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  for Metal Finishing since 1989
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Removal of silica from effluent

2003

Dear readers,

I've learned things about the posts I've found there . Right now I'm doing my master thesis on removal of silica from effluents of an electronic industry, should someone can give me any further indication about this topic or a list of publications to consult would be great.

Thanks

Ndiaye
student - France

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2003

Hi Ndiaye,

Re your silicate problem, may I suggest that whatever you do, you initially take out the bulk of the solids by using a very, very simple method.

I applied this design to Assay labs where the acid effluent goes for treating/neutralization BUT where macro solids of valuable metals, sic. gold, can be easily collected because they will SETTLE, without being disturbed on the bottom of that tank.

1. Get a medium sized round but fairly tall open top tank made, say, from rotationally moulded Polyethylene.

2.Install an outlet (going to the next stage or the neutralization) about l foot below the top of that tank.

3.Ensure that the inlet feed pipe is a few inches, say 6", BELOW the liquid level ... which is anyhow determined by the outlet location. This is to protect the filter mechanism and avoid turbulence inside that settling tank.

4.Make that outlet pipe vastly oversized, say 6" diameter, and have it extend into the tank by 4" or so. Then on the outside of the tank reduce the outlet to a much smaller size, add on a 90 degree bend so that any effluent will drip/pour into the (neutralization?)tank below it.

5.For that overly large inlet, get/make a cap to give a sloppy fit and then cut out a LARGE hole in it. This is so that it will easily slide fit over the inlet pipe.

6.Then get some el-cheapo thin cloth, what we might call a kitchen Terry cloth, and wrap it around the end of the pipe, fit on the cap ... and, if necessary, use a single stainless steel screw to hold the cap in place.

7.You now have a retention tank where any solids will drop down to the bottom without being disturbed ... and where the 'filter mechanism' is easily accessible, very inexpensive but very efficient.

This design, in case you didn't know it, is called using the K.I.S.S. principle .. Keep It Simple Stupid ! ... and it works, too.

This is a preliminary knock-out collection device to allow the settling of any solids in the effluent. The top inlet feed pipe should NOT be open and pour into the tank, but immersed BELOW the liquid level by a few inches in order to improve the settling OUT of any solids in the bottom of the tank.

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).