JPS5831397B2 - Electrolytic refining method - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement in an electrolytic refining method for copper, lead, etc.
The present invention relates to a method for preventing undissolved anode fragments from falling into an electrolytic cell during electrolysis and improving the dissolution rate of the anode.

For example, in copper electrolytic refining, the general method is to use blister copper or refined blister copper as an anode, a pure copper seed plate as a cathode, electrolyze an acidic copper sulfate solution as an electrolyte, and precipitate electrolytic copper on the seed plate. It is being done.

In this electrolytic refining, the undissolved anode is redissolved and
The anode is recast and the electrolytic process is repeated again.

Therefore, in order to reduce the undissolved rate of the anode as much as possible, various attempts have been made regarding the shape of the anode and the electrolysis process, and the present invention provides one of the methods.

After electrolysis has been carried out for a predetermined period of time, the remaining anode is pulled up from the electrolytic cell. Ideally, the immersed part should be uniformly and thinly dissolved, so that the undissolved rate will be small and the work will be easy. In reality, the initial anode thickness and current distribution are non-uniform, resulting in non-uniform dissolution of the anode.

At this time, if the upper part of the anode is preferentially melted, undissolved anode fragments cut at the melted portion fall into the electrolytic cell, damaging the wall of the electrolytic cell or causing a short circuit.

In addition, since the electrical circuit is cut off, the undissolved anode that has fallen will no longer melt and accumulate at the bottom of the electrolytic cell, causing various problems such as lowering current efficiency and adding to the work required to pull it up. arise.

In particular, the dissolution rate at the electrolyte interface is faster than at the immersed part, so
When electrolysis is performed with a constant liquid level relative to the anode,
This position dissolves preferentially, and as shown in FIG. 1, it is cut off near the liquid collapse and the lower part falls into the electrolytic cell.

Therefore, in order to avoid this, conventional methods have been used such as moving the liquid level up and down during the electrolysis period.

The present invention is a method for preventing the anode from falling and effectively dissolving it.

The method of the present invention will be described below as an example with reference to FIG.

Apply one or more lines of acid-resistant paint, resin, etc. in the vertical direction to the upper position (■) when the anode (■) is suspended.

The coating position is determined at an appropriate length above and below, centered on a position corresponding to the electrolyte surface (1) when the anode is immersed in the electrolytic cell.

(In this example, the acid-resistant paint is 3 cm long and 20 cwr.
It was applied to.

) By applying acid-resistant paint, resin, etc. in this way, dissolution is delayed in that area and it remains relatively thick, preventing it from being cut from the liquid surface where the dissolution rate is fastest, so it can be prevented from being cut off from the surface of the liquid where it dissolves the fastest. Various troubles are eliminated, there is no need to fluctuate the liquid level, and melting can be carried out from the top as much as possible due to the structure, and melting is possible especially in the parts immersed in the lower layer of the electrolytic cell or to the permissible limits. Since more current can be passed, the undissolved rate of the anode as a whole decreases, improving efficiency.

Note that the anode residue after electrolysis can be remelted and remolded into an anode without any trouble as in the conventional case.

Furthermore, the present invention does not require complicated equipment or many steps, and can be implemented using conventional equipment, resulting in significant industrial effects.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an anode dissolved in an electrolytic solution, and FIG. 2 is a front view showing the electrolytic refining method of the present invention. (2) is the anode, (2) is the acid-resistant paint, and (2) is the electrolyte surface.

Claims (1)

[Claims] 1. In electrolytic refining of non-ferrous metals, acid-resistant paint or resin coating is applied vertically to the anode surface in advance.
1. An electrolytic refining method characterized in that one or more anodes are applied in a band shape, and the band portions are left until the end of electrolysis to prevent undissolved portions of the anode from falling into an electrolytic cell during electrolysis.