# Poor man's AR



## hosef (Mar 3, 2009)

Hi again. I was wondering what I should do to the by products of the poor man's AR before I dispose of it.


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## goldsilverpro (Mar 3, 2009)

> I was wondering what I should do to the by products of the poor man's AR before I dispose of it.



This is sort of an iffy question. It depends on what you mean by "disposing of it." I assume you mean to get it to a point where you can legally put it down the drain. This may depend on the state you live in.

I don't know exactly what the criteria is. I know you can't dump solutions that contain heavy metals, such as copper or nickel. The solution can't have a too high or too low pH. Beyond that, I don't know.

The heavy metals can be precipitated as a compound with chemicals such 

The heavy metals can be precipitated from an acid solution, as metal powder, by either iron (steel) or aluminum. The pH will tend to rise, as the excess acid eats the Fe or Al. The ideal result is an Fe or Al solution, containing no heavy metals, whose pH is within the legal limits.

I know that Fe or Al solutions are fairly innocuous. However, I don't know the criteria for dumping them. The Fe or Al can be precipitated as hydroxides by raising the pH to 9. The precipitate, however, is slow to settle and very difficult to filter. Aluminum hydroxide may never settle.

There is much info on the forum about waste treatment, but I don't feel that an exact procedure, considering the legalities, has ever been laid out. It definitely should be done. It may be iron - filter (or, not) - pH to 9 - filter. I hope someone else can chime in.

I usually paid to have my toxic waste hauled off by a legal hauler like Univar, but you need a lot of volume. About 5 or 6 years ago, they picked up our raw acid wastes (aqua regia, nitric, etc.) in Houston for less than $1/gallon. Cyanide was $1.25. In Missouri, it cost about $7 a gallon for acid wastes by the same company. Once, in California, a company picked up our raw acid wastes for nothing. We were told it was used to "flush" oil wells.


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