There are many advantages of sintering plants in modern, integrated steelworks. They not only produce sinter for the blast furnace process, but also enable producers to recover valuable materials. Included here are dust and other particulates generated during the sintering process. Right from the start, when sintering technology was first introduced into the smelting process, sinter offgas plants were equipped with dust collectors in the form of cyclones or electrostatic precipitators. Yet today’s legislation demands more drastic cuts in harmful substances and materials. These are beyond the capabilities of conventional downstream dust collectors. That’s why Paul Wurth Umwelttechnik GmbH, part of the SMS group, developed its innovative EFATM process. It effectively cleans the offgases produced during sintering.
The EFATM is installed at the end of the sinter plant process chain, downstream of the electrostatic separator and fan. It essentially consists of an entrained flow absorber (EFATM) and a bag-type filter. The offgas captured from the sinter plant typically contains dust, sulfur oxides, hydrochloric and hydrofluoric acids, as well as dioxins and furans. What makes the entrained flow absorber so powerful is that it contains calcium hydroxide to remove the acidic compounds and brown coal coke to absorb dioxins and furans.
Furthermore, water sprayed into the reactor at high pressure maintains optimum reaction conditions. That maintains a steady reaction temperature within the required 80 to 110 °C range. The injected water completely evaporates so that the dust from the offgas stays dry and is collected in the bag-type filter.
A key feature of the process is that it offers you extremely effective desulphurization, up to concentrations in the clean gas of < 50 mg/m3 STP (standard temperature pressure). This applies to all sinter plant conditions, including start-up and rundown as well as continuous sintering procedures during line stoppages at temperatures of > 250 °C.
Equipped with the EFATM process, your plant meets even the toughest emission standards, including EU limits. What‘s more, the process offers you investment security because it complies with even tighter future regulations without the need for modifications. Paul Wurth has already installed EFATM in four plants, using both the by-pass and end-of-pipe designs.