JPS6393832A - Wet treatment of sintered zinc ore - Google Patents

Abstract

PURPOSE:To permit recovery of zinc and other valuable metals with a high extraction ratio with a min. number of solid-liquid sepn., by subjecting a neutral slurry to the solid-liquid sepn. after high-acid melting, acid melting, iron removal and neutralization at the time of subjecting sintered ore to an extraction treatment with an electrolytic liquid. CONSTITUTION:The sintered zinc ore is added to the zinc electrolytic liquid and is treated under prescribed extraction conditions in a high-acid melting stage. The greater part of zinc ferrite can be melted if the treatment is made for a long period by decreasing the amt. of the sintered ore to be added and elevating the temp. in this case. The sintered ore remaining after the extraction is added at a prescribed ratio to the high acid melting slurry and the treatment is made under the prescribed conditions in an acid melting stage. The greater part of ZnO in the sintered ore added thereto melts but the greater part of the zinc ferrite does not melt in this case. The prescribed conditions are maintained under the addition of the carryover of the sintered ore to the acid melting slurry and the Fe<2+> remaining without settling is settled and removed in an iron removing stage. A neutralizing agent is added to the slurry removed of iron and the slurry is thickened and filtered in a neutralizing stage.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention extracts zinc and other valuable metals contained in the zinc sintered ore with an extremely high extraction rate by extracting zinc sintered ore with a zinc electrolytic tailing liquid. The present invention relates to a method for wet processing of zinc sinter, which involves melting and then removing iron from the melt slurry.

[Conventional technology]

Zinc smelting is broadly divided into pyrometallurgy and hydrometallurgical smelting, and hydrometallurgical smelting (electrolytic smelting) is currently the mainstream. Usually, zinc hydrometallurgy is carried out in a flow as shown in FIG.

When zinc concentrate is roasted, iron contained in the concentrate forms zinc ferrite (20.0.F e20 ) with zinc and the like. Since this zinc ferrite is poorly soluble in dilute sulfuric acid, conventional melting of zinc sintered ore is carried out under conditions that do not dissolve the zinc ferrite.

Therefore, since the dissolved residue contains a large amount of zinc etc. as zinc ferrite, the extraction rate of zinc etc. is almost determined by the iron content, and a high value cannot be expected.

Generally, in order to increase the extraction rate of zinc and other valuable metals, it is necessary to further process the dissolved residue mainly composed of zinc ferrite.

Methods for treating these residues include fuming method,
There are dry methods such as the Wertz method, and wet methods such as the jarosite method, the goethite method, and the hematite method.

In recent years, a wet method has been introduced into actual operations in which the dissolved residue is treated with sulfuric acid to advantageously precipitate and remove dissolved iron along with zinc and other valuable metals.

With the establishment of this technology, the yield of zinc and other valuable metals has been significantly improved.

The above-mentioned wet treatment method of dissolving and soaking is called Javasite method, Goethite method, and Hematite method depending on the form of the iron precipitate removed.

In the Javasite method, iron is converted into X-Fe5(Son)2(OH)
) &(X; Na, K, NH), it is necessary to add an alkali such as NH5 to Na.

In addition, in the goethite method, iron is converted into FeO-OH or F
This method involves precipitation and removal as e2O, .H2O, and requires reduction and oxidation steps.

Furthermore, the hematite method uses Fe,O to remove iron and requires heating to a high temperature of 200° C. under oxygen or air pressure, so an autoclave is used.

All of the above-mentioned methods are a dual melting method consisting of a combination of acidic dissolution of the zinc sintered ore and high-temperature, high-acid dissolution of the dissolved residue. Therefore, there is a drawback that a large amount of investment is required in thickeners and filtration equipment due to frequent concentration or filtration.

(Problems to be Solved by the Invention) In view of the above-mentioned prior art, the present invention minimizes the number of solid-liquid separations, eliminates the need for additives such as alkali, and eliminates the need for zinc and other substances contained in zinc sintered ore. The object of the present invention is to provide a method for wet treatment of zinc sintered ore, which dissolves valuable metals at an extremely high extraction rate, and then precipitates and removes iron from the molten slurry.

(Means for solving the problems) As shown in FIG.
Solid-liquid separation is not performed until iron removal and neutralization, and the neutralized slurry is finally subjected to solid-liquid separation to send the neutral liquid to the cleaning process.The dissolved residue is a mixture of lead and silver residue and iron precipitate. This is a wet processing method for zinc sintered ore used in the lead smelting process.

That is, in the present invention, when extracting zinc lump ore with electrolytic tailings, the burnt ore is dissolved in a highly acidic solution, then the zinc burnt ore is added to the highly acidic dissolved slurry and dissolved in an acidic manner, and then the burnt ore is dissolved in an acidic manner. This is a wet processing method for zinc sintered ore, which is characterized by adding zinc sintered ore to the slurry to remove iron. 60 to 80% of the total amount of burned ore is wet-treated at 80 to 95°C for 3 to 6 hours.
Dissolved under extraction conditions with a final H2So4 concentration of 30 to 100 g/Ω, and during acidic dissolution, 20 to 20% of the total amount of wet processing
adding 40% zinc sinter to the highly acidic dissolved slurry;
Acidic dissolution for 1-3 hours at 80-95 °C, final H2SO
, the concentration was 1 to 20 g/Q, and during the iron removal, zinc sinter was added to the acidic dissolved slurry at 70 to 95°C.
This is a wet processing method for zinc sintered ore to remove iron under extraction conditions of pH 1.4 to 3.4.

Furthermore, it is a wet treatment method for zinc sintered ore, characterized in that a part of the iron precipitate obtained in the iron removal step is repeatedly subjected to the acid dissolution as a seed for iron precipitate.

(Function) A flow sheet of the wet treatment method for zinc sintered ore of the present invention is shown in FIG.

As shown in FIG. 1, in the highly acidic dissolution step, zinc sintered ore is added to the zinc electrolytic tailing solution, and the process is carried out under extraction conditions of 80-95°C and 3-6 hours.

In this case, if the amount of zinc sintered ore added is 60 to 80% of the total extraction treatment weight added in high acidity and acidic dissolution, the final acid concentration of the highly acidic solution will be 30 to 100 g/l,
Can dissolve most of the poorly soluble zinc ferrite.

In this case, the final acid concentration varies depending on the amount of zinc sintered ore added during highly acidic dissolution, and therefore the rate at which zinc ferrite is dissolved will also be affected. In other words, the dissolution of zinc ferrite can be promoted by reducing the amount of zinc sintered ore added, increasing the temperature, and performing the treatment for a long time.

Next, in the acidic dissolution step, 20 to 40% of the extracted zinc sintered ore is added to the highly acidic dissolution slurry, and the temperature is 80 to 95°C.
p) Treat with IO, 5-2 for 1-3 hr.

In this case, the final acid concentration of the acidic solution is 1 to 20 g/l, so the Zn contained in the zinc sintered ore added in the acidic solution is
Most of the O dissolves, but most of the zinc ferrite does not.

The smaller the amount of zinc sintered ore added in highly acidic dissolution, the higher the extraction rate of zinc and other valuable metals in highly acidic dissolution.
Since the amount of zinc sintered ore added during acid dissolution increases, the total extraction rate of zinc and other valuable metals may decrease in some cases.

Therefore, by adjusting the amount of zinc sintered ore added in highly acidic dissolution as described above, the total extraction rate of zinc and other valuable metals can be maximized.

Furthermore, although appropriate ranges for the reaction temperature and reaction time are shown in consideration of economic efficiency, it is clear that higher temperatures and longer times are desirable.

In highly acidic and acidic dissolution, 60 to 80% of the zinc ferrite contained in zinc burnt ore is dissolved, and the iron eluted with zinc is mostly present as ferric ions.

A part of this ferric ion is precipitated by acidic dissolution, and the rest is precipitated and removed by iron removal.

Ferric ions first start to precipitate during the acidic dissolution process, so by repeating the acidic dissolution of the iron-removed slurry, both the sedimentation properties and furnace suitability are stabilized in the presence of iron precipitation seeds. It became possible to obtain good iron precipitates.

In the iron removal process, carryover zinc sintered ore is added to the acidic dissolution slurry at 70-95°C and pH 1°4-3.
By maintaining the condition in step 4 for 1 to 3 hours, the remaining ferric ions are precipitated and removed.

In the neutralization process, an appropriate neutralizing agent is added to the iron removal slurry,
Finally neutralize to p)I 4.8-5.2.

This neutralized slurry is concentrated in a thickener, the supernatant liquid is sent to the cleaning process as a neutral liquid, and the concentrated spigot is washed with water, filtered, dried, and used for the lead smelting process, where valuable metals such as lead and silver are processed. Collect.

In the process of melting zinc sintered ore, there are cases where it is economical to recover high-grade residue such as lead and silver, and where the neutral solution is acidified to extract the maximum amount of zinc and other valuable metal scraps. If it is necessary to repeatedly perform so-called multiple melting, the same effect can be obtained even if the process is carried out using the flow sheet shown in FIG.

Furthermore, the method of the present invention can also be applied to raw materials such as smoke ash, which contains zinc oxide as a main component and contains a large amount of iron.

According to the wet processing method of zinc sintered ore of the present invention, for example, in zinc sintered ore with a low iron content (Fe45.4%), the extraction rate of zinc was 92 to 94% in the conventional method. 95～
98%, while burnt ore with a relatively high iron content (Fe;
9.9%), the extraction rate is significantly improved from 87 to 90% to 92 to 95%.

Next, examples of the present invention will be described.

〔Example〕

[Example 1] 2U of electrolytic tailing liquid (Zn; 51g
/l.

The analytical values of zinc sinter, highly acidic solution, and highly acidic solution are shown in Table 1 below, and the extraction rate of zinc was 99.1%.

Table 1 (Yoi t %) Next, add zinc sintered ore, and the final pH,s~1.0.90
Acidic dissolution was performed under extraction conditions of t and 1.5 hr.

The analysis values of the acidic solution and the acidic solution are shown in Table 2 below, and the extraction rate of zinc was 95.1%.

Table 2 (wt %) The overall zinc extraction rate through high acid dissolution and acid dissolution is 9
At 8.2%, the extraction rate of zinc as ferrite is 66.8
%Met.

[Example 2] Ferrous sulfate and ferric sulfate reagents were added to a neutral solution obtained by the conventional method to obtain ve: a g#! ,Fll:0.
An iron solution adjusted to 1 g/l was obtained. This iron solution was added to a conventional neutral solution maintained at a temperature of 80 DEG C., and during this time iron was removed by controlling the pH to 2.6 to 3.0 with a zinc hydroxide slurry.

After iron removal is complete, neutralize with calcium carbonate and prepare the final p
It was set as H4.8 to 5.2.

This neutralized slurry 19 was added with a coagulant (Cliffrock PN-1).
71) was added, and the sedimentation rate and filtration rate were measured. As a result, the uniform sedimentation rate is 3,3 crtr
1 minute, filtration rate is 4.9111. Q/Cl was 1129 minutes.

(Example 3) In the same manner as in Example 2, the pH of iron removal was changed and the sedimentation rate and overrate were measured. The results are shown in Table 3 below.

As shown in Table 3, the suitable pH for iron removal was found to be in the range of 1.4 to 3.4.

[Example 4] 10 reaction vessels (effective volume: 3.39 cm) were arranged in series, allowing overflow from the first-stage tank to the second-stage tank, and from the second-stage tank to the third-stage tank, each of which could be temperature-controlled with an electric heater. Using a testing device, we conducted consistent continuous tests ranging from highly acidic dissolution to neutralization.

Highly acidic dissolution is carried out in the 1st to 4th tanks, and zinc electrolytic tailings (H2SO, concentration approximately 200g/U) is supplied to the 1st stage tank at 3.34 J/hr using a metering pump. A constant amount calculated from the H, So, and concentration of the zinc electrolytic tail solution was added using a quantitative feeder.

Therefore, the residence time per tank was 1 hour, and all temperatures were controlled at 90±5°C.

5. Acidic dissolution is performed in the 6-stage tank, and p)l in the 6-stage tank is 0.
．． The amount of zinc sintered ore added to the 5-stage tank was controlled so that the amount was 5 to 2.

7. In the 8th stage tank, iron is removed and the pH of the 8th stage tank is 1.4 to 3.
．． A carryover product (smoke ash) of zinc sintered ore was added to the 7-stage tank so that the amount of

9. Neutralization was performed in the 10-layer tank, and a neutralizing agent of calcium carbonate was added to the 9-layer tank to bring the pH of the 10-layer tank to 4.8 to 5.2.

The overflow of the 10-stage tank was sampled, and 12 times of flocculant (Cliffrock PN-171) was added per sentence.
In addition, sedimentation and facultability were measured.

2 for zinc sintered ore with low iron content (test NO. 1) and zinc sintered ore with high iron content (test NO. 2).
The test was conducted continuously for 4 hours.

The results were as shown in Table 4 below.

Example 5 A test was conducted in the same manner as in Example 4 on zinc sintered ore with a low iron content (Example 4, equivalent to Test No. 091).

However, the effect of the type of iron precipitation was investigated by adding the iron removal slurry from the 8-stage tank to the 5-stage tank at an addition rate of 11/min.

The results are shown below as Test No. 3.

The data of Test N001 of Example 4 is attached for comparison.

The sedimentation curves of test Nos. 1 and 3 are shown in FIG.

〔Effect of the invention〕

According to the wet processing method for zinc sintered ore of the present invention, the existing single-type continuous neutral melting equipment can be used almost in its original form, and there is no need for equipment that requires huge investment such as thickeners and filters. This method has the effect of recovering zinc and other valuable metals from ore at an extremely high extraction rate.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are process explanatory diagrams of the method of the present invention,
Figure 3 is a sedimentation curve graph of iron precipitation in [Example],
FIG. 4 is an explanatory diagram of the zinc hydrometallurgy process, and FIG. 5 is an explanatory diagram of the conventional treatment process.

Claims (5)

[Claims] (1) When extracting zinc sintered ore using electrolytic tailings, the zinc sintered ore is dissolved in a highly acidic solution, then the zinc sintered ore is added to the highly acidic dissolved slurry, dissolved in an acidic state, and further added to the acidic dissolved slurry. , a wet processing method for zinc sintered ore characterized by adding zinc sintered ore to remove iron. (2) When dissolving zinc sintered ore in a highly acidic solution using electrolytic tailings,
A total of 60 to 80% of the zinc sintered ore is heated to 80 to 95°C.
, 3-6 hours, final H_2SO_4 concentration 30-100g
The wet processing method for zinc sintered ore according to claim 1, characterized in that the zinc sintered ore is dissolved under extraction conditions of /l. (3) During the acid dissolution, add 20 to 40% of the total wet-processed amount of zinc sintered ore to the acid dissolution slurry, and
Acidic dissolution for 1-3 hours at 95°C, final H_2SO_4
A wet treatment method for zinc sintered ore according to claims 1 and 2, characterized in that the concentration is 1 to 20 g/l. (4) When removing iron, zinc sinter is added to the acidic dissolved slurry to remove iron under extraction conditions of 70 to 95°C and pH 1.4 to 3.4. A wet treatment method for zinc sintered ore according to items 1 to 3. (5) Zinc according to claims 1 to 4, characterized in that a part of the iron precipitate obtained in the iron removal step is repeatedly subjected to the acidic dissolution as a seed for the iron precipitate. Wet processing method for sintered ore.