Development of electrodeposition process- carbon fiber elect
2020-10-27 10:30Introduction：Development of electrodeposition process - carbon fiber electrodeposition At present, the gold-loaded carbon in the carbon in pulpplant is sent to the desorption electrodeposition workshop to recover the gold.General steel wool can only be
Development of electrodeposition process- carbon fiber electrodeposition
At present, the gold-loaded carbon in the carbon in pulp plant is sent to the desorption electrodeposition workshop to recover the gold.General steel wool can only be used 2 ~ 3 times, consumption is large, the grade of gold slime is low, and a lot of broken steel wool is mixed, acid consumption is more, operating conditions are poor.The carbon fiber electrodeposition process developed by Shenyang Gold Institute can effectively solve the above problems.The process uses carbon fiber instead of steel wool as electrodeposition cathode, which has the advantages of simple operation, reliable performance, large capacity of cathode carrying gold, long service life, high gold deposition rate, low consumption of materials and metallurgical solvent, little operation process and small human loss.It has been applied to industrial production.
The process of carbon fiber electrodeposition is divided into forward electrodeposition and reverse electrolysis.The positive electrodeposition method, like the steel wool electrodeposition method, is to deposit the gold in your liquid on the cathode.Reverse electrolysis is the process in which gold is desorbed from the carbon fiber cathode and deposited on the cathode plate made of special materials.When reverse electrolysis occurs, the cell voltage is 3.0 ~ 5.0v, and the cathode current density is 15 ~ 24A/m2. NaCN concentration in the electrolyte is about 1.5%, and the electrolysis cycle is 10~20h, depending on the gold - loaded carbon fiber stripping effect
The industrial test results in a gold mine show that the processing capacity of 6 steel wool electrodeposition slots with the same volume can be achieved by using 2 ~ 3 carbon fiber electrodeposition troughs in series, and the electric deposition rate can be guaranteed to be over 99%.The gold- loaded capacity of carbon fiber cathode is 9 times of its own weight, which is better than that of steel wool.In the test, the physical and chemical properties of the carbon fiber have not changed after 7 times of electrodeposition and 6 times of reverse electrolysis. The appearance, strength, elasticity, conductivity and permeability remain unchanged. The electrodeposition efficiency has not decreased, and there is basically no loss,but the steel wool can only be used 2 ~ 3 times under the same condition.
In addition to the above advantages, the carbon deposition process due to reverse electrolytic cathode product deposit on the special cathode plate, the product features, unlike steel wool product process, the steel wool process to get cathode product is gold slime, the carbon deposition process got density, high grade sheet gold (Au +Ag > 95%), so gold smelting efficiency is also improved.Besides, the process of hand rubbing and acid soaking of steel wool are also omitted.
Using carbon fiber as electrode materials, to replace the traditional steel electrode, gold and silver are deposited by electrolysis from the desorption pregnant solution , technical and economic indexes can be greatly improved, In the case of the same solution grade, the electrodeposition time can be shortened by 1.5h, grade of barren solution can be reduced to 0.5 g/m3, electric deposition rate can reach more than 99%, the cathode current efficiency 7% ~ 11%, the carbon fiber electrode life of more than 3 months, can produce the high grade material (Au + Ag ≈95% ~ 99%) of gold refining, cathode processing pregnant solution capacity per unit area up to 1.0 ~ 1.3 m3/(m2·d).The comparison of technical and economic indexes between two process is shown in table 8.3-1
Table 8.3-1 comparison of carbon fiber and steel wool
| indicators | carbon fiber | steel wool |
|
Cell voltage /V Current density /A·m-1 electrolyte velocity /l·m-2·min-1 Single tank deposition efficiency /% Cathode current efficiency /% cathode consumption /(g·g-1Au) Pregnant solution grade/(g·m-3) |
3~5 20(It can improve) 18 70～80 7～11 ～ 55～180 |
3～4 20（Can't be high） 18 about50 2.6 1.27 55～180 |
Using carbon fiber instead of steel wool for electrodeposition can reduce the electrodeposition trough, save investment, cathode consumption can also be significantly reduced, in addition, it also saves the treatment of steel wool acid solvent and broken steel wool treatment, considerable benefits.
