Re: Gravure & Sulphur Polution
Bas van Velzen (eland@knoware.nl)
Sun, 18 Aug 1996 22:12:05 +0100
>On Sat, 17 Aug 1996, Bas van Velzen wrote:
>
>> if I remember correctly this blue staining of the copper can be
>> caused by ammonia in the air. Was the workshop near the countryside? Dung
>> is a fine producer of ammonia (resulting in acid rain).
>>
>
>Ammonia is basic, and counteracts the effects of acid rain. Acid rain
>comes from burning sulfer containing compounds (in coal and oil)
>producing sulfer dioxide and then sulfuric acid. Ammonia in the soil and
>air will raise the ph.
it is true that ammonia (NH4OH)is basic, it is a gas dissolved in water.
But under the influence of light (UV) and other pollutants in the air it is
the provider for NOx that is very acid (like in HNO3, nitric acid: the
stuff you (can) use to etch your platen with).
Bas
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