How long doe brick take to drain?

[McGrawMan]

My company is replacing four pickle tanks at a steel mill(each about 100 ft long , that will be cut into five sections each). They are lined with refectory brick, and mortared in between. The tank is filled full of acid (HCl) and will be drained. Our question is how long would the brick take to drain so that the tank will not drip when taking it out the sections?

 

[ACtrafficengr]

Depends on the depth and size of the tank, the drain orifice size and shape, the viscosity of the liquid...

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[Ron]

I would suggest that once you get the liquid HCl out of the tank, that you attempt to neutralize the absorbed HCl remaining in the bricks/mortar with lime or similar base. Refractory brick is generally not very absorptive; however the mortar can be.

 

[bimr]

It doesn't take too long.

 

[kenvlach]

I agree with the neutralization idea. Your tanks probably use acid-resistant, high silica brick per ASTM C279, Type III and either silicate (C397) or organic (C395) acid-resistant mortar. The maximum water solubility for these bricks & mortar is 1 %, so it shouldn't take long to drain. There might be cracks and cavities after years of use, so take precautions for trapped liquid that didn't get neutralized.

 

[jheidt2543]

How are you going to dispose of the HCl? This sounds like a lot of liquid to dispose of and I'm sure it would be classified as a "hazardous material". It might be easier to neutralize the entire quantity of liquid in the tank BEFORE draining it. You are also probably REQUIRED to notify the local authorities (fire department and EPA) PRIOR to starting work.