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Title: Pulverized coal firing of aluminum melting furnaces. Final report. [Sulfide capacity of various slags in given temperature range]

Abstract

Significant progress has been achieved in the development of a desulfurizing coal combustion process by the Aluminum Company of America (Alcoa) in a research program funded by the United States Department of Energy. Conceptually, high sulfur coal is burned with additives in a staged cyclone combustor, such that sufficient sulfur to obviate products of combustion (POC) scrubbing is retained in the slag by-product. Bench scale studies conducted during the program have shown that 70% of the sulfur (2.65% sulfur coal) reports to the slag at equilibrium through a 25% addition of iron ore to the coal. Results obtained correlate with published data for similar slag at higher temperatures. In pilot scale combustion tests, equilibrium levels of coal sulfur were retained by the slag (11 to 14%). Equilibrium sulfur capture was limited by low particulate retention and operating temperature higher than optimal. Cost estimates for implementation of the process are included in this report. 28 references, 39 figures, 58 tables.

Authors:
; ;
Publication Date:
Research Org.:
Aluminum Co. of America, Alcoa Center, PA. Alcoa Technical Center
OSTI Identifier:
6841673
Alternate Identifier(s):
OSTI ID: 6841673; Legacy ID: DE84013093
Report Number(s):
DOE/CS/40037-T17
ON: DE84013093
DOE Contract Number:
AC07-78CS40037
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; 20 FOSSIL-FUELED POWER PLANTS; ALUMINIUM; MELTING; COAL; STAGED COMBUSTION; CYCLONE COMBUSTORS; VERY HIGH TEMPERATURE; FLUE GAS; DESULFURIZATION; SLAGS; SOLVENT PROPERTIES; ADDITIVES; BURNERS; ECONOMICS; EXPERIMENTAL DATA; FURNACES; IRON ORES; PARTICULATES; PHASE DIAGRAMS; CARBONACEOUS MATERIALS; CHEMICAL REACTIONS; COMBUSTION; COMBUSTORS; DATA; DIAGRAMS; ELEMENTS; ENERGY SOURCES; FOSSIL FUELS; FUELS; GASEOUS WASTES; INFORMATION; MATERIALS; METALS; NUMERICAL DATA; ORES; OXIDATION; PARTICLES; PHASE TRANSFORMATIONS; THERMOCHEMICAL PROCESSES; WASTES 014000* -- Coal, Lignite, & Peat-- Combustion; 200202 -- Fossil-Fueled Power Plants-- Waste Management-- Noxious Gas & Particulate Emissions

Citation Formats

Stewart, D.L. Jr., Dastolfo, L.E. Jr., and DeYoung, D.H.. Pulverized coal firing of aluminum melting furnaces. Final report. [Sulfide capacity of various slags in given temperature range]. United States: N. p., 1984. Web. doi:10.2172/6841673.
Stewart, D.L. Jr., Dastolfo, L.E. Jr., & DeYoung, D.H.. Pulverized coal firing of aluminum melting furnaces. Final report. [Sulfide capacity of various slags in given temperature range]. United States. doi:10.2172/6841673.
Stewart, D.L. Jr., Dastolfo, L.E. Jr., and DeYoung, D.H.. Sun . "Pulverized coal firing of aluminum melting furnaces. Final report. [Sulfide capacity of various slags in given temperature range]". United States. doi:10.2172/6841673. https://www.osti.gov/servlets/purl/6841673.
@article{osti_6841673,
title = {Pulverized coal firing of aluminum melting furnaces. Final report. [Sulfide capacity of various slags in given temperature range]},
author = {Stewart, D.L. Jr. and Dastolfo, L.E. Jr. and DeYoung, D.H.},
abstractNote = {Significant progress has been achieved in the development of a desulfurizing coal combustion process by the Aluminum Company of America (Alcoa) in a research program funded by the United States Department of Energy. Conceptually, high sulfur coal is burned with additives in a staged cyclone combustor, such that sufficient sulfur to obviate products of combustion (POC) scrubbing is retained in the slag by-product. Bench scale studies conducted during the program have shown that 70% of the sulfur (2.65% sulfur coal) reports to the slag at equilibrium through a 25% addition of iron ore to the coal. Results obtained correlate with published data for similar slag at higher temperatures. In pilot scale combustion tests, equilibrium levels of coal sulfur were retained by the slag (11 to 14%). Equilibrium sulfur capture was limited by low particulate retention and operating temperature higher than optimal. Cost estimates for implementation of the process are included in this report. 28 references, 39 figures, 58 tables.},
doi = {10.2172/6841673},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Apr 01 00:00:00 EST 1984},
month = {Sun Apr 01 00:00:00 EST 1984}
}

Technical Report:

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  • The ultimate objective of this program is the commercial demonstration of an efficient, environmentally acceptable coal firing process suitable for implementation on melting furnaces throughout the aluminum industry. To achieve this goal, the program has been divided into two phases. During Phase I, detailed research and development will be performed to perfect a staged, slagging, cyclone burner for direct coal firing of a 40,000 lb open hearth aluminum melting furnace. Additives will be incorporated to remove sulfur and ash during the combustion process, thus precluding the need for downstream cleanup equipment. Also, two separate heat recuperation techniques will be evaluated.more » This work will be performed at Alcoa's ingot plant in Arnold, Pennsylvania (a production facility until the late 1950's), which is now a full-scale laboratory dedicated to investigations of alternate fuels, melting, ingot casting, and metal treatment. Phase II implementation is currently planned for Alcoa's Lafayette, IN, Works, where two of the ingot plant's five open hearth melting furnaces will be converted to utilize coal. In addition to confirmation of data gathered in Phase I, the effect of extended production schedule operation on equipment and efficiencies will be determined.« less
  • Shakedown operations on a 300 lb/h staged slagging cyclone coal combustor have continued during the 14th quarter of the contracted research and development program. The ultimate objective of the program is the development of an efficient, environmentally acceptable coal firing process suitable for implementation on melting furnaces throughout the aluminum industry. Four extended coal combustion tests with lithium carbonate additive were conducted during the report period, but all were terminated before attainment of steady-state conditions because of mechanical system problems. Work to solve the problems and begin the experimental program will continue in the next quarter. Discussions were held withmore » three outside firms concerning the advisability of retaining the services of one or more as technical consultants for the project. It was determined that retention of a technical consultant would not be desirable at this time because of the unique nature of the existing experimental unit.« less
  • Three coal combustion tests were conducted but all were terminated before steady-state conditions were attained because of mechanical and refractory problems. Lithium carbonate and calcium carbonate were used as fluxing/sulfur capture additives in the experiments. Shakedown of the system will continue in the next quarter.
  • The Alcoa/GE coal combustor is a two-stage, slagging cyclonic unit designed to direct fire an aluminum melting furnace at a rate of approximately 4.4 mm Btu/h (300 lb coal/h). The coal and an additive to trap sulfur compounds in the slag, is burned substoichiometrically in the first stage at 0.55 0 (55% of stoichiometric air) in the design case. Gaseous products leaving the first stage pass through a short analysis section and into the second stage, where sufficient air to complete combustion (total air = 10% excess) is injected. The hot (> 3000/sup 0/F) products of combustion pass directly intomore » a melting furnace, which will be a 7-foot diameter ladle for the first combustor (Burner A), and to the stack. Shakedown operations continued during the fourth year of the contracted research and development program. Fifteen coal combustion tests were conducted, but all were terminated before steady-state conditions were attained because of mechanical and refractory problems. Lithium carbonate and calcium carbonate were used in the tests as fluxing/sulfur capture additives. Following relining with a brick more resistant to slag corrosion, shakedown operations will continue.« less
  • The ultimate objective of this program is the commercial demonstration of an efficient, environmentally acceptable coal firing process suitable for implementation on melting furnaces throughout the aluminum industry. To achieve this goal, the program has been divided into two phases. Phase I has begun with the design and construction of a 350 lb/h (coal) staged slagging cyclone combustor (SSCC) attached to a 7-ft dia aluminum melting ladle furnace. Process development will culminate with a 1000 pph prototype SSCC firing a 40,000 lb capacity open hearth melting furnace at the Alcoa Laboratories. Phase II implementation is currently planned for Alcoa's Lafayette,more » IN, Works, where two of the ingot plant's five open hearth melting furnaces will be converted to utilize coal. In addition to confirmation of data gathered in Phase I, the effect of extended production schedule operation on equipment and efficiencies will be determined. This work would begin in 1982 pursuant to technical and economic evaluation of the process development at that time. A major design subcontract for assistance in the design of the SSCC is 80% completed.« less