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Northern Precision Casting
Replacing 1,1,1-Trichloroethane (TCA)
with Citrus-Based Solvents |
| Standard Industrial Classification
(SIC) |
Investment Casting/3324 |
| Process |
Solvent cleaning of wax pattern assemblies
used in the investment casting process. |
| Type of Waste |
Fugitive emissions of 1,1,1-Trichloroethane
(TCA) |
| Strategies |
Material Substitution - Solvent Replacement |
| Background |
Northern Precision Casting (NPC) is an
investment casting operation located in Lake Geneva, Wisconsin. NPC employs over 150
people and casts more than 200,000 pounds of metal in a month. The
casting process at NPC involves pouring molten metal into ceramic molds. The ceramic molds
are made by coating a wax pattern assembly with ceramic material. In order to have the
ceramic coatings adhere to the wax material, it is necessary to clean the wax surfaces.
NPC cleaned the wax assemblies by washing them in solvent
1,1,1-Trichloroethane (TCA). The TCA would then evaporate leaving a clean wax surface for
the ceramic coating process. NPC had TCA emissions of 18000 pounds (1988) as a result of
this process. |
| Motivation |
Northern Precision Casting was motivated to
change by the concern for environmental regulations pertaining to their TCA emissions. |
| Changes Implemented |
Northern Precision Casting told it's
solvent manufacturer that they wanted to eliminate TCA from the wax cleaning process. The
manufacturer suggested Freon as a substitute until a more suitable alternative could be
identified. NPC went along with the freon substitution on a temporary basis since the
emission levels were less than the TCA material. NPC used freon for six to nine months
before the chemical manufacturer provided a citrus-based non-hazardous solvent. The
citrus-based solvent has been very effective in cleaning the wax assemblies. |
| Problems Encountered |
There was significant concern about the
potential impact of the change on product quality. However, after the solvent
substitution, no change in quality was encountered. Initially, the citrus-based solvent
had an odor that was offensive to the workers. This problem has been resolved. |
| Material/Energy Balance |
Original Process Feedstock
Trichloroethane (TCA) - 18,000 pounds (1988)
Waste
TCA fugitive air emissions - 18,000 pounds (1988)
Disposal
Released from plant as fugitive air emissions
Pollution Prevention Approach
Feedstock
Latrex citrus-based solvent
Waste
Water-soluble liquid waste
Disposal
Discharged to Publicly-Owned Treatment Works (POTW) |
| Economics |
Capital Cost
No capital cost was involvedOperating/Maintenance Cost
There was no significant change in O/M cost.
Payback Period
Not available |
| Company Address |
Northern Precision Casting
Hwy. 36 N./P.O. Box 580
Lake Geneva, WI 53147 |
| Contact Person |
Mr. Jerrie Brown,
Vice President - Operations
Phone: 414/248-4461 |
| Additional Publications available
from Pollution Prevention Clearinghouse |
Aqueous Industrial Cleaning Chemicals
DNR Publication #SW-147Aqueous Parts Washing Equipment
DNR Publication #SW-148
GE Medical Systems Case Study
DNR Publication #SW-168 |
| Pollution Prevention Resources |
Free, On-site Technical Assistance
University of Wisconsin Extension
Solid and Hazardous Waste Education Center
Milwaukee area: 414/475-2845
Remainder of state: 608/262-0385Pollution Prevention
Clearinghouse
Wisconsin Department of Natural Resources
Hazardous Waste Minimization Program
608/264-8852, 608/267-9523 or 608/267-3763 |
 |
Bureau of Cooperative Environmental Assistance
Wisconsin Department of Natural Resources
P.O. Box 7921
Madison, WI 53707
608/267-9700
PUBL-SW-161 95 |
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