LeftyTheBandit
Well-known member
Patent # 3,957,505
I have attached the pdf of the patent for easy familiarization.
Would I be able to use SMB and not effect the solution negatively?
Does this mean hydroxylamine can be acidic or base, or does it mean depending on what you are processing, the solution could be acidic or alkaline due to the make up of the media your processing?
Does this mean hydrazine occurs in both an acid state and a base state and if so you must use the alkaline version?
This makes it sound as if the buffer is used to supply ions and not keep the pH stable. My understanding of buffers is near zero.
I looked up buffers at a chemical supply house and all buffers are named by the pH level they are used for, non of them are identified by an actual name as quoted here. It appears the buffer is being used not to control the pH but to offer Ions that are lost during reducing and regeneration of the stripping solution. Is this what buffers are for or is this the way the inventor keeps his solution active longer?
Is the ammonium acetate being used as a buffer? I believe this is a secondary method of precipitating other than using sulfur dioxide gas, which I would rather use because of it's simplicity but I noticed sodium hydroxide which is alkaline being used here which may be favorable by not adding sulfur to the equation.
Question #7
Does this mean I can use H2O2 instead Hydroxyl amine or are they to be used together to give the effect required?
I can not read scientific notation yet and I feel the answer is here about why they want a buffer. I want to use SMB, what would you suggest I use as a buffer if I am using SMB and peroxide in my reactions?
Question #8b
dibasic ammonium phosphate appears to be suggested as a buffer that serves both functions if I read it right. Unfortunately this stuff is almost $85 per 100g and if there is a better (cheaper) buffer that jumps out could anyone suggest?
I have attached the pdf of the patent for easy familiarization.
1. A process for extracting gold from gold bearing material which comprises:
treating the gold bearing material in an aqueous solution consisting essentially of iodine and a water soluble iodide salt to dissolve gold from said gold bearing material; mixing a reducing agent with said aqueous solution to reduce dissolved gold iodide salts to gold metal and precipitate said gold metal in substantially pure form from said aqueous solution; Removing precipitated gold metal from said aqueous solution; and adding an oxidizing agent to said aqueous solution to thereby restore said solution to substantially its original condition for dissolving gold from further gold bearing material.
Question #14. The process of claim 1 in which the reducing agent is sulfur dioxide.
Would I be able to use SMB and not effect the solution negatively?
Question #25. The process of claim 1 in which the reducing agent is an alkaline solution of hydroxylamine.
Does this mean hydroxylamine can be acidic or base, or does it mean depending on what you are processing, the solution could be acidic or alkaline due to the make up of the media your processing?
Question #36. The process of claim 1 in which the reducing agent is an alkaline solution of hydrazine.
Does this mean hydrazine occurs in both an acid state and a base state and if so you must use the alkaline version?
Question #49. mixing a reducing agent with said aqueous solution in the presence of buffer to reduce dissolved gold iodide salts to gold metal and precipitate said gold metal in substantially pure form from said aqueous solution, said buffer being capable of supplying hydroxyl ions during the precipitation of the gold metal;
This makes it sound as if the buffer is used to supply ions and not keep the pH stable. My understanding of buffers is near zero.
Question #513. The process of claim 9 in which the buffer is dibasic ammonium phosphate.
I looked up buffers at a chemical supply house and all buffers are named by the pH level they are used for, non of them are identified by an actual name as quoted here. It appears the buffer is being used not to control the pH but to offer Ions that are lost during reducing and regeneration of the stripping solution. Is this what buffers are for or is this the way the inventor keeps his solution active longer?
Question #6mixing hydrazine and sodium hydroxide to said aqueous solution in the presence of ammonium acetate to reduce dissolved gold iodide salts to gold metal and precipitate said gold metal in substantially pure form from said aqueous solution;
Is the ammonium acetate being used as a buffer? I believe this is a secondary method of precipitating other than using sulfur dioxide gas, which I would rather use because of it's simplicity but I noticed sodium hydroxide which is alkaline being used here which may be favorable by not adding sulfur to the equation.
Salts will build up after repeated cycles and reduce the effectiveness of the iodide-iodine stripping solution with respect to speed and capacity after repeated additions of H + and OH - ions required for the various reactions of the process. This build up problem is overcome in a preferred embodiment of the invention by adding a buffer to the solution which serves as a source of both H + and OH - ions. The use of a buffer with pH's spanning the pH values (about 5 to about 9) at which H 2 O 2 oxidizes I 3 - and NH 2 OH reduces AuI 4 - permits the same solution to be used repeatedly without the degree of salt buildup which would otherwise occur if acid and/or alkali is employed to adjust acidity. Salts of weak acids and a weak base, for example, store both H + and OH - ions in solution in such a manner as to render them available to hydroxyl amine (NH 2 OH) and hydrogen peroxide (H 2 O 2 ), respectively.
Question #7
Does this mean I can use H2O2 instead Hydroxyl amine or are they to be used together to give the effect required?
Question #8aThe following equation shows the conversion of dibasic ammonium phosphate to ammonium hydroxide and monobasic ammonium phosphate in the presence of water, thereby serving as a source of both H + and OH - ions.
(NH 4 ) 2 HPO 4 + H 2 O ➝ NH 4 OH + NH 4 H 2 PO 4
the gold recovery process of the invention can best be seen by reference to the following series of reactions:
Iodine, I 2 , in an aqueous solution of potassium iodide, KI, is present as the tri-iodide anion:
I 2 + KI ➝ K + + I 3 +
the reaction between gold and tri-iodide anion can be written as follows:
3K + + 3I 3 - + 2Au ➝ 2KAuI 4 + K + + I -
gold in the form of gold hydroxide, Au(OH) 3 , or auric oxide (Au 2 O 3 ), is formed as a yellow-to-brown precipitate, very insoluble in water, when an alkali hydroxide is added to the potassium auric iodide material. Gold itself rather than gold hydroxide is precipitated in the presence of a reducing agent:
KAuI 4 + 4NH 2 OH + OH - ➝ Au ↓ + 2N 2 ↑ + K + + 4I - + 5H 2 O
I can not read scientific notation yet and I feel the answer is here about why they want a buffer. I want to use SMB, what would you suggest I use as a buffer if I am using SMB and peroxide in my reactions?
Question #8b
dibasic ammonium phosphate appears to be suggested as a buffer that serves both functions if I read it right. Unfortunately this stuff is almost $85 per 100g and if there is a better (cheaper) buffer that jumps out could anyone suggest?