JPS60155631A - Method for recovering zinc from material containing zinc compound - Google Patents

Abstract

PURPOSE:To recover inexpensively and easily zinc with high concn. by sintering the briquettes consisting of a zinc compd. and carbonaceous material in a strong reducing atmosphere, metallizing and evaporating the zinc compd. and oxidizing the same in a strong oxidizing atmosphere. CONSTITUTION:A zinc-contg. dust raw material is charged into a kneading machine 1 and the concn. of the carbon and zinc contained is adjusted by a carbonaceous reducing agent and low zinciferous iron material. The raw material is briquetted by a briquetting machine 2 and further Ca compd. is coated thereon by a briquetting machine 3. The briquettes are charged into a laminar state between the sintering raw material 5 of a DL type sintering device and bedding ore 6. The top surface of a sintering raw material 5 is ignited by an ignition furnace 16 and the raw material is sintered by charged air 9 in the stage of moving in the sintering device. The zinc compd. subjected to reduction there is metallized and evaporated. The evaporated zinc is made into zinc oxide in the oxidizing gaseous flow and is separated from the other waste gas. Coarse particle dust is removed by a dust collector 12 and the zinc oxide is captured by a dust collector 13.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for recovering zinc from materials containing zinc compounds, such as metal refining raw materials or dust generated during metal refining processes.

For example, various types of dust generated in steel mills are collected and reused from the standpoint of effective resource use and environmental protection. However, in this case, the zn compound poses the biggest problem. zn@
In some cases, dust with a low concentration is directly supplied to a sintering machine, converter, electric furnace, etc., but in order to reuse blast furnace dust with a high Zn concentration as a raw material for steelmaking, it is necessary to remove Zn as a pretreatment.
It is necessary to carry out processing. At present, typical methods for removing Zn include classification using a wet cyclone and reductive evaporation using a rotary kiln.

The former wet cyclone method utilizes the property of Zn to concentrate on the fine grain side, and the removal rate (dezn''4) by this method is
) is about 60-80%. The latter rotary kiln method takes advantage of the fact that the boiling point of metallic Zn is approximately 910°C, and the Zn in the dust is mainly produced by the reaction of the queen.
2 will be removed.

C(8)+2GO(Q) for CJC9 (pup dowa return response)~(1) zno('8)+, Co(9)+=Zn(9)+1:!
02 (Reduction of ZnO and evaporation of Zn) - (2) Zn(f)
+%Q2(9) +=ZnO(S) (oxidation and recovery of Zn) -+31 The removal rate of Zn by the 0-tally kiln method is 80 to 95%
It is.

Compared to the rotary kiln method, the wet cyclone method has a lower processing cost, but has the disadvantage of a lower Zn removal rate. In comparison, the rotary kiln method has a high Zn removal rate, but the processing cost is high and it is still unprofitable even taking into account the benefit of turning iron-containing dust into reduced pellets. For these reasons, the value of dust as a steelmaking resource is low, and currently it is disposed of for environmental reasons rather than from the standpoint of effective resource utilization.

The present invention solves the above problems and provides an inexpensive dust treatment method (
The purpose of this invention is to provide a method for recovering zinc that combines the effective use of dust and environmental measures based on the Zn removal method. This makes it possible to collect highly concentrated zinc and supply it as a high value-added raw material to the subsequent metal zinc refining process. Furthermore, the present invention not only dezincinates dust generated in steel works, but also dezincinates dust generated from metal refining raw materials or metal refining processes,
It is an object of the present invention to provide a suitable method for recovering zinc.

In order to achieve the above object, the present invention involves mixing a material containing a zinc compound with a carbonaceous material, if necessary, and supplying the material into a sintering device after being coated with a calsulam compound, so that the material is in a combustion temperature range. After metallizing and evaporating the zinc compound in the substance by creating a locally strong reducing atmosphere, zinc oxide is produced by oxidizing the vaporized zinc in the strongly oxidizing atmosphere. , and is characterized in that it is discharged from the device in that state.

An explanation will be given below based on one embodiment of the present invention.

In this example t, dust discharged from a steel mill is selected as the substance containing zinc compounds, and a normal DL type sintering machine is used as the sintering device.

In FIG. 1, A shows the dust kneading and briquette process, and B shows the sintering and dust dezincing process using a p'L type sintering machine. The Zn-containing dust raw material is sent to a kneader 1, where a carbonaceous reducing agent and a low-Zn iron-containing substance are added as necessary to adjust the carbon-containing concentration and Zn-containing concentration. The dust whose carbon-Zn concentration has been adjusted is sent to a briquette machine 2 and briquettered. Further, the briquette mineral is sent to the briquette machine 3 and coated with a calcilum compound. The coating material is for shielding the zinc-containing dust from a strongly oxidizing atmosphere in the subsequent dezincing process, and naturally needs to have zero or very small zinc content, and limestone and Fromite are preferable.

The aggregate mineral is then sent to a sintering machine, as shown in Figure 1.
It is charged in a layer between the sintering raw material 5 and bedding ore 6 which is charged to protect the great bar.

The upper surface of the sintering raw material is first ignited in the ignition furnace 16f, and then, in the process of moving over the sintering machine, the charged air 91
This causes it to be burned. The sintered ore combustion zone continuously moves downward from the upper surface, and after the combustion of the lowest layer is completed, it is discharged to the cooler.

For this reason, combustion of the Zn-containing dust pellets charged into the bottom layer of the sintering raw material occurs near the ore discharge side.

When the Zn-containing dust pellet layer starts to burn, as in the rotary kiln method, due to the action of the carbon-containing material, the above (1)
The reaction (2) occurs, and metal zinc is evaporated and removed from the pellets. Here, since the Zn-containing dust pellets are coated with a coating agent, the pellets are shielded from the oxidizing atmosphere as described in Section 2, and the reaction (2) above is promoted. The evaporated Zn becomes zinc oxide through the reaction (3) above in the oxidizing gas flow, and is led together with the dust generated during the sintering process to the dust collector.

At this time, as shown in FIG.
Separate it from other exhaust gases and collect it! (The dust collector quantity 12 removes wire assembly dust, this dust is recycled as a dust raw material, and the dust collector 18 collects zinc oxide), thereby making it possible to selectively collect dust with a high Zn concentration.

Below, experimental results regarding the recovery and removal of Zn from Zn-containing dust using a small sintering machine will be shown. The Zn removal rate after the experiment was calculated using the following formula.

zn: Zn (qb) Zn' in Be L/, To before removing Zn:
After getting off ZN! (Man T, Fa: T, FJ% in pellet before Zn removal) T,
Fe2: After removing Zn (%) One briquette of raw material dust is a disk type φ6o.

A granulator was used. Preferably, the limestone coating is less than 1 inch thick. Small sintering experimental equipment used in the experiment (Fig. 2) To simulate the operating conditions of the actual machine and sintering machine, a sintered layer of 400 fins, a superficial velocity of 0.33 Nm/sea,
The operation was carried out under actual machine conditions. However, considering the ease of collecting pellet samples after the experiment, approximately 100 crumbs of Zn-containing pellets (approximately 2% per 1 sintered raw material) were charged on top of the sintered raw material, and fuel air was charged from below. (Fig. 2 collagen).

The influence of the amount of carbon contained, the amount of Zn contained, and the coating on the ZN removal rate is shown in FIG. As a result of this, F) There is a strong relationship between the carbon content and Zn content and the Zn removal rate. Therefore, in order to obtain the optimum Zn removal rate as the raw material for blast furnace charging, one
It is necessary to adjust the amount of n, and a coating process is required.

In the above example, the Zn removal treatment using a sintering machine 1 for Zn dust generated at a steelworks and its recovery method are explained in detail.As can be inferred from the above experimental results, It is thought that oxidized pellet firing equipment and the like are also included in the calcination equipment, and it goes without saying that the use of such equipment also falls within the technical scope of the present invention.

As explained above, the processing of Zn-containing dust has become difficult, and not only has sintered ore with a low Zn concentration been supplied to the blast furnace, but also Zn in Zn-containing dust can be recovered easily and cheaply. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, and FIG. 2 is an actual M
1 Schematic diagram of the small sintering experimental equipment used, Figure 3 shows the carbon-containing
Figure 7 shows the influence on the Zn removal rate when Zn-containing pellets are covered with limestone. A... Mixed wire, briquette process B... Dezincing process 1...
Kneading machine 2...Bulking machine 3...Bulking machine 4...Sintering raw material hopper 5...Sintering raw material 6...Bed ore?
...Zn-containing dust group mineral 8...Sintered ore 9...
Charged air 10... Wind box 11... Dust collector 12.
・・Dust collector (pre-duster) 13 Kawa Jl dust machine 14・
...FIIIW 15...Chimney 16...Ignition Furnace Procedure Amendment April 2, 1985 Manabu Shiga, Commissioner of the Patent Office1, Indication of Case Patent Application No. 11069-1982, Title of Invention Method 3 of recovering zinc from materials containing zinc compounds;
Relationship with the case of the person making the amendment Patent applicant address 2-2-1 Otemachi, Chiyoda-ku, Tokyo Name
(210) Sumitomo Heavy Industries Makoto Industries Co., Ltd. 4, Agent address: 6, Sumitomo Heavy Industries Makoto Industries Co., Ltd., 2-2-1 Otemachi, Chiyoda-ku, Tokyo, Japan. The scope of claims is amended as follows. [After briquetting a material containing a carbonaceous material and a zinc compound, and further coating the briquette with a calcilum compound, the material is fed into a DL liquor sintering device, and the sintering temperature range of the material is Extremely! The zinc compound in the substance is metallized and evaporated by producing S1 reduction 81III gas, and after separation from the substance, zinc oxide is produced by oxidation of vaporized zinc in a strongly oxidizing atmosphere. A method for recovering zinc from a substance containing a zinc compound, characterized in that zinc is discharged from the sintering device in that state. ” (2) Ming! In the first line of page 2 of the JJJ book, "metal refining raw materials" is corrected to "pretreatment process of metal refining raw materials." (3) On page 5, line 15 of the specification, "metal ['raw material"] is corrected to "pretreatment process for metal refining raw materials." 0) On page 5 of the specification, lines 4 to 12, "In order to achieve the above-mentioned purpose, the present invention is characterized by..." is corrected as follows. "In order to achieve the above object, the present invention mixes a carbonaceous material if necessary with a material containing a zinc compound, and after coating the briquette with a calcium lam compound, the briquette mineral is DL.
The zinc compound in the substance is evaporated and separated into gold by forming a locally strong reducing atmosphere in the sintering temperature range, and then the strongly oxidizing atmosphere is This method is characterized by generating zinc oxide from the northernmost part of the originally vaporized zinc and discharging it from the device in this state. (5) Correct Figure 2 as attached.

Claims (1)

[Claims] After a material containing a carbonaceous material and a zinc compound is bonded with a calcilum compound, the material is fed into a sintering device and a strongly reducing atmosphere is generated locally in the combustion temperature range of the material. The zinc compound inside is metallized and evaporated,
Zinc is extracted from a material containing zinc compounds, characterized in that after separation from the material, zinc oxide is produced by oxidation of vaporized zinc in a strongly oxidizing backing atmosphere and discharged in this state from the sintering device. How to recover.