JPS583937A - Selectively removing method for calcium in solution - Google Patents

Abstract

PURPOSE:To prevent the occurrence of scale trouble due to Ca in a soln.contg. plural kinds of metals while preventing the loss of the contained metals, by selectively extracting Ca in the soln. with D2EHPA and washing the extracting reagent with nitric acid. CONSTITUTION:To a soln. contg. plural kinds of metals such as Ni and Co is added about 1/10-1/2 time as much D2EHPA as the soln. by volume, and they are agitated at about 300-1,000r.p.m. and about 1.5-3.5pH for about 2-10min to extract Ca in the soln. At this time, to the soln. is added about 10-320g/l ammonium sulfate which prevents a pH reduction and acts as a pH buffer. The extracting reagent contg. a small amount of metals such as Ni and Co extracted together with Ca is scrubbed with a soln. contg. Ca, Ni, etc. acidified by nitric acid to reduce the amount of Ni, Co, etc., and Ca and metals such as Ni and Co are back-extracted with nitric acid having about 50-300g/l concn.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for selectively removing calcium in a solution.

In particular, the present invention relates to a method for selectively removing calcium from a solution containing multiple metals.

For example, in the extraction and separation process of nickel and cobalt, calcium in the solution crystallizes and adheres to the inner wall of the extraction tank.

Due to nuclear adhesion, the internal volume of the cylinder became narrow, making continuous operation impossible.

For this reason, nickel calcium in solution.

There has been a demand for selective recovery and removal separately from recovered metals such as cobalt.

The present invention was made in response to such a demand.

That is, when removing calcium from fB liquid,
The present invention relates to a method for selectively removing calcium in a solution, which comprises extracting calcium with DaHPA and then washing the extractant with nitric acid.

The present invention will be explained in detail below.

The present invention is widely used in the extraction of calcium, and the present invention will be explained below through a method for selectively extracting calcium from a liquid containing nickel and cobalt.

In a liquid containing nickel and cobalt, calcium is α0
25~o, from a solution containing around s t7.

When recovering nickel and cobalt, removing calcium before or after recovering the metals is a preferred method to enable continuous operation.

Fi is an extractant that selectively extracts calcium.
Use HPA.

As shown in FIG. 1, bgapA can efficiently extract calcium from the solution by adjusting the pH to 1.5 to 55. In addition, in order to minimize 0ONiO co-extraction and extract efficiently, it is preferable that 1) H2,O be 2.8 to 2.8.

Furthermore, in order to prevent the pH from decreasing due to extraction, ammonia ions are included in the solution in advance.

This is preferred as a pH buffer.

Ammonia ion is 10 to 320 as ammonium sulfate.
Include f/.

Furthermore, the liquid volume ratio of extractant and processing liquid is 1/1Q~1
/2 is preferred, and more preferably 177 to 1/3.

Stirring and time are 5Q Orpm to 100 Q rpm
Do this for 2 to 10 minutes. This allows the oil layer and the solution layer to preferably come into contact with each other.

Calcium in the treatment solution after contact is I)H=1.5-3.
In the case of 0, a 60-98q6 removal rate is obtained.

A preferred treatment method that efficiently removes calcium while minimizing loss of nickel and cobalt is:
The pH in the extraction process is adjusted to 2,0-'5.5 to maximize calcium extraction, and the nickel and cobalt extracted at the same time are extracted by adjusting the pH to around 1,5 to 2.0 in the scrubbing process. There is a method of reducing the nickel and cobalt values in the agent, and it is preferable to adopt this method.

The liquid used for scrubbing is preferably a nitric acidic liquid. This is due to the high solubility of calcium. In a preferred embodiment, the concentration of calcium, nickel, and cobalt in the liquid is higher than that in the extractant.

The treated extractant that has undergone the scrubbing process or the extraction process is washed with nitric acid in the back extraction process to remove calcium from the extractant.

The nitric acid used in this step is 50 to 7 tons
It is preferable to have a concentration of .

In this step, the ratio of extractant to washing liquid is 3/1 to 10/3.
It is preferable to set it to 1.

Also, in back extraction, by performing nitric acid washing in two or more stages, loss of nickel and cobalt into the extractant can be prevented, and at the same time, calcium can be completely back extracted.

That is, by contacting the treated extractant with a solution containing 100 to 7t of nitric acid, calcium in the extractant is reduced to less than 10'9/, nickel is reduced to less than i''p/,
Cobalt can be less than 10''//!.

In the first back-extraction, the treated extractant and a cleaning solution containing no impurities with a nitric acid concentration of 50 to 100 t/l are mixed into
Calcium, nickel, and cobalt in the treatment extractant are each 1"/1 by contacting at a ratio of 71 to 10/1.
/ can be made as follows.

Further, it is more preferable to use the second stage washing liquid as a part of the first stage back extraction liquid.

This is to reduce the amount of liquid required for back extraction liquid extraction and to facilitate the liquid extraction process.

The cobalt and nickel in the after-liquid are separated from the calcium in the liquid by known removal means and recovered, and used as raw materials for nickel and cobalt smelting.

By performing the above processing, the following effects can be obtained.

(1) Since calcium in the liquid can be selectively extracted and removed, scaling problems caused by reactive species caused by calcium crystallization can be prevented.

(2) Particularly in the solvent extraction of nickel and cobalt, there was no loss of nickel and cobalt, and at the same time, scale troubles were prevented.

Specific examples of the present invention will be shown below.

Further, the present invention will be described in detail.

Example Calcium 145”//l, Nickel 5 o t7t
.

A solution containing 20 r/ml of DsFiHPA and an extractant containing DsFiHPA were brought into contact at a ratio of 5:1 at pH 2.0.

The liquid temperature was 60°C and the stirring was performed at 750 rpm for 5 minutes.

Through this extraction process, calcium in the treatment solution is reduced to 56
”//l, and it was possible to avoid scale troubles in the subsequent extraction and separation process of cobalt and nickel.

Furthermore, the following treatment was performed to remove calcium in the extractant and partially extracted cobalt and nickel from the nucleating agent.

In the scrubbing step, the extractant was mixed with calcium 2.5 f/l and nickel [L96 f/l] at pH=2.0.
.

Contact with a solution containing 9.55 f/l of cobalt and 70 f/l of nitric acid at a ratio of 1=5 to remove nickel in the extractant from Cl.
70 f/l to 0.19 t/l and Z
Of/1. It was lowered from 1.9 r/l to 1.9 r/l.

The post-washing liquid was used as the treatment liquid in the extraction step.

In the back extraction step, calcium in the extractant is removed by contacting with a solution containing 230 f/nitric acid.
It was possible to lower K by 10'//l from 'p7t, reduce Niacel from 190'//l to 1'//l, and reduce cobalt from 1.99/l to 10'/l.

Furthermore, to reduce the calcium, cobalt nickel content in the extractant, 75 f/l of pure nitric acid was added.
Back extraction was carried out using this solution, and calcium, cobalt, and nickel in the extractant were all reduced to 1'f/l or less.

Since nitric acid was used in the above treatment steps, there were no scaling problems caused by calcium, and continuous operation was possible.

[Brief explanation of the drawing]

Figure 1 is from DIEHPA. Calcium in liquid. The extraction curves of cobalt and nickel are shown. Patent applicant: Japan Mining Co., Ltd., patent attorney (7569) Keishi Namikawa

Claims (1)

[Claims] D*KHP when removing calcium from a solution
A method for selectively removing calcium in a solution, which comprises extracting calcium with A and then washing the extractant with nitric acid.