EPA P3 Project

EPA P3 Project

Microtox Presentation

Microtox Presentation

University or Arizona Presentation

University or Arizona Presentation

Red Mud Poster

Red Mud Poster


 

Project Objectives

Aluminum is a packaging material that is almost 100% recyclable at an infinite number of times, using only 5% of the energy it takes to produce it the first time. In its production from bauxite ore, the Aluminum is extracted using a highly basic caustic solution, and the spent ore (tailings) is a red caustic particulate material that poses risks to human health, to the groundwater, livestock, and to the natural and built environment. This project aims to address problems associated with the existence of repositories of bauxite tailings by treatment with neutralizing polymer surfactants. It also aims to address the longer term problem of the reuse of bauxite tailings as a source of useful products.

Project Description

The unique technical approach of this proposal involves the use of reactive biodegradable vinyl acetate-acrylic acid (VA-AA)-based copolymer materials that were co-developed by Michigan Technological University and National Starch and Chemical Co. of Bridgewater, New Jersey, function simultaneously as cleaning surfactant, fast caustic neutralizer, binder, and coupling agent for facilitating reuse of dried red mud powder.

This proposed project would improve the sustainability features of the continued use of Aluminum in recyclable food contact packaging, consumer product, and lightweight structural/ decorative applications. It is a material of choice in modern society due to its high strength- to-weight ratio, natural corrosion resistance, excellent workability, and ability to accept a wide range of finishes. Aluminum is also an excellent material choice for sustainable construction. It is the most abundant metallic element in the earth’s crust, and can be infinitely recycled without degradation of properties. Its high scrap value and well-established recycling infrastructure make it the most frequently recycled metal, so much so that more than 70% of the aluminum ever produced is still in use today.

Addressing the fate of waste materials from the extraction of Aluminum from bauxite ore through the proposed project/design is needed to complete the sustainability characteristics of the use of Aluminum as packaging, structural and decorative material. This is especially true in light of recent events in Hungary in the fall of 2010 when a red mud repository caused several deaths and massive ground and structural contamination.

The education plan for this proposal involves a number of activities. Three of the members of the student team are also members of the Undergraduate Scholars Program at Michigan Tech, in which the PI will be advising from the fall of 2012. Whether this proposal is funded or not, the project has been available for participation from the 15-member undergraduate scholars group and will continue to be so. We have been quite aggressive in educating the university/local/national/global communities about this project and will expand our promotion of its benefits to K-12 schools and community colleges.

Summary of Findings

The team was able to efficiently treat red mud particulates with un-neutralized VA-AA copolymers, down to a VA-AA solid composition of 4.5 wt % relative to total solids, with calculated cost of bulk manufacture of VA-AA at $1.29/lb. This validation was based on Microtox-based aquatic toxicity studies of accelerated leaching of water from treated red mud material. Apparent success application of treated red mud is its use in paint formulations, such as polyurethane and polyacrylic paints. The other apparent successful application is the use of treated red mud as filler material in recycled polymer matrices, such as ABS, PVC or Vinyl, PET, Nylon, etc. Also, the team was involved in a newly discovered application area of the treated red mud, as water superabsorbent gel, wherein the product has been shown to absorb 5X its weight of water. Related to this is the possibility of generating thickened gels for possible application in drilling muds and even in hydraulic fracturing. On the negative side, we found that the treated red mud with the VA-AA copolymer was found to deteriorate mechanical properties of inorganic-based cements.

Conclusions

The red mud hazardous solid waste at the relatively pH of 13 has been effectively treated with un-neutralized VA-AA copolymers, and can be used economically in paint formulations and recycled polymer composites. A newly discovered application area of gels and thickeners have been realized in this Phase I project, is of great interest to industry.

P3 Project Downloads (.PDF)

Executive Summary

Project Scope