How much harmfull is copper slag to human health?
Copper slag is the waste product of copper ore smelting. It is normally processed to produce usable grit for sandblasting of metal surfaces. It is extensively used in shipbuilding, ship repair, and other steel fabrication industries. The copper slag is produced by pumping the molten slag against a jet of water. The slag cools into small granules. Copper slag is relatively inert and quite hard but not very brittle so that it is a good material for sandblasting. In fact it could even be recycled for reuse as much as three times before it is becomes too fine to use. While it is true that harmful metals come along with copper ore, most of these metals go along with the product copper concentrate in the smelting so that there is relatively a very small amount of these metals left in the slag. This plus the fact that water is used in the production of the slag, which is tantamount to washing, makes the slag quite safer than using silica sand in the sandblasting of metal surfaces. Nevertheles
It depends what is present in the ore besides copper. It varies a great deal depending on the mine or even which part of the mine. It also heavily depends on the smelting process and waste recovery processes involved. Arsenic commonly occurs naturally with copper, but not always and not in the same amounts. Copper ore may also contain lead, mercury, and uranium – but it might not too. As far as inhalants go, the smelting process probably involves crushing the rock but there are many different recovery methods after that. Each method has a different potential to generate toxic inhalants. At the least, ore dust may cause silicosis. The EPA would have the actual numbers for the mine or smelter you are concerned about.
Someone answered that copper slag is poisonous and harmful to the soil. From my experience, copper slag is used to grit blast steel (to make it clean for subsequent paint application) and I see the material flying over and landing on the ground if blasting is not confined. The site safety engineer did not say anything about its danger. The workers are just instructed to wear dust mask. And by-passing workers with no protection can easily breath the dust.
