Current density for electrowinning copper removal
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We are preparing the electrolytic leaching solution for copper removal: 45 grams per liter of copper and 30 grams per liter of nickel. We plan to carry out the copper removal in two stages: the first stage aims to reduce the copper concentration to around 20 grams per liter, while the second stage aims to reduce it to below 0.5 grams per liter. The question now is: how should the current density be controlled during this established copper removal process? I plan to use a current of 200 amperes per square meter for Stage 1 of electrowinning; so what current should be used for Stage 2? Listen to what everyone has to say. Principle: During two-stage electrowinning, efforts should be made to remove impurities such as arsenic, antimony, and bismuth! Note: It is an electrolyte purification system designed to recover crude nickel sulfate and sulfuric acid.
What I meant by my question is that, in the later stages of electrowinning, in order to achieve a higher impurity removal efficiency, should the current density be increased when copper ions are relatively scarce, so as to cause the impurity ions to be discharged and precipitated?
Isn’t this just the production method for yellow slag? The current density should not be too high; around 100 is sufficient
-- Personal opinion: It’s a bit idealistic from a manufacturing perspective； From an economic perspective, it seems that little consideration is given to power consumption. --
In fact, the current density is determined by taking into account your electrical equipment, the number of copper removal units, the amount of copper to be removed, and the removal time. It is generally around 180-260 A/M2. Because the electrowinning efficiency is relatively good within this range. Pair it with an appropriate flow rate, and that’s it. The key is. (45-20) g/l * Vs = I * s * 2 * n * g * electrodeposition efficiency ； Where Vs is the inlet flow rate, in l/h*tank ； It is determined based on the amount you remove each day, ensuring that there is no leftover liquid while maintaining optimal utilization of your tank. I, A/m2, current density ； s is the area of the cathode plate, in m2 ； n is the number of cathode plates per slot ； g is the electrochemical equivalent of copper. Simply adjust the flow rate and current density appropriately to meet your production requirements. Keep the current as high as possible to ensure copper quality. That’s how I did it
Two-stage copper removal is also controlled in the same way. The key lies in flow rate control and the control of concentration polarization, which in turn depends on the control of copper ion and impurity ion concentrations. Improving the debinding efficiency involves preventing the formation of hydrogen and arsenic hydride. This is a technical task that involves technology; I can’t really say anything about it. It costs money.
In fact, just from this perspective, it is the best choice in terms of both technology and cost efficiency for liquid purification. However, whether it’s possible to produce standard copper, or even high-purity copper, at concentrations of 45g/l–20g/l depends heavily on the skill of the person handling it. It might be feasible at first, but when impurities increase, it becomes difficult to do so; such capabilities are limited in China. Also, from a process perspective, electrowinning for copper removal is highly detrimental to the copper acid balance in the purification system. It doesn’t matter if the yield is low; but when the yield increases, copper sulfate has to be purchased.
Induction method? Actually, this principle applies to any law. It is the electrodeposition process of cations. Even if two equations are used, that’s fine. One is the Gibbs function, and the other is the Nernst equation. The process of achieving target ion-selective discharge is accomplished through the control of temperature, ion vacancy, and ion activity. One is the degree of control, and the other is the possibility of control. It’s just these two equations; dealing with them is enough
-- Question: What is ion void fraction? --
Concentration. I used pinyin; it’s a tragedy: funk:
This post was last edited by Yang Qing on 2011-3-18 09:10. Hehe, the “function” and “equation” mentioned by the friend above were something I learned back when studying physical chemistry; it involves considering the feasibility of a process from the perspectives of chemical thermodynamics and kinetics. However, some things have become unfamiliar to me; after all, ordinary companies are not engaged in research. I’m also used to being lazy – when reading technical materials, I tend to focus on the conclusions rather than trying to understand them from a fundamental theoretical perspective. Actually, the question I asked might seem a bit childish; it depends on the actual situation of the system, I guess? Rather than delving into complex theories, it’s better to try out various approaches during actual trial production and see the results! I’ve learned something!