Blast furnaces Germany

The Stuckofen or old high bloomery appeared in Germany in ca 1300 AD. This type of furnace was 3—5 m high and enclosed a tapered vertical shaft that was 1—1.2 m in diameter. Small openings near the bottom were provided for no22les (tuyeres, pronounced tweers) that permitted air, suppHed by bellows, to be blown into the furnace. Modem blast furnaces have essentially the same fundamental design. 

The liquefaction of waste plastics is not an entirely new technique, but the challenge to operate commercial plants has been tried in Germany by pyrolysis and hydrogenation. However, the former, operated by BASF was stopped in 1996, and the latter by Veba Oel GmbH in 1999 [1]. It is well known that the reason is not a technical problem, but an economic one the cost is higher than those of competitive techniques, such as mechanical recycling or blast furnace application. 

Bunsen, Robert Wilhelm. (1811-1899). Bom in Germany, Bunsen is remembered chiefly for his invention of the laboratory burner named after him. He engaged in a wide range of industrial and chemical research, including blast-furnace firing, electrolytic cells, separation of metals by electric current, spectroscopic techniques (with Kirchhoff), and production of light metals by electrical decomposition of their molten chlorides. He also discovered two elements, rubidium and cesium. 

Fig. 9.27 Development of blast furnace charge compositions in Germany [B.48, p.l61].

Over the centuries, other pozzolanic substances were blended with slaked lime to produce what are now called synthetic (or artificial) hydraulic limes. Both naturally occurring pozzolans (such as trass, found in Germany), and synthetic pozzolans (such as ground blast furnace slag) have been, and still are used. It was also found that some impure limestones, containing silica and alumina, produced slaked limes with a range of hydraulic properties. Such natural hydraulic limes were widely used in construction and building for mortar and concrete. 

This effect, coupled with the increasing need to produce low sulfur steels (less than 0.001 %) has necessitated the introduction of a desulfurisation stage between the blast furnace and the BOS process. In Germany, for example, some 80 % of pig iron is desulfurised [27.5]. 

The term coke brings an immediate reference to the blast furnace the evolution of the blast furnace reduction process occurred over a period of many centuries (ore smelting being known in the sixteenth century and documented in some detail) (Biringuccio, 1540) and most certainly had become well known in almost all areas of the ancient world two millennia ago (Forbes, 1950). By the early Middle Ages, a shaft blast furnace known in Germany as stuckofen was well established and iron making was a respected trade and not a sporadic part-time occupation. The fuel for these furnaces was provided by wood charcoal, and, consequently, the vitality of the iron and steel industry was controlled by the availability and cost of wood. 

As well as containing iron at around 40 to 45 per cent, matte contained about 12 per cent lead, most of the copper from blast furnace feed, about half the zinc and a substantial proportion of the silver. Matte was initially roasted in open heaps or stalls to remove sulfur and was then recycled to the blast furnace, but later reverberatory roasting furnaces were used. A shaft kiln was used at the Harz smelter in Germany. 

Using larger furnaces and increased air supply mainly achieved an increase of the produced iron quantity. In Germany the volume of the blast furnaces, Sttickofen, increased from ca. 1.5 m to ca. 4 m in the period 1500-1700 and the daily output grew from 1200 to 2000 kg. Around 1830 a blast furnace produced 3000-4000 kg of pig iron a day. For each tonne of iron 1500-2000 kg charcoal was needed. 

Blast furnace coke just before stabilization by quenching with water. Courtesy of Uhde, Germany. 

Figure 6.5.20 Contribution of indirect reduction on the coke consumption of a blast furnace [data from 1957 to 1960 from Germany, Sweden, and Japan (adapted from Heynert and Hedden, 1961), data for blast furnaces from 2004 to 2006 from www. expeditionvoestalpine.com/hochofen].

Cupola Furnace Explosion. A violent expln occurred in one of the cupola furnaces of Germany-, shortly after starting the blast. 

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