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For the refining process, there are also coming from the gases some chemical oxides such SiO (g) that reacts with Oxygen in the Air and generate SiO2 (s), Al203 (g), CaO (g) and other minors oxides such as TiO (g). The typical refining process used in Silicon and Ferrosilicon process is the slagging oxidative process, where dry clean compressed air is injected via plugs in the bottom of the refractory ladle, normally mix with pure oxygen. The oxidation reactions generate a considerable amount of gases (normally is used up to 20Nm3/h per ton of Silicon refined), as presented in the schematic following figure: Figure 51 — Schematic refractory ladle with plug and the overview of the reaction in the oxidative refining (source Viridis.1Q GmbH)

Figure 51 For the refining process, there are also coming from the gases some chemical oxides such SiO (g) that reacts with Oxygen in the Air and generate SiO2 (s), Al203 (g), CaO (g) and other minors oxides such as TiO (g). The typical refining process used in Silicon and Ferrosilicon process is the slagging oxidative process, where dry clean compressed air is injected via plugs in the bottom of the refractory ladle, normally mix with pure oxygen. The oxidation reactions generate a considerable amount of gases (normally is used up to 20Nm3/h per ton of Silicon refined), as presented in the schematic following figure: Figure 51 — Schematic refractory ladle with plug and the overview of the reaction in the oxidative refining (source Viridis.1Q GmbH)

Related Figures (44)

Figure 1 — Global Silicon demand by application source Viridis.iQ estimates
Figure 1 — Global Silicon demand by application source Viridis.iQ estimates
Figure 2 — Global Ferrosilicon consumption by application source Viridis.iQ estimates
Figure 2 — Global Ferrosilicon consumption by application source Viridis.iQ estimates
Figures 3 and 4 — World Si/FeSi Installed capacity divided by country/producer source Viridis.i1Q GmbH
Figures 3 and 4 — World Si/FeSi Installed capacity divided by country/producer source Viridis.i1Q GmbH
In the case of the Ferrosilicon world installed capacity, is important to take a look in the division by producer: Figures 5 and 6 — World Silicon Installed capacity divided by producers (source: Ferroalloys consulting KF)
In the case of the Ferrosilicon world installed capacity, is important to take a look in the division by producer: Figures 5 and 6 — World Silicon Installed capacity divided by producers (source: Ferroalloys consulting KF)
The figure below gives an overview of the Metallurgical Plant (Si and FeS1i):
The figure below gives an overview of the Metallurgical Plant (Si and FeS1i):
Figure 7 — Silicon process overview in basic flow diagram source Viridis.i1Q GmbH Figure 8 — General plant overview — Silicon and Ferrosilicon source Bateman Engineering
Figure 7 — Silicon process overview in basic flow diagram source Viridis.i1Q GmbH Figure 8 — General plant overview — Silicon and Ferrosilicon source Bateman Engineering
To present the main differences between the Silicon and Ferrosilicon process, the author shown in the following figures the block diagram of those 2 processes. The SAF considered on the diagram in the next figures are same, around 27MW active power.
To present the main differences between the Silicon and Ferrosilicon process, the author shown in the following figures the block diagram of those 2 processes. The SAF considered on the diagram in the next figures are same, around 27MW active power.
Figure 9 — Ferrosilicon bloc diagram process (source: Viridis.i1Q GmbH)
Figure 9 — Ferrosilicon bloc diagram process (source: Viridis.i1Q GmbH)
Figure 10 — The parameters of the silicon process (Schei, Tuset, & H.Tveit, 1998). Basically what are the main inputs, processing and outputs of the FeSi and Si general plant are represented in the diagram below:
Figure 10 — The parameters of the silicon process (Schei, Tuset, & H.Tveit, 1998). Basically what are the main inputs, processing and outputs of the FeSi and Si general plant are represented in the diagram below:
Figure 11 — Si/ FeSi process overview — potential 5R’s (rethink, reduce, reuse, refuse, recycle) source Viridis.i1Q GmbH
Figure 11 — Si/ FeSi process overview — potential 5R’s (rethink, reduce, reuse, refuse, recycle) source Viridis.i1Q GmbH
Figure 12 — Example of ATEX Classification zone in typical reductant receive station The main problem related to the environmental emissions for that part of the process, actually is the dust generation during the receipt, discharge and screening of reductant (low ash coal, charcoal, char and/or coke), mainly for the producers who works with charcoal which generate a high level of dust during the raw material handling. One of the biggest concern of carbon source handling are related to health and safety because the screening and receive process of reductant needs to be made under enclosure areas, generating an ATEX (Atmosphere Explosive) zones, as shown in the drawing below:
Figure 12 — Example of ATEX Classification zone in typical reductant receive station The main problem related to the environmental emissions for that part of the process, actually is the dust generation during the receipt, discharge and screening of reductant (low ash coal, charcoal, char and/or coke), mainly for the producers who works with charcoal which generate a high level of dust during the raw material handling. One of the biggest concern of carbon source handling are related to health and safety because the screening and receive process of reductant needs to be made under enclosure areas, generating an ATEX (Atmosphere Explosive) zones, as shown in the drawing below:
= Figure 13 —- Example of ATEX Classification zone in typical Raw Material Handling System
= Figure 13 —- Example of ATEX Classification zone in typical Raw Material Handling System
Substituir figura abaixo (Reverse Air Cleaning) Figure 14 — Schematic view of the simple dust collection system
Substituir figura abaixo (Reverse Air Cleaning) Figure 14 — Schematic view of the simple dust collection system
Figures 15, 16 and 17 — Typical dedusting system for Raw Material Handling System (w/wo cyclone) Images (a) and (b) show the outside raw material dedusting systems which the (c) shows the enclosure raw material batching and feeding system inside the furnace buildings. In terms of environmental emissions, the fact that Ferrosilicon plant uses the different type of ore as iron source, do not impact the overall emissions for the plant, comparing with the Silicon raw material handling system. The following pictures show the example of real dedusting system, with and without cyclone. Normally in Silicon and Ferrosilicon raw material handling systems, it is necessary the installation of cyclones to avoid premature damage of the filter bags by the impact of the dust particles, especially the SIO; particles. That is the same reason for the utilization of the cyclones on the crushing and grinding dedusting system, which will be discussed further on this technical article.
Figures 15, 16 and 17 — Typical dedusting system for Raw Material Handling System (w/wo cyclone) Images (a) and (b) show the outside raw material dedusting systems which the (c) shows the enclosure raw material batching and feeding system inside the furnace buildings. In terms of environmental emissions, the fact that Ferrosilicon plant uses the different type of ore as iron source, do not impact the overall emissions for the plant, comparing with the Silicon raw material handling system. The following pictures show the example of real dedusting system, with and without cyclone. Normally in Silicon and Ferrosilicon raw material handling systems, it is necessary the installation of cyclones to avoid premature damage of the filter bags by the impact of the dust particles, especially the SIO; particles. That is the same reason for the utilization of the cyclones on the crushing and grinding dedusting system, which will be discussed further on this technical article.
Considering as base case scenario, a plant with 3 submerged arc furnaces of 40,5MVA as apparent power (around 27MW active power), the volume to be handled of raw material and the expected dust generation would be in the same order of dimension for metallurgical silicon or ferrosilicon production, which will represent very similar dedusting systems for the raw material handling system. A complete raw material handling system including the correspondent dedusting system is hypothetically represented in the figure 18 in the next page. Figure 18 — Base case scenario 3D plant overview — hybrid plant source: Viridis.i1Q GmbH (in detail the bottom TENOVA)
Considering as base case scenario, a plant with 3 submerged arc furnaces of 40,5MVA as apparent power (around 27MW active power), the volume to be handled of raw material and the expected dust generation would be in the same order of dimension for metallurgical silicon or ferrosilicon production, which will represent very similar dedusting systems for the raw material handling system. A complete raw material handling system including the correspondent dedusting system is hypothetically represented in the figure 18 in the next page. Figure 18 — Base case scenario 3D plant overview — hybrid plant source: Viridis.i1Q GmbH (in detail the bottom TENOVA)
b) Stocking Process, Off gas system and heat recovery in SAF Normally, in the Ferrosilicon and Silicon production process, the submerged arc furnaces used are semi- closed or semi-open in the burden of the raw material, in the top of the furnace, as presented in the following pictures in the next page. Figures 19 and 20 — Picture of FeSi furnaces — Semi-closed (source SMS)/Semi-open (source VAIBHAV)
b) Stocking Process, Off gas system and heat recovery in SAF Normally, in the Ferrosilicon and Silicon production process, the submerged arc furnaces used are semi- closed or semi-open in the burden of the raw material, in the top of the furnace, as presented in the following pictures in the next page. Figures 19 and 20 — Picture of FeSi furnaces — Semi-closed (source SMS)/Semi-open (source VAIBHAV)
Figures 21 and 22 — Reference picture of Silicon Furnaces — Semi-closed (Elkem) / Semi-open (Elkem) The fact that the submerged arc furnace, either for Ferrosilicon or Silicon has a semi-closed or semi-open characteristics, would impact significantly in the off gas system used to collect the gases from the reaction nside the furnace. Based on that, under this sub-topic, we are going to briefly explain the Viridis.iQ off gas nodel based on thermodynamics, heat transfer and fluid dynamics in the top of the furnace.
Figures 21 and 22 — Reference picture of Silicon Furnaces — Semi-closed (Elkem) / Semi-open (Elkem) The fact that the submerged arc furnace, either for Ferrosilicon or Silicon has a semi-closed or semi-open characteristics, would impact significantly in the off gas system used to collect the gases from the reaction nside the furnace. Based on that, under this sub-topic, we are going to briefly explain the Viridis.iQ off gas nodel based on thermodynamics, heat transfer and fluid dynamics in the top of the furnace.
Figure 23 — Top of the submerged arc furnace — Viridis Model For simplicity purposes, the off gas model would be presented and could be applicable either in Ferrosilicon of Silicon production process. The thermodynamics are slightly different between the two mentioned process because the raw material and the reaction kinetics are different, which bring to different thermo-profile in the op of the furnace. Normally, at the same ideal construction conditions (well-designed submerged arc furnace with the good diameter/height/electrode dimensioning/electrical input) and the similar good operational conditions, similar good raw material characteristics; the top of the Silicon submerged arc furnaces have higher temperatures in the top of the burden compared with the Ferrosilicon submerged arc furnaces. Basically, this different is due to the reactions characteristics (exothermic / endothermic).
Figure 23 — Top of the submerged arc furnace — Viridis Model For simplicity purposes, the off gas model would be presented and could be applicable either in Ferrosilicon of Silicon production process. The thermodynamics are slightly different between the two mentioned process because the raw material and the reaction kinetics are different, which bring to different thermo-profile in the op of the furnace. Normally, at the same ideal construction conditions (well-designed submerged arc furnace with the good diameter/height/electrode dimensioning/electrical input) and the similar good operational conditions, similar good raw material characteristics; the top of the Silicon submerged arc furnaces have higher temperatures in the top of the burden compared with the Ferrosilicon submerged arc furnaces. Basically, this different is due to the reactions characteristics (exothermic / endothermic).
Figure 24 — Thermodynamics and kinetics in the top of the submerged arc furnaces The thermodynamic overview of the reactions in the top of the furnace could be verified in the figure below, the schematic thermos kinetics simulation model for the submerged arc furnace off gas design.
Figure 24 — Thermodynamics and kinetics in the top of the submerged arc furnaces The thermodynamic overview of the reactions in the top of the furnace could be verified in the figure below, the schematic thermos kinetics simulation model for the submerged arc furnace off gas design.
Figure 25: NO and the coherence with Silica fume (Kamfjord). production. Recently some measurements done at Elkem Thamsarvn confirm the directly relationship between the environmental emissions and these process, as presented in the next figures.
Figure 25: NO and the coherence with Silica fume (Kamfjord). production. Recently some measurements done at Elkem Thamsarvn confirm the directly relationship between the environmental emissions and these process, as presented in the next figures.
The outside air brings a lot of Nitrogen and Oxygen, this also contributes tremendously for the NOx formation in the Silicon and Ferrosilicon submerged arc furnaces, at higher temperatures.
The outside air brings a lot of Nitrogen and Oxygen, this also contributes tremendously for the NOx formation in the Silicon and Ferrosilicon submerged arc furnaces, at higher temperatures.
Figure 27 — Estimates table waste for Base case scenario operating with 100% of low ash coal, producing Silicon
Figure 27 — Estimates table waste for Base case scenario operating with 100% of low ash coal, producing Silicon
The off gas system would be responsible to capture all the wastes genera ed in the top of the furnace anc these wastes could be capitalized and for this base case scenario, the microsilica that can be captured and solc as by product. Considering the average price of USD200/mt of Microsi ica (at lower quality level), the potential revenue for this base case scenario is equal to, 20.000mt/year x USD 200/mt = USD 4Mio/year of revenue. Of course the a comprehensive financial analysis should be done very basically consider that such off gas system will requires around USD for that type of project, but if you 20 to 25Mio, and considering the operational and maintenance costs listed on the table below, and based possible to consider around 9 to 10 years return on investment (Rol). on that briefly calculation, it’s
The off gas system would be responsible to capture all the wastes genera ed in the top of the furnace anc these wastes could be capitalized and for this base case scenario, the microsilica that can be captured and solc as by product. Considering the average price of USD200/mt of Microsi ica (at lower quality level), the potential revenue for this base case scenario is equal to, 20.000mt/year x USD 200/mt = USD 4Mio/year of revenue. Of course the a comprehensive financial analysis should be done very basically consider that such off gas system will requires around USD for that type of project, but if you 20 to 25Mio, and considering the operational and maintenance costs listed on the table below, and based possible to consider around 9 to 10 years return on investment (Rol). on that briefly calculation, it’s
Figure 28: Illustration of a typical hot gas cleaning system (source Viridis.IQ GmbH) Depending on the electricity local prices, the equipment design and the company owners ‘appetite for investment on environmental and excellence initiatives, the Heat recovery also is an important topic related to the off gas design that could be considered for Silicon and Ferrosilicon submerged arc furnaces. Initially, we can see in the figure above, a typical off gas cleaning system. If the off gas do not consider the heat recovery system, the process that are fundamentally considered on that kind of system consists on a duct responsible to transfer the gases from the furnace stacks to the dedusting system and at this duct normally is installed the off gas measurements systems, which can be a venture, a heat exchange system, normally an
Figure 28: Illustration of a typical hot gas cleaning system (source Viridis.IQ GmbH) Depending on the electricity local prices, the equipment design and the company owners ‘appetite for investment on environmental and excellence initiatives, the Heat recovery also is an important topic related to the off gas design that could be considered for Silicon and Ferrosilicon submerged arc furnaces. Initially, we can see in the figure above, a typical off gas cleaning system. If the off gas do not consider the heat recovery system, the process that are fundamentally considered on that kind of system consists on a duct responsible to transfer the gases from the furnace stacks to the dedusting system and at this duct normally is installed the off gas measurements systems, which can be a venture, a heat exchange system, normally an
Figure 29 — Recovery waste system for Electrical Arc Furnaces (source: Tenova) For the case of heat recovery systems in the off gas equipment of submerged and electric arc furnaces, one of the common systems is demonstrated in the Tenova schema below:
Figure 29 — Recovery waste system for Electrical Arc Furnaces (source: Tenova) For the case of heat recovery systems in the off gas equipment of submerged and electric arc furnaces, one of the common systems is demonstrated in the Tenova schema below:
Figure 30 — Grassmann diagram FeSi furnace 3 — Elkem Iceland (ratios of the streams are based on the input). As reference, the author shows below, a Grassmann diagram of the furnace 3 at Elkem Iceland Grundartang, based on the calculated results from the model published by Hjartarson, et.all during the 20" Ferroalloys conference in 2010, in Helsinki, Finland.
Figure 30 — Grassmann diagram FeSi furnace 3 — Elkem Iceland (ratios of the streams are based on the input). As reference, the author shows below, a Grassmann diagram of the furnace 3 at Elkem Iceland Grundartang, based on the calculated results from the model published by Hjartarson, et.all during the 20" Ferroalloys conference in 2010, in Helsinki, Finland.
Of course such a kind of result normally not depend on exclusively one process of the entire plant, but a conjunct of action that will drive the operational excellence of the plant towards world class results level company. Anyway, the environmental opportunities in any part of the Silicon and/or Ferrosilicon process almost all the time would represent benefits in terms of cash flow, soft or hard money and it worth most of the times invest on that kind of initiatives. Figure 31 — Example for the off gas system in Ferrosilicon plant in China (Erdos)
Of course such a kind of result normally not depend on exclusively one process of the entire plant, but a conjunct of action that will drive the operational excellence of the plant towards world class results level company. Anyway, the environmental opportunities in any part of the Silicon and/or Ferrosilicon process almost all the time would represent benefits in terms of cash flow, soft or hard money and it worth most of the times invest on that kind of initiatives. Figure 31 — Example for the off gas system in Ferrosilicon plant in China (Erdos)
Figure 32 — 3D design of 4 x SAF heat recovery and off gas Ferro Alloy Plant (source Metix)
Figure 32 — 3D design of 4 x SAF heat recovery and off gas Ferro Alloy Plant (source Metix)
Figure 33 — Gas velocity distribution for the tapping off gas (Ravary and Laclau, 1999) A computational fluid dynamics (CFD) simulation of velocity distribution of tap-hole exit gas on a scale from 0-65 m/s in the tapping region is shown in Figure 2. The jet will leave the tap-hole with a velocity of approximately 50 m/s and may become more than 3 metres long (Ravary and Laclau, 1999).
Figure 33 — Gas velocity distribution for the tapping off gas (Ravary and Laclau, 1999) A computational fluid dynamics (CFD) simulation of velocity distribution of tap-hole exit gas on a scale from 0-65 m/s in the tapping region is shown in Figure 2. The jet will leave the tap-hole with a velocity of approximately 50 m/s and may become more than 3 metres long (Ravary and Laclau, 1999).
Figure 35 - Measured crater pressure and electrode load at Elkem Thamshavn [1].
Figure 35 - Measured crater pressure and electrode load at Elkem Thamshavn [1].
Figure 36 - Evolution of maximum flame temperature vs gas velocity (measured in FeSi75 furnace in Elkem) Previous numerical models based on empirical research shows that the gas velocity of Silicon and Ferrosilicon furnaces could oscillate from 10 to 100m/s. For that range of gas velocity, the gas volume in the tapping process could reach up to 60.000Nm3/h, based on the Elkem FeSi furnaces in Norway (study reference).
Figure 36 - Evolution of maximum flame temperature vs gas velocity (measured in FeSi75 furnace in Elkem) Previous numerical models based on empirical research shows that the gas velocity of Silicon and Ferrosilicon furnaces could oscillate from 10 to 100m/s. For that range of gas velocity, the gas volume in the tapping process could reach up to 60.000Nm3/h, based on the Elkem FeSi furnaces in Norway (study reference).
The graph of figure 36 shows that, the tapping gases temperature increase tremendously with the gas velocity, stabilizing around 35 to 40m/s and temperatures in 4.800 K. Although the main gassing outlet either in Silicon and Ferrosilicon processes happens in the top of the furnace, the tap hole process gassing presents a considerable volume, which represents safety and health risk for the operations, and also environmental emissions risks. Some exemplary images are presented in the following figures:
The graph of figure 36 shows that, the tapping gases temperature increase tremendously with the gas velocity, stabilizing around 35 to 40m/s and temperatures in 4.800 K. Although the main gassing outlet either in Silicon and Ferrosilicon processes happens in the top of the furnace, the tap hole process gassing presents a considerable volume, which represents safety and health risk for the operations, and also environmental emissions risks. Some exemplary images are presented in the following figures:
The first and very simple step to reduce environmental emission during the liquid Silicon and/or Ferrosilicon at high temperatures is to implement the product handling procedure with installation of cover on top of the refractory ladles. This measure could help also to reduce the material losses adhered in the internal walls of the refractory ladles, impacting instantaneously in the process output. This initiative would also impact positively in the standard gas refining process, reducing the thermal losses by radiation or convection during the refining process. Figures 40, 41 and 42 —s 3D overview of the casting station (Tenova), the US Patent for top ladle covers number US 5065987A.
The first and very simple step to reduce environmental emission during the liquid Silicon and/or Ferrosilicon at high temperatures is to implement the product handling procedure with installation of cover on top of the refractory ladles. This measure could help also to reduce the material losses adhered in the internal walls of the refractory ladles, impacting instantaneously in the process output. This initiative would also impact positively in the standard gas refining process, reducing the thermal losses by radiation or convection during the refining process. Figures 40, 41 and 42 —s 3D overview of the casting station (Tenova), the US Patent for top ladle covers number US 5065987A.
expected to be in the range of USD 2Mio to USD 3Mhio for all the plant, including the equipment of the system. In some cases, in order to reduce that costs, some technology companies are installing the suspended rails where the smaller hood can move during the casting, being on top of each mould during that specific casting time. The expected flow in this area for the base case scenario is around 160.000 Nm3/h Figure 43 and 44 — Casting picture and dedusting system example (Tenova)
expected to be in the range of USD 2Mio to USD 3Mhio for all the plant, including the equipment of the system. In some cases, in order to reduce that costs, some technology companies are installing the suspended rails where the smaller hood can move during the casting, being on top of each mould during that specific casting time. The expected flow in this area for the base case scenario is around 160.000 Nm3/h Figure 43 and 44 — Casting picture and dedusting system example (Tenova)
Figure 45 and 46 — slag free continuous casting process (source Viridis.i1Q GmbH)
Figure 45 and 46 — slag free continuous casting process (source Viridis.i1Q GmbH)
Figure 47 — Example of de dusting system for casting process (source Tenova) There are also different types of Casting well know and used in the Silicon and Ferrosilicon Industry, like carrousel (Ferroatlantica), and copper water cooled casting table (developed by GFAT and similar casting design copper cooled table used in producers of Silicon, in Germany, for example). For this type of casting, the single suction point is enough and the complexity of the off gas hood for the casting process is considerable cheaper. One design solution in this case considers the connection of the suction duct to directly to the furnace stack together with the tapping hood duct, another solution is to use the gases to establish a insufflation system for the furnace bins together with the ducts from the tapping hood, and a third solution is to install a secondary dedusting system for the casting area.
Figure 47 — Example of de dusting system for casting process (source Tenova) There are also different types of Casting well know and used in the Silicon and Ferrosilicon Industry, like carrousel (Ferroatlantica), and copper water cooled casting table (developed by GFAT and similar casting design copper cooled table used in producers of Silicon, in Germany, for example). For this type of casting, the single suction point is enough and the complexity of the off gas hood for the casting process is considerable cheaper. One design solution in this case considers the connection of the suction duct to directly to the furnace stack together with the tapping hood duct, another solution is to use the gases to establish a insufflation system for the furnace bins together with the ducts from the tapping hood, and a third solution is to install a secondary dedusting system for the casting area.
Figures 49 and 50 — Carrousel casting table developed in FeSi and Silicon production and example of fumes during casting
Figures 49 and 50 — Carrousel casting table developed in FeSi and Silicon production and example of fumes during casting
The installation of this type of equipment is required even for the crushing in the range of millimetres, due to the fine dust “micrometres” that is generated during the crushing and screening activities. Some examples could be presented in the images below:
The installation of this type of equipment is required even for the crushing in the range of millimetres, due to the fine dust “micrometres” that is generated during the crushing and screening activities. Some examples could be presented in the images below:
It is mandatory the instalation of explosion vent panels, rupture plates on the pulse jet bag houses. Is also important to mention that there are in the market, different types the crushing and different project types. The correct system dimensioning, based on the input and output in terms of size is one of the most important factors to achieve a good design. Once the design is correctly dimensioned, the energy consumption is low, the risk for quality, safety and health also is lower and the environmental emissions are also lower.
It is mandatory the instalation of explosion vent panels, rupture plates on the pulse jet bag houses. Is also important to mention that there are in the market, different types the crushing and different project types. The correct system dimensioning, based on the input and output in terms of size is one of the most important factors to achieve a good design. Once the design is correctly dimensioned, the energy consumption is low, the risk for quality, safety and health also is lower and the environmental emissions are also lower.
Figure 55 and 56 — water granulation processes of (55) Silicon and (56) Ferrosilicon (source google and UHT)
Figure 55 and 56 — water granulation processes of (55) Silicon and (56) Ferrosilicon (source google and UHT)
Figures 57 and 58 — granshot plant at Voestalpine, Donawitz and schematic drawing of Granshot System (UHT) in Sweden
Figures 57 and 58 — granshot plant at Voestalpine, Donawitz and schematic drawing of Granshot System (UHT) in Sweden
Figure 59 — typical atomization unit design (source: Viridis.i1Q GmbH) In specific case of Silicon, the atomization of liquid Silicon, as well as the recycling of the fines generated in crushing (up to 2%) and grinding (up to 3%), will reduce the overall production costs as well as to minimize the environmental emissions due to the recycling factor and based on the fact that the atomization process happens in a closed chamber, with inert gas such as Argonium or Nitrogen and the temperature and the environmental is total under control, avoiding the pollution source such as in the Electrical Arc or Induction furnaces, used in some cases to reduce these process losses and underflow material coming from crushing, screening and grinding processes.
Figure 59 — typical atomization unit design (source: Viridis.i1Q GmbH) In specific case of Silicon, the atomization of liquid Silicon, as well as the recycling of the fines generated in crushing (up to 2%) and grinding (up to 3%), will reduce the overall production costs as well as to minimize the environmental emissions due to the recycling factor and based on the fact that the atomization process happens in a closed chamber, with inert gas such as Argonium or Nitrogen and the temperature and the environmental is total under control, avoiding the pollution source such as in the Electrical Arc or Induction furnaces, used in some cases to reduce these process losses and underflow material coming from crushing, screening and grinding processes.
The Viridis.IQ had developed the Operational Excellence Diagnostics for Silicon and Ferrosilicon production process that basically take a “picture” of the process and the opportunities on that very specific plant, from the equipment, technology, process, procedure, environmental, health, safety and quality risk assessment standpoint. On that Diagnostic, there is also a classification of the quick hits (low hanging fruits) that could be immediately implemented without any considerable investment and also the short, medium and long term opportunities that must match the business and strategic company plan. In any case, the return on investment related to the already applied Diagnostics and operational excellence plan by Viridis.i1Q GmbH (based on Lean Six Sigma and PMI best practices) exceeds the USD3,2 per dollar invested in the initial 6 months of application.
The Viridis.IQ had developed the Operational Excellence Diagnostics for Silicon and Ferrosilicon production process that basically take a “picture” of the process and the opportunities on that very specific plant, from the equipment, technology, process, procedure, environmental, health, safety and quality risk assessment standpoint. On that Diagnostic, there is also a classification of the quick hits (low hanging fruits) that could be immediately implemented without any considerable investment and also the short, medium and long term opportunities that must match the business and strategic company plan. In any case, the return on investment related to the already applied Diagnostics and operational excellence plan by Viridis.i1Q GmbH (based on Lean Six Sigma and PMI best practices) exceeds the USD3,2 per dollar invested in the initial 6 months of application.
Estimates with low accuracy — reference of conceptual engineering phase, +/-60%-70% Base case scenario used in the article — 3 x 27MW Active Power — Submerged Arc Furnaces (Silicon) The author is responsible for the estimates. To summarize the opportunities to reduce environmental emissions in Silicon and Ferrosilicon production processes discussed here plus the efficiency increase opportunities, is possible to present the overview in the table sheet below:
Estimates with low accuracy — reference of conceptual engineering phase, +/-60%-70% Base case scenario used in the article — 3 x 27MW Active Power — Submerged Arc Furnaces (Silicon) The author is responsible for the estimates. To summarize the opportunities to reduce environmental emissions in Silicon and Ferrosilicon production processes discussed here plus the efficiency increase opportunities, is possible to present the overview in the table sheet below:
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Environmental EngineeringMetallurgical EngineeringChemical EngineeringThermodynamicsEnvironmental EconomicsEnvironmental SustainabilityMetallurgical and Materials Engineering
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