WO2017045566A1

WO2017045566A1 - System and method for manufacturing sulphur and iron oxide from pyrite

Info

Publication number: WO2017045566A1
Application number: PCT/CN2016/098509
Authority: WO
Inventors: 刘慧南
Original assignee: 刘慧南
Priority date: 2015-09-15
Filing date: 2016-09-09
Publication date: 2017-03-23
Also published as: CN105084323B; CN105084323A

Abstract

Provided are a system and method for manufacturing sulphur and iron oxide from pyrite. The system comprises a primary desulphurisation apparatus, an oxidation apparatus and a secondary desulphurisation apparatus, wherein the primary desulphurisation apparatus comprises a closed desulphurisation furnace (3), a waste heat utilisation device (5), a waste heat power generation device (6), a dust collection device (7), a sulphur recovery device (8), etc.; the oxidation apparatus comprises an oxidation furnace (11), the dust collection device (7), a safety pipe (13), a water tank (14), etc.; and the secondary desulphurisation device comprises the closed desulphurisation furnace (3), the dust collection device (7), the sulphur recovery device (8), etc. The method comprises: performing desulphurisation on pyrite using the primary desulphurisation apparatus to obtain ferrous sulphide and sulphur; performing oxidation on the ferrous sulphide using the oxidation apparatus to obtain a mixture of ferric oxide and elemental sulphur; and performing a secondary desulphurisation on the mixture of ferric oxide and elemental sulphur using the secondary desulphurisation apparatus to obtain ferric oxide and sulphur. Directly manufacturing sulphur and ferric oxide from pyrite has the advantages of having a low production process cost, being environmentally friendly, having a high sulphur utilisation rate, etc.

Description

System and method for producing sulfur and iron oxide by using pyrite

Technical field

The invention relates to a system and a method for manufacturing sulfur and iron oxide by using pyrite, and belongs to the technical field of pyrite smelting in the field of metallurgy.

Background technique

Pyrite is widely found in the earth and is produced in many mines around the world. There are mines that produce pyrite alone, and many pyrites that are produced by non-ferrous mines. Some coal mines also contain a certain amount of pyrite.

Many ore of non-ferrous mines contain a certain amount of pyrite, but because of the low value of pyrite, most of them cannot be recycled and are directly discharged into tailings. Since pyrite will gradually oxidize over time, it will cause serious environmental pollution. In China, pyrite is mostly used to produce sulfuric acid. However, sulfur production of sulfuric acid produces sulfuric acid compared to pyrite, and the project investment is more economical and more environmentally friendly.

The use of pyrite to produce sulfur has appeared in China before the 1980s. It mainly uses pyrite and coal to obtain sulfur under depleted oxygen conditions. Sulfur utilization rate generally does not exceed 70%, thus causing extremely serious environmental problems. Therefore, the process of producing sulfur from pyrite is basically stopped. Domestic technology uses a two-step process to produce sulfur. The sulfur of the pyrite is first oxidized to sulfur dioxide, which is then reduced by coal, but it is not used in production because of its high cost. So far, there are no low-cost, economical and environmentally friendly technical solutions that can use pyrite to produce sulfur and iron oxide.

Summary of the invention

In order to solve the above technical problems, an object of the present invention is to provide a system and method for producing sulfur and iron oxide using pyrite. The system and method provided by the invention can directly produce sulfur and iron oxide by using pyrite, and has the advantages of low process production cost, environmental protection, high sulfur utilization rate and the like.

In order to achieve the above object, the present invention first provides a system for producing sulfur and iron oxide using pyrite, which comprises: a primary desulfurization device, an oxidation device, and a secondary desulfurization device;

Wherein, the primary desulfurization equipment comprises a closed desulfurization furnace, a waste heat utilization device, a waste heat power generation device, a dust removal device and a sulfur recovery device; the lower part of the furnace body of the closed desulfurization furnace is connected with a feed hopper and a discharge hopper provided on opposite sides The closed desulfurization furnace is provided with a heating device, and the bottom of the furnace body of the closed desulfurization furnace is provided with an intake duct; the first interface of the waste heat utilization device is connected to the closed desulfurization furnace through a pipeline a second interface of the waste heat utilization device is connected to a first interface of the waste heat power generation device through a pipe, and a second interface of the waste heat power generation device is connected to the first dust removal device through a pipeline The second interface of the dust removing device is connected to the first interface of the sulfur recovery device through a pipeline, and the second interface of the sulfur recovery device is connected to the third interface of the waste heat utilization device through a pipeline The primary desulfurization equipment is used to remove pyrite Sulfur to obtain ferrous sulfide and sulfur;

The oxidation device comprises an oxidation furnace, a dust removal device, a safety pipe and a water tank; a lower portion of the furnace body of the oxidation furnace is provided with a feed hopper and a discharge hopper provided on opposite sides, and a heat transfer device is arranged inside the furnace body of the oxidation furnace The bottom of the furnace body of the oxidation furnace is provided with an air inlet duct, and a fan is arranged on the pipeline; the upper part of the furnace body of the oxidation furnace is connected to the dust removing device through a pipeline; the top of the furnace body of the oxidation furnace is connected At one end of the safety pipe, and the other end of the safety pipe is immersed in the water pool; the oxidation device is used for oxidizing ferrous sulfide produced by the primary desulfurization device to obtain iron oxide and elemental sulfur mixture;

The secondary desulfurization device comprises a closed desulfurization furnace, a dust removal device and a sulfur recovery device; the lower part of the furnace body of the closed desulfurization furnace is connected with a feed hopper and a discharge hopper provided on opposite sides, and the closed desulfurization furnace is provided a heating device, the bottom of the furnace body of the closed desulfurization furnace is provided with an intake pipe; an interface of the dust removal device is connected to the upper part of the furnace body of the closed desulfurization furnace through a pipe, and another interface of the dust removal device And connecting to an interface of the sulfur recovery device through a pipeline; the secondary desulfurization device is configured to perform secondary desulfurization on a mixture of iron oxide and elemental sulfur produced by the oxidation device to separate iron oxide and sulfur.

In the above system, preferably, the closed desulfurization furnace in the primary desulfurization equipment and the secondary desulfurization equipment respectively comprises a boiling roaster, a disc rotary roaster or a rotary kiln, etc., and other applicable conventional devices may also be used. . Different closed desulfurization furnaces can be selected according to the particle size of the pyrite (into a desulfurization equipment) that enters the closed desulfurization furnace, or the particle size of the mixture of iron oxide and elemental sulfur (into the secondary desulfurization equipment). Moreover, the closed desulfurization furnace in the primary desulfurization equipment and the secondary desulfurization equipment may be the same or different.

In the above system, preferably, the oxidation furnace includes a boiling roaster, a disk rotary roaster or a rotary kiln, and the like, and other suitable conventional devices may be employed. Different oxidizing furnaces can be selected according to the particle size of the ferrous sulphide which is processed into the oxidizing furnace.

In the above system, preferably, the heat transfer device is composed of a plurality of pipes uniformly distributed and vertically disposed and/or horizontally disposed inside the furnace body of the oxidation furnace, and a heat transfer medium is circulated therein . Wherein, the number of the pipelines may be set as needed; the heat transfer medium in the pipeline may be a liquid or a gas.

In the above system, preferably, the heating device is a heating device (for example, an electric heating device) disposed inside the furnace body of the closed desulfurization furnace, or a furnace body connected to the closed desulfurization furnace. External heating device.

In the above system, preferably, the primary desulfurization apparatus further includes a pipe connecting the bottom of the furnace body of the closed desulfurization furnace and the fourth interface of the waste heat utilization device, and is provided on the pipe Fan.

In the above system, preferably, the secondary desulfurization apparatus further includes a pipe connecting the bottom of the furnace body of the closed desulfurization furnace and another interface of the sulfur recovery device, and is provided on the pipe Fan.

In the above system, the waste heat utilization device, the waste heat power generation device, the dust removal device, and the sulfur recovery device are both It can be a conventional device in the art. Wherein, the function of the waste heat power generation device is mainly to cool down, and the generated steam is used for power generation, the conventional power generation can be used for power generation, and the generated electricity can be used for factory use.

According to a specific embodiment of the present invention, preferably, the system further includes a high temperature oxidation boiling roaster for performing high temperature oxidation boiling roasting treatment on the iron oxide produced by the secondary desulfurization apparatus to further remove the Sulfur remaining in iron oxide.

In another aspect, the present invention also provides a method for producing sulfur and iron oxide using pyrite, which is a method for producing sulfur and iron oxide using pyrite using the above system, the method comprising the steps of:

Step (1): feeding the pyrite to the closed desulfurization furnace through the feed hopper of the closed desulfurization furnace of the primary desulfurization equipment, and simultaneously passing through the intake pipeline to the closed desulfurization furnace Into a non-oxidizing gas, the temperature in the closed desulfurization furnace is brought to 445-1000 ° C (preferably 600-700 ° C) by the heating device, and the pyrite is desulfurized to be decomposed into ferrous sulfide and elemental Sulfur; the elemental sulfur is discharged to the closed desulfurization furnace along with the non-oxidizing gas, and then cooled by the waste heat utilization device and the waste heat power generation device, passes through the dust removal device, and finally enters the sulfur recovery device. Forming sulfur; the ferrous sulfide is discharged from a discharge hopper of the closed desulfurization furnace;

Step (2): feeding the ferrous sulfide obtained in the step (1) to the oxidation furnace through the feed hopper of the oxidation furnace; and simultaneously introducing an oxidizing gas into the oxidation furnace through the intake pipe And controlling the temperature in the oxidation furnace to be 60 to 100 ° C (preferably 65 to 80 ° C) by the heat transfer device, the ferrous sulfide being oxidized to iron oxide and elemental sulfur, and from the oxidation furnace The discharge hopper is discharged; the gas product generated by the oxidation is discharged through the dust removing device; and water is poured into the pool, and the port of the safety pipe is immersed below the water surface (the safety pipe and the pool are arranged to ensure When the oxidation furnace is flashing, the gas in the furnace can be smoothly discharged);

Step (3): passing the mixture of iron oxide and elemental sulfur obtained in the step (2) to the closed desulfurization furnace through the feed hopper of the closed desulfurization furnace of the secondary desulfurization apparatus, while passing through the Passing a non-oxidizing gas into the closed desulfurization furnace, and passing the heating device to bring the temperature in the closed desulfurization furnace to 445-1000 ° C (preferably 480-500 ° C), so that Desulfurizing the mixture of iron oxide and elemental sulfur to separate iron oxide and elemental sulfur; the elemental sulfur is discharged from the closed desulfurization furnace along with the non-oxidizing gas, and then passes through the dust removing device to enter the sulfur recovery The apparatus forms sulfur; the iron oxide is discharged from the discharge hopper of the closed desulfurization furnace.

In the above method, steps (1), (2) and (3) can be carried out under normal pressure. The reaction time of the steps (1), (2) and (3) is directly related to the amount of the feed, and can be determined by a person skilled in the art according to the specific circumstances.

In the above method, preferably, the step (1) further comprises: desulfurizing the pyrite in a feed hopper of the closed desulfurization furnace of the primary desulfurization apparatus, and then sending to the closed desulfurization In the furnace. Wherein The method of oxygen can be carried out by a conventional method such as introducing nitrogen gas and/or water vapor into the feed hopper or the like.

In the above method, preferably, the step (1) further comprises: passing the non-oxidizing gas discharged from the sulfur recovery device into the waste heat utilization device to raise the temperature to 540-560 ° C, and then returning it to the fan through the fan The closed desulfurization furnace is recycled. At this time, a part of the non-oxidizing gas may be replenished into the closed desulfurization furnace only through the intake duct to circulate the non-oxidizing gas.

In the above method, preferably, in the step (1), after the waste heat utilization device and the waste heat power generation device are cooled, the temperature of the non-oxidizing medium gas having the elemental sulfur is 450 to 480 °C.

In the above method, preferably, in the step (2), the ferrous sulfide sent to the oxidizing furnace is ferrous sulfide after the temperature-lowering treatment. More preferably, the ferrous sulfide fed to the oxidizing furnace is added with 1% to 20% of water, which is added in an amount based on the total weight of the ferrous sulfide after the addition of water. The right amount of water can greatly increase the oxidation rate of ferrous sulfide.

In the above method, preferably, the step (3) further comprises: returning the non-oxidizing gas discharged from the sulfur recovery unit to the closed desulfurization furnace through the fan to be recycled. At this time, a part of the non-oxidizing gas may be replenished into the closed desulfurization furnace only through the intake duct to circulate the non-oxidizing gas.

In the above method, preferably, the step (3) further comprises: deactivating the mixture of the iron oxide and the elemental sulfur obtained in the step (2) in a feed hopper of the closed desulfurization furnace of the secondary desulfurization apparatus And then sent to the closed desulfurization furnace. Wherein, the method for removing oxygen may be carried out by a conventional method such as introducing nitrogen gas and/or water vapor into the feed hopper or the like.

In the above method, preferably, in the step (1) and the step (3), the non-oxidizing gas includes deoxygenated water vapor and/or nitrogen gas or the like, or other non-oxidizing gas. And the non-oxidizing gases in the step (1) and the step (3) may be the same or different. The action of the non-oxidizing gas in the step (1) and the step (3) is mainly to bring the mixture of pyrite, iron oxide and elemental sulfur into a boiling state, and carry out elemental sulfur, the amount of which can be determined by those skilled in the art. Determined by specific circumstances.

In the above method, preferably, in the step (2), the oxidizing gas used includes air, oxygen-enriched or pure oxygen or the like. The action of the oxidizing gas is mainly to bring the ferrous sulfide into a boiling state and to oxidize, and the amount thereof can be determined by a person skilled in the art according to the specific circumstances.

According to a specific embodiment of the present invention, preferably, the method further comprises a step (4) of subjecting the iron oxide obtained in the step (3) to a high temperature oxidation boiling roasting treatment to further remove residual sulfur in the iron oxide. The specific reaction conditions of the high-temperature oxidation boiling roasting treatment may be conventional reaction conditions in the art, and are not described herein again.

The system and method for producing sulfur and iron oxide using pyrite are mainly characterized by: (1) in the whole process, sulfur in pyrite is not oxidized at all, but is in the form of elemental sulfur. Separated, this Not only greatly reduces the production cost, but also eliminates the problem of sulfur dioxide pollution; (2) there is no endothermic reaction in the process, the process equipment used adopts the insulation measures and the waste heat recovery device, so it has the advantage of low energy consumption; (3) In addition to the required heat source, basically no other raw materials are needed, so the comprehensive production cost is low and the economic benefits are good; (4) the process is relatively simple, and most of the devices involved in the process equipment are conventional devices, and the project investment It is low and therefore technically and economically feasible and has strong enforceability.

In summary, the system and method for producing sulfur and iron oxide using pyrite can provide direct production of sulfur and iron oxide from pyrite; and, in the process, there is no oxidation and reduction process of sulfur element in the process. Therefore, compared with the prior art, the invention has the advantages of low production cost and low energy consumption, and solves the environmental protection problem in the production process, and the utilization rate of sulfur is close to one hundred percent. The invention realizes the low-cost, low-pollution conversion of pyrite to sulfur and iron oxide, and greatly increases the value of pyrite, so that the pyrite originally discarded in the tailings can be utilized. It can be seen that the invention has high economic value and environmental protection value, and is beneficial to environmental protection in the world nonferrous mine areas.

DRAWINGS

The system and method for producing sulfur and iron oxide using pyrite according to the present invention will be further described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic structural view of a primary desulfurization apparatus according to an embodiment of the present invention.

2 is a schematic structural view of an oxidation apparatus according to an embodiment of the present invention.

3 is a schematic structural view of a secondary desulfurization apparatus according to an embodiment of the present invention.

Main component symbol description:

Feed hopper 1, heating device 2, closed desulfurization furnace 3, discharge hopper 4, waste heat utilization device 5, waste heat power generation device 6, dust removal device 7, sulfur recovery device 8, intake pipe 9, fan 10, oxidation furnace 11 , heat transfer device 12, safety tube 13, pool 14.

detailed description

The detailed description of the technical features, the advantages and the advantages of the present invention will be understood by the following detailed description of the invention.

Example 1

The embodiment provides a system for producing sulfur and iron oxide by using pyrite, which comprises: a primary desulfurization device, an oxidation device, and a secondary desulfurization device;

As shown in FIG. 1 , the primary desulfurization apparatus includes a closed desulfurization furnace 3, a waste heat utilization device 5, a waste heat power generation device 6, a dust removal device 7 and a sulfur recovery device 8; and a lower portion of the furnace body of the closed desulfurization furnace 3 The feed hopper 1 and the discharge hopper 4 are disposed on opposite sides, and the closed desulfurization furnace 3 is provided with a heating device 2, the closed type The bottom of the furnace body of the desulfurization furnace 3 is provided with an intake duct 9; the first interface of the waste heat utilization device 5 is connected to the upper part of the furnace body of the closed desulfurization furnace 3 through a pipe, and the second part of the waste heat utilization device 5 The interface is connected to the first interface of the waste heat power generation device 6 through a pipe, and the second interface of the waste heat power generation device 6 is connected to the first interface of the dust removal device 7 through a pipe; the dust removal device 7 The second interface is connected to the first interface of the sulfur recovery device 8 through a pipe, and the second interface of the sulfur recovery device 8 is connected to the third interface of the waste heat utilization device 5 through a pipe, the waste heat utilization The fourth interface of the device 5 is connected to the bottom of the furnace body of the closed desulfurization furnace 3 through a pipe, and a fan 10 is arranged on the pipe; the primary desulfurization device is used for desulfurizing the pyrite to obtain vulcanization. Ferrous and sulphur;

As shown in FIG. 2, the oxidation apparatus includes an oxidation furnace 11, a dust removal device 7, a safety pipe 13, and a water tank 14. The lower portion of the furnace body of the oxidation furnace 11 is provided with a feed hopper 1 and a discharge hopper 4 disposed on opposite sides. The furnace body of the oxidizing furnace 11 is provided with a heat transfer device 12, the bottom of the furnace body of the oxidizing furnace 11 is provided with an air inlet duct 9, and a fan 10 is arranged on the pipeline; the furnace body of the oxidizing furnace 11 The upper portion is connected to the dust removing device 7 by a pipe; the top of the furnace body of the oxidation furnace 11 is connected to one end of the safety pipe 13, and the other end of the safety pipe 13 is submerged in the water tank 14; The device is configured to oxidize ferrous sulfide produced by the primary desulfurization device to obtain a mixture of iron oxide and elemental sulfur;

As shown in FIG. 3, the secondary desulfurization apparatus includes a closed desulfurization furnace 3, a dust removing device 7 and a sulfur recovery device 8; the lower part of the furnace body of the closed desulfurization furnace 3 is connected with a feed hopper 1 disposed on the opposite side and a discharge hopper 4, the closed desulfurization furnace 3 is provided with a heating device 2, and the bottom of the furnace body of the closed desulfurization furnace 3 is provided with an intake duct 9; an interface of the dust removing device 7 is connected to the In the upper part of the furnace body of the closed desulfurization furnace 3, the other interface of the dust removing device 7 is connected to an interface of the sulfur recovery device 8 through a pipe, and the other interface of the sulfur recovery device 8 is connected to the closed pipe through a pipe. a bottom of the furnace body of the desulfurization furnace 3, and a fan 10 is arranged on the pipeline; the secondary desulfurization device is used for secondary desulfurization of the mixture of iron oxide and elemental sulfur produced by the oxidation device to separate Iron oxide and sulfur.

In the above system, the closed desulfurization furnace 3 in the primary desulfurization equipment and the secondary desulfurization equipment are respectively a boiling roaster, a disc rotary roaster or a rotary kiln, and the like, and other suitable conventional devices may also be employed. The closed-type desulfurization furnace can be selected according to the particle size of the pyrite (into a desulfurization equipment) processed into the closed desulfurization furnace 3, or the particle size of the mixture of iron oxide and elemental sulfur (into the secondary desulfurization equipment). . Moreover, the closed desulfurization furnace 3 in the primary desulfurization equipment and the secondary desulfurization equipment may be the same or different. The oxidation furnace 11 is a boiling roaster, a disc rotary roaster or a rotary kiln, and the like, and other suitable conventional devices can also be employed. Different oxidation furnaces can be selected according to the particle size of the ferrous sulfide which is processed into the oxidation furnace 11. The heat transfer device 12 is composed of a plurality of pipes uniformly distributed and vertically disposed and/or horizontally disposed inside the furnace body of the oxidation furnace 11. And a heat transfer medium flows through the pipe. Wherein, the number of the pipelines may be set as needed; the heat transfer medium in the pipeline may be a liquid or a gas. The heating device 2 is a heating device (for example, an electric heating device) provided inside the furnace body of the closed desulfurization furnace 3, or a heating device connected to the outside of the furnace body of the closed desulfurization furnace 3. In the primary desulfurization apparatus and the secondary desulfurization apparatus, the horizontal position of the feed hopper 1 of the closed desulfurization furnace 3 is equal to or higher than the horizontal position of the discharge hopper 4.

The above system may further comprise a high temperature oxidation boiling roasting furnace for performing high temperature oxidation boiling roasting treatment on the iron oxide produced by the secondary desulfurization apparatus to further remove residual sulfur in the iron oxide.

Example 2

The present embodiment provides a method for producing sulfur and iron oxide using pyrite, which is a method for producing sulfur and iron oxide using pyrite from the system of Example 1, the method comprising the steps of:

Step (1): the pyrite is sent to the feed hopper 1 of the closed desulfurization furnace 3 of the primary desulfurization apparatus for oxygen removal (a conventional method such as introducing nitrogen gas into the feed hopper 1 and/or Or water vapor, etc., and then sent to the closed desulfurization furnace 3, while a non-oxidizing gas is introduced into the closed desulfurization furnace 3 through the intake duct 9, and is passed through the heating device 2 The temperature in the closed desulfurization furnace 3 reaches 445-1000 ° C (preferably 600-700 ° C), and the pyrite is desulfurized to decompose into ferrous sulfide and elemental sulfur; the elemental sulfur follows the non-oxidation The gas is discharged from the closed desulfurization furnace 3, and then cooled by the waste heat utilization device 5 and the waste heat power generation device 6, so that the temperature of the non-oxidizing medium gas with the elemental sulfur is lowered to 450-480 ° C, and then The dust removing device 7 finally enters the sulfur recovery device 8 to form sulfur; and the non-oxidizing gas discharged from the sulfur recovery device 8 enters the waste heat utilization device 6 to raise the temperature to 540-560 ° C, and then passes through the The fan 10 is sent back to the closed desulfurization furnace 3 for recycling (at this time, The non-oxidizing gas may be recirculated to the closed desulfurization furnace 3 through the intake duct 9 to recycle the non-oxidizing gas; the ferrous sulfide from the closed desulfurization furnace 3 The discharge hopper 4 is discharged;

Step (2): cooling the ferrous sulfide obtained in the step (1), and then adding 1%-20% of water to the ferrous sulfide after the temperature reduction treatment, the water is added after adding water The total weight of the ferrous sulfide (the appropriate amount of water can greatly increase the oxidation rate of the ferrous sulfide), and then sent to the oxidation furnace 11 through the feed hopper 1 of the oxidation furnace 11; 14 is injected with water, and the port of the safety pipe 13 is submerged below the water surface (the arrangement of the safety pipe and the pool can ensure that the gas in the furnace can be smoothly discharged when the oxidation furnace is flashing); The intake duct 9 introduces an oxidizing gas into the oxidation furnace 11, and the temperature in the oxidation furnace 11 is controlled by the heat transfer device 12 to be 60 to 100 ° C (preferably 65 to 80 ° C). The ferrous sulfide is oxidized to iron oxide and elemental sulfur, and is discharged from the discharge hopper 4 of the oxidation furnace 11; the gas product generated by oxidation is discharged through the dust removing device 7;

Step (3): sending the mixture of iron oxide and elemental sulfur obtained in the step (2) to the feed hopper 1 of the closed desulfurization furnace 3 of the secondary desulfurization apparatus for oxygen removal, and then sending to the closed type In the desulfurization furnace 3, a non-oxidizing gas is introduced into the closed desulfurization furnace 3 through the intake duct 9, and the temperature in the closed desulfurization furnace 3 is brought to 445 by the heating device 2. 1000 ° C (preferably 480-500 ° C), the mixture of iron oxide and elemental sulfur is desulfurized to separate iron oxide and elemental sulfur; the elemental sulfur is discharged from the closed desulfurization with the non-oxidizing gas The furnace 3 then passes through the dust removing device 7 to enter the sulfur recovery device 8 to form sulfur; the non-oxidizing gas discharged from the sulfur recovery device 8 is returned to the closed desulfurization furnace through the fan 10 3 recycling (in this case, only the non-oxidizing gas may be replenished into the closed desulfurization furnace 3 through the intake duct 9 to recycle the non-oxidizing gas); The discharge hopper 4 of the closed desulfurization furnace 3 is discharged.

In the above method, in the step (1) and the step (3), the non-oxidizing gas includes deoxygenated water vapor and/or nitrogen gas or the like, or other non-oxidizing gas, and the step (1) and the step The non-oxidizing gases in (3) may be the same or different. In the step (2), the oxidizing gas used includes air, oxygen-enriched or pure oxygen, and the like.

The above method may further comprise a step (4) of subjecting the iron oxide obtained in the step (3) to a high temperature oxidation boiling roasting treatment to further remove residual sulfur in the iron oxide.

Example 3

This example employs the system of Example 1 and the method of Example 2 to produce sulfur and iron oxide from granular pyrite. The granular pyrite has a particle diameter of about 3.0 mm.

In the step (1), the closed desulfurization furnace used in the primary desulfurization equipment is a boiling roaster, and the method for desulfurizing the pyrite in the feed hopper is to introduce nitrogen and/or water into the feed hopper. The vapor, the non-oxidizing gas is nitrogen, the non-oxidizing gas is used in an amount of 5 to 50 m ³ /sec, and the temperature in the closed desulfurization furnace at the time of desulfurization is 600 to 700 ° C, and the waste heat utilization device and waste heat power generation The temperature of the non-oxidizing medium gas with elemental sulfur after the device is cooled is 450-480 ° C, and the non-oxidizing gas discharged from the sulfur recovery device enters the waste heat utilization device and reaches 540-560 ° C after heating. The particle size of the ferrous sulfide obtained in the step (1) is about 3.0 mm.

In the step (2), the oxidation furnace is a boiling roaster, and the amount of water added to the ferrous sulfide after the temperature reduction treatment is 8-15% (the amount of water added is the total amount of ferrous sulfide after the addition of water). The oxidizing gas is oxygen-rich, the oxidizing gas is used in an amount of 5 to 50 m ³ /sec, and the temperature in the oxidizing furnace at the time of oxidation treatment is 65 to 80 °C. The mixture of the iron oxide and the elemental sulfur obtained in the step (2) has a particle diameter of about 3.0 mm.

In the step (3), the closed desulfurization furnace in the secondary desulfurization equipment is a boiling roaster, and the method of deoxidizing the mixture of iron oxide and elemental sulfur in the feed hopper is to introduce nitrogen gas into the feed hopper and/or Or water vapor, the non-oxidizing gas is nitrogen, the non-oxidizing gas is used in an amount of 5 to 50 m ³ /sec, and the temperature in the closed desulfurization furnace at the time of desulfurization is 480 to 500 °C.

The granular pyrite is charged at 50 tons/hour, the iron oxide output is 32.20 tons/hour, and the total sulfur output (the total amount of steps (1) and (3)) is 26.65 tons / hour. The chemical element of the product iron oxide was tested and found to have a very low residual sulfur content.

Example 4

This example employs the system of Example 1 and the method of Example 2 to produce sulfur and iron oxide from granular pyrite. The granular pyrite has a particle diameter of about 50.0 mm.

In the step (1), the closed desulfurization furnace used in the primary desulfurization equipment is a rotary kiln or a rotary roaster, and the method for desulfurizing the pyrite in the feed hopper is to pass into the feed hopper. Nitrogen and/or steam are introduced, the non-oxidizing gas is nitrogen, the non-oxidizing gas is used in an amount of 5-30 m ³ /sec, and the temperature in the closed desulfurization furnace at the time of desulfurization is 600-700 ° C. The temperature of the non-oxidizing medium gas with elemental sulfur after cooling by the waste heat utilization device and the waste heat power generation device is 450-480 ° C, and the non-oxidizing gas discharged from the sulfur recovery device enters the waste heat utilization device and reaches 540-560 ° C after heating. The particle size of the ferrous sulfide obtained in the step (1) is about 50.0 mm.

In the step (2), the oxidation furnace is a rotary kiln or a rotary roaster, and the amount of water added to the ferrous sulfide after the temperature reduction treatment is 8-15% (the amount of water added is after adding water) The total weight of the ferrous sulfide is oxidizing gas, the oxidizing gas is used in an amount of ^{5 to 30} m ³ /sec, and the temperature in the oxidizing furnace at the time of the oxidation treatment is 65 to 80 °C. The mixture of the iron oxide and the elemental sulfur obtained in the step (2) has a particle diameter of about 50.0 mm.

In the step (3), the closed desulfurization furnace in the secondary desulfurization equipment is a rotary kiln or a rotary roaster, and the method of deoxidizing the mixture of iron oxide and elemental sulfur in the feed hopper is to feed the hopper. Nitrogen and/or steam are introduced therein, the non-oxidizing gas is nitrogen, the non-oxidizing gas is used in an amount of 5-30 m ³ /sec, and the temperature in the closed desulfurization furnace at the time of desulfurization is 480-500 ° C .

It can be seen from the above embodiments that the system and method for producing sulfur and iron oxide using pyrite can provide direct production of sulfur and iron oxide from pyrite; and, in the process, there is no oxidation of sulfur element. And the reduction process; thus, compared with the prior art, the invention has the advantages of low production cost and low energy consumption, and solves the environmental protection problem in the production process, and the utilization rate of sulfur is close to one hundred percent. The invention realizes the low-cost, low-pollution conversion of pyrite to sulfur and iron oxide, and greatly increases the value of the pyrite, so that the pyrite which is originally abandoned in the tailings of the mine can be utilized. It can be seen that the invention has high economic value and environmental protection value, and is beneficial to environmental protection in the world nonferrous mine areas.

Claims

A system for producing sulfur and iron oxide using pyrite, comprising: primary desulfurization equipment, oxidation equipment, and secondary desulfurization equipment;

Wherein, the primary desulfurization equipment comprises a closed desulfurization furnace, a waste heat utilization device, a waste heat power generation device, a dust removal device and a sulfur recovery device; the lower part of the furnace body of the closed desulfurization furnace is connected with a feed hopper and a discharge hopper provided on opposite sides The closed desulfurization furnace is provided with a heating device, and the bottom of the furnace body of the closed desulfurization furnace is provided with an intake duct; the first interface of the waste heat utilization device is connected to the closed desulfurization furnace through a pipeline a second interface of the waste heat utilization device is connected to a first interface of the waste heat power generation device through a pipe, and a second interface of the waste heat power generation device is connected to the first dust removal device through a pipeline The second interface of the dust removing device is connected to the first interface of the sulfur recovery device through a pipeline, and the second interface of the sulfur recovery device is connected to the third interface of the waste heat utilization device through a pipeline The primary desulfurization device is used for desulfurization of pyrite to obtain ferrous sulfide and sulfur;

The oxidation device comprises an oxidation furnace, a dust removal device, a safety pipe and a water tank; a lower portion of the furnace body of the oxidation furnace is provided with a feed hopper and a discharge hopper provided on opposite sides, and a heat transfer device is arranged inside the furnace body of the oxidation furnace The bottom of the furnace body of the oxidation furnace is provided with an air inlet duct, and a fan is arranged on the pipeline; the upper part of the furnace body of the oxidation furnace is connected to the dust removing device through a pipeline; the top of the furnace body of the oxidation furnace is connected At one end of the safety pipe, and the other end of the safety pipe is immersed in the water pool; the oxidation device is used for oxidizing ferrous sulfide produced by the primary desulfurization device to obtain iron oxide and elemental sulfur mixture;

The secondary desulfurization device comprises a closed desulfurization furnace, a dust removal device and a sulfur recovery device; the lower part of the furnace body of the closed desulfurization furnace is connected with a feed hopper and a discharge hopper provided on opposite sides, and the closed desulfurization furnace is provided a heating device, the bottom of the furnace body of the closed desulfurization furnace is provided with an intake pipe; an interface of the dust removal device is connected to the upper part of the furnace body of the closed desulfurization furnace through a pipe, and another interface of the dust removal device And connecting to an interface of the sulfur recovery device through a pipeline; the secondary desulfurization device is configured to perform secondary desulfurization on a mixture of iron oxide and elemental sulfur produced by the oxidation device to separate iron oxide and sulfur.
The system for producing sulfur and iron oxide by using pyrite according to claim 1, wherein the closed desulfurization furnace in the primary desulfurization equipment and the secondary desulfurization equipment respectively comprises a boiling roaster, a disc rotary roaster or a rotary kiln; and the closed desulfurization furnace in the primary desulfurization equipment and the secondary desulfurization equipment are the same or different;

The oxidation furnace comprises a boiling roaster, a disc rotary roaster or a rotary kiln;

The heat transfer device is composed of a plurality of pipes uniformly distributed and vertically disposed and/or horizontally disposed inside the furnace body of the oxidation furnace, and a heat transfer medium is circulated therein;

The heating device is a heating device disposed inside the furnace body of the closed desulfurization furnace, or is connected to the A heating device outside the furnace body of the closed desulfurization furnace.
A system for producing sulfur and iron oxide using pyrite according to claim 1, wherein said primary desulfurization apparatus further comprises a pipe connecting the bottom of the furnace body of said closed desulfurization furnace and said waste heat utilization device The fourth interface has a fan on the pipe.
The system for producing sulfur and iron oxide using pyrite according to claim 1, wherein the secondary desulfurization apparatus further comprises a pipe connecting the bottom of the furnace body of the closed desulfurization furnace and the sulfur recovery device Another interface and a fan on the pipe.
The system for producing sulfur and iron oxide using pyrite according to claim 1, further comprising a high temperature oxidation boiling roaster for performing high temperature oxidation boiling roasting treatment on the iron oxide produced by the secondary desulfurization apparatus, To further remove residual sulfur in the iron oxide.
A method for producing sulfur and iron oxide using pyrite, which is a method for producing a system for producing sulfur and iron oxide using pyrite according to any one of claims 1 to 5, the method comprising the steps of:

Step (1): feeding the pyrite to the closed desulfurization furnace through the feed hopper of the closed desulfurization furnace of the primary desulfurization equipment, and simultaneously passing through the intake pipeline to the closed desulfurization furnace a non-oxidizing gas, the temperature in the closed desulfurization furnace is brought to 445-1000 ° C by the heating device, and the pyrite is desulfurized to be decomposed into ferrous sulfide and elemental sulfur; Discharging the non-oxidizing gas out of the closed desulfurization furnace, then cooling the waste heat utilization device and the waste heat power generation device, passing through the dust removal device, and finally entering the sulfur recovery device to form sulfur; Iron is discharged from the discharge hopper of the closed desulfurization furnace;

Step (2): feeding the ferrous sulfide obtained in the step (1) to the oxidation furnace through the feed hopper of the oxidation furnace; and simultaneously introducing an oxidizing gas into the oxidation furnace through the intake pipe Controlling the temperature in the oxidation furnace to 60 to 100 ° C by the heat transfer device, the ferrous sulfide being oxidized to iron oxide and elemental sulfur, and discharged from the discharge hopper of the oxidation furnace; The gas product is discharged through the dust removing device; and water is poured into the pool, and the port of the safety pipe is submerged below the water surface;

Step (3): passing the mixture of iron oxide and elemental sulfur obtained in the step (2) to the closed desulfurization furnace through the feed hopper of the closed desulfurization furnace of the secondary desulfurization apparatus, while passing through the a gas pipe is connected to the closed desulfurization furnace to pass a non-oxidizing gas, and the temperature in the closed desulfurization furnace is brought to 445-1000 ° C by the heating device, so that the mixture of the iron oxide and the elemental sulfur is performed. Desulfurization to separate iron oxide and elemental sulfur; the elemental sulfur is discharged from the closed desulfurization furnace along with the non-oxidizing gas, and then passes through the dust removing device to enter the sulfur recovery device to form sulfur; the oxidation Iron is discharged from the discharge hopper of the closed desulfurization furnace.
The method for producing sulfur and iron oxide using pyrite according to claim 6, wherein the step (1) further comprises: after the non-oxidizing gas discharged from the sulfur recovery device is introduced into the waste heat utilization device, Pass The fan is sent back to the closed desulfurization furnace for recycling.
A method of producing sulfur and iron oxide using pyrite according to claim 6, wherein the step (3) further comprises: returning the non-oxidizing gas discharged from the sulfur recovery unit to the It is recycled in the closed desulfurization furnace.
The method for producing sulfur and iron oxide using pyrite according to claim 6, wherein in step (1), after cooling by the waste heat utilization device and the waste heat power generation device, non-oxidation with the elemental sulfur The temperature of the medium gas is 450-480 °C.
The method for producing sulfur and iron oxide using pyrite according to claim 6, wherein the step (1) further comprises: causing the pyrite to be in a feed hopper of the closed desulfurization furnace of the primary desulfurization apparatus Deoxidation is carried out and then sent to the closed desulfurization furnace.
The method for producing sulfur and iron oxide using pyrite according to claim 6, wherein, in the step (2), the ferrous sulfide sent to the oxidation furnace is ferrous sulfide after the temperature-lowering treatment; The ferrous sulfide sent to the oxidizing furnace is added with 1% to 20% of water, and the amount of water added is based on the total weight of the ferrous sulfide after the addition of water.
The method for producing sulfur and iron oxide using pyrite according to claim 6, wherein the step (3) further comprises: reacting the mixture of the iron oxide and the elemental sulfur obtained in the step (2) in the secondary desulfurization apparatus The feed hopper of the closed desulfurization furnace is deaerated and then sent to the closed desulfurization furnace.
The method for producing sulfur and iron oxide using pyrite according to claim 6, wherein in the step (1) and the step (3), the non-oxidizing gas comprises deoxygenated water vapor and/or nitrogen, and The non-oxidizing gases in the steps (1) and (3) are the same or different; in the step (2), the oxidizing gas used includes air, oxygen-enriched or pure oxygen.
The method for producing sulfur and iron oxide using pyrite according to claim 6, further comprising a step (4) of subjecting the iron oxide obtained in the step (3) to a high temperature oxidation boiling roasting treatment to further remove the Sulfur remaining in iron oxide.