Is it possible to safely clean an asphalt storage tank for water-based emulsion?

[RonL]

I have looked everywhere i can think of trying to find information on how to clean a tank that has been used to store water based emulsion.
The tank measures 10.5' X 30' and by rough calculation holds around 18,000 gallons of liquid.
I took a hard chunk of the material and put a torch to it, it seemed to melt, but would not continue to burn.
There is about 25 gallons of thick, but still liquid material that needs to be removed from each side (it is a center divided tank).

I,m not sure how to make best use of the tank (there are several options) but i do need to assure that it will be safe to weld on or cut into at some time in the near future, i can use steam, and if needed, fill it with water. Whatever process is used i need study material, in order to proceed with safety.

Thanks in advance for any information

RonL

 

[chemisttree]

Put a strong surfactant in it such as polyethoxylated nonylphenol (ethoxy = 8-12 units per nonylphenol) and heat the tank while agitating/spraying the stuff in. Use enough to produce about a 50% solution of asphalt so you will need about 55 gallons of it. Don't use an aqueous solution of it... use it straight. When you have dissolved everything off the sides, add water slowly with agitation and pump it out. Dispose of as hazardous waste.

 

[RonL]

Thanks chemisttree
Something to start studying, i have very little knowledge about chemicals, will this produce a foam reaction?
I have a loader large enough to lift each end of the tank, if i crib it up, i might be able to get the two manholes, bottom dead center and high enough off the ground to collect the last of the liquid, i would then only have to clean the film coating on the walls.
I have an air agitated paint pot, and would hope this will work for the spraying of the material. You mention heat, how hot would this need to be ( the summer sun will get to around 130 degrees F. maybe a little more ) starting to sound like a hot dirty job.

There is a chemical company i can use, so i need to get the rest of my information from them and the data sheets.

Thanks again

Ron

 

[chemisttree]

Thanks chemisttree
Something to start studying, i have very little knowledge about chemicals, will this produce a foam reaction?
I have a loader large enough to lift each end of the tank, if i crib it up, i might be able to get the two manholes, bottom dead center and high enough off the ground to collect the last of the liquid, i would then only have to clean the film coating on the walls.
I have an air agitated paint pot, and would hope this will work for the spraying of the material. You mention heat, how hot would this need to be ( the summer sun will get to around 130 degrees F. maybe a little more ) starting to sound like a hot dirty job.

There is a chemical company i can use, so i need to get the rest of my information from them and the data sheets.

Thanks again

Ron

The asphalt should knock down the foam pretty well. Definitely remove as much of the residue as possible before starting. Steam might be a good idea for cleanup followed by (much less of) the surfactant. The undiluted surfactant will behave as a solvent for the residue. I was thinking of recirculating the soap/asphalt residue to affect cleanup. Definitely not spraying it with a paint sprayer... more like a garden hose or Vylon hose attached to a diaphram pump. You could try a Witco Desonic 1.5 N or Rhodia's Igepal CO. If environmental concerns are present, substitute these with biodegradeable ethoxolates such as Neodol 1-3 (Shell) or Surfonamide TD-2 (Huntsman). If those are too expensive, you could try biodiesel. It is only ~$3.25/gallon and should solubilize tar fairly easily.

 

[RonL]

Thanks
I do have a Teel diaphragm pump, i once used it to spray water based organic bug spray on my yard with a regular garden hose and sprayer, it moved around 30gpm with pressure to spray almost 60'.
Setting up a good drain system, i could wash to my hearts content.
It will be easy to set up a spark free operation, and after removing the emulsion, a good wash down with soapy water should take care of the job. It might involve some risk, but it is within my area of experience, and i am cautious to an extreme.