Green, low-carbon and intelligent lead the transformation and upgrading of the steel industry

As the world's largest and strongest metallurgical construction contractor and metallurgical enterprise operation service provider, China Metallurgical Group Co., LTD. (referred to as "MCC Group") has always stood at the high-end of the international level and the height of the development of the entire metallurgical industry. With the leading international first-class core technology, continuous innovation and research and development of independent controllable ability, irreplaceable metallurgical industry chain integration and integration advantages, to assume the responsibility of leading China's metallurgy to achieve intelligent, green, low-carbon, efficient development of the "iron and steel power". MCC has made every effort to draw a carbon emission reduction technology roadmap, promote low-carbon and carbon-free smelting, and focus on innovative breakthroughs and iterative upgrades in the fields of hydrogen smelting, electric furnace steelmaking, ultra-low emission, and efficient use of resources and energy. It has accumulated a number of key technologies for independent research and development, and relies on intelligent technologies to accelerate the process of carbon reduction and reduction. Help to achieve green, low-carbon, intelligent and efficient development of the iron and steel metallurgy industry.

Optimize system capacity building to open a new era of green and low-carbon

In order to meet the needs of green and low-carbon development of the steel industry, it is urgent to establish a carbon emission calculation method and a corresponding carbon emission reduction evaluation standard system that adapt to the actual situation of the steel industry. To this end, MCC South is building a "Steel production low-carbon management system", which includes two parts: "Steel production carbon emission intelligent analysis software" and "steel production carbon emission reduction intelligent management system".

The steel production carbon emission intelligent analysis software is deeply compatible with authoritative and common carbon emission accounting methods at home and abroad, fully integrates the differences of raw fuel, process flow and product structure at home and abroad, and has functions and features such as emission source heuristic inventory, emission factor intelligent correction, emission activity data intelligent cleaning, verification and accounting efficient and accurate, and intelligent suggestions for emission reduction activities. It is a skillful helper for iron and steel enterprises to carry out digital carbon asset management. The software presets a variety of normative accounting report templates at home and abroad, and supports highly flexible customization with the wizard mode, which can realize the one-click generation and submission of common reports. The software data interface is deeply integrated with the enterprise energy management system and manufacturing execution system, and the intelligent suggestions and emission reduction potential evaluation of process-level emission reduction activities are given by applying big data analysis.

The steel production carbon emission reduction intelligent management system can realize real-time online collection of emission activity data, and the collected data can be efficiently and intelligentially analyzed, so as to provide real-time and reliable carbon asset prediction and early warning for enterprises, and help enterprises plan future carbon emission reduction activities and carbon emission trading. The instant snapshot can generate a digital label of the carbon footprint of steel products, which can help steel products avoid low-carbon barriers to export overseas.

Promote process technology change to accelerate carbon emission reduction in short process

Focusing on the theme of carbon emission reduction, MCC strives to give full play to the advantages of core process technology, from the perspective of optimizing the production structure, in-depth analysis of key and core technology shortcomings such as technology and equipment, shorten the process flow, optimize the process interface, and provide strong technical support for the green and low-carbon development of the steel industry.

Reducing the carbon emission of "blast furnace + converter" long process steel production is the key work at present. MCC Jingcheng, a subsidiary of MCC Group, has developed low-carbon metallurgical technologies based on long processes, including key technologies such as hydrogen rich sintering, oxygen rich large coal injection, high proportion pellets, low carbon iron making in blast furnaces, thin slab continuous casting, and long wood direct rolling. "Hydrogen based shaft furnace + electric arc furnace short process or scrap electric furnace + headless rolling, direct rolling, casting rolling" is the forefront of green and low-carbon development of the steel industry. MCC Jingcheng overall design, the world's first development and implementation of "coke oven gas self-reforming gas base shaft furnace direct reduction" preparation of high-quality deoxidation pellet technology, can achieve carbon reduction of 60%, while the self-developed CERI-S1-Arc new scrap preheating furnace adopts a new "shaft + push steel mechanism + horizontal charging" composite scrap preheating technology. Through "high temperature flue gas + quench preheating boiler + activated carbon adsorption" the whole process of ultra-clean elimination of dioxins, through "activated carbon adsorption + electrocoagulation coupling bag dust removal" to achieve collaborative emission reduction of particulate matter, dioxins and carbon dioxide.

In addition, strengthening the recycling of scrap steel resources and improving the ratio of converter scrap is an important way to reduce carbon emissions in the steel industry, and short-process electric furnace steelmaking has become the first choice under the trend of transformation and upgrading of this process technology. Short-process electric furnace steelmaking can directly shorten the process from sintering to blast furnace ironmaking, and then to converter steelmaking. It is estimated that a single electric furnace can achieve carbon emission reduction of 70%-80% and save comprehensive energy consumption of 45%-50%. In recent years, MCC South has laid out in advance in this field, reserved its strength for technological exploration and updating, and successively implemented five quantum electric furnace projects.

Based on the advantages of simplifying the production process, reducing the rolling process and improving the yield rate, near-final continuous casting and rolling technology also help to reduce the carbon emission in the steel production process. As early as a few years ago, MCC South carried out continuous exploration and innovation in the field of technology, and promoted the iterative upgrading of efficient continuous casting technology. From 2019 to 2021, relying on Yangchun New Iron and Steel billet continuous casting machine and Fujian Sansteel 3# continuous casting machine project, the pulling speed test was carried out, and the pulling speed of billet continuous casting was successfully promoted to 6.02 m/min, which reached a new high in China. It can completely realize that the billet casting billet is directly sent into the rolling mill without heating furnace, eliminating the heating furnace process, and reducing the energy consumption of rolling steel up to 60%-70%.

ESP headless continuous casting and rolling production line, which represents the highest level of hot-rolled strip technology in the world today, can realize the "hot instead of cold" of some products, saving about 66% of energy consumption per ton compared with conventional rolling, and saving energy and reducing carbon. MCC South has taken the lead in carrying out engineering technology practice in this field. At present, there are a total of 8 ESP production lines in the world, and 5 of the 7 domestic production lines are contracted by MCC South.

Deepen the reform of the energy structure and take multiple measures to promote the low-carbon transition

The energy structure of traditional iron and steel enterprises is mainly carbon-based (coal). To achieve green and low carbon, the existing energy structure must be adjusted and optimized. As early as 2011, MCC South passed the approval of the Ministry of Science and Technology, established the "National Steel Production Energy Efficiency Optimization Engineering Technology Research Center", and took the lead in undertaking the national 863 program project "Metallurgical industry system energy efficiency monitoring, evaluation and optimization control technology and system". Carried out hundreds of consulting projects such as capacity identification and energy consumption analysis of iron and steel enterprises in Hubei Province, energy conservation and environmental protection planning of iron and steel joint enterprises, presided over the drafting of dozens of national and industry standards for industrial energy conservation and green environmental protection, and successfully selected the National Ministry of Industry and Information Technology "Industrial Energy Conservation and green Development Evaluation Center" in 2017. Fully equipped with the technical strength of energy-saving and green planning, consulting, design and optimization of the whole process of the metallurgical industry and even the industrial industry.

In recent years, MCC South has been committed to promoting the innovation and reform of the energy structure of steel production, focusing on energy reduction, reuse and resource utilization, reducing coal use by reducing the total amount of coal and coke used in blast furnaces and substituting clean energy, and actively developing recycling efficiency improvement technologies for waste heat and energy in steel production processes, so as to achieve different degrees of reducing carbon dioxide emissions.

Replacing carbon with hydrogen (coal) is an important direction of current low-carbon development and energy reform. Starting from the positive response to the hydrogen energy strategic requirements of the national clean energy industry, MCC South actively carries out the storage and research of hydrogen energy technology, and is researching and developing serialized technology project groups such as hydrogen-rich blast furnace smelting and low-carbon blast furnace technology based on the low-carbon process route. In blast furnace smelting, the use of high hydrogen carbon ratio raw materials to partially replace coke or pulverized coal, and partially realize the conversion of carbon metallurgy to hydrogen metallurgy, not only can improve the production efficiency of the blast furnace, but also can reduce about 10% of the blast furnace carbon dioxide emissions.

The by-product gas produced in the process of iron and steel metallurgy is a high-quality raw material of carbon chemical industry. Coke oven gas and converter gas can be purified and used to synthesize a variety of chemical products, so that resources can be used more effectively and carbon emissions can be reduced more greatly. The integrated intelligent control system for the production and energy of tempered joint enterprises developed by MCC South, through the flat monitoring, management and system optimization of the global energy production and consumption of enterprises, establishes an objective energy assessment and evaluation system, promotes the optimization of the allocation of gas resources in iron and steel enterprises, improves the energy utilization rate, and builds an energy industry chain, thereby reducing carbon emissions.

In order to solve the problem of energy waste and environmental pollution caused by the emission of a large amount of low-calorific value gas in the process of iron and steel smelting, MCC South developed a series of high-parameter miniaturized gas power generation technology, which is the best guarantee means of "zero gas emission" dispatching, and the technology won the first prize of metallurgical science and technology. This technology has been iteratively upgraded to the 6th generation - supercritical gas power generation technology, the thermal efficiency of the whole plant can reach 46%, which is 50% higher than the power generation efficiency of traditional technology.

The primary gas purification and recovery process of traditional converter adopts spray method for initial dust removal, which not only causes waste of sensible heat resources below 900℃ in the flue gas, but also consumes water, steam and electricity. As a leader in the domestic primary flue gas treatment technology of converter, MCC South has developed pure dry purification and deep recovery technology of waste heat from converter flue gas. Sensible heat resources of 200℃-900℃ in flue gas are recovered by waste heat recovery device, and ceramic fiber filter is used for flue gas purification, the whole process does not require water spray and steam, and the steam recovery amount of tons of steel is increased by about 60 kg. Reduce the water consumption of tons of steel by 0.4-0.6 cubic meters, and the treated flue gas dust content meets the ultra-low emission requirements.

In addition, MCC Jingcheng original sintering flue gas constant temperature composite cycle waste heat recovery technology, aiming at sintering process flue gas sensible heat and cooling exhaust gas waste heat utilization, can achieve sintering flue gas and cooling exhaust gas dual heat source balance complementary heat, generating capacity up to 25kWh tons of sinter. In terms of converter flue gas heat recovery, MCC Jingcheng has developed a complete set of high-efficiency long-life technology, which can recover 90kg-120kg steam per ton of steel, and the service life of vulnerable sections such as active smoke hoods can reach more than 3 years, and the waste heat recovery amount is 10%-20% higher than that of traditional technology. In terms of ultra-high parameter gas power generation technology, it has achieved full coverage of single superunit, double superunit and sub-critical unit performance in the steel industry. In the field of energy saving of metallurgical heating furnaces, ultra-low nitrogen burners and combustion systems and whole-furnace intelligent control systems have been developed, which can save 3%-8% of energy. The above product indicators have been at the leading level in the industry.

Enhance the level of scientific and technological empowerment polishing green intelligent ecological background color

In recent years, MCC South has continued to promote the deep integration of the Internet, big data, artificial intelligence and the steel industry, and built a new green intelligent manufacturing integrated technology system with the whole production process, comprehensive management, and the whole life cycle of products, accelerating the process of carbon reduction and carbon reduction, leading to the peak of carbon and carbon neutrality.

The fuel ratio level of blast furnace iron-making process determines the carbon dioxide emission intensity. MCC South Intelligent blast furnace system will open the blast furnace smelting "black box", dynamic display of the blast furnace from the top to the entire production process, and has evaluation, diagnosis and early warning functions, to achieve "intelligent perception - intelligent analysis - intelligent decision - intelligent execution" scientific closed loop. After the successful application of the system in Ningsteel, WisCO and other enterprises, it will show the effect of furnace top distribution in real time, accurately obtain the airflow state, timely diagnose the abnormal operation furnace type, reduce the fuel ratio of blast furnace, and significantly improve the gas utilization rate.

The South automatic steelmaking technology of MCC adopts the control model of "static model + sub-gun detection + dynamic model", which has been successfully applied in many projects such as WisCO, Shougang, Liugang, Indonesia Dexin Steel, etc., which can effectively reduce the amount of molten iron and improve the utilization rate of scrap steel resources, so as to achieve carbon emission reduction.

In 2020, MCC South and Hubei University of Technology jointly completed the "Key technology and application of green intelligent energy saving and Consumption reduction in Steel Industry under Complex Manufacturing Environment" won the first prize of Hubei Province Science and Technology Progress Award. Under the support of the national 863 Program and the major science and technology projects of MCC Group, the technical system of energy-saving optimization combustion of BF hot blast furnace has been established, and the software of energy-saving combustion optimization system of BF hot blast furnace has been developed, which can effectively raise the air temperature by 9 ℃-20℃ and reduce the gas consumption by 3%-6%. The key technology of intelligent and low-cost production control of reheating furnace is invented, the furnace temperature setting model based on the billet optimal temperature curve is established, and the energy-saving combustion optimization control technology of various reheating furnaces is developed and the intelligent vision system of automatic loading of steel on the bench is pioneered at home and abroad, which effectively reduces the gas consumption by 4%-6%.

Build a comprehensive governance plan to protect the clear water, blue sky and pure land

MCC South has built a pollution control technology system that integrates source emission reduction, process control and end treatment, uses advanced, mature and efficient waste gas, waste liquid and solid waste treatment technologies, expands new ways of energy conservation and emission reduction, uses scientific and technological innovation to promote the balanced improvement of energy conservation and environmental protection level of iron and steel enterprises, promotes the green development of the steel industry, and helps win the battle of blue sky, clear water and clean land.

High-quality implementation of ultra-low emission transformation, promoting the coordinated emission reduction of conventional air pollutants and carbon, is the most feasible way to reach the peak of carbon at this stage, and can also lay a solid foundation for the next step of carbon neutralization. At present, MCC South has mastered various flue gas desulfurization and denitrification, dust removal and emission reduction technologies in the steel industry. In view of the uneven quality of active coke, the core raw material for desulfurization and denitrification of flue gas sintering machine, MCC South designed a modern active coke preparation process that integrates safety, intelligence, green and high efficiency, and built the first set of environmentally friendly active coke production line in Shenglong in China. The core index of active coke granules produced is also better than similar products in the market. The wear strength can reach more than 98%, the compressive strength can reach more than 50 kg, and the desulfurization value can reach more than 22 mg.

The TISCO industrial wastewater treatment system designed with "integrated technology of integrated advanced wastewater treatment process for Iron and steel enterprises" has stabilized the actual effluent water quality to the special discharge limit of water pollutants in iron and steel enterprises and the surface quasi-Class IV water quality standard, setting a new benchmark for ultra-low discharge of integrated wastewater treatment in iron and steel enterprises.

Construction of "One Belt, One Road" green steel service exploration

Since the "Belt and Road" initiative was put forward, China has undertaken more than 60 steel projects in countries related to the "Belt and Road", with the contract value reaching 3 billion US dollars. These technologies and products have not only won the contract orders of developed economies with the strongest product competitiveness, such as providing the first set of BF dry bag dust removal system and coal injection technology and equipment for PoSCO in South Korea, but also exporting technology and the most advanced standards for economic developing countries, such as providing the full process of steel turnkey projects for Indonesia and Vietnam. In the past 10 years, MCC has been taking the most advanced steel technology and products into the "Belt and Road" as its own responsibility, so as to lead the development of the steel industry in these countries directly into the first echelon of the world's steel development and achieve the purpose of green and sustainable development. All new steel projects in the "Belt and Road" countries adopt the highest domestic pollutant emission standards as the engineering guarantee value. In terms of energy consumption, it is first planned in accordance with the most advanced process, and it is recommended to choose the domestic and foreign advanced equipment with the lowest energy consumption and arrange it into the most compact production line, so that the energy consumption of the whole system can reach the first-class level of domestic steel enterprises. Due to long-term adherence to the implementation of green and low-carbon steel projects in the "Belt and Road", both domestic and foreign advanced standards as the basis, and domestic performance enterprises as a reference, so that MCC Group continues to provide continuous high-quality services for the "Belt and Road" steel projects.

Looking to the future, MCC will thoroughly implement the important decision-making and deployment of the Party Central Committee and The State Council on carbon peaking and carbon neutrality, vigorously promote the green low-carbon transformation of the steel industry throughout the whole process, practice the mission and responsibility of central enterprises, actively and continuously promote the supply-side structural reform of the industry, and continue to promote the adjustment of the production process structure and energy consumption structure. Promote the steel industry to green, low-carbon, intelligent and high-quality development continues to accelerate!