Technical solutions
About technical solutions
We as Ferro Duo offer various technical solutions for the treatment of your waste or by-products from the cement, steel or chemical industry. Our goal is to avoid waste and to return the treated materials to the material cycle in order to conserve resources, as well as to save CO2 emissions. In addition to many years of experience, research and pilot-scale test facilities for optimal process design, we have strong partners as well as competent plant engineers on board for the respective projects in the various industries.
Bypass Dust
The use of alternative fuels to heat the rotary kiln in cement production leads to the accumulation of chloride-containing compounds in the process, as chlorine is introduced into the system by the raw materials and fuels used. In addition, heavy metals accumulate in the dust. To control the chloride content in the cement and to avoid malfunctions in the cyclone preheater, bypasses are installed that specifically discharge salt-rich dust (mainly alkaline earth chlorides and sulphates) as so-called bypass dust. Thanks to a patented process, we are able to purify the bypass dust and effectively remove heavy metal and alkali metal salts. This enables the reuse of the CO2-free cement raw material, conserves natural resources and saves CO2. Furthermore, this process can also be used to purify dust containing salts from other incineration plants.
What does Ferro Duo do with it?
Ferro Duo uses a patented scrubbing process to remove chlorine and heavy metals from the bypass dust.
What comes out of it?
Due to the effective washing process, the cement dust freed from chlorine and heavy metals can be used again in the cement kiln. The heavy metals are precipitated from the washing solution, thus additionally obtaining a purified mixed salt for the fertilizer industry, consisting mainly of potassium chloride and sulfate and sodium chloride, depending on the raw material.
How can Ferro Duo help?
The purified dust represents a CO2-free raw material, since it has already been fired. By avoiding waste, more precisely the dumping of polluted bypass dust, natural resources can be conserved.
Calcined Clay
CO2 plays a central role in global warming. According to the Kyoto Protocol, steps have been taken to slow down and at best stop climate change through CO2 reduction. Cement production, due to the high energy input and the CO2 emission caused by raw materials, is a process that requires a major change in this respect. It is necessary to consider other raw materials that can be used as a climate-neutral substitute for cement clinker. For this purpose, we examine your clay in cooperation with the accredited laboratories of the VDZ and calcine the clay for use as a hydraulic swelling agent and pozzolanic binder in building materials.
What does Ferro Duo do with it?
In a partnership with the “Verein deutscher Zementwerke e. V.” (VDZ for short), Ferro Duo investigates the mineralogy of the clay, which is dried and then calcined under optimum conditions in an indirectly heated rotary kiln.
What comes out of it?
In einer Partnerschaft mit dem Verein deutscher Zementwerke e. V. (kurz VDZ) untersucht Ferro Duo die Mineralogie des Tons, der getrocknet und anschließend unter optimalen Bedingungen in einem indirekt beheizten Drehrohrofen gebrannt wird. The electricity-based process is virtually CO2-free.
How can Ferro Duo help?
Clinker-based building materials are no longer competitive in view of the coming CO2 prices, and in view of the necessary reduction of CO2 emissions they are also no longer ecologically sustainable. With this project, we offer the customer a virtually CO2-free substitute as a mineral binder in cement, concrete and the building materials of the future.
Ground Granulated Blast Furnace Slag (GGBFS)
Granulated blast-furnace slag is produced during the production of pig iron when liquid blast-furnace slag is quenched in cold water. The material is particularly suitable as an additive in cement and can drastically reduce the CO2 balance of building materials. For this purpose, the blast-furnace slag is subjected to grinding and thus made directly usable as a cement substitute.
What does Ferro Duo do with it?
Ferro Duo receives granulated blast furnace slag from the steel industry and, through a grinding-drying process, produces a fine material that can replace much of the cement as an additive in concrete.
What comes out of it?
The result is a CO2-free cement substitute.
How can Ferro Duo help?
Ferro Duo thus provides a CO2-neutral material for the substitution of cement, which in addition could save natural raw materials.
Concrete recycling
Nowadays, degraded concrete materials are partly processed into road construction materials (so-called RC material). However, this is not material recycling in the strict sense, but downcycling. Even this is not always possible and often the material has to be disposed of in landfills. In view of the CO2 footprint of cement production and the desired avoidance of waste, concrete is to be completely recycled in the future. In a patented process, the individual phases of the concrete are selectively separated and can be reused.
Oily mill scale and grinding sludge
Due to the process, aqueous, oil-containing iron oxide residues, so-called mill scale, accumulate during steel production. Due to the high oil content, this material cannot be reused in the steelworks. Landfilling the contaminated material is not possible in Germany and would deprive the material cycle of valuable ferrous material. In a patented process, we are able to separate water and oil from the mill scale and make the iron oxide available again in the context of the circular economy and enable recycling of the oil. For easy handling, the powdery material obtained can be briquetted or compacted. The plant can be set up and operated directly at the point of origin.
What does Ferro Duo do with it?
Ferro Duo removes oil from mill scale by thermal treatment in an indirectly heated rotary kiln. This process can be integrated directly at the hot metal production site.
What comes out of it?
The deoiled mill scale consists mainly of iron oxide and represents a potential secondary raw material for pig iron production. In addition, the gently removed oil can be recycled.
How can Ferro Duo help?
Mill scale containing oil must be disposed of or landfilled at great expense. Through our process, waste can be avoided and reused by generating a secondary raw material through circular economy. This conserves natural iron ore sources and saves CO2 through correspondingly reduced mining and transport.
Top gas sludge
Top gas sludge is produced in the blast furnace process during pig iron production in the wet separator. This sludge consists mainly of fine ferrous materials and coke, but contains noticeable amounts of heavy metals such as zinc, lead and cadmium. To prevent these interfering substances from accumulating in the furnace, the contaminated sludge is not reused and requires costly disposal in landfills. In cooperation with BAM, we have succeeded in developing a patented process for the treatment of top gas sludge. The heavy metals are removed and the ferrous material is made available to the iron and steel industry again. By setting up and operating the plant at the point of origin, logistical effort can be minimised and the recycled materials can be returned directly into the process.
What does Ferro Duo do with it?
Ferro Duo removes volatile heavy metals such as zinc, lead and cadmium, which make direct reuse of the ferrous material in the steel mill difficult, by thermal treatment in an indirectly heated rotary kiln.
What comes out of it?
Under the reducing conditions by the carbon contained in the blast furnace gas slurry, a kind of iron sponge with high metallic iron content is obtained. This can be reused in compacted form for steel production. The heavy metals are obtained as zinc concentrate and can be reused by further purification.
How can Ferro Duo help?
By avoiding waste of the iron carrier containing heavy metals, landfill costs can be saved. The transformation into a kind of iron sponge causes the possible use in steel production. This makes it possible to conserve natural sources of iron ore.
Electric arc furnace (EAF) and Basic oxygen furnace (BOF) dusts
Steel scrap is used in the electric arc process for steel production, which leads to the introduction of heavy metals such as zinc, lead and cadmium. Until now, the resulting dusts have had to be disposed of or treated at great expense. Thanks to a process developed in cooperation with BAM, we can easily purify these dusts directly at the point of origin and thus free them from heavy metal contamination and make the ferrous material available again for its reuse in the processes. This protects natural resources and minimises logistical effort.
What does Ferro Duo do with it?
Ferro Duo removes volatile heavy metals such as zinc, lead and cadmium, which make direct reuse of the ferrous material in the steel mill difficult, by thermal treatment in an indirectly heated rotary kiln.
What comes out of it?
An iron oxide is obtained by thermal purification. This can be reused in compacted form as a secondary raw material for pig iron production. The heavy metals are obtained as zinc concentrate and can be reused by further purification.
How can Ferro Duo help?
By avoiding waste of the iron carrier containing heavy metals, landfill costs can be saved. Purification results in the possible use in pig iron production and thus the conservation of natural iron ore sources.
Ferrous sulphate production
In order to secure the demand for ferrous sulphates in the future, we have the possibility to produce ferrous sulphate from alternative ferrous raw materials by means of licensed and patented processes. Both spent pickling liquor from the steel industry and digestion liquor from the titanium dioxide industry can be used for this purpose. The solutions containing ferrous chloride provide hydrochloric acid as a valuable by-product in addition to the desired ferrous sulphate.
Another possibility is the use of iron oxides and scrap as raw materials for the production of ferrous sulphates. The ferrous sulphate can be produced as mono- or heptahydrate and even as ferric sulphate.
What does Ferro Duo do with it?
Ferro Duo takes solutions containing ferric chloride, for example used pickling solution from steel production or digestion solutions of iron-bearing ores, and adds sulfuric acid to them.
Similarly, Ferro Duo converts magnetite and scrap with sulfuric acid.
What comes out of it?
This yields ferrous sulfate, which is mainly present as a monohydrate. By selective recrystallization the heptahydrate can be obtained and by suitable oxidation iron(III) sulfate. During the production of ferrous sulfate from the ferric chloride solution, additional hydrochloric acid is produced as a valuable by-product.
How can Ferro Duo help?
This process serves to prevent waste and at the same time to secure long-term iron sulfate requirements for various industries.
Sewage sludge pyrolysis and phosphate recovery
Phosphate is vital for organisms, but natural sources are finite and will be exhausted in the foreseeable future. For this reason, it will be obligatory in Germany to recycle phosphate from sewage sludge. In a thermal and chemical process, the phosphate contained can be converted into a form that is available to plants and purified from heavy metals, which enables it to be used as fertiliser.
What does Ferro Duo do with it?
Ferro Duo accepts sewage sludge from wastewater treatment plants. This is dried, pyrolyzed and the contained phosphorus is made available by a chemical process. It also reduces heavy metal contamination.
What comes out of it?
Thus, a phosphate-containing ash is obtained, which can be used as fertilizer. The phosphorus contained is directly available to plants.
How can Ferro Duo help?
Phosphates represent a scarce raw material, which is only available in a few areas of the earth. Recycling from sewage sludge ensures the supply of this essential raw material for living things and conserves naturally occurring sources.
Magnesium sulphate
During titanium dioxide production in the sulphate process, a weak sulphuric acid with process residues remains. This so-called weak acid is partially neutralised with lime or limestone. The resulting red gypsum is landfilled. We use this weak acid to synthesise valuable minerals. By adding magnesium oxide, magnesium sulphate can be obtained from the dilute acid, which can serve the fertiliser market independently of imports and leads to the avoidance of waste in the titanium dioxide industry.
What does Ferro Duo do with it?
Magnesium sulfate can be produced from dilute acid, a weakly concentrated sulfuric acid from ore digestion in titanium dioxide production, by adding magnesium oxide.
What comes out of it?
A magnesium sulfate is obtained, which can be used in the fertilizer industry.
How can Ferro Duo help?
By recycling the dilute acid, the generation of waste can be avoided. The production of magnesium sulfate in Europe secures local supply of the material otherwise generated mainly in the uncertain Chinese market.
Red gypsum
Red gypsum is produced during the neutralisation of the so-called weak acid in the titanium dioxide production in the sulphate process. The weak acid is a weak sulphuric acid with residues from the digestion process. The addition of calcium carbonate produces gypsum, which is coloured red by ferrous residues. Landfilling is cost-intensive and partly prohibited. In order to avoid landfilling, we recycle the red gypsum and produce high-quality gypsum products from it. In addition to plasterboard, hemihydrates or anhydrite, the material can be used as an additive in the cement industry.
What does Ferro Duo do with it?
Ferro Duo dries the red plaster.
What comes out of it?
The dried red gypsum can thus be used as gypsum in cement or further processed by Ferro Duo for applications in gypsum board, alpha-gypsum or further, as well as used for gypsum granules in the fertilizer industry.
How can Ferro Duo help?
The red gypsum currently accumulates as waste and requires costly landfilling. Ferro Duo can thus contribute to waste reduction and thereby reduce the depletion of natural gypsum deposits. Above all, the coming elimination of FGD gypsum will thus preserve a valuable raw material.
Rare earths
Natural ores often contain rare earth elements. These elements are becoming increasingly important due to technological progress. Natural sources are scarce and limited to a few countries worldwide, which causes dependency. In order to be able to act independently, we enable the extraction of rare earths from the digestion liquor of ore-based industries such as the titanium dioxide industry. Special ion exchange and extraction processes can be used to selectively extract and process rare earth elements.
What does Ferro Duo do with it?
Rare earths are specifically extracted from the digestion solution of natural ores using special extraction and ion exchange processes.
What comes out of it?
As the name suggests, rare earths are rare raw materials. Rare earths are essential for modern technology and to achieve the goal of energy transformation.
How can Ferro Duo help?
Waste can be avoided by recycling the dilute acid. In addition, important raw materials can be preserved, and their finite natural sources can thus be conserved. A major advantage is the resulting local availability of rare earths, which can bring about independence from China.
Wind turbine blade
The first wind turbines can no longer be used profitably and are dismantled, e.g. as part of re-powering. The blades made of glass or carbon fibers and resins cannot be easily recycled. Some of them are stored until a solution is found. We treat the wind turbine blades by using the thermal energy of the organic synthetic resin and processing the fibrous material for further use.
What does Ferro Duo do with it?
Wind turbine blades are first crushed and then pyrolyzed.
What comes out of it?
The energy released can be used, the ash can be used in cement, for example, and the fibrous material can be used to make tabletops, among other things.
How can Ferro Duo help?
Recycling wind turbine blades is not trivial due to the fibrous composite materials. Ferro Duo has developed a concept that addresses this problem and enables material utilization. Since landfilling of wind turbine blades is not permitted, this process presents itself as extremely important in the current times of older generation wind turbine decommissioning.
- Bypass Dust
- Calcined Clay
- Ground Granulated Blast Furnace Slag (GGBFS)
- Concrete recycling
- Oily mill scale and grinding sludge
- Top gas sludge
- Electric arc furnace (EAF) and Basic oxygen furnace (BOF) dusts
- Ferrous sulphate production
- Sewage sludge pyrolysis and phosphate recovery
- Magnesium sulphate
- Red gypsum
- Rare earths
- Wind turbine blade