Method for preparing blast furnace injection fuel by dealkalizing and upgrading furfural carbon

Abstract

The invention discloses a method for preparing blast furnace injection fuel through furfural carbon dealkalization and quality improvement, which comprises the following steps: mixing furfural carbon with a first dealkalization solution to obtain primary dealkalized furfural carbon and dealkalized waste liquid; mixing the second dealkalized solution with the primary dealkalized furfural carbon to obtain secondary dealkalized furfural carbon and a first dealkalized waste liquid; and drying and granulating the secondary dealkalized furfural carbon. According to the method, through multiple times of solution dealkalization and solid-liquid separation, efficient dealkalization and quality improvement of the furfural carbon are achieved, so that application of the furfural carbon in the blast furnace coal injection process is achieved, the utilization value of waste can be improved, the consumption of fossil fuel in ironmaking production can be reduced, and good environment-friendly and economic benefits are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of utilizing biomass energy in blast furnace ironmaking production, and in particular to a method for preparing blast furnace injection fuel by carbon dealkalization and upgrading of furfural. Background Art

[0002] The steel industry is an important basic industry for my country's national economic and social development, and is also the main source of CO2 emissions in my country. In 2023, my country's crude steel output reached 1.019 billion tons, accounting for 53.9% of the world's total crude steel output. The industrial energy consumption consumed by steel production accounts for about 16% of the country's total industrial energy consumption each year, and CO2 emissions also account for about 15% of the country's total industrial CO2 emissions. Reducing energy consumption and CO2 emissions in steel production is the key to achieving the country's "dual carbon" strategic goals. At the same time, my country is also a major agricultural producer, producing a large amount of agricultural and forestry residue resources every year. Compared with traditional fossil fuels such as coal, oil, and natural gas, biomass is a large-scale, widely distributed, and renewable clean energy. Its carbon-neutral properties prevent it from releasing additional greenhouse gases into the atmosphere during industrial applications, which is of great significance to alleviating the increasingly serious global greenhouse effect. Applying the rich agricultural and forestry residue resources in China to steel production has important practical significance for reducing CO2 emissions in the steel industry and improving the utilization rate of agricultural and forestry residue resources.

[0003] In recent years, many research institutions and scholars at home and abroad have conducted research on the application of biomass energy in steel production and have achieved a series of results. However, except for cases of industrial application in individual countries and regions such as Brazil, most of them are still in the theoretical research stage in the laboratory. The reasons for this are mainly two-fold. On the one hand, the collection and processing costs of agricultural and forestry residues are high. Compared with the characteristics of concentrated coal production and stable supply, the production areas of agricultural and forestry residues are scattered, and there are regional and seasonal characteristics, which makes it difficult for enterprises to collect biomass energy on a large scale, and the transportation, storage and processing costs are high. On the other hand, agricultural and forestry residues generally have the disadvantages of high moisture and alkali metal content, low fixed carbon and calorific value, and poor crushing and processing performance. Without quality improvement, it is difficult to meet the requirements of fuel metallurgical properties for steel production. my country already has a relatively mature biomass chemical industry. Through the high-value utilization of agricultural and forestry residues, the high cost of collection, transportation, storage and other links has been overcome, and it has also provided the possibility for the large-scale application of biomass energy in the field of steel metallurgy. Therefore, in the context of the country's active promotion of the coordinated development strategy of pollution reduction and carbon reduction, breaking down the information and technological barriers between the biomass chemical industry and the steel industry is the key to achieving high-value utilization of agricultural and forestry residues and coordinated cost reduction and carbon reduction in the steel industry. It is of great significance to the sustainable and healthy development of my country's biomass chemical industry and steel industry and "carbon neutrality".

[0004] Furfural charcoal is the residue of the production of furfural and other chemical products in the biomass chemical industry. Its raw materials include corn cobs, agricultural straw, waste wood, etc. It has the characteristics of large output, low price and carbon neutrality. However, the alkali metal content in furfural charcoal is high, which makes it difficult to be directly used in ironmaking production. In view of this, it is necessary to design a method for furfural charcoal dealkalization and upgrading to prepare blast furnace injection fuel, and to make the carbon-containing residue in the biomass furfural industry into high-quality fuel that meets the requirements of blast furnace injection, and use it in blast furnace smelting production to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing blast furnace injection fuel by dealkalization and quality improvement of furfural charcoal, wherein furfural charcoal is dealkalized and ash-reduced to obtain dealkalized furfural charcoal particles that meet the requirements of blast furnace injection, and the dealkalized furfural charcoal particles are mixed with blast furnace coal injection to obtain blast furnace injection fuel. The method creatively treats solid waste from the furfural industry and applies it to blast furnace injection fuel, thereby ensuring its efficient utilization, reducing resource consumption and waste, and achieving greater economic benefits.

[0006] To achieve the above-mentioned purpose of the invention, the present invention provides a method for preparing blast furnace injection fuel by carbon dealkalization of furfural, comprising the following steps:

[0007] S1, mixing furfural charcoal with a first dealkalization solution to obtain a first mixture, performing wet grinding on the first mixture to strengthen dealkalization to obtain a primary solid-liquid mixed product, and performing filter pressing on the primary solid-liquid mixed product to achieve solid-liquid separation to obtain a primary dealkalization furfural charcoal and dealkalization waste liquid;

[0008] S2, mixing the second dealkalization solution with the first dealkalization furfural charcoal to obtain a second mixture, subjecting the second mixture to wet grinding and enhanced dealkalization to obtain a secondary solid-liquid mixed product, and subjecting the secondary solid-liquid mixed product to filter press to achieve solid-liquid separation to obtain a secondary dealkalization furfural charcoal and the first dealkalization waste liquid;

[0009] S3. Dry and granulate the secondary dealkalized furfural charcoal to obtain dealkalized furfural charcoal particles, mix the dealkalized furfural charcoal particles with blast furnace injection coal to obtain blast furnace injection mixed fuel, and the blast furnace injection mixed fuel is injected into the cyclotron zone of the blast furnace through a crushing device and a conveying device to burn in the blast furnace tuyere, so as to provide hydrogen-rich reducing gas and heat for blast furnace smelting.

[0010] As a further improvement of the present invention, in step S1, the furfural charcoal includes the residue of furfural and similar compound products extracted from biomass raw materials.

[0011] As a further improvement of the present invention, in step S1, the first de-alkali solution is a mixture of one or more of fresh water, industrial water, domestic wastewater, furfural distillation waste liquid, and first de-alkali waste liquid, and the water content in the first mixture is 75%-90%.

[0012] As a further improvement of the present invention, in step S1, the wet grinding enhanced dealkalization temperature is 15°C-95°C, and the wet grinding enhanced dealkalization time is 1min-15min.

[0013] As a further improvement of the present invention, in step S1, one or more combinations of plate and frame filter press, belt filter press and high-pressure filter press are used for solid-liquid separation, and the moisture content of the once-dealkalized furfural charcoal obtained after filtration is 40%-60%.

[0014] As a further improvement of the present invention, in step S2, the second dealkalization solution is a mixture of one or more of fresh water, industrial water, domestic wastewater and furfural distillation waste liquid, and the water content of the second mixture is 75%-90%.

[0015] As a further improvement of the present invention, in step S2, the wet grinding enhanced dealkalization temperature is 10°C-95°C, and the wet grinding enhanced dealkalization time is 1min-15min.

[0016] As a further improvement of the present invention, in step S2, one or more combinations of plate and frame filter press, belt filter press and high-pressure filter press are used for solid-liquid separation, and the moisture content of the secondary de-alkalized furfural charcoal obtained after filtration is 40%-60%.

[0017] As a further improvement of the present invention, in step S3, one or more combinations of a rotary drying furnace, a belt drying furnace, a tunnel kiln drying furnace, and a drying room are used to dry the secondary dealkalized furfural charcoal, the drying temperature is 80°C-200°C, the drying time is 5min-150min, and the moisture content of the dried secondary dealkalized furfural charcoal is 5%-15%.

[0018] As a further improvement of the present invention, in step S3, one of an extrusion pelletizer, a flat die pelletizer, and a ring die pelletizer is used to extrude the dried dealkalized furfural carbon to prepare dealkalized furfural carbon particles, and the resulting dealkalized furfural carbon particles have a bulk density of 0.5 t / m 3 -1.1t / m 3 , moisture content is 4.5%-13.5%, dry basis ash content is 1.5%-4.5%, dry basis alkali metal content is 0.05%-0.25%, dry basis fixed carbon content is 19.5%-33.5%, and dry basis calorific value is 20MJ / kg-25MJ / kg.

[0019] The beneficial effects of the present invention are:

[0020] 1. A method for preparing blast furnace injection fuel by dealkalizing furfural charcoal of the present invention comprises the following steps: de-alkalizing furfural charcoal with high ash content and high alkali metal content is washed with water to effectively remove alkali metal potassium and sodium elements in the furfural charcoal, thereby obtaining a dealkalized furfural charcoal product that meets the performance requirements of blast furnace injection, and mixing the de-alkalized furfural charcoal product with blast furnace coal injection to obtain blast furnace injection fuel, thereby improving the recycling value of furfural charcoal waste, reducing resource consumption and waste, and achieving greater economic benefits.

[0021] 2. The alkali metal in the furfural carbon of the present invention exists in the form of chloride and sulfate, which has high solubility in water. The alkali metal compounds can be completely transferred to the aqueous phase by adopting a wet grinding and enhanced water washing method. The dealkalization of the furfural carbon can be achieved by combining press filtration for solid-liquid separation. The dealkalized waste liquid after solid-liquid separation can be returned to the furfural production system, thereby avoiding the generation of wastewater. The production process of dealkalized furfural carbon is characterized by high efficiency, low consumption and zero pollution emission.

[0022] 3. The furfural carbon used in the present invention has the characteristics of wide source, low price and carbon neutrality, and the dealkalized furfural carbon particles obtained have the characteristics of low ash content, low harmful elements, high density, high calorific value and excellent blast furnace coal injection metallurgical properties, etc., and can replace expensive washed clean coal for blast furnace injection, which is of great significance for reducing blast furnace ironmaking costs and reducing carbon dioxide emissions. Its promotion and implementation has significant economic, social and ecological benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention is a flow chart of a method for preparing blast furnace injection fuel by carbon dealkalization and upgrading of furfural. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the scheme of the present invention are shown in the drawings, while other details that are not closely related to the present invention are omitted.

[0026] In addition, it should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0027] A method for preparing blast furnace injection fuel by carbon dealkalization and upgrading of furfural, comprising the following steps:

[0028] S1, mixing furfural charcoal with a first dealkalization solution to obtain a first mixture, performing wet grinding on the first mixture to strengthen dealkalization to obtain a primary solid-liquid mixed product, and performing filter pressing on the primary solid-liquid mixed product to achieve solid-liquid separation to obtain a primary dealkalization furfural charcoal and dealkalization waste liquid;

[0029] S2, mixing the second dealkalization solution with the first dealkalization furfural charcoal to obtain a second mixture, subjecting the second mixture to wet grinding and enhanced dealkalization to obtain a secondary solid-liquid mixed product, and subjecting the secondary solid-liquid mixed product to filter press to achieve solid-liquid separation to obtain a secondary dealkalization furfural charcoal and the first dealkalization waste liquid;

[0030] S3. Dry and granulate the secondary dealkalized furfural charcoal to obtain dealkalized furfural charcoal particles, mix the dealkalized furfural charcoal particles with blast furnace injection coal to obtain blast furnace injection mixed fuel, and the blast furnace injection mixed fuel is passed through a crushing device and a conveying device and then sprayed through the blast furnace tuyere and the cyclotron zone for combustion to provide hydrogen-rich reducing gas and heat for blast furnace smelting; wherein the dealkalized furfural charcoal particles are low in ash, low in alkali, high in density and high in calorific value.

[0031] The furfural charcoal in step S1 includes the residue of furfural and similar compound products extracted from biomass raw materials, wherein the extraction is carried out by acid hydrolysis, solvent extraction and other processes.

[0032] In step S1, the first de-alkali solution is a mixture of one or more of fresh water, industrial water, domestic wastewater, furfural distillation waste liquid, and the first de-alkali waste liquid recycled from the furfural carbon refining process, and the water content in the first mixture is 75%-90%.

[0033] In step S1, the wet grinding enhanced dealkalization temperature is 15°C-95°C, and the wet grinding enhanced dealkalization time is 1min-15min.

[0034] In step S1, one or more combinations of a plate and frame filter press, a belt filter press, and a high-pressure filter press are used for solid-liquid separation, and the moisture content of the once-dealkalized furfural charcoal obtained after filtration is 40%-60%.

[0035] In step S2, the second dealkalization solution is a mixture of one or more of fresh water, industrial water, domestic wastewater and furfural distillation waste liquid, and the water content of the second mixture is 75%-90%.

[0036] In step S2, the wet grinding enhanced dealkalization temperature is 10°C-95°C, and the wet grinding enhanced dealkalization time is 1min-15min.

[0037] In step S2, one or more combinations of a plate and frame filter press, a belt filter press, and a high-pressure filter press are used for solid-liquid separation, and the moisture content of the secondary de-alkalized furfural charcoal obtained after filtration is 40%-60%.

[0038] In step S3, the secondary dealkalized furfural charcoal is dried by one or more combinations of a rotary drying furnace, a belt drying furnace, a tunnel kiln drying furnace, and a drying room. The drying temperature is 80° C.-200° C., the drying time is 5 min-150 min, and the moisture content of the dried secondary dealkalized furfural charcoal is 5%-15%.

[0039] In step S3, one of an extrusion pelletizer, a flat die pelletizer, and a ring die pelletizer is used to extrude and pelletize the dried dealkalized furfural carbon, and the resulting dealkalized furfural carbon particles have a bulk density of 0.5 t / m 3 -1.1t / m 3 , moisture content is 4.5%-13.5%, dry basis ash content is 1.5%-4.5%, dry basis alkali metal content is 0.05%-0.25%, dry basis fixed carbon content is 19.5%-33.5%, dry basis calorific value is 20MJ / kg-25MJ / kg. Among them, dry basis alkali metal contains K and / or Na.

[0040] In step S3, the blast furnace coal injection includes one or more of lignite, bituminous coal, anthracite, semi-coke, and other carbon-containing fuels.

[0041] In the prior art, furfural carbon has not been applied to blast furnace injection fuel, because the content of alkali metal potassium and sodium in the biomass carbon product obtained by the existing furfural carbon treatment technology is still high, which is difficult to meet the application requirements of blast furnace injection fuel. If it is applied to blast furnace injection, it will cause an increase in alkali metal load, affecting the safe production and molten iron quality of blast furnace smelting. The present invention, by dealkalizing and deashing the furfural carbon, obtains dealkalized furfural carbon particles that meet the requirements of blast furnace injection, and mixes them with blast furnace coal injection to obtain blast furnace injection fuel. The method creatively treats the furfural carbon and applies it to blast furnace injection fuel, realizing the low-cost and low-carbon production of the blast furnace ironmaking process with high-value utilization of furfural carbon waste, reducing resource consumption and waste, and achieving greater economic benefits.

[0042] Example 1

[0043] This embodiment provides a method for preparing blast furnace injection fuel by carbon dealkalization of furfural, comprising the following steps:

[0044] S1, 1 part of furfural charcoal (water 50%, dry basis ash 6.5%, dry basis alkali metal 0.96%, dry basis calorific value 19.6MJ / kg) is mixed with 2 parts of new water to obtain a first mixture with a moisture content of 83.3%, the first mixture is subjected to wet grinding and intensive dealkalization, the dealkalization temperature is 50°C, the wet grinding time is 5min, and a solid-liquid mixed product is obtained after the wet grinding is completed; the solid-liquid mixed product is subjected to filter pressing by a plate and frame filter press to achieve solid-liquid separation, and the moisture content of the dealkalized furfural charcoal is 50%;

[0045] S2, 2 parts of new water and 1 part of the first dealkalized furfural charcoal are mixed to obtain a second mixture with a moisture content of 83.3%, the second mixture is subjected to wet grinding for enhanced dealkalization, the dealkalization temperature is 30° C., the wet grinding time is 5 min, and a secondary solid-liquid mixed product is obtained after the wet grinding is completed; the first solid-liquid mixed product is filtered by a plate and frame filter press to achieve solid-liquid separation, and the moisture content of the second dealkalized furfural charcoal is 50%;

[0046] S3. The secondary dealkalized furfural charcoal is transported to a rotary drying furnace for drying at a temperature of 150° C. for 20 min. The moisture content of the dried secondary dealkalized furfural charcoal is 10%. The dried secondary dealkalized furfural charcoal is pelletized by a flat die pelletizer to obtain low-ash, low-alkali, high-density, high-calorific value dealkalized furfural charcoal pellets.

[0047] Example 2

[0048] This embodiment provides a method for preparing blast furnace injection fuel by furfural charcoal dealkalization. Compared with Example 1, the difference is that in step S1, furfural distillation waste liquid is used instead of new water as the dealkalization solution, and the rest is roughly the same as Example 1 and will not be repeated here.

[0049] Comparative Example 1

[0050] Comparative Example 1 provides a method for preparing blast furnace injection fuel by dealkalization of furfural carbon. Compared with Example 1, the difference is that in steps S1 and S2, wet desulfurization waste liquid is used instead of new water for dealkalization, and the rest is roughly the same as Example 1 and will not be repeated here.

[0051] Comparative Example 2

[0052] Comparative Example 2 provides a method for preparing blast furnace injection fuel by furfural charcoal dealkalization. Compared with Example 1, the difference is that in steps S1 and S2, papermaking waste liquid is used instead of furfural distillation waste liquid for dealkalization, and the rest is roughly the same as Example 1 and will not be repeated here.

[0053] The components of the dealkalized furfural carbon particles obtained in Examples 1-2 and Comparative Examples 1-2 were analyzed, and the blast furnace injection fuel prepared therefrom was analyzed and tested. The results are shown in the following table.

[0054] Table 1 Performance of dealkalized furfural carbon particles and blast furnace injection fuel of Examples 1-2 and Comparative Examples 1-2

[0055]

[0056] As shown in Table 1, when new water and furfural distillation waste liquid are used as dezincification reagents, the alkali metal (K+Na) content in the prepared dealkalized furfural carbon particles is less than 0.11%, the ash content is less than 2.3%, and the calorific value is higher than 21.3MJ / kg, which can be used as a substitute for blast furnace pulverized coal. When the dealkalized furfural carbon particles are mixed with blast furnace pulverized coal to obtain blast furnace injection fuel for blast furnace injection, the calorific value of the blast furnace injection fuel exceeds 25.5MJ / kg, and the combustion rate before the tuyere exceeds 68.8%, providing sufficient heat and reducing agent for blast furnace smelting production. When wet desulfurization waste liquid and papermaking waste liquid are used as dealkalization solution, due to poor removal of K and Na under alkaline conditions, and a large amount of calcium ions in the desulfurization waste liquid react with sulfate ions in furfural carbon to generate calcium sulfate attached to the surface of furfural carbon, resulting in an increase in ash content. The Na element content in the papermaking waste liquid is high, and precipitates and enriches in the furfural carbon during the drying process, resulting in an increase in alkali metal and ash content. The alkali metal (K+Na) content in the prepared dealkalized furfural carbon is greater than 0.58%, and the ash content exceeds 6.7%, which does not meet the requirements of blast furnace injection fuel and is difficult to be used as a substitute fuel for blast furnace injection coal.

[0057] Examples 3 to 6 and Comparative Examples 3 to 6

[0058] Examples 3 to 5 and comparative examples 3 to 6 provide a method for preparing blast furnace injection fuel by carbon dealkalization of furfural. Compared with Example 1, the difference is that the adjustment of various parameters in step S1 is shown in the following table; the rest is roughly the same as Example 1 and will not be repeated here.

[0059] Table 2 Parameter settings in Examples 3 to 6 and Comparative Examples 3 to 6

[0060]

[0061]

[0062] Example 7

[0063] This embodiment provides a method for preparing blast furnace injection fuel by furfural carbon dealkalization. Compared with Example 1, the difference is that in step S1, 50% industrial water + 50% domestic waste water replaces the new water in Example 1, and the rest is roughly the same as Example 1 and will not be repeated here.

[0064] The components of the dealkalized furfural carbon particles obtained in Examples 3 to 7 and Comparative Examples 3 to 6 were analyzed, and the blast furnace injection fuel prepared therefrom was analyzed and tested. The results are shown in the following table.

[0065] Table 3 Performance of dealkalized furfural carbon particles and blast furnace injection fuel of Examples 3 to 7 and Comparative Examples 3 to 6

[0066]

[0067] As shown in Table 3, it can be seen from the data of Examples 3 to 7 and Comparative Examples 3 to 5 that increasing the moisture content of the mixture, the wet grinding temperature, the extended wet grinding time and the reduced moisture content of the dealkalized furfural carbon after filter pressing can improve the dealkalization and deashing effects of the furfural carbon, and the dealkalized furfural carbon prepared has the characteristics of low alkali, low ash and high calorific value, and can be used as a high-quality injection fuel for blast furnaces. However, when the wet grinding temperature is too high, although it can promote the removal of harmful alkali metal elements in the furfural carbon, it provides more stringent requirements for the equipment in the wet grinding and filter pressing process, resulting in shortened equipment service life, reduced production efficiency and other problems. When the moisture content of the mixture is too low, the wet grinding temperature is too low, the wet grinding time is too short and the moisture content of the dealkalized furfural carbon after filter pressing is too high, it is not conducive to the removal of the alkali metal in the furfural carbon, especially when the moisture content in the dealkalized furfural carbon after filter pressing is too high, the alkali metal that has entered the liquid phase will once again precipitate and adhere to the surface of the furfural carbon in the drying stage, resulting in an increase in the alkali metal content and ash content in the dealkalized furfural carbon.

[0068] Example 8

[0069] The present embodiment provides a method for preparing blast furnace injection fuel by dealkalization and upgrading of furfural charcoal. Compared with Example 1, the difference lies in that, in step S2, the dealkalized furfural char particles are mixed with blast furnace injection bituminous coal, anthracite and semi-coke in a ratio of 20%:50%:20%:10% to prepare blast furnace injection fuel; the rest is roughly the same as Example 1 and will not be repeated here.

[0070] The blast furnace injection fuel prepared in Example 8 has a higher calorific value on a dry basis of 25.5 MJ / kg, and the combustion rate before the tuyere when the mixed fuel is injected into the blast furnace is 68.9%.

[0071] Example 9

[0072] The present embodiment provides a method for preparing blast furnace injection fuel by dealkalization and upgrading of furfural charcoal. Compared with Example 2, the difference lies in that, in step S2, the ratio of dealkalized furfural charcoal particles to blast furnace injection lignite coal and anthracite is 20%:40%:40%; the rest is roughly the same as Example 1 and will not be repeated here.

[0073] The blast furnace injection fuel prepared in Example 9 has a higher calorific value on a dry basis of 26.8 MJ / kg, and the combustion rate before the tuyere when the mixed fuel is injected into the blast furnace is 67.1%.

[0074] In summary, the present invention provides a method for preparing blast furnace injection fuel by dealkalization and upgrading of furfural charcoal, comprising the steps of mixing furfural charcoal with a first dealkalization solution to obtain a first mixture, subjecting the first mixture to wet grinding and enhanced dealkalization to obtain a primary solid-liquid mixed product, subjecting the primary solid-liquid mixed product to filter pressing to achieve solid-liquid separation, and obtaining a primary dealkalized furfural charcoal and a dealkalized waste liquid; mixing a second dealkalization solution with a primary dealkalized furfural charcoal to obtain a second mixture, subjecting the second mixture to wet grinding and enhanced dealkalization to obtain a secondary solid-liquid mixed product, subjecting the secondary solid-liquid mixed product to filter pressing to achieve solid-liquid separation, and obtaining a secondary dealkalized furfural charcoal and a first dealkalized waste liquid; drying and granulating the secondary dealkalized furfural charcoal to obtain low-ash, low-alkali, high-density, high-calorific value dealkalized furfural charcoal particles, mixing the dealkalized furfural charcoal particles with blast furnace injection coal to obtain a blast furnace injection mixed fuel, and the blast furnace injection mixed fuel is passed through a crushing device and a conveying device and then sprayed in a cyclotron zone through a blast furnace tuyere for combustion, thereby providing hydrogen-rich reducing gas and heat for blast furnace smelting. The present invention carries out dealkalization and ash reduction treatment on the residue - furfural charcoal produced in the process of preparing furfural in the biomass chemical industry, so as to prepare dealkalized biomass charcoal meeting the requirements of blast furnace injection, and mixes the dealkalized biomass charcoal with blast furnace coal injection to prepare blast furnace injection fuel, thereby realizing high-value utilization of solid waste in the biomass chemical industry, improving its recycling value, reducing resource consumption and waste, and reducing the consumption of fossil fuels such as coal in the blast furnace ironmaking production process. In addition, the biomass charcoal has the property of zero carbon emission, and can replace coal powder for blast furnace injection, thereby reducing the carbon dioxide emission of ironmaking production, and achieving greater economic, social and environmental benefits.

[0075] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for preparing blast furnace injection fuel by furfural carbon dealkalization and upgrading, characterized in that: The steps include: S1, mixing furfural charcoal with a first dealkalization solution to obtain a first mixture, performing wet grinding on the first mixture to strengthen dealkalization to obtain a primary solid-liquid mixed product, and performing filter pressing on the primary solid-liquid mixed product to achieve solid-liquid separation to obtain a primary dealkalization furfural charcoal and dealkalization waste liquid; S2, mixing the second dealkalization solution with the first dealkalization furfural charcoal to obtain a second mixture, subjecting the second mixture to wet grinding and enhanced dealkalization to obtain a secondary solid-liquid mixed product, and subjecting the secondary solid-liquid mixed product to filter press to achieve solid-liquid separation to obtain a secondary dealkalization furfural charcoal and the first dealkalization waste liquid; S3. Dry and granulate the secondary dealkalized furfural charcoal to obtain dealkalized furfural charcoal particles, mix the dealkalized furfural charcoal particles with blast furnace injection coal to obtain blast furnace injection mixed fuel, and the blast furnace injection mixed fuel is injected into the cyclotron zone of the blast furnace through a crushing device and a conveying device to burn in the blast furnace tuyere, so as to provide hydrogen-rich reducing gas and heat for blast furnace smelting.

2. The method for preparing blast furnace injection fuel by furfural carbon dealkalization and upgrading according to claim 1, characterized in that: In step S1, the furfural charcoal comprises the residue of furfural and similar compound products extracted from biomass raw materials.

3. The method for preparing blast furnace injection fuel by furfural carbon dealkalization and upgrading according to claim 1, characterized in that: In step S1, the first dealkalization solution is a mixture of one or more of fresh water, industrial water, domestic wastewater, furfural distillation waste liquid, and first dealkalization waste liquid, and the water content of the first mixture is 75%-90%.

4. The method for preparing blast furnace injection fuel by furfural carbon dealkalization and upgrading according to claim 1, characterized in that: In step S1, the wet grinding enhanced dealkalization temperature is 15°C-95°C, and the wet grinding enhanced dealkalization time is 1min-15min.

5. The method for preparing blast furnace injection fuel by furfural carbon dealkalization and upgrading according to claim 1, characterized in that: In step S1, one or more combinations of a plate and frame filter press, a belt filter press, and a high-pressure filter press are used for solid-liquid separation, and the moisture content of the once-dealkalized furfural charcoal obtained after filtration is 40%-60%.

6. The method for preparing blast furnace injection fuel by furfural carbon dealkalization and upgrading according to claim 1, characterized in that: In step S2, the second dealkalization solution is a mixture of one or more of fresh water, industrial water, domestic wastewater and furfural distillation waste liquid, and the water content of the second mixture is 75%-90%.

7. The method for preparing blast furnace injection fuel by furfural carbon dealkalization and upgrading according to claim 1, characterized in that: In step S2, the wet grinding enhanced dealkalization temperature is 10°C-95°C, and the wet grinding enhanced dealkalization time is 1min-15min.

8. The method for preparing blast furnace injection fuel by furfural carbon dealkalization and upgrading according to claim 1, characterized in that: In step S2, one or more combinations of a plate and frame filter press, a belt filter press, and a high-pressure filter press are used for solid-liquid separation, and the moisture content of the secondary de-alkalized furfural charcoal obtained after filtration is 40%-60%.

9. The method for preparing blast furnace injection fuel by furfural carbon dealkalization and upgrading according to claim 1, characterized in that: In step S3, the secondary dealkalized furfural charcoal is dried by one or more combinations of a rotary drying furnace, a belt drying furnace, a tunnel kiln drying furnace, and a drying room. The drying temperature is 80° C.-200° C., the drying time is 5 min-150 min, and the moisture content of the dried secondary dealkalized furfural charcoal is 5%-15%.

10. The method for preparing blast furnace injection fuel by carbon dealkalization of furfural according to claim 1, characterized in that: In step S3, one of an extrusion pelletizer, a flat die pelletizer, and a ring die pelletizer is used to extrude the dried dealkalized furfural carbon to prepare dealkalized furfural carbon particles, and the resulting dealkalized furfural carbon particles have a bulk density of 0.5 t / m 3 -1.1t / m 3 , moisture content is 4.5%-13.5%, dry basis ash content is 1.5%-4.5%, dry basis alkali metal content is 0.05%-0.25%, dry basis fixed carbon content is 19.5%-33.5%, and dry basis calorific value is 20MJ / kg-25MJ / kg.

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