Powders for metallurgy

Metal powders are mixed with other ingredients to produce a uniform composition. Lubricants include stearic acid, stearin and metallic stearates, particularly zinc stearate.

The powder mix is compacted under pressure into the required form in a rigid steel or carbide die at ambient temperature. The compact maintains shape through the cold welding of the powder.

What you must do

Powder blending and compacting can have significant impacts on air quality and can cause noise pollution. You may need to take measures to control emissions to air and noise from your premises.

Air quality

You must comply with your duty of care responsibilities when dealing with waste.

Duty of care - your waste responsibilities

If the material that you are handling has hazardous properties, you may need to deal with it as hazardous/special waste. Examples of substances that may have hazardous properties include:

• obsolete zinc stearate
• zinc and copper
• lead flue dusts
• lead drosses.

Hazardous / special waste

Good practice

• Contain and cover powders to avoid producing excessive amounts of dust.
• To prevent dust blowing around your site, collect excess powder from the ejection of compacts from the die. Collect the powder in containers placed as close to the source as possible.
• Locate presses as far away as possible from the site boundary. It may be necessary to contain presses in acoustic booths. This will help you to prevent causing a noise nuisance.
• Keep doors to the factory closed to contain noise and reduce draughts that could blow powder around.
• Contact your local plastics recycler to arrange collection of your nylon powder bags.
• Carefully inspect compacted parts so that you can recycle obvious rejects before sintering.