Sponsored by: LMD Aluminum Committee
Program Organizer: C.G. Hendriks, Kaiser Aluminum and Chemical Corp.,9131 Interline Drive, Baton Rouge, LA 70809
Wednesday, AM Room: A6
February 7, 1996 Location: Anaheim Convention Center
Session Chairperson: Dr. R.S. Thakur, Regional Research Laboratory, Bhubaneswar, Orissa, India
8:30 am
RED MUD AND SANDS HANDLING: NEW THOUGHTS ON AN OLD PROBLEM: N.C.R. Oeberg, Consultant, Kirschweg 37, CH - Oberengstringen, Schweix, Austria; A.E. Steinlechner, Maschinenfabrik Andritz Actiengesellschaft, Statteggerstrasse 18, A-8045 Graz, Austria
The Alumina industry is facing worldwide a growing disposal problem. Red Mud creates increasingly technical, economic and environmental problems. Available solutions are reviewed, and an old idea using a new approach with Pressurized disk or Drum Filters for Red Mud is herewith presented and submitted for consideration as a potential and prospective solution to the problem.
9:00 am
RED MUD PROJECT DEVELOPMENT: D. B. Kirkpatrick, Kaiser Aluminum & Chemical Corp., P. O. Box 337, Gramercy, LA 70052
Kaiser Aluminum & Chemical Co. impounds the byproducts of alumina production in lakes at the Gramercy, La. facility. Kaiser recognizes that this action cannot be maintained indefinitely. Therefore, the physical benification to recover value from the impounded material and the reduction of stored residue is being investigated. The Gramercy site faces two major challenges, Louisiana has a net negative evaporation rate, meaning the mud cannot be dried by passive means. Second, Kaiser exclusively uses Jamaican North Coast bauxite. This material is very fine which causes problems with the handleability and dustiness of potential products. The product development strategy addresses environmental and product liability issues as well as meeting customer needs. Engineers at Kaiser have developed techniques to dewater and dry the existing mud lakes to high solid levels. Currently, two products are being tested in solid-waste landfills. Other products are being developed for use outside of these controlled areas.
9:30 am
IMPROVING THE OPERATION OF RED MUD PRESSURE FILTERS: John T. Malito, Ph. D., Research Scientist, Alumina Processing Chemicals, Nalco Chemical Company, One Nalco Center, Naperville, IL 60563-1198
Almost all alumina refineries clarify bauxite digestion slurry using a combination of sedimentation and filtration. Typically, greater than 99% of the mud solids are removed in the settler, while the majority of the remaining solids suspended in the settler overflow is removed by pressure filtration or less commonly, sand filtration. The performance of the pressure filter, with regards to filtration rate, filtrate clarity, and filter cycle time, is strongly influenced by several important factors. In this study, the effects of suspended mud, quantity of filter aid, and residual flocculent and starch in the filter feed slurry on filtration rate are quantified. This information is useful in optimizing the operation of pressure filters, as well as troubleshooting filtration problems which occur periodically. The use of a reagent specifically for increasing filtration rate is also discussed.
10:00 am
CHARACTERIZATION OF INDIAN RED MUDS AND RECOVERY OF THEIR METAL VALUES: J. Pradhan, S. N. Das, J. Das, S. B. Rao, R. S. Thakur, Regional Research Laboratory, Bhubaneswar 751013, Orissa, India
The huge reserve of bauxite, large scale industries and good export potential have made the aluminum industry a promising enterprise in India. At the same time growing concern for environment and raw material conservation has intensified the research and development work on the safe disposal and bulk utilization of red mud, and alkali enriched solid waste generated in alumina manufacturing plants. However, in India, the problem has received scant attention especially from aluminum industries. The present paper outlines the physico-chemical characteristics and mineralogical phases of some Indian red muds. Attempts have been made to study the dissolution behavior of red muds, which of course, depends upon the chemical composition, for the recovery of metal values in mineral acids of different concentrations.
10:30 am BREAK
11:00 am
EFFECT OF CALCINATION OF PHYSICO-CHEMICAL PROPERTIES OF RED MUD: M. G. Sujana, R. S. Thakur, B. C. Acharya, S. N. Das & S. B. Rao, Regional Research Laboratory, Bhubaneswar 751013, Orissa, India
Physico-chemical studies were carried out on a sample of red mud collected from NALCO, Orissa after calcination up to 1200deg.C at an interval of 100deg.C. The observed change in properties like surface area, particle size, bulk density and mineral phases etc. can be profitably used while finding an appropriate application of this polluting waste from alumina plants.
11:30 am
USE OF RED MUD IN CONSTRUCTION MATERIALS: C. Fernadez, P. Garcia, J. M. Avala, F. Blanco, J.P. Sancho; Departmento de Ciencia de los Materiales e Ingenieria Metalurgica, Escuela de Minas, Universidad de Oviedo, Indepondencia 13. 33004, Oviedo, Spain
Most of the industrial processes generate, at the same time as the principal product by-products or residuals of minor or no economical value. The storage of which represent, from the environmental point of view, problems of different magnitude depending on the type of residual. Solving or minimizing these problems would involve, on one hand the improvements or optimization of the production process, with the purpose of generating the minimum possible amount of such materials for obtaining same profit of them. The residuals utilized in this work are fly ashes from powder stations burning powdered coal and red muds generated in Bayer Plants during bauxite digestion. The possibility of getting construction materials such as "raised or bare face red-brown bricks" or red-brown polishable hard tales has been studied.
ALUMINUM ALLOYS FOR PACKAGING II Session III
Sponsered by: SMD Non-Ferrous Metals Committee and Light Metals Division
Program Organizer: Professor James G. Morris, Chemical & Materials Engineering, Director, Light Metals Research Labs., University of Kentucky, Lexington, KY 40506
Wednesday, AM Room: A2-3
February 6, 1996 Location: Anaheim Convention Center
Session Chairperson: Gyan Jha, ARCO Aluminum, Inc., 2900 First National Tower, P.O. Box 32860, Louisville, KY 40232
8:30 am Invited
THE INFLUENCE OF ALLOYING AND PROCESSING ON THE DEEP DRAWING PERFORMANCE OF FOOD CAN MATERIALS: S.E. Naess, Hydro Aluminium, N- 3080 Holmestrand, Norway
The effect of some variations of processing parameters as well as alloy selection on the stretch formability and earing behaviour are illustrated by using industrially fabricated cans. Stretch forming fracture problems may be experienced in the upper part of the corner region in the second step of two- step deep-drawn conical rectangular cans. Of the two alternative alloys, AA3005 and AA5050A, the problem was confined to the latter, even though this alloy has the best work hardening properties as sheet metal. However, by tensile testing, a much more pronounced decrease in the work hardening for the 5050A compared to 3005 was measured after the strong predeformation (first draw). Flange cracking may also be a problem with rectangular cans. The defect is avoided by using a material with not a too highly developed deformation texture. Round cans produced from Al- Mg- alloys may develop ears parallel to the rolling direction. By adding Mn, the Al- Mg alloys may change to low 45[[ring]] earing materials. The rivets of easy open ends are produced by biaxial stretchforming, and alloys from the 3000 series exhibit superior properties compared to 5000 series alloys.
9:00 am
COMPUTER ASSISTED METALLURGY FOR PACKAGING ALLOYS: C. Sigli, H. Vichery, Pechiney CRV, BP 27,38340 Voreppe, France
A software has been developed in order to predict the yield strength of 3000 and 5000 alloys as a function of the process parameters. The main subroutines perform the calculation of:
* microstructure in the as- cast, homogenized and hot rolled conditions,
* yield strength as a function of microstructure and cold rolling reduction,
* yield strength as a function of the baking treatment.
A graphic module enables to readily visualize the stress- strain curve and recovery kinetics of a given alloy. An inverse modeling module (simplex method) has also been implemented in order to perform backward calculation, i.e. to optimize alloy composition and rolling parameters as a function of the required properties. Several examples of application will be demonstrated.
9:20 am
NUCLEATION AND GROWTH OF RECRYSTALLIZATION IN AN Al- 1Mn ALLOY DURING THERMOMECHANICAL PROCESSING: P.L. Orsetti Rossi, C.V.G. Industria Venezolana de Aluminio, C.A., Zona Industrial Matanzas, PO BOX 302, Puerto Ordaz, Venezuela; C.M. Sellars, The University of Sheffield, Department of Engineering Materials, Mappin Street, Sheffield S1 3JD, UK
A procedure based on quantitative optical microscopy has been used to investigate nucleation and growth of recrystallization in hot rolled and annealed Al- 1Mn (AA3003) as a function of strain (0.4- 0.71) and temperature (420[[ring]] C and 460[[ring]] C) at a constant mean strain rate of about 5 s- l. Despite the experimental scatter, site saturation seems to be a reasonable approximation for modelling purposes. During recrystallisation, the average growth rate decreases continuously probably due to concurrent recovery in the unrecrystallised fraction although the magnitude of the reduction suggests that a non uniform distribution in stored energy and concurrent precipitation must also play an important role.
9:40 am
SINGLE STEP PREHEATING OF AA3104 CAN BODY STOCK INGOTS: Scott L. Palmer, Ravenswood Aluminum Corporation, P.O. Box 98, Ravenswood, WV 26164; Zhong Li, Light Metals Research Labs., Dept. of Chemical and Materials Engineering, University of Kentucky, 177 Anderson Hall, Lexington, KY 40506
Comparison of a single- step versus two- step (controlled cooling) preheating practice has been investigated for AA3104 can stock ingots. Earing and tensile tests performed on final gauge H19 sheet revealed that earing tendencies were very similar for both processes, while tensile properties were slightly lower for the single- step practice. The difference in tensile properties was correlated to a difference in Mn supersaturation. Manganese precipitated in the form of a fine (<1 um) second phase dispersion was found to be a more effective hardener than if it was retained in solid solution. Texture development in the single step preheated material followed a different path than the two step process, but with the same final earing result in the H19 sheet. Manganese dissolution curves were developed for a variety of thermal histories based on resistivity measurements.
10:00 am BREAK
10:20 am
A TECHNIQUE TO MEASURE INTERMETALLIC SIZE DISTRIBUTION IN ALUMINUM CAN BODY STOCK: X. Wang, Corporate R&D, Reynolds Metal Co., Muscle Shoals, AL 35661; R. G. Kamat, Corporate R&D, Reynolds Metals Co., Richmond, VA 23261
Quantification of the intermetallic constituents in aluminum alloys is important in evaluating the metal performance during fabrication of products. For example, in aluminum D&I can body alloys the intermetallics play an important role in cleaning aluminum build- up on the ironing dies during the can- making process. On the other hand, beyond a certain size these constituents could potentially contribute to the tool wear and/or tear- offs. Hence, optimizing the size distribution of the constituents is very important. Differentiating the intermetallics by conventional etching and metallographic techniques has drawbacks. This technique is time consuming and the results can be subjective due to poor etching response for color differentiation of particles. In this study, a technique for quantifying the intermetallics using a scanning electron microscope coupled with an energy dispersive X- ray spectrometer integrated with an image analyzer is described. The intermetallic phase distribution in aluminum can body alloys is measured in an efficient manner. Particularly, the [[alpha]]-Al12(Fe,Mn)3Si phase fractions and size distributions were determined. The technique has been successfully used for evaluation of industrial homogenization practices and for intermetallic particle distribution in can body sheets from various producers.
10:40 am
BUCKLE STRENGTH LOSS IN 202 DIAMETER BEVERAGE CAN ENDS: M. S. Nagorka, T. C. Sun, Kaiser Aluminum and Chemical Corp., Center for Technology, 6177 Sunol Blvd., Pleasanton, CA 94566
202 diameter beverage can ends show a significant time- dependent drop in buckle strength. This drop, which can be over 83 kPa (12 psi) after 30 days at 38[[ring]]C (100[[ring]]F), is of concern to beverage packagers. This presentation will examine the temperature dependence of the strength loss phenomenon and how different alloys affect the magnitude of the strength loss. The process appears to be thermally activated- - activation energies calculated from strength loss data obtained at different temperatures will be compared with those of mechanisms that might be responsible for the strength loss.
11:00 am
PERFORMANCE EVALUATION OF CANSTOCK ALLOYS USING THE DRAW BEAD SIMULATOR: Jean V. Reid, Rajeev G. Kamat, Corporate Research and development, Reynolds Metals Company, P. O. Box 27003, Richmond, VA 23261
The DBS test has been found useful to evaluate lubrication conditions in the
drawbead during sheet metal forming operations. A study was undertaken to
evaluate the usefulness of this test in differentiating metallurgical, surface
texture, and lubrication conditions for canstock. The test allows the
determination of a friction coefficient under plastic deformation conditions.
In addition, the frictional force can be separated from the deformation force.
In this study, performance in the test is based on friction coefficient and
forces generated during the test as well as an evaluation of drawbead and
sample galling. The performance data is correlated with canstock mechanical
properties, metallurgical structure, surface texture characterization and
lubrication mode.
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