Nouran Alaa
Active member
Hi Everyone
I know Zinc isn't the preferred method for cementation on this Forum but it was the available metal at the time and copper wasnt available.
I did have a thread before about major gold losses and with your help I was able to recover most of the gold lost and was left satisfied with the results. I used Dave's when in doubt cement it out as a reference and Hoke's book as a guide.
The first time we recovered with zinc was a great success ( Beginners luck I guess!), the second time wasnt a charm.
I had two water tanks (each 1000 liters)
The first was suspected to have 10.5 grams of gold (21 Carat) and the second was suspected to have 20.5 grams of gold (21 Carat)
Before working on any of the tanks they were filtered to remove any gold that was precipitated at the bottom and all the other waste from cotton or gloves were burnt and recovered as waste.
There was an unnecessary step that was made by the technician which is adding Casutic Soda to the tanks believing it will create Gold Hydroxide which will be insoluble. Needless to say this was of no gain and I tested the PH of the water and it was 1, so I assume the caustic soda was of no use and much greater quantities should hav been used.
The First Tank:
I tested with stannous chloride (which I made sure is working by testing on a stock containing gold) and it gave a negative.
I suspected and tested with Hydrazine which gave a positive by forming a light brown cloud (indicating a few amount of gold).
1/2 a kilo of Zinc Powder was added gradually with HCL and the bubbling effect was achieved as described in Hokes book and the tank water did turn green indicating the drop of the metal.
I'm aware that powder was not the best option but my resources were very limited, the tank was stirred by a rod for a while but i do not have a pump or air flow to mix properly as described by Dave.
The tank was left to sit for two days , then filtered and then the filter papers were treated with slightly diluted aqua regia and left in the acids for a day and half and then precipitated with SMB and left to precipitate for three hours then filtered and the filter paper was smelted and it gave no gold.
The Second Tank:
Same procedure was followed
I tested with stannous chloride (which I made sure is working by testing on a stock containing gold) and it gave a negative.
I suspected and tested with Hydrazine which gave a positive by forming a dark brown cloud (indicating a decent amount of gold).
more than 1/2 a kilo of Zinc Powder was added gradually with HCL and the bubbling effect was milder than described in Hokes book and the tank water did not turn green despite adding HCL and Zinc but the tank was filled to the max so I had to stop adding the HCL.
The tank was left to sit for two days , then filtered and then the filter papers were treated with slightly diluted aqua regia and left in the acids for a day and half and then precipitated with SMB and left to precipitate for three hours then filtered and the filter paper was smelted and it gave no gold.
(I'll attach the pictures of both tanks)
There is now a third tank which holds the acid water used in the zinc process its very turbid and I couldnt test it properly with hydrazine due to its turbidity.
after all the process was completed:
The first tank tested negative for gold with Hydrazine
The second tank tested positive for gold with Hydrazine
Stannous chloride keeps providing negative results.
I'm not sure how I can go from here and if at this point its possible to recover the gold.
These pictures are all taken today and there is a new sediment forming at the bottom
![image5.jpeg image5.jpeg](https://cdn.imagearchive.com/goldrefiningforum/data/attachments/49/49541-75930e1eea1de33c618a94c78473cda8.jpg)
![image0.jpeg image0.jpeg](https://cdn.imagearchive.com/goldrefiningforum/data/attachments/49/49542-75930e1eea1de33c618a94c78473cda8.jpg)
Tank 1
![image3.jpeg image3.jpeg](https://cdn.imagearchive.com/goldrefiningforum/data/attachments/49/49543-1b7992c615eb5267e80310afb3dbb76d.jpg)
![image1.jpeg image1.jpeg](https://cdn.imagearchive.com/goldrefiningforum/data/attachments/49/49544-e9f1064b4e86b51a80dc3da0e4aa5192.jpg)
Tank 2
![image4.jpeg image4.jpeg](https://cdn.imagearchive.com/goldrefiningforum/data/attachments/49/49545-746de3e4ce8f50099e28b020c678cce8.jpg)
Tank 3 ( after the use of zinc the water and acids filtered )
I know Zinc isn't the preferred method for cementation on this Forum but it was the available metal at the time and copper wasnt available.
I did have a thread before about major gold losses and with your help I was able to recover most of the gold lost and was left satisfied with the results. I used Dave's when in doubt cement it out as a reference and Hoke's book as a guide.
The first time we recovered with zinc was a great success ( Beginners luck I guess!), the second time wasnt a charm.
I had two water tanks (each 1000 liters)
The first was suspected to have 10.5 grams of gold (21 Carat) and the second was suspected to have 20.5 grams of gold (21 Carat)
Before working on any of the tanks they were filtered to remove any gold that was precipitated at the bottom and all the other waste from cotton or gloves were burnt and recovered as waste.
There was an unnecessary step that was made by the technician which is adding Casutic Soda to the tanks believing it will create Gold Hydroxide which will be insoluble. Needless to say this was of no gain and I tested the PH of the water and it was 1, so I assume the caustic soda was of no use and much greater quantities should hav been used.
The First Tank:
I tested with stannous chloride (which I made sure is working by testing on a stock containing gold) and it gave a negative.
I suspected and tested with Hydrazine which gave a positive by forming a light brown cloud (indicating a few amount of gold).
1/2 a kilo of Zinc Powder was added gradually with HCL and the bubbling effect was achieved as described in Hokes book and the tank water did turn green indicating the drop of the metal.
I'm aware that powder was not the best option but my resources were very limited, the tank was stirred by a rod for a while but i do not have a pump or air flow to mix properly as described by Dave.
The tank was left to sit for two days , then filtered and then the filter papers were treated with slightly diluted aqua regia and left in the acids for a day and half and then precipitated with SMB and left to precipitate for three hours then filtered and the filter paper was smelted and it gave no gold.
The Second Tank:
Same procedure was followed
I tested with stannous chloride (which I made sure is working by testing on a stock containing gold) and it gave a negative.
I suspected and tested with Hydrazine which gave a positive by forming a dark brown cloud (indicating a decent amount of gold).
more than 1/2 a kilo of Zinc Powder was added gradually with HCL and the bubbling effect was milder than described in Hokes book and the tank water did not turn green despite adding HCL and Zinc but the tank was filled to the max so I had to stop adding the HCL.
The tank was left to sit for two days , then filtered and then the filter papers were treated with slightly diluted aqua regia and left in the acids for a day and half and then precipitated with SMB and left to precipitate for three hours then filtered and the filter paper was smelted and it gave no gold.
(I'll attach the pictures of both tanks)
There is now a third tank which holds the acid water used in the zinc process its very turbid and I couldnt test it properly with hydrazine due to its turbidity.
after all the process was completed:
The first tank tested negative for gold with Hydrazine
The second tank tested positive for gold with Hydrazine
Stannous chloride keeps providing negative results.
I'm not sure how I can go from here and if at this point its possible to recover the gold.
These pictures are all taken today and there is a new sediment forming at the bottom
![image5.jpeg image5.jpeg](https://cdn.imagearchive.com/goldrefiningforum/data/attachments/49/49541-75930e1eea1de33c618a94c78473cda8.jpg)
![image0.jpeg image0.jpeg](https://cdn.imagearchive.com/goldrefiningforum/data/attachments/49/49542-75930e1eea1de33c618a94c78473cda8.jpg)
Tank 1
![image3.jpeg image3.jpeg](https://cdn.imagearchive.com/goldrefiningforum/data/attachments/49/49543-1b7992c615eb5267e80310afb3dbb76d.jpg)
![image1.jpeg image1.jpeg](https://cdn.imagearchive.com/goldrefiningforum/data/attachments/49/49544-e9f1064b4e86b51a80dc3da0e4aa5192.jpg)
Tank 2
![image4.jpeg image4.jpeg](https://cdn.imagearchive.com/goldrefiningforum/data/attachments/49/49545-746de3e4ce8f50099e28b020c678cce8.jpg)
Tank 3 ( after the use of zinc the water and acids filtered )