After the cementation is done, don´t forget to brush that copper pipe - some values tend to stick to the surface and they don´t fall off on their own, or with just rinsing.
Be aware that in mining waste solutions, mercury and arsenic could be present as well - and these are severly toxic. If you immerse copper pipe to the solution, mercury will precipitate from the solution together with other values.
If you aren´t sure, never smelt the cemented metals. Rather dissolve them again in AR and proceed from there. By doing this, you circumvent possible mercury volatilization during heating and smelting.
Stay safe
Thank you for the advice
let me tell you the process that i was doing and the ore that i was use it.
and let see what you guys are thinking about
I was use a very rusty Rhyolite
i pulvurize and put the material in a beaker with sulfurix acid and a bit of distiled water
heated but not boiled for 40 minutes
in open air outside my home
let cool down,decanted the solution
washed the material several times
them i put aqua regia
with little nitric acid enought for the process
and few drop of sulfuric acid
them heated but not boiled for 1 Hour
let it cools down and cotton filter
twice
after that i separate it in two parts
i put one part with the copper pipe and the other part
i save it until i know i good process to get the value of it.
i apologize for english
i still learning