JPH02104687A - Method for removing bismuth from copper electrolytic solution - Google Patents

Abstract

PURPOSE:To separate and recover Bi as a valuable metal from a used soln. discharged from a cell for electrolytically refining copper by adding anhydrous gypsum to the used soln., allowing Bi in the soln. to be adsorbed on the gypsum and carrying out solid-liq. separation. CONSTITUTION:An electrolytic soln. S1 used to electrolytically refine Cu is fed to a concentrating apparatus composed essentially of a first evaporator 1 and a first heating drum 2, anhydrous gypsum is added to the soln. S1 and this soln. S1 is circulated by a pump 3 between the evaporator 1, the drum 2 and fed as a concd. electrolytic soln. S2 by a pump 10 to a concentrating apparatus composed essentially of a second evaporator 8 and a second heating drum 9. A further concd. electrolytic soln. S3 overflowing the evaporator 8 is fed by a pump 14 to a settling vessel 15 and the gypsum with adsorbed Bi is settled and fed again to the evaporator 1 together with a used electrolytic soln. S1 to adsorb Bi in the soln. S1. The resulting Bi-free soln. overflowing the vessel 15 is reutilized after copper sulfate remaining in the soln. is recovered. The settled gypsum in the vessel 15 is treated to recover the adsorbed Bi.

Description

[Detailed Description of the Invention] Production'l It>'! The present invention generally relates to a method for separating and removing bismuth (Bi) contained in a copper electrolyte, and in particular, it relates to a method for separating and removing bismuth (Bi) contained in a copper electrolytic solution. ) can be suitably used as a liquid purification method to remove. Nu1 The present invention uses bismuth (Bi), which is a valuable material.
) is effectively applied to the separation and recovery of

BACKGROUND ART Conventionally, in copper electrolytic smelting systems, decopper removal electrolysis has been adopted as a solution purification method for removing impurities from the copper electrolyte used.

On the other hand, in recent years, bismuth (Bi) has been widely used in pharmaceuticals, alloy materials, coolants for 1fX sub-reactors, and various other technical fields. is also well known.

However, in particular, in the decopper removal process in the copper electrolytic smelting system, a concentrated electrolyte with a high impurity concentration is used as the electrolyte, and bismuth (Bi) is contaminated with other impurities. Certain As, Sb, and Fe.

It is precipitated in copper deposits along with others. Therefore, more treatments were required to separate and recover bismuth (Bi) alone.

As a result of many research experiments, the present inventors found that when anhydrite (CaS04) was added to the copper electrolyte used in copper electrolytic smelting, only bismuth (Bi) in the copper electrolyte was removed from the anhydrite f(C
It was found that it was adsorbed to a S 04 ) and co-precipitated.

In addition, high-purity bismuth (
It was found that Bi) could be easily separated and recovered.

The present invention has been made based on this new knowledge.

Therefore, one object of the present invention is to convert copper electrolyte into bismuth (Bi).
) in a cylinder.

Another object of the present invention is to provide a method for simply separating and recovering bismuth (Bi) from a copper electrolyte.

The above objects are achieved by the method for removing bismuth from a copper electrolyte according to the present invention. In summary, the present invention.

Anhydrite in copper solution! (CuSOs) to remove bismuth (Bi) in the copper electrolyte.
) is a method for removing bismuth from a copper solution by adsorption and precipitation.

笈i1 Next, the method for removing bismuth from a copper electrolyte according to the present invention will be explained in more detail with reference to the drawings.

FIG. 1 schematically shows a part of a liquid purification plant for purifying impurities from a copper electrolyte in a copper electrolytic smelting system.

In this embodiment, the liquid purification plant has a first evaporator l and a first heating can 2, and the first evaporator l and the first heating can 2 are connected to a pipe line 4 and a pipe line equipped with a pump 3. It is connected at 5. ts
The used electrolyte S1 from the electrolytic cell (not shown) of the TSS Chiren system is supplied via a supply pipe line 6 connected to a pipe line 3 connecting the first evaporator l and the first heating can 2. In this embodiment, the electrolytic solution Sl is supplied to the first heating can 2 by operating the pump 3 at a rate of 100 liters per minute.
was supplied to.

In this embodiment, the electrolytic solution S1 is heated in the first heating can 2 to a predetermined temperature, for example, 60° C., and is supplied to the first evaporator l via the pipe line 5. The first evaporator l is maintained at 60°C and 0.89 atm, and the first concentration of the electrolytic solution S1 is performed. In this embodiment, the electrolysis @ S1 is approximately 1 .3 times concentrated.

The lower electrolyte in the first evaporator 1 is circulated through the pipe 3 to the first heating can 2 and heated.

Further, in this embodiment, the liquid purification plant has a second evaporator 8 and a second heating can 9, and the second evaporator 8 and the second heating can 9 are connected to a pipe line 11 equipped with a pump 10t and a second heating can 9. They are connected through a conduit 12.

The upper layer of the first evaporator L overflowed. The primary concentrated electrolyte S2, which has been concentrated to approximately 1.3 times, is transferred to pipe 7.11.
is supplied to the second heating can 9 by the pump 10 via. The first concentrated electrolytic solution S2 is heated in the second heating can 9 to a predetermined temperature 1, for example, 80° C., and is supplied to the second evaporator 8 via the conduit 12. The second evaporator 8 is 8 in this embodiment.
The temperature was maintained at 0° C. and 0.43 atm, and the electrolytic solution was subjected to secondary concentration. In this example, the electrolytic solution was concentrated to about 1.8 times in the secondary concentration.

The lower electrolyte in the second evaporator 8 is transferred to the second evaporator via the pipe line 11.
It is circulated to the heating can 9 and heated. Further, the overflowing second concentrated electrolyte S3 in the upper layer of the second evaporator 8, which has been concentrated to about 1.8 times, is sent to the settling tank 15 by the pump 14 via the pipe line 13.

The upper overflow electrolyte of settling tank 15 is fed to a conventional vacuum crystallizer (not shown) well known to those skilled in the art to crystallize copper sulfates (CuSOs) and other impurities in the electrolyte. I can sleep. Furthermore, the purified electrolytic solution is subjected to filtration and other treatments, and then returned to the electrolytic cell.

According to the invention, as illustrated in FIG.

Anhydrous gypsum (CaS04) is added to the electrolyte solution SI supply pipe line 6. The amount of anhydrite (CaSO4) added is
:V can be arbitrarily selected depending on the amount of bismuth (Bi) in the electrolytic solution, but for example, bismuth (Bi) in the electrolytic solution is
/n, good results could be obtained by continuously adding 13 g/l. Generally, anhydrite (CaS04) is mixed with bismuth (CaS04) in a copper electrolyte.
Bi) It is preferable to add 70 times or more of the paste to i.

FIG. 2 shows the feed electrolyte 51. before and after anhydrite (Canoe) is added. It is a graph showing changes in I4 of bismuth (Bi) in the first concentrated electrolyte Sz and the second concentrated electrolyte S3 with respect to the time axis.

From the graph in Figure 2, bismuth (B i) in the secondary concentrated electrolyte S3 is ! ! It will be appreciated that almost complete removal can be achieved by adding hydrogypsum (Ca5O4).

The precipitate adsorbed and co-precipitated by anhydrite (Canoe) in the settling tank 15 is, for example, (1) Ca5O containing Bi;
+ is dissolved using salt, precipitated using iron, and melted in a graphite crucible. Or, (2) neutralize the leachate with soda carbonate or lime and 11! Precipitated as basic bismuth chloride, if
1 Milk of lime is added and stirred in a flat iron pot, and bismuth (Bi) is separated and recovered by the 1st treatment in which the B iz O3 obtained here is quintupled with carbon to form Bi.

By this method, bismuth (Bi) with a purity of 99% could be obtained.

Incidentally, a part of the sediment in the settling tank 15 is added to the above-mentioned '+((
It is also possible to circulate to the liquid-resistant supply line 6.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment in which the method according to the present invention is applied to the explosive liquid 1-1 of a copper smelting system. Figure 2 shows the feed electrolyte SI, the primary concentrated 1il TL solution 52 and the secondary electrolyte SI before and after anhydrite (Canoe) is added.
It is a graph showing the change of 1- of bismuth (Bi) in the next concentrated electrolytic solution S3 with respect to the time axis. 1: First evaporator 2: pJ41 heating can 8: Second evaporator 9: Second heating can 15: Sedimentation tank Fig. 1

Claims (1)

[Claims] 1) Anhydrous gypsum (CaSO_4) is added to the copper electrolyte, and bismuth (Bi) in the copper electrolyte is mixed with the anhydrous gypsum (CaSO_4).
_4) A method for removing bismuth from a copper electrolyte, characterized by adsorption and precipitation. 2) The copper electrolyte according to claim 1, wherein the copper electrolyte is a used electrolyte from a copper electrolytic smelting system, and the copper electrolyte to which anhydrite (CaSO_4) is added is concentrated 1.8 times or more. Method for removing bismuth from electrolytes. 3) The method for removing bismuth from a copper electrolyte according to claim 1 or 2, wherein anhydrous gypsum (CaSO_4) is added in an amount of 70 times or more the amount of bismuth (Bi) in the copper electrolyte.