CN1243167A

CN1243167A - Method for extracting zinc from zinc-contained waste residue and apparatus thereof

Info

Publication number: CN1243167A
Application number: CN98103329A
Authority: CN
Inventors: 金云龙; 史宝龙
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-07-28
Filing date: 1998-07-28
Publication date: 2000-02-02

Abstract

The present invention relates to a method for extracting zinc and its equipment. Said method includes the process of preparing zinc-bearing raw material pellets, simultaneously making sintering and distillation and simultaneously making deslagging and feeding, and its equipment includes a furnace whose upper portion is a cavity chamber and lower portion is a firebox, feed buskets uniformly and vertically placed in the furnace and dust-removing system formed from main dust-suction pipe, cyclone separator, dust suction pipe, draught fan, dust-discharging pipe and cloth bag recoverer which are connected in sequence. The vertical bucket is made of silicon carbide, its cross-section is made into the form of oval, and is formed from upper portion extended from furnace and lower portion placed in furnace. Its zinc recovery rate is up to above 95%, and its service life is long.

Description

Method and equipment for extracting zinc from zinc-containing waste residue

The invention relates to the field of metal refining, in particular to a method and equipment for refiningzinc from zinc-containing waste residues.

At present, zinc in industrial zinc-containing waste residues is not fully recycled, for example, when several manufacturers for producing containers in China spray paint the containers with zinc-rich primer, a large amount of waste paint residues fall on the ground. The main components of the waste paint slag are simple substance zinc, micro zinc oxide and carbon macromolecule, wherein the zinc content can reach about 60-70%. All industrial waste residues are discarded in the past, more than five thousand tons of industrial waste residues can be obtained every year, and the method is astonishing in waste and polluting the environment.

At present, a small number of people use an earth method (namely a horizontal tank furnace) to refine the zinc ingot from the industrial waste residue, but the recovery rate can only reach about 65 percent, so that zinc resources are not fully recycled, the problem of environmental pollution is not solved, and the method is forbidden to be used by national plain text regulations; some large-scale smelteries also utilize the waste slag to smelt zinc, because such as sintering and distillation two-step methods, a large amount of simple substance zinc in the waste slag is changed into zinc oxide in the sintering process and is leaked out, the quality of raw material balls is influenced, the recovery rate of zinc is greatly reduced, or an electrolytic zinc process is used, calcining equipment needs to be added, the recovery rate of zinc is not high, and the like, so far, an extracting method and equipment which can fully recycle the zinc in the waste slag and meet the requirements of the national environmental protection department are not available.

The invention aims to solve the problems in the prior art and provides a method for extracting zinc from zinc-containing waste residue.

Another object of the invention is to provide an apparatus for implementing said method.

The first purpose of the invention is realized by improving the method of sintering and distilling in two steps in the prior art to synchronously carry out sintering and distilling.

The method for refining zinc comprises the steps of preparing zinc-containing raw material balls, sintering, distilling, deslagging and feeding, wherein the sintering and the distilling are synchronously carried out in a vertical shaking tank uniformly arranged in a sintering distilling furnace, the prepared zinc-containing raw material balls are fully filled in a vertical material tank at the moment, the sintering distilling furnace is gradually heated to 1300 ℃ by using fire coal, so that the raw material balls in each area naturally formed from bottom to top in the vertical material tank are subjected to oxidation-reduction reaction, solid zinc gasification, zinc gas liquefaction, sintering and preheating in sequence, and zinc liquid after the zinc gas liquefaction flows out and is cast into zinc ingots; the slag discharge and the charging are synchronously carried out at 1300 ℃ every 2 hours after the furnace is opened until the sintering distillation furnace is overhauled.

The other purpose of the invention is realized by combining two furnaces in the prior art into a sintering distillation furnace and improving a horizontal charging bucket into a vertical charging bucket.

The equipment for extracting zinc comprises a furnace 1, a charging bucket 2 and a dust removal system, wherein the furnace 1 is divided into an upper part and a lower part, the upper part is provided with a cavity for placing the charging bucket 2, and the lower part is provided with a furnace bore 3, a furnace bar 4, a fuel inlet 5, a central upper fire hole 6, two side lower fire holes 7 and a discharging slag channel 8; the charging bucket 2 is made of silicon carbide and has elliptical cross section and is erected in the cavity of the upper part of the furnace 1 uniformly, each charging bucket 2 consists of an upper part extending out of the furnace and a lower part arranged in the furnace, the top of the upper part is a cone 10 with a feeding port 9, the peripheral surface of the lower part of the cone is provided with an outward extending zinc liquid storage part 11 communicated with the inner part of the cone, and the bottom of the lower part of the cone is communicated with a blanking slag channel 8 at the lower part of the furnace 1; the dust removal system comprises a main dust collection pipe 12, a cyclone dust collector 13, a dust collection pipe 14, an induced draft fan 15, a dust discharge pipe 16 and a cloth bag recoverer 17 which are sequentially connected, wherein a dust collection cap 18 arranged above the outward extending zinc liquid storage part 11 of the charging bucket 2 is arranged on the main dust collection pipe 12, a dust discharge port 19 is arranged on the side surface of the outward extending zinc liquid storage part 11, and an overflow port 20 is arranged at the lower part of the outward extending zinc liquid storage part 11.

The furnace 1 and the charging bucket 2 in the equipment are the sintering distillation furnace and the vertical charging bucket in the method.

The method and the equipment have the advantages that:

1. the zinc refining is synchronously carried out in the sintering and distillation, wherein the zinc-containing raw material ball almost has no oxidation loss, so the recovery rate of zinc in the industrial zinc-containing waste paint slag can reach more than 95 percent;

2. because the equipment adopts the vertical charging bucket which is uniformly erected in the furnace and is made of silicon carbide and has an oval cross section, the vertical charging bucket has good heat-conducting property and uniform heating, and the vertical charging bucket cannot crack when the temperature changes rapidly, the service life of the vertical charging bucket is prolonged to 16 months from 1 month in the prior art;

3. the equipment has a more perfect dust removal system, thereby meeting the national environmental protection requirements.

Preferred embodiments of the method and apparatus of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a front view of a preferred embodiment of an apparatus for extracting zinc according to the present invention.

Fig. 2 is a top view of the embodiment shown in fig. 1.

Fig. 3 is a cross-sectional view at fig. 2A-a.

Fig. 4 is an enlarged sectional view of the 1-bucket portion in the embodiment shown in fig. 1.

The method for extracting zinc comprises the steps of preparing zinc-containing raw material balls, sintering, distilling, deslagging and feeding, wherein the zinc-containing raw material balls are prepared by taking zinc-rich waste paint residues as raw materials, performing closed ball milling on the zinc-rich waste paint residues, adding coke powder accounting for 17% of the weight of the zinc-rich waste paint residues, mixing the raw material balls to prepare the raw material balls, drying the raw material balls at a low temperature of 120 ℃, and preserving heat until water in the raw material balls is evaporated, so that the mechanical strength of the raw material balls is improved. Sintering and distillation as well as slag and feed are carried out in the zinc refining plant according to the invention.

Referring to fig. 1 to 4, the zinc refining apparatus of the present invention comprises a furnace 1, 22 buckets 2 uniformly erected in the chamber of the furnace 1, and a dust removing system consisting of a main dust suction pipe 12, a cyclone 13, a dust suction pipe 14, an induced draft fan 15, a dust discharge pipe 16 and a cloth bag recoverer 17 which are connected in sequence. The furnace 1 is divided into an upper part and a lower part, wherein the upper part is a cavity, and the lower part is provided with a furnace bore 3, a furnace bar 4, a fuel inlet 5, a central upper fire hole 6, two side lower fire holes 7 and a discharging slag channel 8. The 22 vertical charging pots 2 are made of silicon carbide material, have oval cross sections and are respectively composed of an upper part extending out of the furnace and a lower part arranged in the furnace. The top of the upper part of the device is provided with a cone 10 with a feeding port 9, and the peripheral surface of the lower part of the cone is provided with an outward extending zinc liquid storage part 11 communicated with the cone; the bottom of the tank at the lower part is communicated with a blanking slag channel 8 at the lower part of the furnace 1. The main dust suction pipe 12 is provided with 22 dust suction caps 18 which are arranged above the zinc liquid storage part 11 extending out of 22 charging pots 2. The side surface of the extended zinc liquid storage part 11 is provided with a dust discharge port 19, and the lower part is provided with an overflow port 20.

In the case of using the apparatus for zinc extraction shown in FIGS. 1 to 4, the raw material pellets prepared as described above are filled in the 22 vertical buckets 2, and then charged from the fuel inlet 5 of the lower portion of the furnace 1Adding fire coal, gradually heating the furnaceto 1300 ℃, and carrying out oxidation-reduction reaction on the raw material balls in the lower part of the vertical charging bucket 2 ) While the raw material pellets in the upper part of the charging bucket 2 are gasified, liquefied, sintered and preheated from bottom to top. Wherein the redox reaction is carried out in a region of the vertical bucket 2 at a height of about 2 m from the bottom thereof, and the temperature of the zinc gas is 1300 ℃; the solid zinc gasification is carried out in a heat exchange area which is about 0.4 meter higher than the oxidation-reduction reaction area, and the solid zinc in the area is converted into the zinc gas with the temperature of 1000 ℃ by the rising of the zinc gas with the temperature of 1300 ℃; the zinc gas liquefaction is realized by that the zinc gas with the temperature of 1000 ℃ enters the zinc liquid storage part 11 which extends outwards on the peripheral surface of the vertical charging bucket 2 and is naturally cooled to 800-500 ℃ to become zinc liquid; sintering in a region about 0.3 m above the heat exchange zone wherein said feedstock pellets are sintered by the excess heat of the heat exchange zone at 700 ℃; the preheating is carried out in a zone about 0.3 m above the sintering zone, wherein the raw material pellets are preheated to 300-700 ℃ by the residual heat of the sintering zone. The slag discharging and charging are that waste slag is discharged from a slag removing opening of a blanking slag channel 8 every 2 hours after the furnace is opened, and the prepared raw material ball is fully charged from a feeding opening 9 of a vertical charging bucket 2 until the furnace 1 is overhauled.

The micro zinc oxide, dust and carbon dioxide which are removed in the process of extracting zinc by the method are discharged and recovered through a dust removal system of the equipment, namely a main dust absorption pipe 12, a cyclone dust collector 13, a dust absorption pipe 14, an induced draft fan 15, a dust exhaust pipe 16, a cloth bag recoverer 17 and a suction hood 18 on the main dust absorption pipe which are connected in sequence.

If four furnaces are built, 160 kg of zinc ingots can be produced by using 1 vertical charging bucket for 24 hours to extract zinc liquid, 14 tons of zinc ingots can be produced by using the four furnaces every day, and 4200 tons of zinc ingots No. 1 can be produced by calculating 300 working days in the whole year. The equipment does not compete with large-scale enterprises in China for resources, can change waste materials into zinc with industrial utilization value, and does not pollute the environment.

Claims

1. The method for extracting zinc comprises the steps of preparing zinc-containing raw material balls, sintering, distilling, deslagging and feeding, and is characterized in that: sintering and distilling are synchronously carried out in vertical material tanks uniformly arranged in a sintering and distilling furnace, the vertical material tanks are filled with prepared zinc-containing raw material balls, the sintering and distilling furnace is gradually heated to 1300 ℃ by using fire coal, so that the raw material balls in each area naturally formed from bottom to top in the vertical material tanks are subjected to oxidation-reduction reaction, solid zinc gasification, zinc gas liquefaction, sintering and preheating in sequence, and zinc liquid after zinc gas liquefaction flows out and is cast into zinc ingots; the slag discharge and the charging are synchronously carried out at 1300 ℃ every 2 hours after the furnace is opened until the sintering distillation furnace is overhauled.

2. A method of extracting zinc according to claim 1, characterized in that: the zinc-containing raw material ball is prepared by carrying out closed ball milling on a zinc-containing industrial waste residue raw material, adding coke powder accounting for 15-20% of the weight of the raw material at the same time, mixing to prepare the raw material ball, drying at a low temperature of 100-150 ℃, and keeping the temperature until water in the raw material ball is evaporated, so that the mechanical strength of the raw material ball is improved.

3. A method for extracting zinc according to claim 2, characterized in that: the zinc-containing industrial waste residue raw material is a zinc-rich waste paint residue raw material.

4. A method for extracting zinc according to claim 3, characterized in that: the oxidation-reduction reaction is carried out in the area of the vertical charging bucket with the height of about 2 meters from the bottom of the vertical charging bucket, and the temperature of the zinc gas is 1300 ℃; the solid zinc gasification is carried out in a heat exchange area which is about 0.4 meter higher than the oxidation-reduction reaction area, and the solid zinc in the area is converted into the zinc gas with the temperature of 1000 ℃ by the rising of the zinc gas with the temperature of 1300 ℃; the zinc gas liquefaction is realized by that the zinc gas with the temperature of 1000 ℃ enters a part which extends outwards to store zinc liquid on the peripheral surface of the vertical charging bucket, and the zinc liquid is naturally cooled to 800-500 ℃ to become the zinc liquid; sintering in a region about 0.3 m above the heat exchange zone wherein said feedstock pellets are sintered by the excess heat of the heat exchange zone at 700 ℃; the preheating is carried out in a zone about 0.3 m above the sintering zone, wherein the raw material pellets are preheated to 300-700 ℃ by the residual heat of thesintering zone.

5. A method for extracting zinc according to any one of claims 1 to 4, characterized in that: the dust and carbon dioxide discharged in the process of the method are discharged and recovered through a dust removal system.

6. The equipment for extracting zinc comprises a furnace 1 and a charging bucket 2, and is characterized in that: the furnace is characterized by also comprising a dust removal system, wherein the furnace 1 is divided into an upper part and a lower part, the upper part is provided with a cavity for placing the charging bucket 2, and the lower part is provided with a furnace bore 3, a furnace bar 4, a fuel inlet 5, a central upper fire hole 6, two side lower fire holes 7 and a discharging slag channel 8; the charging bucket 2 is made of silicon carbide and has elliptical cross section and is erected in the cavity of the upper part of the furnace 1 uniformly, each charging bucket 2 consists of an upper part extending out of the furnace and a lower part arranged in the furnace, the top of the upper part is a cone 10 with a feeding port 9, the peripheral surface of the lower part of the cone is provided with an outward extending zinc liquid storage part 11 communicated with the inner part of the cone, and the bottom of the lower part of the cone is communicated with a blanking slag channel 8 at the lower part of the furnace 1; the dust removal system comprises a main dust collection pipe 12, a cyclone dust collector 13, a dust collection pipe 14, an induced draft fan 15, a dust discharge pipe 16 and a cloth bag recoverer 17 which are sequentially connected, wherein a dust collection cap 18 arranged above the outward extending zinc liquid storage part 11 of the charging bucket 2 is arranged on the main dust collection pipe 12, a dust discharge port 19 is arranged on the side surface of the outward extending zinc liquid storage part 11, and an overflow port 20 is arranged at the lower part of the outward extending zinc liquid storage part 11.

7. The apparatus of claim 6, wherein: the material jar 2 is 22, and they are arranged into four lines, and two lines in the middle respectively are 6 material jars of equidistance, and two lines outside each are 5 material jars of equidistance, and arrange in the middle during the equidistance of two lines, dust absorption cap 18 also is 22.