Improving environmental performance while keeping regulatory compliance costs at a minimum is one of the key challenges affecting the future competitiveness of metalcasters.

Table 1: Major Environmental Statutes Affecting U.S. Foundries

Environmental regulations are expected to become increasingly strict over the next two decades and will have significant impacts on metalcasters in terms of cost and economic viability. Surveys of U.S. foundries indicate that environment, health, and safety issues -- and the regulations that govern these areas -- are the top concerns facing the future of their businesses.

Sand casters face major environmental issues related to treatment and disposal of spent sands that may be contaminated with toxic or hazardous wastes.

Technologies that reduce or eliminate waste and improve performance will greatly enhance the future success and world-wide competitiveness of the industry. Some new technologies and materials are being investigated, including non-toxic binders, sand reclamation systems, and air and water purification systems, all of which have made important contributions to cleaning up metalcasting processes. In addition, metalcasters have been working with some success to develop new alloys that have less environmental impacts (e.g., alternates to lead-bearing copper alloys).

The long-term targets to improve its overall environmental performance and to become publicly recognized for responsible environmental management practices are:

Some people believe a target of 100% pre- and post-consumer recycling is probably unrealistic. The reasoning here is that the theoretical maximum is closer to 95%, and achieving the theoretical maximum recycling rate would be difficult and costly.

In addition, to reduce confusion about "eliminating" waste streams, an alternative goal of achieving "zero discharge" levels has been proposed. So most "waste" materials should be processed and beneficially reused.

Many of the impediments to the environmental progress of the metal casting industry are associated with the fractionated, small-business nature of metalcasting. It has been difficult for small businesses to invest in R&D and long-term goals (e.g., eliminating waste streams entirely, or increasing recycling of foundry products).

Environmental technology barriers that currently prevent the industry from achieving its environmental goals have been identified. These barriers are categorized as:

The ability to develop effective approaches to environmental problems must be based on a comprehensive characterization of foundry waste streams, an analysis which has not yet been performed. A full characterization could identify missed opportunities for beneficial reuse of waste and help overcome the concern of potential users of the waste byproducts.

There is a severe lack of data on foundry emissions and currently used and best available control technology. For example, if data were available to adequately assess the environmental impact of mold/core binders or other sand additives, the environmental impact of the casting process could be optimized while at the same time maintaining world-class quality for castings. Data to properly select the technology to produce or deliver molten metal to molds would minimize the environmental impact of the casting process while at the same time maintaining world-class quality for castings.

Waste utilization barriers include a lack of knowledge of the potential uses of foundry residuals as substitutes for other raw materials and the lack of viable uses of waste streams. The large number of alloys used makes post-consumer recycling more difficult, compounded by the lack of a comprehensive materials identification system. In addition, no economical technologies currently exist to recover usable waste oil and zinc from water.

Foundries are adversely impacted by provisions that pull inert materials into a hazardous waste regulatory framework. Certain RCRA provisions (e.g., restrictions on scrap metal consumers, new requirements for industrial non-hazardous waste, mandated toxics use reduction) could discourage the beneficial re-use of non-hazardous materials.

Long-term changes in the composition and manufacturing practices of the metalcasting industry make the identification and application of environmental solutions a moving target. The industry should consider developing effective and resilient strategies for the application of pollution prevention technologies to respond to both long-term environmental and market needs.

Many of the barriers listed under waste utilization are also technological barriers, such as the separation of zinc and waste oil from water. Some additional technological barriers include the lack of technologies for recovering low-temperature waste heat from metalcasting processes and the inability to die cast aluminum without using lubricants because of problems with sticking.

The institutional side of environmental management also presents barriers to environmental technology improvements. For example, regulatory requirements are often shaped by social, not technical, considerations. An important crosscutting barrier to achieving the industry's long-term goals in environment as well as other areas is the lack of a technically educated work force.