white powdery substance
white powdery substance
(OP)
I found a light white powdery substance with a pH of 13 on a Phase I ESA site. The powder does not react with HCl. Any ideas as to what the powdery substance is? The site used to manufacture acetylene in the 70's.





RE: white powdery substance
One of the waste products from acetylene is a lime sludge. The lime sludge is usually neutralized with waste acid to form calcium sulfate.
The principal raw materials for acetylene manufacture are calcium carbonate (limestone) and coal. The calcium carbonate is first converted into calcium oxide and the coal into coke, then the two are reacted with each other to form calcium carbide and carbon monoxide:
CaO + 3C ? CaC2 + CO
Calcium carbide (or calcium acetylide) and water are then reacted by any of several methods to produce acetylene and calcium hydroxide.
CaC2 + 2H2O ? Ca(OH)2 (waste) + C2H2 (acetylene)
Ca(OH)2 + H2SO4 ? CaSO4 + H2O
http://www.answers.com/calcium%20sulfate
http
RE: white powdery substance
One of the waste products from acetylene is a lime sludge. The lime sludge is usually neutralized with waste acid to form calcium sulfate.
The principal raw materials for acetylene manufacture are calcium carbonate (limestone) and coal. The calcium carbonate is first converted into calcium oxide and the coal into coke, then the two are reacted with each other to form calcium carbide and carbon monoxide:
CaO + 3C -> CaC2 + CO
Calcium carbide (or calcium acetylide) and water are then reacted by any of several methods to produce acetylene and calcium hydroxide.
CaC2 + 2H2O -> Ca(OH)2 (waste lime) + C2H2 (acetylene)
Ca(OH)2 + H2SO4 -> CaSO4 + H2O
http://www.answers.com/calcium%20sulfate
http
RE: white powdery substance
Perhaps, the pH value is not from a representative sample. Or maybe the material is a mixture of calcium sulfate and lime.
Some time ago I worked at a plant where the byproduct lime waste was given to a neighboring facility where it was used to neutralize excess waste acid from refrigerant manufacturing.
RE: white powdery substance