"ferroalloy"

Ferroalloys (English Ferroalloys), an intermediate alloy consisting of iron and one or more elements, is mainly used for iron and steel smelting. In the iron and steel industry, generally all intermediate alloys for steelmaking, whether iron or not (such as silicon-calcium alloys), are also called "iron alloys." It is also customary to include certain pure metal additives and oxide additives.

Ferroalloy general effect

1 Deoxidizer. During the steelmaking process, oxygen is removed from the molten steel. Some ferroalloys can also remove other impurities such as nitrogen and nitrogen from the steel. 2 alloy additives. According to steel composition requirements, add alloying elements to the steel to improve the performance of the steel. 3 Inoculants. Adding molten iron before cast iron casting improves the crystal structure of the casting. In addition, it is also used as a reducing agent for the production of other iron alloys and non-ferrous metals by the metallothermic reduction method; alloying additives for non-ferrous alloys; also used in small quantities in the chemical industry and other industries. 4 Iron and steel, all steels are a kind of ferroalloy, which also makes ferroalloys the most widely used and most used alloys. In high school textbooks, some high carbon irons and all iron-containing alloys are all ferroalloys.

nature

The main element of the ferroalloy generally has a high melting point, or its oxide is difficult to reduce, and it is difficult to refine the pure metal. If it is together with the iron, it is easier to reduce the smelting. The use of ferroalloys in iron and steel smelting, in which iron is not only harmless, but because of the fusing of molten steel is more favorable. Therefore, deoxidation and alloying during steelmaking are mostly added in the form of iron alloys. Iron alloys are generally brittle and cannot be used as metal materials.

Industrial refining

Smelting of low-grade iron alloys with yttrium begins around 1860. Later, the development of ferromanganese in blast furnaces and ferrosilicon containing less than 12% of silicon. From 1890 to 1910, electric arc furnaces were used to produce ferroalloys in France. H. Moissan used an electric arc furnace to conduct systematic tests on difficult-to-reduce elements. PLTH?roult was used in industrial production. At that time, coke and charcoal were used as reducing agents to reduce the ore. Most of the products were high-carbon. of. After 1920, in order to meet the development needs of high-quality steel and stainless steel, a new phase of production of low-carbon iron alloys began. On the one hand, on the basis of the Al-thermal method for the preparation of metals proposed by K. Goldschmidt in 1898, the development of aluminothermic methods for the smelting of some carbon-free ferroalloys and pure metals; A desiliconization refining method for oxidizing a silicon-containing alloy in an electric furnace. Due to the high production cost of the aluminothermic method, the desiliconization refining method has been applied more. Until now, medium-carbon, low-carbon, and micro-carbon ferrochromium, medium-carbon, low-carbon ferromanganese, and most of metallic manganese are still refined by this method. The thermal conversion of refined ferrochromium means that the liquid ore, lime melt and silicon-chromium alloy accelerate the reaction by thermal mixing, which is a further development of the desiliconization refining method. In addition, pure alloy additives (such as metal manganese) are also produced by electrolysis, and ultra-micro carbon-containing ferrochromium containing carbon is produced by vacuum decarburization. In recent years, methods for refining ferrochromium and ferromanganese by pure oxygen blowing have also been developed.

China produced ferrosilicon and ferromanganese in small electric furnaces around 1940. In 1955, Jilin Ferroalloy Factory began mass production. Subsequently, a number of ferroalloy plants were built in various places and manganese iron was produced using small blast furnaces to meet the needs of the national steel industry.

Variety use

Basic use

As a deoxidizer for steelmaking, the most widely used are silicon manganese, ferromanganese and ferrosilicon. Strong deoxidizers are aluminum (aluminum iron), silicon calcium, silicon zirconium, etc. (see deoxidation reaction of steel). Commonly used alloy additives are: ferromanganese, ferrochromium, ferrosilicon, ferrotungsten, ferromolybdenum, ferrovanadium, ferrotitanium, ferronickel, niobium (neodymium) iron, rare earth iron alloys, ferroboron, ferrophosphorus and so on. A variety of ferroalloys, in accordance with steelmaking needs, are regulated in many grades based on the content of alloying elements or the level of carbon, and the impurity content is strictly limited. Ferroalloys containing two or more alloying elements are called composite ferroalloys. The use of such ferroalloys can add deoxidizing or alloying elements at the same time, which is beneficial to the steelmaking process and enables the more comprehensive and efficient utilization of symbiotic ore resources. Commonly used: manganese silicon, silicon calcium, silicon zirconium, silicon manganese aluminum, silicon manganese calcium and rare earth ferrosilicon.

Pure metal additives for steelmaking include aluminum, titanium, nickel and metallic silicon, metallic manganese, and metallic chromium. Certain easily reducible oxides such as MoO, NiO, are also used instead of iron alloys. In addition, there are also iron nitride alloys such as ferrochromium, ferromanganese, and the like, which are subjected to nitriding treatment, and heat-generating iron alloys mixed with a heat-generating agent.

Basic types

Ferrosilicon, ferromanganese, silicomanganese, ferrochromium, ferrotungsten, ferrovanadium, ferronickel, ferromolybdenum, ferrotitanium, rare earth magnesium silicon, rare earth ferrosilicon, silicon-calcium alloy, silicon-germanium alloy, silicon aluminum alloy, tantalum, Phosphorus, ferroboron, etc.

The future development direction of China's ferroalloy industry China's ferroalloy industry has grown up with the development of the steel industry. Before the liberation, only a few ferroalloy products were trial-produced and produced in small quantities. After the founding of New China; with the construction and transformation of a number of iron alloy backbone enterprises, by 1979, China's ferroalloy production was suddenly exceeded one million tons, reaching 1.163 million tons, and the national iron alloy supply situation was eased.

After the reform and opening up, with the growth of demand for ferroalloy products in Japan, South Korea, and Southeast Asia, China's ferroalloys began to enter the international market while meeting the needs of the domestic market. In the late 1990s, due to the continuous expansion of foreign trade and the increasing demand in the domestic market, the development of the ferroalloy industry in China entered the "fast track," and several major ferro-alloy enterprise reforms, expansions, and constructions were completed one after another. Privately-owned ferroalloy companies spring up. With rapid development, ferroalloy production capacity has doubled. With the disintegration of the Soviet Union, China has become the world’s largest producer and exporter of ferroalloys, and has played a pivotal role in the world’s ferroalloy industry.

Development Overview

The variety is complete, basically able to meet the development needs of China's steel industry. China's ferroalloy product varieties are relatively complete, except for a few excellent grades of special varieties of product production technology is still immature pending research and development, almost all deoxidizers, alloying agents, inoculants, powders and various types of cored wire products can be basically Satisfy the production needs of China's steel industry.

The simultaneous increase in production volume and export volume. From 2003 to 2007, the output of ferroalloys in China increased rapidly, which was approximately 10% faster than the average annual growth rate of crude steel. The oversupply of domestic ferroalloy products prompted the export of ferroalloy products to increase continuously. Since the export of ferroalloy products began in 1981, the export volume has increased year by year. In 1994, the export volume was close to 1 million tons. From 1995 to 2002, there were slight fluctuations, with an average annual export of 1,247,400 tons. From 2003 to 2007, exports have been increasing. The average export is 2.2623 million tons.

The main problem

China's ferroalloy industry has achieved fruitful results from scratch, from small to large, and from weak to strong, but it still has a big gap with the ferroalloy industry powers, mainly in the following four aspects:

The development of production enterprises is not balanced. The number of ferro-alloys enterprises in China is large, and the layout is decentralized. The number of submerged arc furnaces above 25,000 dry volt-amperes accounts for only 0.81% of the total number of submerged arc furnaces in the country; the number of enterprises with production capacity over 100,000 tons accounts for only 1.8% of the total, and the production capacity 10,000 tons of companies accounted for 50.1% of the total. This has led to the failure of China's ferroalloy industry to form a healthy competitive environment, which has restricted the healthy and orderly development of the industry.

Technological progress and innovation are slow. In the process of ferroalloy industry development and expansion, China has invested in the construction of a number of large-scale ferroalloy enterprises. However, due to the heavy burden of enterprises and insufficient funds, they are unable to carry out technological innovation and the development is slow. The newly built ferroalloy enterprises have weak technical capabilities and most of them have not adopted advanced technologies. As a result, the level of process equipment in the industry is low, and technological progress and innovation are slow.

There are few high-grade varieties, high energy consumption and material consumption, and low labor productivity. China's ferroalloy varieties can basically meet the needs of domestic steel industry development, but pure products, nitriding products, furnace refining products, composite deoxidants, multi-alloy agents, granulation and powder products, core-core products, and other technological content and added value High product yield is less.

With the implementation of the access system for the industry and the gradual implementation of energy conservation and emission reduction policies, the overall energy consumption and material consumption of ferroalloy products have been reduced, but the energy consumption and material consumption of products are high, and the comprehensive utilization of secondary energy sources lags behind that of advanced countries.

Due to the large number of small electric furnaces in China, the process is simple, equipment is obsolete, and the degree of mechanization and automation is low. The per capita physical labor productivity is only about 45 tons per year, while the per capita physical labor productivity of the same industry in foreign countries is about 300 tons per year.

The ferroalloy production capacity is large and the industrial concentration is low. In the process of the development of the ferroalloy industry in China, in some areas, regardless of the level of industrial policies and process equipment, the development of ferroalloy projects blindly, the low level of repeated construction is serious, resulting in ferroalloy production enterprises are widely spread, scattered layout, and low level of equipment technology.

At present, the total capacity of ferroalloys in China has reached about 34 million tons per year, and the total number of enterprises has reached more than 2,000. The average production capacity of each enterprise is only about 17,000 tons, and the output is less than 10,000 tons. According to statistics, there are only 28 ferroalloy enterprises with a capacity of more than 100,000 tons in China, and only 8 enterprises with a production capacity of 200,000 tons or more, and only two companies with a production capacity of 500,000 tons or more, while the production capacity is less than 10,000 tons. As many as 1,000 companies, the industry's huge production capacity, low industrial concentration.

Future direction

In the future, China's ferroalloy industry should focus on transforming the development mode, controlling the total size, eliminating backward production capacity, and improving the overall level of equipment; optimizing industrial distribution and resource allocation and increasing industrial concentration; implementing the “going out” strategy, enhancing international competitiveness, and realizing China’s Ferroalloy industry is fully sustainable.

Efforts will be made to eliminate backward production capacity and strictly control new construction projects. At present, China's ferroalloy production equipment has a large proportion of 6300 dry volt-ampere and below electric furnaces. It is necessary to eliminate the outdated production capacity, control new construction projects, and improve the overall technological and equipment level of China's ferroalloy electric furnaces.

In view of the serious overcapacity problem in the ferroalloy industry, the relevant state departments should proceed from both the macro-control and micro-governance, strictly examine and approve new ferroalloy projects, control the total amount, and eliminate low-level redundant construction.

Rationally allocate resources and energy and vigorously develop circular economy. In vigorously developing the ferroalloy industrial recycling economy, the following points should be achieved: First, to effectively utilize manganese ore and chromium ore resources, improve resource and energy use efficiency, and implement the implementation of manganese ore enrichment and dephosphorization, ore preheating and Pre-reduction treatment, sintering, pellets and other powder ore block technology. The second is to optimize the ratio of domestically produced poor mines to imported rich mines, improve the grade of ore entering the furnace, and ensure that the energy consumption indicators of manganese and chromium-based products and the main element recovery rate reach a certain level. The third is to comprehensively utilize and recycle the gas, slag, smoke and dust recovered from the semi-enclosed and totally enclosed electric furnaces. Fourth, the above-mentioned coal and electricity industry chain is the link, and a ferroalloy enterprise group integrating “coal, electricity, and metallurgy” has been formed, and the circular economy has been vigorously developed.

Make use of regional advantages to establish large-scale enterprise groups and increase industrial concentration. In order to truly become a strong ferroalloy producer in China, it is necessary to make the company bigger and stronger, form large-scale production and operation, and establish a group of new industrial groups with larger production scale, higher management standards and high-quality products. The main should be the following:

The first is to accelerate the implementation of mergers and acquisitions and expand the scale of production in accordance with market principles, based on existing large enterprise groups. The second is to encourage and support large-scale enterprises that hold strengths, and use assets, resources, brands, and industrial chains as links to implement cross-border, cross-regional, and cross-industry mergers and acquisitions, and build new large-scale enterprise groups for upstream and downstream communications. Third, it is necessary to standardize the construction of high-capacity energy industrial parks in various regions, strengthen the integration of enterprises in local regions, and promote the development of industries in the direction of concentration, large-scale, and base.

In recent years, Sinosteel, CITIC, Minmetals, and Chuantou Company have respectively integrated and reorganized the Ji-Jin, Jin-Jie, Hu-Tie, and Shan Iron. However, the overall pace is small and progress has been slow. In accordance with the planning for the revitalization of the steel industry, it is imperative to implement large-scale ferroalloy industries and large-scale industrial integration and restructuring.

Implement the "going out" strategy, strengthen strategic guarantees for resources, and improve industrial safety. China is not only a big producer of ferroalloys, but also a big consumer of ferroalloy products. In 2008, China's ferroalloys met the domestic demand for 500 million tons of crude steel production, supported the rapid development of China's steel industry, and 1/6 of the ferroalloy products went out of the country under strict export policy restrictions. This shows that China's ferroalloy industry has considerable influence in the international market, whether it is production capacity or supply capacity. Therefore, under the circumstances of rational development and utilization of domestic chromium ore, poor manganese ore, and other mineral resources, China should encourage qualified production, trade, and mining companies to work together to optimize resource allocation, mutual benefit, and common development.

In short, from the perspective of the development of the world's steel industry, the characteristics of globalization have become increasingly prominent, and the development model of circular economy has been widely recognized. The situation of joint reorganization has become more and more urgent. China's ferroalloy industry should adapt to the development trend of the world steel industry, focus on adjusting and optimizing the product structure, the development model to achieve the transformation from quantity to quality, increase efforts to do a good job of resources and environmental protection, and strive to achieve industrial development and resource and environment coordination , take the road of sustainable and healthy development.