Источник: http://www.vai.at/view.php3?f_id=3337&LNG=EN
As a result of repeated dust recycling to the LD (BOF) or EAF steel shop, the zinc content of the dust continually increases. Above a certain limit, various problems may arise such as shorter refractory lifetimes and ZnO caking in the cooler zones of the off-gas system. During certain phases of steelmaking, the zinc content of the emitted dust is typically in excess of 20%. VAI and Voestalpine Stahl have therefore developed and installed a special on-line laser-based zinc measuring system in the latter's LD Works, which allows for the continual separation of these dust fractions and subsequent pelletizing. These pellets represent a valuable source of zinc for the industry and also reduce waste disposal costs.
Integrated technological and environmental solutions have become a key challenge for the iron and steel industry. End-of-pipe thinking, or the approach to solve all emission-related problems solely by ex-process cleaning systems, is neither a long-term economic solution nor a satisfactory environmental answer. VAI's long-term environmental strategy emphasizes process integration, minimized emission generation as well as by-product and waste-management concepts. In this way a low impact on the environment and economic operation is assured.
VAI AIRFINE® and WETFINE® Technology, featuring the most effective waste-gas cleaning solution for sinter plants. A high degree of production flexibility is provided in that the rate of residue recycling to the sinter strand can even be increased with the simultaneous fulfillment of strictest emission regulations. COREX® Technology, which features the lowest rate of environmental emissions in comparison with any existing process for the production of hot metal worldwide.
As the first step in the steel production route from raw materials to the finished product VAI engineers, supplies and implements individual solutions for ore processing, from simple ore concentration plants up to large-scale open pit or underground iron-ore mines. In dependence of the specific iron ore properties and customer requirements proven solutions ensure a high concentration efficiency and peak throughput rates. This is the precondition for low-cost production, high-value-added products and maximized profits.
Plant integration is an art. More than just the supply of equipment, it is the total responsibility for a project's successful outcome, from the initial investment idea to the plant start-up. Plant integration means the perfect linkage of optimized technologies and the total focus on the demands of the market. It includes a careful assessment of all relevant financial, operational, logistical, marketing and personnel factors. In order to meet these goals, VAI has at its disposal a vast background of engineering, plant building, operational, metallurgical, automation and project management experience, particularly for turnkey metallurgical complexes.
The path between the investment idea and successful project completion is a complex undertaking. It involves considerable expenditures of time, money and human effort. In order to minimize investment risk for investors and operators alike, VAI's project-related activities focus on a clear definition of project goals and accurate project scheduling. The ideal production route and product mix is also selected on the basis of steelmaking trends and a careful forecast of the future steel market for a particular region. In this way producers can be assured of the greatest potential for long-term, profitable steelmaking.
Of the many technological possibilities to convert ferrous materials into quality steel products, every process variant within a number of mill concepts is supplied by VAI. Examples: Integrated Mills (IM) featuring proven technologies in combination with latest state-of-the-art design from the conventional blast furnace route to the finished product. VAI's experience and technological competence ensures that the optimum process route will be selected to meet all production, product mix, quality and environmental demands.