CASE STUDY: Kennametal Inc.

Location: Henderson, N.C. (Warren County) Industry: Manufacturer of Carbide Powders (SIC code 2819) Pollution Prevention Application: Product Substitution, Equipment/Process Change Waste Reduction: 50,000 pounds emissions, 50 percent to 70 percent reduction in n-hexane emissions, 5-10 tons/year waste containers Annual Savings: $121,500 Payback Period: Less than two years Contact: Robert McGee, (252) 430-3303

Background Kennametal is a global manufacturer, marketer and distributor of a broad range of tools for the metalworking, mining and highway construction industries. Kennametal is one of the leading producers of cutting tools and wear-resistant parts made of cemented carbides and other hard materials. Kennametal’s Henderson Plant produces metal powders that are used at other Kennametal sites to produce metal-cutting tools. The processes at the Henderson plant include production of tungsten metal powder, carburizing tungsten metal powder, weighing powders, blending powders, milling and drying powders, and packaging finished graded powders for shipping. Waste reduction activities have focused on tungsten metal powder production, milling and drying, and packaging.

Waste Reduction The tungsten production process previously used paratungstate. Activities Testing was conducted on tungsten to compare the quality of the tungsten metal produced from the oxide. The results showed comparable quality, and the tungsten oxide was gradually introduced.

Solvent replacement was done for an n-hexane-based solvent used in the milling and drying process. The new solvent has less than one percent n-hexane, significantly reducing emissions, though the new solvent costs 15 percent more.

Automated packaging equipment was purchased to package the finished powders into three-kilogram aluminum containers. These containers are ergonomically friendly to both the packaging personnel and the customer plants where the powder is used. There has been a significant reduction in labor, a decline in worker exposure, and the elimination of scooping powders from larger bins, reducing spillage at customer plants. The aluminum containers are returned to the Henderson plant, where they are shredded and sent to a sister plant to be recycled in a thermic process. This has eliminated waste polyethylene containers and waste plastic bags while reducing space requirements for the packaging process.

Waste Reduced By converting to a tungsten oxide, ammonia emissions have been reduced from 50,000 pounds to 27,000 pounds the first year, and since January 1999, ammonia emissions have been totally eliminated. The solvent substitute used in the milling and drying process led to a 50 percent-70 percent reduction in n-hexane emissions.

1999 Case Study SIC 2819

Annual Savings Although the cost of the tungsten oxide is slightly higher than the previously used ammonium paratungstate, the cost is offset by savings associated with reduced utilities, nitrogen process gas, labor and increased productivity, resulting in a projected annual savings of $35,000. The solvent substitute used in the milling and drying process costs approximately 15 percent more than the previously used solvent. The packaging system previously used cost an average of $0.227 per kilogram of powder. The new packaging system costs an average of $0.104 per kilogram of powder. The annual savings are estimated at $86,500 per year. The payback period for the new equipment was less than two years.

1999 Case Study SIC 2819