scholarly journals Homogenised model for the electrical current distribution within a submerged arc furnace for silicon production

2021 ◽  
pp. 1-36
Author(s):  
ELLEN K. LUCKINS ◽  
JAMES M. OLIVER ◽  
COLIN P. PLEASE ◽  
BENJAMIN M. SLOMAN ◽  
ROBERT A. VAN GORDER
Keyword(s):  
Steady State ◽  
Electrical Current ◽  
Industrial Practice ◽  
Silicon Production ◽  
Arc Furnaces ◽  
Averaged Equations ◽  
Slow Evolution ◽  
Submerged Arc Furnace ◽  
Steady State Solutions ◽  
Submerged Arc

Silicon is produced in submerged arc furnaces which are heated by electric currents passing through the furnace. It is important to understand the distribution of heating within the furnace in order to accurately model the silicon production process, yet many existing studies neglect aspects of this current flow. In the present paper, we formulate a model that couples the electrical current to thermal, material flow and chemical processes in the furnace. We then exploit disparate timescales to homogenise the model over the timescale of the alternating current, deriving averaged equations for the slow evolution of the system. Our numerical simulations predict a minimum applied current that is required in order to obtain steady-state solutions of the homogenised model and show that for high enough applied currents, two spatially heterogeneous steady-state solutions exist, with distinct crater sizes. We show that the system evolves to the steady state with a larger crater radius and explain this behaviour in terms of the overall power balance typically found within a furnace. We find that the industrial practice of stoking furnaces increases the overall rate of material consumption in the furnace, thereby improving the efficiency of silicon production.

scholarly journals Replacing Fossil Carbon in the Production of Ferroalloys with a Focus on Bio-Based Carbon: A Review

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1286
Author(s):  
Marcus Sommerfeld ◽  
Bernd Friedrich
Keyword(s):  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Reducing Agents ◽  
General Description ◽  
Arc Furnace ◽  
Gas Emissions ◽  
Fossil Carbon ◽  
Arc Furnaces ◽  
Submerged Arc Furnace ◽  
Submerged Arc

The production of ferroalloys and alloys like ferronickel, ferrochromium, ferromanganese, silicomanganese, ferrosilicon and silicon is commonly carried out in submerged arc furnaces. Submerged arc furnaces are also used to upgrade ilmenite by producing pig iron and a titania-rich slag. Metal containing resources are smelted in this furnace type using fossil carbon as a reducing agent, which is responsible for a large amount of direct CO2 emissions in those processes. Instead, renewable bio-based carbon could be a viable direct replacement of fossil carbon currently investigated by research institutions and companies to lower the CO2 footprint of produced alloys. A second option could be the usage of hydrogen. However, hydrogen has the disadvantages that current production facilities relying on solid reducing agents need to be adjusted. Furthermore, hydrogen reduction of ignoble metals like chromium, manganese and silicon is only possible at very low H2O/H2 partial pressure ratios. The present article is a comprehensive review of the research carried out regarding the utilization of bio-based carbon for the processing of the mentioned products. Starting with the potential impact of the ferroalloy industry on greenhouse gas emissions, followed by a general description of bio-based reducing agents and unit operations covered by this review, each following chapter presents current research carried out to produce each metal. Most studies focused on pre-reduction or solid-state reduction except the silicon industry, which instead had a strong focus on smelting up to an industrial-scale and the design of bio-based carbon for submerged arc furnace processes. Those results might be transferable to other submerged arc furnace processes as well and could help to accelerate research to produce other metals. Deviations between the amount of research and scale of tests for the same unit operation but different metal resources were identified and closer cooperation could be helpful to transfer knowledge from one area to another. Life cycle assessment to produce ferronickel and silicon already revealed the potential of bio-based reducing agents in terms of greenhouse gas emissions, but was not carried out for other metals until now.

scholarly journals Pragmatic analysis of the electric submerged arc furnace continuum

2017 ◽  
Vol 4 (9) ◽  
pp. 170313 ◽  
Author(s):  
K. Karalis ◽  
N. Karkalos ◽  
G. S. E. Antipas ◽  
A. Xenidis
Keyword(s):  
Electric Potential ◽  
Operating Conditions ◽  
Immersion Depth ◽  
Operating Variables ◽  
Arc Furnaces ◽  
Pragmatic Analysis ◽  
Electrical Conductivities ◽  
Flow Heat ◽  
Submerged Arc Furnace ◽  
Submerged Arc

A transient mathematical model was developed for the description of fluid flow, heat transfer and electromagnetic phenomena involved in the production of ferronickel in electric arc furnaces. The key operating variables considered were the thermal and electrical conductivity of the slag and the shape, immersion depth and applied electric potential of the electrodes. It was established that the principal stimuli of the velocities in the slag bath were the electric potential and immersion depth of the electrodes and the thermal and electrical conductivities of the slag. Additionally, it was determined that, under the set of operating conditions examined, the maximum slag temperature ranged between 1756 and 1825 K, which is in accordance with industrial measurements. Moreover, it was affirmed that contributions to slag stirring due to Lorentz forces and momentum forces due to the release of carbon monoxide bubbles from the electrode surface were negligible.

The Research on Effects of Different Binders on Performances of Carbonaceous Pelletizing in Industrial Silicon Production

2015 ◽  
Vol 833 ◽  
pp. 101-106
Author(s):  
Ni Yang ◽  
Gang Xie ◽  
Chong Jun Bao ◽  
Huai Ren Li ◽  
Xiao Hua Yu ◽  
...  
Keyword(s):  
Production Cost ◽  
Production Costs ◽  
Smelting Process ◽  
Powder Materials ◽  
Arc Furnace ◽  
Pore Former ◽  
Silicon Production ◽  
Submerged Arc Furnace ◽  
Submerged Arc

The use of powder materials in smelting process has some impact on the breathability of the burden, and it ultimately results in poor production and quality of industrial silicon. If pelletizing is prepared by these powder materials, it not only reduces production cost but also reuses waste effectively. It could protect forest resources productively and contributes to sustainable development if charcoal is replaced by pelletizing using as carbonaceous reducing agent. Different powders such as anthracite fine, petroleum coke powders, charcoal powders, silica fume have been produced in the production process of industrial silicon. Briquetting of these powders with a binder starch D was voted into submerged arc furnace not only utilizes the resources sufficiently, but also reduces the production costs. Effects of content of starch D as binder and CaO as pore former on compressive strength, the shatter strength, the heat intensity and porosity of pelletizing were investigated in this paper. The following results were got: first, the performances of pelletizing except porosity were excellent when starch D was used as binder; second, CaO could efficiently improve porosity, and the pelletizing could satisfy requirement of industrial silicon production.

scholarly journals Effect of Carbonaceous Reducers on Carbon Emission during Silicon Production in SAF of 8.5 MVA and 12.5 MVA

2021 ◽  
Author(s):  
Kaizhi Jiang ◽  
Zhengjie Chen ◽  
Wenhui Ma ◽  
Shijie Cao ◽  
Hongmei Zhang ◽  
...  
Keyword(s):  
Carbon Emissions ◽  
Carbon Dioxide Emissions ◽  
Carbon Emission ◽  
Raw Materials ◽  
Chinese Government ◽  
Arc Furnace ◽  
Silicon Production ◽  
Soft Coal ◽  
Submerged Arc Furnace ◽  
Submerged Arc

Abstract The silicon manufacturing process produces a large amount of carbon emissions, which is of deep concern to the Chinese government. Previous research has calculated the amount of carbon emissions incurred in silicon production, while research on the factors that affect carbon emissions during the silicon production process has been scarce. The effect of the carbonaceous reducers' consumption on the carbon emission during silicon production was investigated using statistical analysis of the actual production data in order to lower the carbon emissions of silicon production. The effect of different type furnaces (8.5MVA and 12.5MVA) on the carbon emission were also investigated in the study. Based on the results, the soft coal has the greatest impact on carbon emissions when using the 8.5MVA submerged arc furnace. When using the 12.5MVA furnace, petroleum coke has the greatest impact on carbon emission. The use of the 12.5MVA furnace reduces the carbon dioxide emissions of the production of one ton of silicon by approximately 74 kg compared to the 8.5MVA furnace. To obtained reduced carbon emissions in silicon production, we suggest that the silicon manufacturers should (1) use the 12.5MVA submerged arc furnace as much as possible; (2) and optimize the ratio of carbonaceous reducing agents in raw materials for the different furnace types.

Sign in / Sign up

Export Citation Format

Share Document