the particle size difference between blue charcoal particles and bituminous coal or anthracite is used to accelerate the grinding effect of blue charcoal particles and solve the problem of difficulty in grinding blue charcoal in the prior art. .
  • Chinese invention patent CN201610339590.X discloses a low-temperature retort furnace for preparing blue charcoal and a preparation method for blue charcoal, and blue charcoal is obtained by optimizing processes such as carbonization temperature, heating gas, cooling, etc., but this method does not target
  • the blue carbon process is optimized according to the requirements of blast furnace injection, and the prepared blue carbon may not be suitable for blast furnace injection. Therefore, in order to prepare blown blue carbon that meets the requirements of blast furnace smelting, it is necessary to comprehensively consider various metallurgical properties of blue carbon from the perspective of blast furnace, and based on this, discuss the preparation process parameters and raw material pretreatment scheme of blue carbon that match the optimal metallurgical properties. , and then realize directional production.
  • the present invention provides a complete set of directional preparation technology of blue charcoal for blast furnace injection and an optimization method of blue charcoal injection scheme, which can expand the blast furnace ironmaking injection fuel resources, efficiently inject and save energy. Platoon has important guiding significance.
  • the purpose of the present invention is to provide a directional preparation technology of blue carbon for blast furnace injection.
  • the volatile and ash content of the target blue carbon the volatile removal percentage and ash removal percentage of the raw coal can be obtained, and through the systematic experimental test, the relationship between the carbonization process parameters of blue carbon and the performance parameters of blue carbon injection can be established. According to the relationship, the preparation process route of blue carbon with optimal injection performance was obtained, and finally high-performance blue carbon was obtained by carbonization.
  • the purpose of the present invention is also to provide an optimization method for efficient use of blue carbon for blast furnace injection, which can quickly and accurately obtain blue carbon and low-rank coal through the evaluation coefficient of cost performance, the volatile content of mixed coal is less than 25% and the principle of no strong explosiveness the optimal matching structure.
  • the present invention adopts the following technical solutions to realize:
  • a directional preparation technology of blue charcoal for blast furnace injection which includes dry distillation of raw coal to remove part of volatile matter to prepare blue charcoal for blast furnace injection, comprising the following steps:
  • the suitable ash content of blast furnace injection coal is below 12%, and the ash content of large furnace capacity blast furnaces requires ash content ⁇ 9%, so the target blue carbon
  • the limit value of the percentage of ash content should meet the
  • the main components of raw coal include ash, fixed carbon and volatile matter (based on dry basis). Therefore, before removing the ash, the quality of the blue charcoal obtained is equal to the quality of the raw coal minus the volatile removal; after removing the ash, the quality of the blue char is equal to the quality of the raw coal minus the volatile removal.
  • the removal amount and the ash removal amount are the mass of the blue carbon obtained before the ash removal minus the ash removal amount. According to this situation, let the ash removal amount be x, the total mass of raw coal is m coal , and the total mass of blue carbon obtained before removal is m blue carbon , then the following formula is satisfied:
  • formula (1) is obtained according to the percentage of ash removal equal to the ash removal amount divided by the quality of raw coal. According to formula (1), when the ash removal percentage is less than or equal to 0, it means that deashing treatment is not required, and when the ash removal percentage is greater than 0, it means that deashing treatment is required, that is, the formula given in step S12 is obtained. (2).
  • step S12 the percentage of volatile removal during dry distillation is preset, and if the preset percentage of volatile removal is If formula (2) is satisfied, deashing is performed on the raw coal, and the ash removal percentage should be greater than or equal to the calculation result of formula (1); otherwise, deashing of the raw coal is not required:
  • the ash removal percentage in the raw coal is correlated with the volatile removal percentage, and the volatile content in the blue char to be prepared can be designed in advance.
  • the volatile removal percentage can be obtained; then according to the volatile removal percentage, it can be determined whether the ash needs to be removed and the ash removal percentage can be obtained, so as to judge whether the raw coal needs to be subjected to deashing pretreatment , and can design the preparation parameters such as volatile removal percentage and ash removal percentage according to the target blue carbon.
  • step S13 The raw coal processed in step S12 is subjected to dry distillation to remove part of the volatile matter, and the method for determining the carbonization temperature of the dry distillation includes: using the preset volatile matter removal percentage described in step S12 As a guide, preliminarily determine the carbonization temperature and carbonization time of several groups of dry distillation, and then according to the carbonization temperature and carbonization time of several groups, the raw coal is carbonized by dry distillation and carbonization under different carbonization temperatures and carbonization times to prepare blue carbon, and then different carbonization temperatures and carbonization times.
  • the blue charcoal under the conditions is tested for the injection performance, and the relationship between the parameters including the burning rate, the grindability index, the explosiveness index and the jet flow index of the blue charcoal and the carbonization temperature and time are obtained respectively;
  • the carbonization temperature and time corresponding to the removal percentages of volatiles in several groups can be obtained by analyzing the weight loss behavior of pyrolysis in the carbonization process, or by performing carbonization on a small amount of raw coal at different carbonization temperatures and times, and then testing its performance. The percent volatile removal was obtained.
  • the experimental results show that when the carbonization temperature is lower, the explosiveness is stronger, so the lower limit of the carbonization temperature can be preliminarily determined by the explosiveness index. Then, according to the combustion rate, grindability index and jet flow index, a temperature range with better combustion rate, grindability index and jet flow index can be obtained, which is the actual carbonization temperature of the raw coal dry distillation.
  • step S15 Perform dry distillation and carbonization on the raw coal according to the carbonization time obtained in step S13 and the actual carbonization temperature obtained in step S14, and then cool to obtain the blue carbon for blast furnace injection.
  • the carbonization temperature and carbonization time are determined by parameters such as the heating gas temperature of the shaft furnace and the charge speed. Therefore, CFD numerical simulation is used to further determine the heating gas temperature and charge speed during dry distillation and carbonization.
  • blue carbon can be injected alone, or mixed with low-rank coal.
  • the process is simple, that is, the blue charcoal after pulverizing is sprayed, and it can be uniformly sprayed to each tuyere of the blast furnace.
  • blue carbon is usually mixed with cheap low-rank coal, and the ratio of blue carbon and low-rank coal, that is, the coal blending scheme, needs to be optimized to achieve economic benefits and use. maximization of value. Therefore, the following technical solutions are adopted to optimize the coal blending plan:
  • An optimization method for efficient use of blue charcoal for blast furnace injection The blue charcoal is mixed with low-rank coal to obtain a mixed fuel, and the mixed fuel is used for mixed injection.
  • the optimization method for the efficient use of the mixed fuel includes the following steps: The following steps:
  • step S21 The cost performance evaluation coefficient obtained in step S21 is used as a constraint condition.
  • the combustion performance of the blast furnace during injection can be taken into account, as well as the purchase cost, pulverizing cost and transportation cost of the injected fuel, and the obtained cost-effectiveness evaluation coefficient is reliable. It has high reliability and rationality, and has strong guiding significance for the coal blending scheme of actual blast furnace injection fuel. Using this cost performance evaluation coefficient, the coal blending scheme can be obtained quickly and accurately, thereby realizing the economic maximization and value maximization of blue carbon in blast furnace injection.
  • the directional preparation technology of blue charcoal for blast furnace injection obtained by the present invention, obtains volatile matter and ash content removal percentage in raw coal according to the volatile matter and ash content content of target blue charcoal for blast furnace injection, removes ash content; Then several groups of carbonization temperature and carbonization time are obtained through theoretical calculation, and the relationship between carbonization temperature and blast furnace injection performance parameters, such as combustion rate, grindability, explosiveness and jet flow, is established through dry distillation and carbonization experiments of a small amount of raw materials, thereby obtaining The optimal actual carbonization temperature, and finally carbonized to obtain high-performance blue carbon.
  • the present invention can obtain ash removal percentage, carbonization temperature and carbonization time through theoretical calculation according to the volatile content of the target blue charcoal, and further obtain parameters such as heating gas temperature and charge speed.
  • the theoretical parameters of dry distillation and carbonization can be directed to obtain high-performance blue carbon suitable for blast furnace injection.
  • the whole preparation technology has strong theoretical support, high reliability and repeatability, and effectively expands the preparation and application of blue carbon in blast furnace injection.
  • the directional preparation technology of blue charcoal for blast furnace injection provided by the present invention, firstly, according to the volatile content of the target blue charcoal for blast furnace injection, several groups of blue charcoal preparation experiments of dry distillation carbonization temperature and carbonization time are designed. The relationship between combustion rate, grindability, explosiveness and jet flow and carbonization temperature was established, so as to obtain the optimal actual carbonization temperature. Therefore, the present invention can reasonably and accurately design the process parameters of dry distillation and carbonization, and can also correlate the carbonization temperature with the properties that the blue carbon for blast furnace injection needs to meet, so as to directionally prepare high-performance blue carbon suitable for blast furnace injection. carbon.
  • the directional preparation technology of blue charcoal for blast furnace injection provided by the present invention adopts inert gas to cool blue charcoal, which can significantly reduce the moisture content in blue charcoal, and overcomes the water-cooling method commonly used in the prior art to obtain blue charcoal moisture content Higher, which is not conducive to the problem of blast furnace smelting.
  • the cooled blue charcoal is ground into powder, and the mass percentage with a particle size of less than 0.074 mm is not less than 75%, indicating that the prepared blue charcoal has good grindability.
  • the optimization method for efficient use of blue charcoal for blast furnace injection uses blue charcoal mixed with low-rank coal to maximize economic benefits and use value.
  • the optimal ratio of blue carbon and low-rank coal can be obtained through the constraints of the cost-effectiveness evaluation coefficient, the volatile content of less than 25%, and the principle of no strong explosiveness.
  • the cost-effectiveness evaluation coefficient summed up in the present invention as the main determinant of the coal blending plan, it is possible to take into account the combustion performance of the blast furnace during injection and the purchase cost, pulverizing cost and transportation cost of the injected fuel at the same time, and the obtained cost-effectiveness
  • the evaluation coefficient has high reliability and rationality, and has strong guiding significance for the actual coal blending scheme of blast furnace injection fuel. Using this cost performance evaluation coefficient, the coal blending scheme can be obtained quickly and accurately, thereby realizing the economic maximization and value maximization of blue carbon in blast furnace injection.
  • the present invention provides a complete set of directional preparation technology of blue carbon for blast furnace injection and optimization method of blue carbon blast furnace injection scheme, which can expand the blast furnace ironmaking injection fuel resources, efficiently inject and save energy. Platoon has important guiding significance.
  • Fig. 1 is the flow chart of the directional preparation technology of blue charcoal for blast furnace injection provided by the present invention
  • Fig. 2 is the flow chart of the optimization method of the efficient use of blue charcoal for blast furnace injection provided by the present invention
  • Fig. 3 is the relation curve of the blue charcoal explosiveness index and dry distillation temperature of embodiment 1;
  • Fig. 4 is the relation curve of the burning rate of blue charcoal and dry distillation temperature of embodiment 1;
  • Fig. 5 is the relation curve of the blue charcoal grindability index and dry distillation temperature of embodiment 1;
  • Fig. 6 is the relation curve of the jetness index of blue charcoal and the dry distillation temperature of Example 1.
  • the volatile content in the target blue carbon 1 is designed in advance to be 10.71%, then when the raw coal is not subjected to deashing treatment (as shown in the coal type target blue carbon 1-1 (not deashed) in Table 1), the After removing volatile matter, the ash content obtained by theoretical calculation is 14.79%, which is greater than 12%, so it is necessary to pre-deash the raw coal. According to the ash content, fixed carbon and volatile content percentage of target blue carbon 1 in Table 1, the volatile content removal percentage can be obtained according to the following formula
  • the ash removal percentage can also be obtained by the following formula:
  • the raw coal is treated with heavy medium coal preparation technology to remove ash, that is, in the gravity beneficiation process, water or air with a density lower than that of the beneficiation is used as the separation medium, and the raw coal is divided into particles in the heavy medium. Density difference and retrograde sorting, the ash percentage after deashing of raw coal is about 8.21%.
  • the invention correlates the removal percentage of ash in raw coal with the removal percentage of volatile content, and can pre-design the volatile content in the target blue charcoal.
  • the volatile removal percentage can be obtained; then according to the volatile removal percentage, it can be determined whether the ash needs to be removed and the ash removal percentage can be obtained, so as to judge whether the raw coal needs to be subjected to deashing pretreatment , and can design the preparation parameters such as volatile removal percentage and ash removal percentage according to the target blue carbon.
  • the method for determining the carbonization temperature of the dry distillation includes: taking the preset volatile matter removal percentage of 29.36% described in step S12 as the guide, The carbonization temperature and carbonization time of several groups of dry distillation were preliminarily determined, as shown in Table 2.
  • the raw coal is carbonized by dry distillation under different carbonization temperature and carbonization time to prepare blue charcoal, and the injection performance of blue charcoal under different process conditions is analyzed.
  • the relationship between parameters including combustion rate, grindability index, explosiveness index and jet flow index and the carbonization temperature are shown in Figs. 3 to 6 .
  • the combustion rate was measured by a comprehensive thermal analyzer; the grindability index was measured by a Hastelloy grinder; the jet flow was measured by a comprehensive powder property tester.
  • the injection fuel has high flammability, high grindability, high safety and high injection performance. Therefore, suitable blue carbon needs to have good flammability, non-explosiveness, grindability and Features of good jet flow. Therefore, the relationship between different carbonization temperatures and performance parameters such as combustion rate, grindability index, explosiveness index and jet flow index is established to determine the optimal carbonization temperature.
  • step (3) Dry distillation carbonization is carried out within the optimum range of the actual carbonization temperature, and the carbonization time is determined by the same method as in step (3).
  • the carbonization temperature and carbonization time are determined by parameters such as heating gas temperature and charge speed. Therefore, the heating gas temperature and charge speed during dry distillation and carbonization are further determined, so as to carry out carbonization.
  • the blue carbon is cooled by the CDQ process, that is, the high temperature blue carbon discharged from the carbonization furnace is loaded into the CDQ furnace through the collection tank, and the cooling inert gas is blown into the bottom of the CDQ furnace to exchange heat with the high temperature blue carbon in the furnace.
  • the high-temperature blue charcoal is gradually cooled and discharged from the bottom of the furnace, and the high-temperature flue gas is discharged from the top of the furnace, cooled and dedusted, and then recycled. Then, the coal is ground into powder to obtain powdery blue carbon with a particle size of less than 0.074 mm and a mass percentage of more than 75%.
  • the performance parameters of the prepared blue carbon are shown in Table 3.
  • the blue charcoal prepared by the present invention has good combustion performance, weak explosiveness, high grindability and high jet flow.
  • the present invention performs the actual carbonization treatment on the raw coal that has not been deashed (as shown in Table 1, the target coal charcoal 1-2 (not deashed)) , test the technical indicators of the obtained blue carbon, and verify the difference between the actual value and the theoretical calculation (as shown in the coal type target blue carbon 1-1 (not delimed) in Table 1).
  • the raw coal is carbonized by the method roughly the same as the above steps (3) and (4), and the actual value finally obtained is as shown in Table 1. Carbons 1-2 (not delimed) are shown.
  • a directional preparation technology of blue charcoal for blast furnace injection comprising the following steps:
  • the raw coal for preparing blue charcoal is selected, and the composition of raw coal 2 is shown in Table 1.
  • the raw coal is dried and screened to obtain raw coal with a particle size of 5-20 mm.
  • the method for determining the carbonization temperature of the dry distillation includes: taking the preset volatile matter removal percentage of 20.17% described in step S12 as the guide, The carbonization temperature and carbonization time of several groups of dry distillation were preliminarily determined, as shown in Table 4.
  • the blue charcoal prepared by the present invention has good combustion performance, weak explosiveness, high grindability and high jet flow.
  • a kind of directional preparation technology of blue charcoal for blast furnace injection select the raw coal for preparing blue charcoal, the composition of raw coal 3 and target blue charcoal 3 are shown in Table 1, the raw coal is dried and screened to obtain a particle size of 5 ⁇ 20mm of raw coal.
  • the upper limit of coal powder ash content is different.
  • the upper limit may be 12%, and for large blast furnaces, the upper limit may preferably be 9%, and the requirements are more stringent.
  • the ash content in the actual blue carbon of the target blue carbon 3 is also slightly higher than the theoretical calculation value, but still lower than 12%, so it meets the ash content requirements of blue carbon for blast furnace injection. Therefore, in actual production, it can be reduced by reducing Calculate the theoretical value according to the theoretical value, and then design the carbonization process parameters according to the theoretical value to ensure that the actual blue carbon can meet the requirements of blast furnace injection.
  • An optimization method for efficient use of blue carbon for blast furnace injection comprising the following steps:
  • bituminous coal 6.59 59.61 33.80 blue charcoal 12 77.29 10.71
  • H mixed H low rank coal ⁇ W low rank coal + H blue carbon ⁇ W blue carbon
  • I mixed I low rank coal ⁇ W low rank coal + I blue carbon ⁇ W blue carbon
  • the low calorific value Q low is determined and calculated according to the international standard ISO1928:1995 or calculated according to Mendeleev's empirical formula.
  • the range with a larger R is selected as the ratio range of bituminous coal, as shown in Table 9.
  • the ratio range of blue carbon With the increase of the ratio of blue carbon, the low calorific value of the mixed fuel gradually increases, the combustion rate gradually decreases, and the cost reduce. Based on the calculation of the cost performance evaluation coefficient, it can be seen that in this case, with the increase of the amount of blue carbon added, the cost performance index of the mixed fuel first increased and then decreased. When the proportion of blue carbon is about 40%, it reaches the maximum.
  • the combustion performance of the blast furnace during injection can be taken into account, as well as the purchase cost, pulverizing cost and transportation cost of the injected fuel, and the obtained cost-effectiveness evaluation coefficient is reliable. It has high reliability and rationality, and has strong guiding significance for the coal blending scheme of actual blast furnace injection fuel. Using this cost performance evaluation coefficient, the coal blending scheme can be obtained quickly and accurately, thereby realizing the economic maximization and value maximization of blue carbon in blast furnace injection.
  • W bituminous coal represents the proportion of low-rank coal
  • V blue carbon represents the volatile content in blue carbon
  • V bituminous coal represents the volatile percentage in low-rank coal
  • step (3) In the range of the proportioning amount of bituminous coal determined by step (2) and step (3), the mixed fuel composed of the proportioning amount of low-rank coal and blue carbon corresponding to the cost-effectiveness evaluation coefficient from large to small is subjected to explosive explosion. Test to verify whether it has strong or weak explosiveness, and when there is no strong explosiveness, the optimal coal blending scheme of the mixed fuel is obtained. The experimental results show that the optimal coal blending scheme is: 57.27% bituminous coal + 43.73% blue carbon.
  • the directional preparation technology of blue charcoal for blast furnace injection and the optimization method for efficient use provided by the present invention, according to the volatile matter and ash content of the target blue charcoal, the volatile matter removal percentage and the ash removal percentage are obtained, Then, several groups of carbonization temperature and carbonization time were designed, and the relationship between carbonization temperature and blast furnace injection performance parameters was established through the test of a small amount of raw materials, and the optimal actual carbonization temperature was obtained. Finally, high-performance blue carbon was obtained by carbonization. Through the evaluation coefficient of cost performance, the volatile content is less than 25% and the principle of no strong explosiveness, the optimal proportion of blue carbon and low-rank coal can be obtained quickly and accurately. It expands the application of blue carbon in blast furnace injection, which can realize high-efficiency injection and energy saving and emission reduction.

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Abstract

一种高炉喷吹用兰炭的定向制备技术及高效使用的优化方法。首先预设出目标兰炭中挥发份和灰份含量，然后计算得到原煤中挥发份和灰份脱除百分比；脱除灰份后，根据挥发份脱除百分比得到若干组干馏炭化温度和炭化时间，分别建立燃烧率、可磨性、爆炸性和喷流性与炭化温度的关系，得到最优的实际炭化温度；在实际炭化温度下得到高炉喷吹用兰炭。通过性价比评价系数、挥发份小于25％以及无强爆炸性原则，得到兰炭和低阶煤的最优配比量。定向制备适于高炉喷吹的兰炭，得到最优配煤方案，实现高炉炼铁燃料高效安全喷吹和节能减排。

Description

高炉喷吹用兰炭的定向制备技术及高效使用的优化方法 技术领域
本发明属于冶金技术领域，尤其涉及一种高炉喷吹用兰炭的定向制备技术及高效使用的优化方法。
背景技术
高炉炼铁目前面临着节能减排的巨大的压力，高炉喷煤是降低高炉炼铁焦炭消耗量的重要技术手段，对高炉炼铁减少稀缺焦煤资源的消耗和降低焦炭生产过程中污染排放具有重要的意义。然而，传统的高炉喷煤主要以优质的无烟煤资源为主，无烟煤在中国储量很少且为不可再生资源，稀缺性不断凸显，因此不断拓展高炉喷吹燃料的范围是中国炼铁工作者一直努力的方向。兰炭作为一种煤化工行业低阶煤提油改质后的副产品半焦，价格远低于焦炭，在中国具有很大的产能。近年来，研究学者根据兰炭的固定碳含量高、硫含量低和灰份低等优点，提出利用兰炭作为高炉喷吹原料。如中国发明专利CN201210018465.0公开了一种低成本的高炉炼铁方法，将兰炭引入高炉喷吹中进行二次利用，与捣固焦搭配用于高炉炼铁。该方法虽然取得一定的成效，但也一直面临诸多问题，限制了高炉大比例使用兰炭，比如兰炭的成分波动大、可磨性低等特点，给高炉喷煤的制粉和喷吹工序的安全性带来了较大的隐患，且使磨煤成本明显增加，限制了其在高炉喷吹中的应用。
针对可磨性较低的问题，中国发明专利CN201810419081.7公开了一种利用兰炭作为高炉喷吹原料制备高炉喷吹煤粉的方法。该方法首先将兰炭制成预制粉，再与烟煤或无烟煤混合，利用兰炭颗粒与烟煤或无烟煤形成粒度差，从而加速兰炭颗粒的研磨效果，解决现有工艺中兰炭研磨困难的问题。但仅仅利用粒度差对可磨性指数提高的程度有限，而且可磨性与兰炭和烟煤或无烟煤的配比有关，而兰炭与烟煤或无烟煤的配比又与高炉喷吹的性价比密切相关，因此，兰炭与烟煤或无烟煤的配比可能无法同时兼顾高性价比和高可磨性。邹冲等提出采用较低炭化温度可以改善兰炭的可磨性(邹冲，李宝，赵俊学，干馏温度对高炉喷吹用半焦可磨性能的影响研究[J]，洁净煤技术，2016，22(1)：71-76)，但制定最佳炭化温度还需要考虑高炉喷吹煤的成分、燃烧性、反应性等诸多特性。中国发明专利CN201610339590.X公开了一种制备兰炭的低温干馏炉及兰炭的制备方法，通过对炭化温度、加热煤气、冷却等工艺进行优化，制得兰炭，但该方法未针对性地根据高炉喷吹 的需求对兰炭工艺进行优化，制备得到的兰炭可能并不适宜高炉喷吹用。因此，制备满足高炉冶炼需求的喷吹兰炭，必须从高炉的角度，全面考虑兰炭的多种冶金性能，据此探讨与最优冶金性能相匹配的兰炭制备工艺参数和原料预处理方案，进而实现定向化生产。
此外，钢铁企业在高炉混合喷吹方面往往会采用兰炭与煤粉混合喷吹，如中国发明专利CN201610331158.6公开了一种以兰炭作为部分燃料的高炉喷煤方法，该方法将兰炭与普通煤粉混合使用，并给出了兰炭的配加量与高炉喷吹过程中的热风温度、富氧率、焦炭热态反应性、焦炭热态反应后强度等参数的关系式。然而合适的兰炭与煤粉的搭配比例，不仅仅与高炉喷吹条件有关，还与兰炭和煤粉的成分组成、结构、燃烧率等因素有关，而且在实际应用中，还应综合考虑兰炭在高炉喷吹中的应用性价比，从而实现兰炭喷吹方案的最优化以及经济效益最大化。目前，尚无科学的评价方法用来获得较优的兰炭与煤粉的搭配方案，限制了兰炭在高炉喷吹中的实际应用价值。
有鉴于此，本发明提供了一套完整的面向高炉喷吹用兰炭的定向制备技术及兰炭喷吹方案的优化方法，对高炉炼铁喷吹燃料资源的拓展、高效喷吹和节能减排具有重要的指导意义。
发明内容
针对上述现有技术存在的缺陷，本发明的目的在于提供一种高炉喷吹用兰炭的定向制备技术。可以实现根据目标兰炭的挥发份和灰份含量获知原煤的挥发份脱除百分比和灰份脱除百分比，并通过系统的实验测试，建立兰炭炭化工艺参数与兰炭喷吹性能参数的相互关系，得到最优喷吹性能的兰炭制备工艺路线，最终炭化得到高性能兰炭。
本发明的目的还在于提供一种高炉喷吹用兰炭高效使用的优化方法，通过性价比评价系数、混煤挥发份小于25％以及无强爆炸性原则，能够快速准确地得到兰炭和低阶煤的最优搭配结构。
为实现上述目的，本发明采用以下技术方案实现：
一种高炉喷吹用兰炭的的定向制备技术，包括对原煤进行干馏脱除部分挥发份，制备得到高炉喷吹用兰炭，包括以下步骤：
S11.根据目标兰炭的灰份百分含量的限定值
Figure PCTCN2020102745-appb-000001
得到原煤中灰份脱除百分比
Figure PCTCN2020102745-appb-000002
与干馏时挥发份脱除百分比
Figure PCTCN2020102745-appb-000003
的关系式，如公式(1)所示：
Figure PCTCN2020102745-appb-000004
式中，
Figure PCTCN2020102745-appb-000005
代表原煤中灰份的百分比；
根据国标GB/T 33969-2017高炉富氧喷煤技术规范中规定的高炉喷吹煤适宜的灰份含量在12％以下，对于大炉容高炉要求灰份≤9％，因此所述目标兰炭中灰份百分含量的限定值应满足
Figure PCTCN2020102745-appb-000006
公式(1)的推导过程如下：
通常情况下，原煤主要组成成分包括灰份、固定碳和挥发份(以干燥基为分析基准)，原煤通过干馏炭化得到兰炭后，损失的成分主要为挥发份。因此，在脱除灰份前，制得的兰炭的质量就等于原煤质量减去挥发份脱除量；脱除灰份后，制得的兰炭的质量就等于原煤质量减去挥发份脱除量和灰份脱除量，即为在脱除灰份前制得的兰炭的质量减去灰份脱除量。根据此情况，设灰份脱除量为x，原煤总质量为m 煤，脱除前制得的兰炭的总质量为m 兰炭，则满足如下公式：
Figure PCTCN2020102745-appb-000007
Figure PCTCN2020102745-appb-000008
式中，
Figure PCTCN2020102745-appb-000009
代表脱除灰份后制得的兰炭中的灰份含量，m 兰炭-x代表脱除灰份后制得的兰炭的质量；
根据公式(11)和(12)得到灰份脱除量的公式如下：
Figure PCTCN2020102745-appb-000010
Figure PCTCN2020102745-appb-000011
因此，根据灰份脱除百分比等于灰份脱除量除以原煤质量，就得到公式(1)。根据公式(1)可知，当灰份脱除百分比小于等于0时，说明无需进行脱灰处理，当灰份脱除百分比大于0时，说明需要进行脱灰处理，即得到步骤S12中给的公式(2)。
S12.根据步骤S11得到的所述公式(1)预设出干馏时挥发份脱除百分比，若所述预设的挥发份脱除百分比
Figure PCTCN2020102745-appb-000012
满足公式(2)，则对所述原煤进行脱灰处理，灰份的脱除百分比应大于等于公式(1)的计算结果；否则不需要对所述原煤进行脱灰处理：
Figure PCTCN2020102745-appb-000013
通过采用上述技术方案，将原煤中灰份脱除百分比与挥发份脱除百分比相关联起来，可以预先设计出待制备的兰炭中挥发份含量。根据兰炭中挥发份含量能够得到挥发份脱除百分比；再根据挥发份脱除百分比，确定是否需要脱除灰份以及得到灰份脱除百分比，从而既能判断原煤是否需要进行脱灰预处理，又能根据目标兰炭定向设计挥发份脱除百分比和灰份脱除百分比等制备参数。
S13.将经步骤S12处理后的原煤进行干馏脱除部分挥发份，所述干馏的炭化温度的确定方法包括：以步骤S12所述预设的挥发份脱除百分比
Figure PCTCN2020102745-appb-000014
为导向，初步确定若干组干馏的炭化温度及炭化时间，然后按若干组所述炭化温度及炭化时间，在不同的炭化温度及炭化时间下对所述原煤进行干馏炭化制备兰炭，随后对不同条件下的兰炭进行喷吹性能测试，分别得到所述兰炭的包括燃烧率、可磨性指数、爆炸性指数和喷流性指数在内的参数与所述炭化温度和时间的关系；
通常情况下，要脱除预设的挥发份脱除百分比，主要需要对原煤的干馏炭化温度和时间进行限定。一般炭化温度越高，炭化时间就应相应缩短，因此可以得到若干组对应的炭化温度和时间。而不同炭化温度和时间虽然能得到挥发份含量相同的兰炭，但兰炭的燃烧率、可磨性、爆炸性和喷流性等性能会有差别。高炉要求喷吹燃料具有高燃烧性、高可磨性、高安全性和高喷吹性，因此适宜的兰炭需要在成分满足要求的同时，具有燃烧 性好、无爆炸性、可磨性和喷流性好的特点。因此建立不同炭化温度和燃烧率、可磨性指数、爆炸性指数和喷流性指数等性能参数的关系，以确定最优炭化温度。
其中，若干组挥发份脱除百分比对应的炭化温度和时间，可以根据干馏炭化过程中的热解失重行为分析得到，或者通过对少量原煤在不同炭化温度和炭化时间下进行干馏炭化，然后测试其挥发份脱除百分比得到。
S14.根据步骤S13所述爆炸性指数所述炭化温度的关系，确定所述炭化温度的下限值，然后在所述炭化温度的下限值以上的温度区间，根据所述燃烧率、可磨性指数和喷流性指数与所述炭化温度的关系，选取所述燃烧率、可磨性指数和喷流性指数均较优的温度区间作为所述原煤干馏的实际炭化温度；
爆炸性指数越大表示兰炭的爆炸性越强，高炉喷吹用兰炭需要满足弱爆炸性或无爆炸性。实验结果表明，炭化温度较低时，爆炸性较强，因此通过爆炸性指数能够初步确定炭化温度的下限值。再根据燃烧率、可磨性指数和喷流性指数，能够得到燃烧率、可磨性指数和喷流性指数均较优的温度区间，即为所述原煤干馏的实际炭化温度。
S15.根据步骤S13得到的所述炭化时间及步骤S14得到的所述实际炭化温度对所述原煤进行干馏炭化，然后冷却，得到所述高炉喷吹用兰炭。
在兰炭实际生产过程中，炭化温度和炭化时间由竖炉加热煤气温度和炉料速度等参数决定，因此采用CFD数值模拟进一步确定干馏炭化时的加热煤气温度和炉料速度。
在高炉喷吹时可以单独喷吹兰炭，也可以将兰炭与低阶煤混合喷吹。兰炭单独喷吹时，工艺简单，即制粉后的兰炭经过喷吹后，均匀的喷吹到高炉各个风口即可。为了进一步降低高炉喷吹燃料的成本，通常将兰炭与廉价的低阶煤混合喷吹，则需要对兰炭和低阶煤的配比量即配煤方案进行优化，以实现经济效益和使用价值的最大化。因此，采用下述技术方案对配煤方案进行优化：
一种高炉喷吹用兰炭高效使用的优化方法，将所述兰炭与低阶煤进行混合得到混合燃料，采用所述混合燃料进行混合喷吹，所述混合燃料的高效使用的优化方法包括以下步骤：
S21.根据兰炭和低阶煤的成本及燃烧性能，得到所述混合燃料的性价比评价系数的计算公式，如式(3)所示：
Figure PCTCN2020102745-appb-000015
式中，Q 低位为混合燃料的低位发热值，kJ/kg；η为混合燃料的燃烧率；C 低阶煤为低阶煤的采购成本，元/kg；C 兰炭为兰炭的采购成本，元/kg；W 低阶煤为低阶煤配比量；W 兰炭为兰炭的配比量；H 混为混合燃料的可磨性指数；C 磨为每千克标准煤的制粉成本，元/kg；I 混为混合燃料的喷流性指数；C 喷为每千克标准煤的气体输送成本，元/kg；
S22.将步骤S21得到的所述性价比评价系数作为约束条件，所述性价比评价系数越大，则兰炭配煤方案越优，根据此原则确定混合燃料中兰炭和低阶煤的配比量区间。
通过将上述性价比评价系数公式作为配煤方案的主要决定因素，能够将高炉喷吹时的燃烧性能与喷吹燃料的采购成本、制粉成本和输送成本同时考虑在内，得到的性价比评价系数可靠性和合理性高，对实际高炉喷吹燃料的配煤方案具有较强的指导意义。采用此性价比评价系数，能够快速准确的得到配煤方案，从而实现兰炭在高炉喷吹中的经济最大化和价值最大化。
有益效果
与现有技术相比，本发明提供的高炉喷吹用兰炭的定向制备技术及高效使用的优化方法具有如下有益效果：
(1)本发明提供的高炉喷吹用兰炭的定向制备技术，根据高炉喷吹用目标兰炭的挥发份和灰份含量得到原煤中挥发份和灰份脱除百分比，脱除灰份；然后通过理论计算得到若干组干馏炭化温度和炭化时间，通过少量原料的干馏炭化实验，建立炭化温度与高炉喷吹性能参数，如燃烧率、可磨性、爆炸性和喷流性的关系，从而得到最优的实际炭化温度，最终炭化得到高性能兰炭。本发明通过采用上述技术方案，能够根据目标兰炭的挥发份含量，通过理论计算，得到灰份脱除百分比、炭化温度和炭化时间，进而还能得到加热煤气温度和炉料速度等参数，依据得到的理论参数进行干馏炭化，能够定向得到适宜高炉喷吹用的高性能的兰炭。整个制备技术具有有力的理论依据支撑，可靠性和可重复性高，有效拓展了兰炭在高炉喷吹中的制备和应用。
(2)本发明提供的高炉喷吹用兰炭的定向制备技术，首先根据高炉喷吹用目 标兰炭的挥发份含量，设计若干组干馏炭化温度和炭化时间的兰炭制备实验，据此能够建立燃烧率、可磨性、爆炸性和喷流性与炭化温度的关系，从而得到最优的实际炭化温度。因此，本发明能够合理准确地对干馏炭化的工艺参数进行设计，还能将炭化温度与高炉喷吹用兰炭需要满足的性能关联起来，从而定向制备出适宜高炉喷吹用的高性能的兰炭。
(3)本发明提供的高炉喷吹用兰炭的定向制备技术，采用惰性气体冷却兰炭，能够显著减少兰炭中的水分含量，克服了现有技术常用的水冷方式得到的兰炭水分含量较高，不利于高炉冶炼的问题。本发明对冷却后的兰炭进行磨煤制粉，能够实现粒度小于0.074mm的质量百分比不低于75％，说明制得的兰炭具有良好的可磨性。
(4)本发明提供的高炉喷吹用兰炭高效使用的优化方法，将兰炭与低阶煤混合使用，实现经济效益和使用价值最大化。通过性价比评价系数、挥发份小于25％以及无强爆炸性原则等约束条件，能够得到兰炭和低阶煤的最优配比量。通过将本发明总结出的性价比评价系数作为配煤方案的主要决定因素，能够将高炉喷吹时的燃烧性能与喷吹燃料的采购成本、制粉成本和输送成本同时考虑在内，得到的性价比评价系数可靠性和合理性高，对实际高炉喷吹燃料的配煤方案具有较强的指导意义。采用此性价比评价系数，能够快速准确的得到配煤方案，从而实现兰炭在高炉喷吹中的经济最大化和价值最大化。
(5)本发明提供了一套完整的面向高炉喷吹用兰炭的定向制备技术及兰炭高炉喷吹方案的优化方法，对高炉炼铁喷吹燃料资源的拓展、高效喷吹和节能减排具有重要的指导意义。
附图说明
图1为本发明提供的高炉喷吹用兰炭的定向制备技术的流程框图；
图2为本发明提供的高炉喷吹用兰炭高效使用的优化方法的流程框图；
图3为实施例1的兰炭爆炸性指数与干馏温度的关系曲线；
图4为实施例1的兰炭燃烧率与干馏温度的关系曲线；
图5为实施例1的兰炭可磨性指数与干馏温度的关系曲线；
图6为实施例1的兰炭喷流性指数与干馏温度的关系曲线。
具体实施方式
以下将对本发明各实施例的技术方案进行清楚、完整的描述，显然，所描述的实施例仅仅是本发明的一部分实施例，而不是全部的实施例；基于本发明的实施例，本领 域普通技术人员在没有做出创造性劳动的前提下所得到的所有其它实施例，都属于本发明所保护的范围。
实施例1
请参阅图1所示，一种高炉喷吹用兰炭的的定向制备技术，包括以下步骤：
(1)选取制备兰炭的原煤，原煤的成分组成如表1所示，将原煤进行干燥和筛选，得到粒度在5～20mm的原煤。
表1原煤及目标兰炭的技术指标(以干燥基为分析基准)
煤种 灰份/％ 固定碳/％ 挥发份/％
原煤1 10.49 52.83 36.68
目标兰炭1 12 77.29 10.71
目标兰炭1-1(未脱灰) 14.79 74.5 10.71
目标兰炭1-2(未脱灰) 13.20 76.09 10.71
原煤2 6.39 58.19 35.42
目标兰炭2 8.02 73.03 18.95
目标兰炭2-1 8.71 72.34 18.95
原煤3 6.15 59.80 34.05
目标兰炭3 7.29 70.88 21.82
目标兰炭3-1 9.05 69.13 21.82
(2)预先设计出目标兰炭1中挥发份含量为10.71％，则当不对原煤进行脱灰处理时(如表1中煤种目标兰炭1-1(未脱灰)所示)，脱除挥发分后，理论计算得到的灰份含量为14.79％，大于12％，因此需要对原煤进行预脱灰处理。根据表1中目标兰炭1的灰份、固定碳和挥发份百分比，可根据下式得到挥发份脱除百分比
Figure PCTCN2020102745-appb-000016
Figure PCTCN2020102745-appb-000017
则
Figure PCTCN2020102745-appb-000018
因此，需要对原煤进行脱灰处理。
式中，
Figure PCTCN2020102745-appb-000019
为目标兰炭中给的固定炭含量；
Figure PCTCN2020102745-appb-000020
为原煤中的固定碳含量；
Figure PCTCN2020102745-appb-000021
为原煤中的挥发份含量；
Figure PCTCN2020102745-appb-000022
为兰炭中的挥发份含量；
则灰份脱除百分比根据公式(1)计算得到：
Figure PCTCN2020102745-appb-000023
或者，灰份脱除百分比还可以通过下式得到：
Figure PCTCN2020102745-appb-000024
根据灰份脱除百分比对原煤进行重介质选煤技术处理脱除灰份，即在重力选矿过程中，采用密度低于入选矿密度的水或空气为分选介质，原煤在重介质中按颗粒密度的差异及逆行分选，原煤脱灰后灰份百分比约为8.21％。本发明将原煤中灰份脱除百分比与挥发份脱除百分比相关联起来，可以预先设计出目标兰炭中挥发份含量。根据兰炭中挥发份含量能够得到挥发份脱除百分比；再根据挥发份脱除百分比，确定是否需要脱除灰份以及得到灰份脱除百分比，从而既能判断原煤是否需要进行脱灰预处理，又能根据目标兰炭定向设计挥发份脱除百分比和灰份脱除百分比等制备参数。
(3)将经步骤(2)处理后的原煤进行干馏脱除部分挥发份，所述干馏的炭化温度的确定方法包括：以步骤S12所述预设的挥发份脱除百分比29.36％为导向，初步确定若干组干馏的炭化温度及炭化时间，如表2所示。
表2若干组炭化温度和炭化时间
组别 1 2 3 4 5
炭化温度(℃) 300 400 500 600 700
炭化时间(min) 120 120 90 60 30
按若干组所述炭化温度及炭化时间，在不同的炭化温度及炭化时间下对所述原煤进行干馏炭化制备兰炭，分析不同工艺条件下兰炭的喷吹性能，分别得到所述兰炭的包括燃烧率、可磨性指数、爆炸性指数和喷流性指数在内的参数与所述炭化温度的关系，如图3至图6所示。其中，燃烧率采用综合热分析仪测定；可磨性指数采用哈氏可磨仪测定；喷流性采用粉体性能综合测定仪测定。
根据图3爆炸性指数与炭化温度的关系，可以看出当爆炸性指数为200mm时，温度约为400℃，因此炭化温度的下限值为400℃，然后根据图4至6可以得出，当燃烧率、可磨性指数和喷流性指数均较高时，确定炭化温度的上限值为500℃。因此，实际炭化温度的最优区间为400～500℃。
根据高炉要求喷吹燃料具有高燃烧性、高可磨性、高安全性和高喷吹性，因此适宜的兰炭需要在成分满足要求的同时，具有燃烧性好、无爆炸性、可磨性和喷流性好的特点。因此建立不同炭化温度和燃烧率、可磨性指数、爆炸性指数和喷流性指数等性能参数的关系，以确定最优炭化温度。
(4)在实际炭化温度的最优区间内进行干馏炭化，炭化时间采用与步骤(3)相同的方法确定。而炭化温度和炭化时间又由加热煤气温度和炉料速度等参数决定，因此进一步确定干馏炭化时的加热煤气温度和炉料速度，从而进行炭化。炭化完成后，采用干熄焦工艺冷却兰炭，即由炭化炉排出的高温兰炭，经收集罐装入干熄炉，干熄炉底部鼓入冷却惰性气体与炉内高温兰炭发生热交换，高温兰炭逐渐冷却后由炉底排出，高温烟气从炉顶排出后经降温、除尘后循环使用。然后磨煤制粉，得到粒度小于0.074mm的质量百分在75％以上的粉状兰炭。制得的兰炭的性能参数如表3所示。
表3兰炭的性能参数
Figure PCTCN2020102745-appb-000025
从表3可以看出，本发明制备的兰炭，具有良好的燃烧性能、弱爆炸性、高可磨性和高喷流性。
鉴于对原煤进行实际炭化的结果与理论计算存在一定差别，本发明对未进行脱灰处理的原煤进行实际炭化处理(如表1中煤种目标兰炭1-2(未脱灰)所示)，测试得到 的兰炭的技术指标，验证实际值与理论计算(如表1中煤种目标兰炭1-1(未脱灰)所示)的差别性。按预先设计的目标兰炭中的挥发分含量为10.71％，采用与上述步骤(3)和(4)大致相同的方法对原煤进行炭化处理，最终得到的实际值如表1中煤种目标兰炭1-2(未脱灰)所示。
实施例2
一种高炉喷吹用兰炭的的定向制备技术，包括以下步骤：
选取制备兰炭的原煤，原煤2的成分组成如表1所示，将原煤进行干燥和筛选，得到粒度在5～20mm的原煤。
根据表1中目标兰炭2的挥灰份、固定碳和挥发份百分比，采用与实施例1相同的方法计算得到挥发份脱除百分比为：
Figure PCTCN2020102745-appb-000026
则
Figure PCTCN2020102745-appb-000027
因此，不需要脱灰处理。
(3)将经步骤(2)处理后的原煤进行干馏脱除部分挥发份，所述干馏的炭化温度的确定方法包括：以步骤S12所述预设的挥发份脱除百分比20.17％为导向，初步确定若干组干馏的炭化温度及炭化时间，如表4所示。
表4若干组炭化温度和炭化时间
组别 1 2 3 4 5
炭化温度(℃) 300 400 500 600 700
炭化时间(h) 120 120 90 60 30
其他步骤与实施例1大致相同，在此不再赘述。最终制得的兰炭的性能参数如表5所示。
表5兰炭的性能参数
Figure PCTCN2020102745-appb-000028
从表5可以看出，本发明制备的兰炭，具有较好的燃烧性能、弱爆炸性、高可磨性和高喷流性。
对目标兰炭2进行实际炭化处理，得到的实际兰炭技术指标如表1中目标兰炭2-1所示，实际得到的兰炭中灰份含量略大于理论值，但仍低于12％，因此复合高炉喷吹用兰炭的灰份要求。
实施例3
一种高炉喷吹用兰炭的的定向制备技术，选取制备兰炭的原煤，原煤3及目标兰炭3的成分组成如表1所示，将原煤进行干燥和筛选，得到粒度在5～20mm的原煤。
其他步骤与实施例1大致相同，在此不再赘述。最终制得的兰炭的性能参数如表6所示。
表6兰炭的性能参数
Figure PCTCN2020102745-appb-000029
需要说明的是，对于不同高炉冶炼时，煤粉灰份上限值要求不一样。对于小高炉，上限值可以是12％，对于大高炉，上限值可优选为9％，要求更为严格。
目标兰炭3的实际兰炭中灰份含量也略高于理论计算值，但仍低于12％，因此符合高炉喷吹用兰炭的灰份要求。因此，在实际生产中，可以通过降低
Figure PCTCN2020102745-appb-000030
值来计算理论值，然后按理论值对炭化工艺参数进行设计，以保证实际得到的兰炭满足高炉喷吹的要求。
实施例4
一种高炉喷吹用兰炭高效使用的优化方法，包括以下步骤：
(1)采用烟煤与实施例1制备的兰炭作为混合燃料，其技术指标如表7所示和表8所示。表8中燃烧率对烟煤和兰炭进行实际测试得到的。
表7烟煤和兰炭的性能参数
煤种 灰份％ 固定碳％ 挥发份％
烟煤 6.59 59.61 33.80
兰炭 12 77.29 10.71
表8混合燃料的性能参数
性能指标 低位发热值(kJ/kg) 燃烧率(％) 可磨性 喷流性
烟煤 27893.29 99.59 65 60
兰炭 30224.07 81 60 72
根据下述公式得到性价比评价系数与烟煤配比量的关系：
Figure PCTCN2020102745-appb-000031
H 混＝H 低阶煤×W 低阶煤+H 兰炭×W 兰炭
I 混＝I 低阶煤×W 低阶煤+I 兰炭×W 兰炭
W 兰炭＝1-W 低阶煤
其中，低位发热值Q 低位是按照国际标准ISO1928:1995进行测定和计算或按照门捷列耶夫经验公式进行计算得到。
表9不同配比方案时的性价比指数
Figure PCTCN2020102745-appb-000032
选取R较大的区间作为烟煤的配比量区间，具体如表9所示，该案例中，随着兰炭配比量的增加，混合燃料的低位发热值逐渐增加，燃烧率逐渐降低，成本降低。基于性价比评价系数的计算，可以看出在本案例中，随着兰炭添加量的增加，混合燃料的性价比指数先增加后降低。当兰炭配比量为40％左右时达到最大。
通过将上述性价比评价系数公式作为配煤方案的主要决定因素，能够将高炉喷吹时的燃烧性能与喷吹燃料的采购成本、制粉成本和输送成本同时考虑在内，得到的性价比评价系数可靠性和合理性高，对实际高炉喷吹燃料的配煤方案具有较强的指导意义。采用此性价比评价系数，能够快速准确的得到配煤方案，从而实现兰炭在高炉喷吹中的经济最大化和价值最大化。
(2)基于国标规定的喷吹燃料挥发份小于25％的原则，根据下式计算所述混合燃料中烟煤的最大配比量：
Figure PCTCN2020102745-appb-000033
式中，W 烟煤表示低阶煤的配比百分比；V 兰炭表示兰炭中的挥发份含量；V 烟煤表示低阶煤中的挥发份百分比。
(3)依次对由步骤(2)和步骤(3)确定的烟煤的配比量区间中，性价比评价系数由大到小对应的低阶煤和兰炭的配比量组成的混合燃料进行爆炸性测试，验证其是否具有强弱爆炸性，当无强爆炸性时，即得到所述混合燃料最优的配煤方案。实验结果表明，最优配煤方案为：57.27％烟煤+43.73％兰炭。
实施例5
一种高炉喷吹用兰炭高效使用的优化方法，采用烟煤与实施例2制备的兰炭作为混合燃料，其他步骤与实施例4大致相同，在此不再赘述。
实验结果表明，最优配煤方案为：59.25％兰炭+40.75％烟煤。
实施例6
一种高炉喷吹用兰炭高效使用的优化方法，采用烟煤与实施例3制备的兰炭作为混合燃料，其他步骤与实施例4大致相同，在此不再赘述。
实验结果表明，最优配煤方案为：73.48％兰炭+26.52％烟煤。
综上所述，本发明提供的高炉喷吹用兰炭的定向制备技术及高效使用的优化方法，根据目标兰炭的挥发份和灰份含量得到挥发份脱除百分比和灰份脱除百分比，然后设计若干组干馏炭化温度和炭化时间，通过少量原料的试验，建立炭化温度与高炉喷吹性能参数的关系，得到最优的实际炭化温度，最终炭化得到高性能兰炭。通过性价比评价系数、挥发份小于25％以及无强爆炸性原则，快速准确地得到兰炭和低阶煤的最优配比量。拓展 了兰炭在高炉喷吹中的应用，能够实现高效喷吹和节能减排。
以上所述，仅为本发明较佳的具体实施方式，但本发明的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本发明揭露的技术范围内，根据本发明的技术方案及其发明构思加以等同替换或改变，都应涵盖在本发明的保护范围之内。

Claims (17)

  1. 一种高炉喷吹用兰炭的的定向制备技术，其特征在于，包括对原煤进行干馏脱除部分挥发份，制备得到高炉喷吹用兰炭，包括以下步骤：
    S11.根据目标兰炭的灰份百分含量的限定值
    Figure PCTCN2020102745-appb-100001
    得到原煤中灰份脱除百分比
    Figure PCTCN2020102745-appb-100002
    与干馏时挥发份脱除百分比
    Figure PCTCN2020102745-appb-100003
    的关系式，如公式(1)所示：
    Figure PCTCN2020102745-appb-100004
    式中，
    Figure PCTCN2020102745-appb-100005
    代表原煤中灰份的百分比；
    所述灰份百分含量的限定值满足
    Figure PCTCN2020102745-appb-100006
    S12.根据步骤S11得到的所述公式(1)预设出干馏时挥发份脱除百分比，若所述预设的挥发份脱除百分比
    Figure PCTCN2020102745-appb-100007
    满足公式(2)，则对所述原煤进行脱灰处理，否则不需要对所述原煤进行脱灰处理：
    Figure PCTCN2020102745-appb-100008
    S13.将经步骤S12处理后的原煤进行干馏脱除部分挥发份，所述干馏的炭化温度的确定方法包括：以步骤S12所述预设的挥发份脱除百分比
    Figure PCTCN2020102745-appb-100009
    为导向，初步确定若干组干馏的炭化温度及炭化时间，然后按若干组所述炭化温度及炭化时间，在不同的炭化温度及炭化时间下对所述原煤进行干馏炭化制备兰炭，分别得到所述兰炭的包括燃烧率、可磨性指数、爆炸性指数和喷流性指数在内的参数与所述炭化温度的关系；
    S14.根据步骤S13所述爆炸性指数所述炭化温度的关系，确定所述炭化温度的下限值，然后在所述炭化温度的下限值以上的温度区间，根据所述燃烧率、可磨性指数和喷流性指数与所述炭化温度的关系，选取所述燃烧率、可磨性指数和喷流性指数均较优的温度区间作为所述原煤干馏的实际炭化温度；
    S15.根据步骤S13得到的所述炭化时间及步骤S14得到的所述实际炭化温度对所述原 煤进行干馏炭化，然后冷却，得到所述高炉喷吹用兰炭。
  2. 根据权利要求1所述的高炉喷吹用兰炭的的定向制备技术，其特征在于，在步骤S11中，所述灰份百分含量的限定值满足
    Figure PCTCN2020102745-appb-100010
  3. 根据权利要求1所述的高炉喷吹用兰炭的的定向制备技术，其特征在于，在步骤S12中，所述脱灰处理的方法包括但不限于为重介质选煤技术处理。
  4. 根据权利要求1所述的高炉喷吹用兰炭的的定向制备技术，其特征在于，在步骤S13中，所述炭化温度及炭化时间是通过所述原煤在炭化炉中干馏炭化的热解行为进行初步确定。
  5. 根据权利要求1所述的高炉喷吹用兰炭的的定向制备技术，其特征在于，在步骤S13中，采用CFD数值模拟，建立加热煤气温度与所述炭化温度的关系，然后根据所述加热煤气温度与所述炭化温度的关系，得到不同炭化温度对应的加热煤气温度。
  6. 根据权利要求1所述的高炉喷吹用兰炭的的定向制备技术，其特征在于，在步骤S13中，所述爆炸性指数是通过长管式煤粉爆炸性测定装置测定所述兰炭引燃后产生的返回火焰长度，选取所述爆炸性指数≤200mm的炭化温度作为所述炭化温度的下限值。
  7. 根据权利要求1所述的高炉喷吹用兰炭的的定向制备技术，其特征在于，在步骤S14中，所述实际炭化温度为400～600℃。
  8. 根据权利要求1所述的高炉喷吹用兰炭的的定向制备技术，其特征在于，在步骤S15中，所述冷却采用干熄焦工艺，得到水分含量＜5％的高炉喷吹用兰炭。
  9. 根据权利要求1所述的高炉喷吹用兰炭的的定向制备技术，其特征在于，所述定向制备技术还包括如下步骤：将所述高炉喷吹用兰炭进行磨煤制粉，得到高炉喷吹用粉状兰炭。
  10. 根据权利要求9所述的高炉喷吹用兰炭的的定向制备技术，其特征在于，所述高炉喷吹用粉状兰炭中粒度小于0.074mm的质量百分比不低于75％。
  11. 根据权利要求1所述的高炉喷吹用兰炭的的定向制备技术，其特征在于，所述定向制备技术还包括如下步骤：将经步骤S12处理后的原煤进行粒度筛分，得到粒度在5～20mm的原煤，然后再进行步骤S13处理。
  12. 一种高炉喷吹用兰炭高效使用的优化方法，其特征在于，将所述兰炭与低阶煤进行混合得到混合燃料，采用所述混合燃料进行混合喷吹，所述混合燃料的高效使用的优化方法包括以下步骤：
    S21.根据兰炭和低阶煤的成本及燃烧性能，得到所述混合燃料的性价比评价系数的计算公式，如式(3)所示：
    Figure PCTCN2020102745-appb-100011
    式中，Q 低位为混合燃料的低位发热值，kJ/kg；η为混合燃料的燃烧率；C 低阶煤为低阶煤的采购成本，元/kg；C 兰炭为兰炭的采购成本，元/kg；W 低阶煤为低阶煤配比量；W 兰炭为兰炭的配比量；H 混为混合燃料的可磨性指数；C 磨为每千克标准煤的制粉成本，元/kg；I 混为混合燃料的喷流性指数；C 喷为每千克标准煤的气体输送成本，元/kg；
    S22.将步骤S21得到的所述性价比评价系数作为约束条件，所述性价比评价系数越大，则兰炭配煤方案越优，根据此原则确定混合燃料中兰炭和低阶煤的配比量区间。
  13. 根据权利要求12所述的高炉喷吹用兰炭高效使用的优化方法，其特征在于，所述可磨性指数通过对所述混合燃料进行可磨性测试或者通过公式(4)计算得到：
    H 混＝H 低阶煤×W 低阶煤+H 兰炭×W 兰炭     (4)
    式中，H 低阶煤为低阶煤的可磨性指数；H 兰炭为兰炭的可磨性指数；
    所述喷流性指数通过对所述混合燃料进行喷流性测试或者通过公式(5)计算得到：
    I 混＝I 低阶煤×W 低阶煤+I 兰炭×W 兰炭  (5)
    式中，I 低阶煤为低阶煤的喷流性指数，I 兰炭为兰炭的喷流性指数。
  14. 根据权利要求12所述的高炉喷吹用兰炭高效使用的优化方法，其特征在于，所述低阶煤包括但不限于为烟煤、褐煤、不粘煤、弱粘煤、长焰煤、泥煤中的一种或多种。
  15. 根据权利要求12至14中任一项权利要求所述的高炉喷吹用兰炭高效使用的优化方法，其特征在于，所述混合燃料的高效使用的优化方法还包括：基于高炉喷吹燃料挥发份小于25％的原则，根据公式(6)计算所述混合燃料中低阶煤的最大配比量：
    Figure PCTCN2020102745-appb-100012
    式中，W 低阶煤表示低阶煤的配比百分比；V 兰炭表示兰炭中的挥发份含量；V 低阶煤表示低阶煤中的挥发份百分比；
    根据所述低阶煤的最大配比量，确定步骤S22中所述低阶煤的配比量区间的上限值和/或所述兰炭的配比量区间的下限值。
  16. 根据权利要求15所述的高炉喷吹用兰炭高效使用的优化方法，其特征在于，所述混合燃料的高效使用的优化方法还包括：
    依次对所述低阶煤的上限值以下的配比量区间中，或者对所述兰炭的下限值以上的配比量区间中，性价比评价系数由大到小对应的低阶煤和兰炭的配比量组成的混合燃料进行爆炸性测试，若无强爆炸性，则此配比量即为所述混合燃料最优的配煤方案；若有强爆炸性，则继续对下一组性价比评价系数对应的低阶煤和兰炭的配比量组成的混合燃料进行爆炸性测试，直到所述爆炸性测试的结果为无强爆炸性，即为所述混合燃料最优的配煤方案。
  17. 根据权利要求16所述的高炉喷吹用兰炭高效使用的优化方法，其特征在于，所述无强爆炸性是指爆炸性指数≤200mm。
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CN101899343A (zh) * 2009-05-25 2010-12-01 杨兴平 高炉喷吹材料
WO2013108768A1 (ja) * 2012-01-18 2013-07-25 三菱重工業株式会社 高炉設備
CN103952503A (zh) * 2014-05-15 2014-07-30 北京科技大学 一种高炉喷吹煤性价比评价模型的建立方法
CN105295975A (zh) * 2015-11-19 2016-02-03 西安建筑科技大学 利用低阶碎煤生产高炉喷吹用高燃烧反应性半焦粉的方法
CN107400743A (zh) * 2016-05-18 2017-11-28 鞍钢股份有限公司 一种以兰炭作为部分燃料的高炉喷煤方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101899343A (zh) * 2009-05-25 2010-12-01 杨兴平 高炉喷吹材料
WO2013108768A1 (ja) * 2012-01-18 2013-07-25 三菱重工業株式会社 高炉設備
CN103952503A (zh) * 2014-05-15 2014-07-30 北京科技大学 一种高炉喷吹煤性价比评价模型的建立方法
CN105295975A (zh) * 2015-11-19 2016-02-03 西安建筑科技大学 利用低阶碎煤生产高炉喷吹用高燃烧反应性半焦粉的方法
CN107400743A (zh) * 2016-05-18 2017-11-28 鞍钢股份有限公司 一种以兰炭作为部分燃料的高炉喷煤方法

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