A laboratory accelerated leaching test was carried out on the treated cubes to determine the amount of copper leached
as a percentage of the initial copper retention following protocol E11-97 described in the American Wood-Preservers' Association book of standards (AWPA 2002) with some slights modifications, as described below.
Analysis of nitrogen in the leached
blocks and solid chemicals.
Black spruce, jack pine, and southern pine CCA-treated lumber exposed to natural rainfall for about 1 year in Toronto, Canada, leached
CCA components in the ranges: 7.
When that glass was crushed to pieces less than 5 millimeters in diameter, it had the largest surface area and leached
the most--often tainting water with 400 mg/l lead.
Previous studies at West Virginia University (3,4,6,7) and elsewhere (5,8,10) have indicated great variability in the amounts of copper, chromium, and arsenic leached
from CCA-treated hardwoods in comparison to softwoods.
Last year, a study conducted at the University of Granada in Spain concluded that hormone-mimicking compounds leached
into saliva from a plastic resin used to protect pits and fissures on tooth surfaces against cavities.
The results also showed that the AFS leach test did indicate qualitatively the species likely to be leached
from the wastes tested in the small landfills.
Lower grade mineralization being crushed to 3/8" to 1/2" and heap leached
with recovery of the gold again by CIP or similar methods.
Though none of the leachates would present a great environmental threat according to present criteria, upon reviewing Table 2 it can be seen that two binder systems are more likely to be of concern than the others, both from the number of compounds leached
and the concentrations of the compounds.
Cisterns also removed metals in rain or leached
from rooftop collectors, precipitating them into their tank sediment.
A central elongated leached
breccia pipe, abutting the main zone to the north, with approximate dimensions of 1800 metres long by 225 metres wide consisting of fragments cemented with quartz and limonite suggesting a 5 - 10% sulphide content prior to leaching.
EPA's proposed Toxicity Characteristic Leaching Procedure (TCLP) was chosen to leach the samples because it is likely to be adopted by the EPA for determining the toxicity characteristic and allows the sample to be leached
without the loss of volatile organics.
Geologically speaking, this is significant in that a leached
cap can overlie enriched copper mineralization.
These two sets of samples were column leached
for 100 days.
One thousand grams of the sample were then leached
in an aqueous sulfuric acid solution for 24 hours.