C2769 - Barclay Engineering Ltd - Wellington Region

Summary
As a result of a number of no and low costs CP options, Barclay Engineering saves over $10,000 per year.

Business Profile
Barclay Engineering Limited manufactures plant of electrical and plumbing fasteners and fittings and employs 40 staff. The company designs and manufactures a range of 2000 to 3000 products by metal stamping and pressing. Products are manufactured from brass, copper, aluminium, steel and stainless steel.

Type of Project
Water-based coolant, recycling of metalworking fluid through centrifugation, bath lids to control evaporation, water-based cleaning of aluminium parts, recycling of 111-trichloroethylene, treatment of sludge with cement.

Reasons for Project
Barclay Engineering Ltd was interested in improving the environmental performance of the business, by formally addressing CP opportunities.

The Project

Water-based coolant

Details	A working fluid is required for cooling and lubrication. A water-based metal working fluid rather than an oil-based fluid is used for the machining of brass, copper and aluminium. This green coolant consists of 60-80 parts water (acting coolant) and 1 part oil (acting lubricant). Oil consumption is reduced with 1,400 L per year (1,600 oil based coolant used previously compared to 200 L green coolant base oil now). Chemical consumption in subsequent metal cleaning steps is also reduced but could not be quantified. Note that water-based fluid is only used for metals that are machined on capsums. The machining of steel, stainless steel and aluminium takes place automatically and requires straight cutting oil.
Economics	Economics Savings are $ 1,793 ($2,080/1,600 L oil based coolant - $287/200 L green coolant). No costs involved.
Benefits	Benefits Reduced coolant consumption. Reduced chemical consumption in cleaning phase.

Recycling of metalworking fluid through centrifugation

Details	Cutting oil is used for metals fabricated on automatic machines. Some oil attaches to metal fines. As the metal fines are contaminated with oil they are not accepted for metal recycling. A centrifuge was purchased from a drycleaner and is used to centrifuge the oil from the fines. A timer was installed to standardise centrifugation times. The oil is reused and the metal fines are recycled off-site. Annual oil consumption is reduced by 4,095 L or thirty six 25 gallon drums (from 5,460 L to 1,395 L). Metal waste reduction was not determined.
Economics	Savings: cutting oil 36 drums X $220/drum = $7,920 per year. Reduced waste disposal costs (metal fines) One-off costs: $450 for purchase centrifuge, $150 for timer. Ongoing costs: electricity for centrifuge 8,831 X $0.10/kWh = $883 per year.
Benefits	Reduced cutting oil consumption. Reduced metal waste

METAL CLEANING PROCESSES

Water-based cleaning of aluminium parts

Details	Water is used for the cleaning of aluminium instead of kerosene, after it was determined that the same results were obtained. The consumption of 200 L kerosene per year is eliminated.
Economics	Economics Savings of kerosene are approximately $800 per year.
Benefits	Elimination of kerosene consumption and emissions. Improved health and safety conditions for employees

Bath lids to control evaporation

Details	Evaporation takes place from cleaning baths, especially 111-trichloroethylene and caustic soda, because the chemicals are volatile and baths are heated to 80-90oC. A lid was already used for the 111-trichloroethylene bath and has now also been installed on the caustic soda and chromic acid baths.
Economics	Savings of cleaning bath chemicals could not be determined. One-off costs: $10 ($5 per lid).
Benefits	Reduced emissions to the atmosphere. Reduced chemical and water consumption for cleaning baths. Improved health and safety conditions for employees.

Recycling of 111-trichloroethylene

Details	As a result of metal cleaning, 111-trichloroethylene (111-tri) baths become contaminated with metal fines, dirt and water from previous rinsing. Each year 300 L of 111-tri is recycled onsite through distillation. Less chemicals are used and disposed of as trade waste.
Economics	Savings on 111-tri are $961 per year. Costs for the distillation system are $460. The payback period is 6 months
Benefits	Reduced 111-tri consumption and costs. Reduced trade waste.

Treatment of sludge with cement

Details	Approximately 3 kg of sludge is accumulated annually from the metal cleaning baths. Amounts of less than 5 kg can be disposed of as solid waste at the landfill. However, it is likely that the sludge contains metals and acids, even though concentrations have not been determined. Sludge used to be rinsed with water prior to disposal to remove contaminants, creating a contaminated wastewater stream. To treat the sludge prior to disposal one shovel of cement should be mixed with each kg of sludge to fix metals and neutralise acids. This will work effectively where the pH is higher than 3.
Economics	Costs: $10 year for 40 kg bag cement.
Benefits	Reduction of chemicals discharged to trade waste. Compliance with trade waste bylaws.

For additional information contact:
Arthur Barclay,
Barclay Engineering Ltd,
PO Box 35019,
Naenae,
Wellington
Ph 04-5676500
Fax 04-5679345

For further information about Cleaner Production in the Metal Industry see:

Opus International Consultants (September 1997): Cleaner Production Guide for the Metal Industry- Minimising waste, reducing costs and caring for the environment.