JPS60161339A - Recovering method of vanadium - Google Patents

Abstract

PURPOSE:To recover Vanadium (expresses V hereunder) economically and efficiently by separating a V-contg. condensed precipitate from ash contg. V and blowing oxidizing gas therein and extracting the C-contents with an alkaline soln. and neutralizing it with CO2-contg. gas to remove the precipitate and thereafter adding ammonium salt. CONSTITUTION:V-contg. ash is separated by means of specific gravity to divide it into a suspended matter and precipitate in which the V-component is condensed and while blowing oxidizing gas (e.g. compressed air) in the precipitate, said V-component is extracted with an alkaline soln. Then, after condensing the V-enriched soln. with steam or the like, CO2-contg. gas is blown therein to neutralize it at about 8-9pH. After the precipitate is removed from the soln., ammonium salt (e.g. NH4Cl or the like) is added to recover the V-component as ammonium salt. By said method, V can be recovered almost completely at low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention is directed to (1) a method for recovering hadzium from containing ash, in particular a combination of specific gravity separation by flotation and alkali extraction;
1. Concerning a method for recovering vanadium from ash containing:

(Prior art) Vanadium, a heavy metal, has recently been used in large quantities due to its basic uses. , an average of 10 to 10 to petroleum crude oil as in the past
Various improvements have been proposed to improve the method of recovering vanadium containing 0 ppm from the combustion ash of heavy residues such as heavy oil.

In principle, the conventional method consists of (1) soda burning;
(2) Potassium hydroxide method, (3) A civil law acid extraction method, (4) Alkali extraction method, (5) Acid-alkali extraction method, (
There are methods such as 61/8 medium extraction method.

Here, soda burning is a method in which ① soda salt is added to the ash containing ash, oxidized burnt for 700 to 900 degrees Celsius, and then the harnodium is extracted with water, acid, or alkali. However, in this method, since the roasting temperature is high, there is a risk that (1) may melt and adhere to the furnace wall surface, etc., and it is necessary to strictly control the temperature to prevent this. In addition, since alkali is used at high temperatures, there is significant erosion due to oxidation. In addition, since some of the soda reacts with impurities, not only is the 9JJ ratio low and the Na/V ratio needs to be high, but also the prevention of V205 scattering and SOX
Large-scale dust collection and
It is necessary to install an absorber.

Also, for example, as disclosed in JP-A-52-66812), even in the potassium hydroxide method, ko+1
Not only is a large amount of KOJ+ required for the raw material ash, such as: 2 - 2, but also energy such as heating up to 250 to 400°C, 6, 2 electricity, or dregs is required.

Furthermore, since P() is added in a kneaded state, there is a risk that dry powder will scatter as it dries.

By the way, the alkaline extraction method is a method in which the V-containing ash is directly dissolved in an alkaline solution to extract the V component, or because the extraction rate is low, it contains a high concentration of ■. It has only been considered that it applies only to mediums.

Further, there is an acid extraction method in which ① and other valuable metals in the raw material ash are extracted with acid in the range of p110 to 0.3. However, this method requires a large amount of acid and also extracts a large amount of impurities such as 5i02 at the same time, making the post-processing complicated and troublesome.

On the other hand, the acid-alkali extraction method, for example,
As disclosed in No. 06, pHi, 5-4 and HC
! , H3SO, etc., heated to 60-110°C, the precipitate obtained at that time was then dissolved in alkali, and acid was added again to adjust the pH to 1.5-4.0. This is a method in which V salt is precipitated and recovered by heating to ~110°C.

However, this method involves complicated steps and requires a large amount of chemicals, so it cannot be called a practical method.

(Objective of the Invention) The object of the present invention is to provide a more economical and efficient recovery method that eliminates the drawbacks of the prior art as described above.

(Summary of the Invention) As a result of various studies conducted by the present inventors on methods to achieve the two objectives, it was found that (1) When the ash containing ash is separated by specific gravity, for example, by flotation, the shrinkage ratio of (2) becomes significantly high. As a result of further research and development focusing on this point, we found that by combining the various processing steps specified in the present invention as described below, we can achieve a much higher recovery rate than before and at a lower cost. The present invention was completed based on the discovery that this can be recovered.

According to the present invention: (Separation and recovery step of separating and recovering al V-containing ash into floating matter and precipitate in which V content is concentrated by specific gravity separation; (b
l Note (alkaline extraction stage in which the precipitate separated and recovered in stage a1 is extracted with alkaline liquid while blowing oxidizing gas; +Cj above (h1 stage - (obtained
and (d) a neutralization stage in which CO2-containing gas is injected to neutralize it; A method for recovering vanadium from ash containing ■ a precipitation recovery step of adding and recovering ■ as an ammonium salt.

(Aspects of the Invention) Next, Figure 1 of the accompanying drawings shows a flow saw 1- of the method according to the present invention.
The present invention will now be described in more detail.

Examples of the ash containing 1iii. There are no restrictions. Also, even in such combustion ash,
This includes not only in-furnace ash, but also fly ash, which has a significantly low content. In particular, according to the present invention,
Since the concentration ratio is very high, it has a great practical effect when applied to low concentration materials such as fly ash.

Such ■Contained ash is the internal pressure of heavy oil combustion furnace and 1! The scattered ash generally has the composition shown in Tables 1 and 2, respectively.

40~80 1~71~200~33~10cy-total
Lou ul 910~701~50.5~230~603~201~8
First, according to the present invention, (1) the containing ash is chopped and subjected to specific gravity separation. Gravity separation typically involves flotation, but other methods such as centrifugation and coagulation and sedimentation can also be used. Preferably it is carried out by flotation. The present invention will be explained below by taking as an example the case where flotation is carried out using kerosene, Pineura or other flotation oil.

Through this flotation, 7F-free substances containing C, etc., and ■, Ni
, and a precipitate in which Fe etc. are concentrated. In addition,
Preferably, since the suspended matter at this time also contains a portion of ■, Ni, Fe, etc., it is washed with an alkaline solution and recovered again. The step of recovering the V-concentrated precipitate from flotation involves concentrating and separating the content based on the difference in specific gravity.
Processing conditions such as temperature and time are not particularly limited.

Table 3 summarizes the changes in the solid content before 65 selections and in the precipitate after 4 selections. In addition, in the example of expression, a V-containing fire containing V8 to 10% was used as a starting material.

Table 3 (Table 3, continued) (Note) Test positive 2.3 is obtained by flotation after neutralization. The precipitate rich in The alkali solution is extracted by blowing the molten metal into the molten metal.As the alkali solution for extraction, desulfurization/dephosphorization slag by adding soda ash to the hot metal is preferably used for operation at a steelworks because of its ease of labor. A slurry obtained by cooling with water, from which the solid content has been removed, can be advantageously used. In addition, in the present invention, since alkaline extraction is performed while blowing in oxidizing gas, (1) the dissolution rate is improved.

Here, two types of heavy oil combustion ashes, A and B, having the compositions shown in Table 4 are used. An example of ζ-alkali extraction used as an extractant is shown below. The alkaline liquid at this time is an alkaline liquid obtained by removing the solid content from the desulfurization/dephosphorization slag made by adding soda ash and cooling it with water to form a slurry, and has a pH of 9 to 11 and contains Na 2 and CO38 = 10%. It was something.

Table 4 (% by weight) Old translation alkaline solution 1.5 II! 1 kg of ash was mixed and compressed air at a pressure of 5 = 7 kg/cot was poured into an alkaline extraction bath at a rate of 2 e/m, il for 6 to 7 hours. Bath/l! ! The T degree is 60-70 ゛.

Cumulative compressed air input and V for the case of V-containing 4 ash-
The relationship with elution rate (%) is shown graphically in FIG. 2, and a similar relationship was shown in the case of J-0V R-containing ash-13.

Next, hydrogen peroxide is added as an auxiliary oxidant, and in combination with compressed air, the elution rate is improved to the extent of (1).

I bent down. ■For the case of ash-A, calculate the elution rate of 35% hydrogen peroxide (kg/kg of V-containing ash)! It is shown in Figure 3. In the case of Fig. 3, the extraction process was carried out at 60°C for 3 hours, or the blowing of compressed air was carried out for 5 hours, and a total of 600 a of air was used. Incidentally, in the case of ash-B containing ■, a similar upward orientation was also observed.

As is clear from the results shown in FIG. 3, if a sufficient amount of compressed air is blown, an auxiliary oxidizer is not necessarily required.

The solution enriched in (1) is then concentrated in (V) by, for example, introducing steam, if necessary. ■ Approximately 3-6% of the time
After adding water, the mixture is solubilized as an alkaline solution, and then neutralized by blowing in 002-containing residue, such as combustion waste residue, to adjust the pH to 8 to 9, for example.

The results of neutralization treatment by CO2-containing waste injection are summarized in Table 5 and are not shown. Without using chemicals such as H2SO, t, p)l can be reduced to 10 by simply blowing 002-containing gas.
We were able to reduce it from 8 to 8. 7 as a comparative example
5% H2SO4 2.04kg/Vkg and 35%
■ When using 1.09kg/V kg of H202
The yield is also shown.

In addition, the relationship between the amount of C02-containing gas blown and the change in alkaline solution PL+ is shown in a graph in No. 41 No. 1. In this case as well, the starting point is
5%) and knead for 7 minutes at 30.61! /Q
Contains i+' Ryo Karin Yong, (k is 41! i19 and 7-
(from 11.riai-C1O%Cal of 2I/min,
Injected with self-containing gas. 〆(shi?ll!t L;1.'
29-35° (,ζ was.

As shown in Table 5, since the dehydrated cake has a slight trace of v or 1', it can be washed with water, or if necessary, it can be washed with C cleaning may be performed using alkaline l&.

Next @ NiN1, C7! By adding ammonium salts such as ■
) is recovered as ammonium salt. This 7-minute precipitation recovery] 1 culm is already well known in the industry, and steps 2 and 8 will be unnecessary.

Next, the present invention will be further explained with reference to Examples, which are merely illustrative and should not be interpreted as limiting the present invention in any way.

) (Fartff1LI 1.OOkg of 5%■ heavy oil combustion or fly ash was treated by neglecting Flowchart 1 shown in Figure 1. At this time, the amount recovered (kg) in treatment rows 11 and 7 was Summary C not shown in table.

In this example, 100 kg of ash from a 9% heavy oil combustion furnace was treated in the same manner as in Example 1. Processing conditions at this time,
The amount of L-7 recovered (kg) is summarized in Table 7.

Total recovery rate 78% Total 11. Ij yield: 80% As described above, through the series of steps according to the present invention, the recovery rate (2) from the starting material (1)-containing ash is about 80%.

Thus, according to the method according to the present invention, not only can it be completely recovered, but the recovery cost is also lower than that of conventional methods because it does not use any special energy or chemicals. As is easily understood, much less is required. In addition, since it is a wet method, there is no need to handle v205, which is designated as a special compound, so the present invention is a highly practical method.

[Brief explanation of drawings]

Fig. 1 shows a flow note of the method according to the present invention; Fig. 2 shows the amount of oxidizing gas blown during alkaline liquid extraction and V? Figure 3 is a graph showing the relationship between the amount of 8202 input and the elution rate. It is a graph showing the relationship between the amount of gas input and /8 liquid (■)11. (al: if Separation and recovery stage (b) of free products and precipitates
: Alkaline extraction stage (C); Neutralization stage + d) : Precipitation and recovery stage of ammonium salt of V

Claims (1)

[Scope of Claims] (Separation and collection of al V-containing ash into / $ free products and precipitate with v content of /1% fiii according to specific gravity 1ii11; tb + above (a + stage An alkaline extraction stage in which the precipitate separated and collected is extracted with an alkali solution while blowing in oxidizing residue; sum stage; and (df
(1) Precipitation recovery step in which precipitates are removed from the liquid containing liquid neutralized by CO2 injection in the Cl step, and ammonium salt is added to precipitate and recover V as an ammonium salt. ■ A method for recovering Harishira J from containing ash.