When In Doubt, Cement It Out _cementation_

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Thanks FrugalRefiner for your information
I have questions about testing
1- Some time When i use tin chloride to test pregnant AR solution it gives dark purple color then after short time color disappear
When i read about this the information i received is "this is due to excess nitric
If i denox the AR and do the test and wait until the color doesn't disappear

Can this be the start to begin the cementation process?

3- if i used copper as powder that cemented by iron do i need continuous motion

2- after denox when i add copper
does gold replace copper immediately or it wait until the solution saturated with copper then replace "in another word can cementation suite to large amounts of solution"
 
Thanks FrugalRefiner for your information
I have questions about testing
1- Some time When i use tin chloride to test pregnant AR solution it gives dark purple color then after short time color disappear
When i read about this the information i received is "this is due to excess nitric
If i denox the AR and do the test and wait until the color doesn't disappear

Can this be the start to begin the cementation process?

3- if i used copper as powder that cemented by iron do i need continuous motion

2- after denox when i add copper
does gold replace copper immediately or it wait until the solution saturated with copper then replace "in another word can cementation suite to large amounts of solution"
1. If there is too much Nitric the Gold will redissolve and the color in the Stannous disappears.
2. No need to deNOx if you cement on Copper. The Gold will cement out and redissolve until there is no more excess of Nitric.

3. I have no idea what you say here.
A guess.
If you cement on Iron all metals below Iron will drop out including Gold.
And then you will have to put it into solution again to separate it from the "junk" metals.
 
I mean if i use powder copper do i still need to circle the solution
whenever you cement metals no matter which metal you use it is more effective to circulate the solution. The reactions only take place when the metal you are cementing with comes into contact with the metal you are trying to cement. That is why mixing is important, it makes for more collisions.
 
What about excess HCL
if i dissolve 1gram of gold in amount of HCL and HNO3 say for example 10 ml HCL and 3ml HNO3
Then i add more HCL say another 10ml
Assume that the solution was denox perfectly

In this case
Does i need 1gram of copper for gold to precipitate?
Or i need much copper for excess HCL
 
Ok when i use powder copper it will be easier to collide with gold right
The reason for using copper is not ease of collisions, it is due to coppers electrical charge in the electromotive series. It will only drop metals beneath it on the electromotive series chart. With the exception of mercury.
 
Does i need 1gram of copper for gold to precipitate?
Or i need much copper for excess HCL
These things are difficult to calculate precisely for many reasons, but an important thing to remember is that stannous chloride is your friend, it will tell you when you have cemented out all of the metals.
 
For
1. If there is too much Nitric the Gold will redissolve and the color in the Stannous disappears
Can this phenomenon be indication for end point of denox_ing process
no matter what type of recovery method used _SMP, cementation and...... many other method that i don't know
 
These things are difficult to calculate precisely for many reasons, but an important thing to remember is that stannous chloride is your friend, it will tell you when you have cemented out all of the metals.
Thanks a lot for introducing me my new friend
And for your time
 
The cementation process does not begin until all of the free nitric acid is used up dissolving any metals in solution. That means the excess nitric will no longer be in excess as it will have been consumed by metallic copper. So the stannous will work.
 

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