CN113494711A

CN113494711A - High-temperature roasting solid waste treatment device and method

Info

Publication number: CN113494711A
Application number: CN202010202696.1A
Authority: CN
Inventors: 孙凌玉
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-03-20
Filing date: 2020-03-20
Publication date: 2021-10-12

Abstract

The invention discloses a high-temperature roasting solid waste treatment device and method. The device includes: the device comprises a conveying device, a drying device, a heating device, a roasting device, a homogenizing device, a first cooling device, a second cooling device and a third cooling device; a solid waste treatment finished product particle layer covers on the conveying device, and a particle layer to be subjected to solid waste treatment covers on the solid waste treatment finished product particle layer; the homogenizing device is used for homogenizing the particles treated by the roasting device; the roasting device is connected with the first cooling device; the heating device is connected with the second cooling device; the drying device is connected with the third cooling device. By adopting the high-temperature roasting solid waste treatment device and method, the silicon oxide in the solid waste is in a molten state through high temperature in an oxidation atmosphere, and then is gradually cooled, so that the silicon oxide is bonded with the metal elements in the solid waste, and the device and method have the advantages of capability of preventing metal ions from being released into water or soil, low energy consumption, large treatment capacity, high particle strength after high-temperature roasting, and recyclability.

Description

High-temperature roasting solid waste treatment device and method

Technical Field

The invention relates to the technical field of solid waste treatment, in particular to a high-temperature roasting solid waste treatment device and method.

Background

The solid waste treatment, which is called as the treatment of solid waste, generally refers to a process of converting solid waste into a material suitable for transportation, storage, utilization or disposal by adopting physical, chemical, biological, physical and chemical methods, and the aim of the solid waste treatment is harmlessness, reduction and recycling.

However, the amount of sludge generated by municipal sewage treatment plants is large, the organic matter content of municipal sludge is low, and the sludge can only be stockpiled after biological treatment, drying and reduction, and sludge incineration energy recovery cannot be realized. Because of more people and less land, the water-rising ship cost of stockpiling becomes higher, and the urban sludge becomes an increasingly serious environmental pollution problem.

In order to improve the living environment, the rivers and lakes need to be dredged every several years, a large amount of sludge generated by dredging is not piled up and buried like municipal sludge, the sludge often contains harmful viruses, bacteria and other harmful microorganisms, pollution is also generated, and the sludge cannot be incinerated to recover energy like the municipal sludge, so that the sludge becomes waste which is difficult to treat.

Red mud produced in the alumina industry shows red color due to certain iron oxide, and red mud can be only stockpiled in large quantities as solid waste, which causes serious environmental problems.

The recycling value of the fly ash generated by coal-fired power generation as solid waste is almost zero, wherein the recycling of valuable elements needs to consume a large amount of energy, the method is not cost-effective, and the daily amount of fly ash needs to be stockpiled, so that a serious environmental problem is generated.

At present, a large amount of tailings such as iron ore, vanadium titano-magnetite, magnesite, rare earth ore and the like are piled up, the amount of the tailings is large, the tailings are piled up in the form of a tailing dam, the particles of the tailings are fine, the tailings are not easy to separate from water, the fluidity of slurry is good, dam break often occurs, the destructive power is large, the human life loss and the property loss are caused, and the serious environmental disaster is caused.

With the industrial development, many soils are seriously polluted by heavy metals and chemicals, land remediation is urgently needed, but the large-scale technology and equipment for treating the polluted soil are lacked, only a rotary kiln can be used for treating the polluted soil, and the efficiency is extremely low.

The solid wastes have extremely low content of valuable elements and do not have the basic condition of economic development, but the metal elements pollute the underground water along with the erosion of rainwater after the stockpiling. Some municipal sludge and pond sludge contain bacteria, viruses and heavy metal elements, and the stacking without treatment can cause serious environmental disasters, even after microbial treatment, reduction and drying, because the content of organic matters is too small, the subsequent sludge incineration cannot be carried out, and the sludge has to be stacked, thereby causing environmental problems.

At present, the following ways are mainly used for treating solid waste:

landfill, which is the main treatment means, occupies a large area of the ground and brings a large amount of pollution, and is an unsustainable method.

Chemical acid leaching or alkaline leaching is suitable for scenes with less solid waste, and for hundreds of millions of tons of solid waste, the method is not cost-effective in economy and is not feasible in technology.

The sintering method has the advantages that the technology is mature, the method is a common process in the metallurgical industry, and the defects that harmful metal elements such as lead, zinc and the like in solid wastes return to a process route to form lead and zinc accumulation, so the method is limited in use, and the method is poor in economical efficiency and low in feasibility for millions of tons of solid wastes every year.

Firing, for example using a shaft or rotary kiln, but shaft or rotary kilns have the disadvantages: the energy consumption is high, and the tail gas purification amount is large, so the cost is high; the treatment capacity is small, and the treatment capacity of one rotary kiln or shaft furnace is only about ten thousand tons, so that huge solid wastes such as municipal sludge, river and lake sludge or red mud are treated, and sensible heat cannot be realized by using a rotary kiln or shaft furnace method; the firing temperature is low and the strength of the finished pellets is low, so that the finished pellets are useless. The temperature field is not uniform, the quality of final finished product particles is different, solid waste particles collide with each other in the thermal processing process, and the pulverization rate is high.

Disclosure of Invention

The invention aims to provide a high-temperature roasting solid waste treatment device and method, wherein silicon oxide in solid waste is in a molten state at high temperature in an oxidation atmosphere, and then is gradually cooled, so that the silicon oxide is bonded with metal elements in the solid waste, and the device has the advantages of capability of preventing metal ions from being released into water or soil, low energy consumption, large treatment capacity, high particle strength after high-temperature roasting, and recyclability.

In order to achieve the purpose, the invention provides the following scheme:

a high-temperature roasting solid waste treatment device comprises:

the device comprises a conveying device, a drying device, a heating device, a roasting device, a homogenizing device, a first cooling device, a second cooling device and a third cooling device;

the drying device, the heating device, the roasting device, the homogenizing device, the first cooling device, the second cooling device and the third cooling device are sequentially arranged along the conveying direction of the conveying device;

a solid waste treatment finished product particle layer covers on the conveying device, and a particle layer to be subjected to solid waste treatment covers on the solid waste treatment finished product particle layer; the conveying device sequentially penetrates the particles to be treated by solid waste through the drying device, the heating device, the roasting device, the homogenizing device, the first cooling device, the second cooling device and the third cooling device to obtain solid waste treatment finished product particles;

the homogenizing device is used for homogenizing the particles treated by the roasting device;

the roasting device is connected with the first cooling device; the first cooling device is used for introducing cold air into the homogenized particles from the bottom of the conveying device and then conveying the air subjected to heat exchange to the roasting device;

the heating device is connected with the second cooling device; the second cooling device is used for introducing cold air into the particles cooled by the first cooling device from the bottom of the conveying device and then conveying the air subjected to heat exchange to the heating device;

the drying device is connected with the third cooling device, and the third cooling device is used for introducing cold air into the particles cooled by the second cooling device from the bottom of the conveying device and then conveying the heat-exchanged air to the drying device.

Optionally, the solid waste treatment device further includes:

the system comprises a first tail gas treatment device, a second tail gas treatment device, a third tail gas treatment device and an emptying device;

one end of the first tail gas treatment device is connected with the bottom end of the roasting device, and the other end of the first tail gas treatment device is connected with the emptying device; the first tail gas treatment device is used for purifying gas generated in the roasting device;

one end of the second tail gas treatment device is connected with the bottom end of the heating device, and the other end of the second tail gas treatment device is connected with the emptying device; the second tail gas treatment device is used for purifying the gas generated in the heating device;

one end of the third tail gas treatment device is connected with the bottom end of the drying device, and the other end of the third tail gas treatment device is connected with the emptying device; the third tail gas treatment device is used for purifying the gas generated in the drying device.

Optionally, the solid waste treatment device further includes:

the first explosion-proof device, the second explosion-proof device and the third explosion-proof device;

the first explosion-proof device is arranged between the first tail gas treatment device and the roasting device; the second anti-explosion device is arranged between the second tail gas treatment device and the heating device; the third explosion prevention device is arranged between the third tail gas treatment device and the drying device.

Optionally, the solid waste treatment device further includes:

the first bin and the second bin are sequentially arranged along the conveying direction;

the first bin is positioned above the conveying device, solid waste treatment finished product particles are filled in the first bin, and the solid waste treatment finished product particles are placed on the conveying device through a discharge hole of the first bin;

the second bin is positioned above the conveying device, particles to be treated by solid waste are filled in the first bin, and the particles to be treated by solid waste are placed on finished particles treated by solid waste through a discharge hole of the second bin.

Alternatively to this, the first and second parts may,

the first cooling device specifically includes:

the first fan, the first cooling air box and the first combustion device;

the first fan is connected with the bottom end of the first cooling air box and used for blowing cold air into the first cooling air box; one end of the first combustion device is connected with the top end of the first cooling air box, the other end of the first combustion device is connected with the top end of the roasting device, and the first combustion device is used for heating air output from the top end of the first cooling air box; the temperature in the roasting device is 1000-1450 ℃;

the second cooling device specifically includes:

a second fan, a second cooling windbox, and a second combustion device;

the second fan is connected with the bottom end of the second cooling air box and used for blowing cold air into the second cooling air box; one end of the second combustion device is connected with the top end of the second cooling air box, the other end of the second combustion device is connected with the top end of the heating device, and the second combustion device is used for heating air output from the top end of the second cooling air box; the temperature in the heating device is 800-1000 ℃;

the third cooling device specifically includes:

a third fan and a third cooling windbox;

the third fan is connected with the bottom end of the third cooling air bellow and used for blowing cold air into the third cooling air bellow; the top end of the third cooling air box is connected with the top end of the drying device; the temperature in the drying device is 300-500 ℃.

The invention also provides a high-temperature roasting solid waste treatment method, which comprises the following steps:

carrying out mixing, ball milling, filtering and granulation treatment on solid waste and auxiliary materials to obtain particles to be treated by solid waste, which meet the preset size, and placing the particles to be treated by solid waste, which meet the preset size, on a conveying device paved with finished particles of solid waste treatment;

drying the particles placed on the conveying device to obtain dried particles;

heating the dried particles to obtain heated particles;

roasting the heated particles to obtain roasted particles;

homogenizing the roasted particles to obtain homogenized particles;

and carrying out cooling treatment on the homogenized particles for three times to obtain solid waste treatment finished product particles.

Optionally, mixing, ball-milling, filtering and granulating the solid waste and the auxiliary materials to obtain particles to be treated with the solid waste, which meet the preset size, and specifically comprises:

mixing the solid waste and the auxiliary materials without bentonite according to a dry basis weight ratio, and then sending the mixture to a ball mill to be added with water for ball milling to obtain slurry;

sending the slurry to a filter for filtering treatment to obtain a filter cake with the water content not exceeding the first water content;

feeding the filter cake to a strong mixer, adding water, and stirring to obtain a mixture with a second water content; while adding water and stirring, bentonite is added or not added according to the dry weight proportion of the bentonite;

and conveying the mixture to a roller granulator for granulation, screening particles to be subjected to solid waste treatment meeting the preset size, conveying the particles smaller than the preset size to the roller granulator for continuous granulation, and crushing the particles larger than the preset size and then conveying the crushed particles to the roller granulator for granulation.

Alternatively to this, the first and second parts may,

the temperature of the drying treatment is 300-500 ℃;

the temperature of the heating treatment is 800-1000 ℃;

the temperature of the roasting treatment is 1000-1450 ℃.

Alternatively to this, the first and second parts may,

the preset size is 12 mm;

the first water content is 9%;

the second water content is 10%.

Optionally, the particle size of the solid in the slurry is more than 80% and minus 200 meshes.

Compared with the prior art, the invention has the beneficial effects that:

the invention provides a high-temperature roasting solid waste treatment device and a high-temperature roasting solid waste treatment method, wherein in the drying stage, particles to be treated by solid waste are heated and water in the particles is taken away; in the heating stage, the silicon oxide in the particles to be treated by solid waste begins to be in a molten state and is adhered to the heavy metal particles in the particles to be treated by solid waste, so that the viruses and bacteria in the particles to be treated by solid waste are killed; in the roasting stage, heavy metal elements in the particles to be treated by solid waste are oxidized, silicon oxide in the raw particles is fully melted and wraps the particles of heavy metals and oxides thereof in the raw particles, and viruses, bacteria or other microorganisms in the raw particles are thoroughly killed; in the homogenization stage, no additional energy or gas is input, the high-temperature material layer particles are resident and calmed for a period of time, and the silicon oxide in the molten state in the material layer particles still in the high-temperature state can still flow and adhere to other solid phases under the action of gravity, so that the homogenization of the internal tissues of the particles is realized; then, after three times of cooling treatment, the first cooling gas is recycled to the roasting device, the second cooling gas is recycled to the heating device, and the third cooling gas is recycled to the drying device, so that the energy is recycled, and the energy consumption is low; the high-temperature roasting treatment of the solid waste utilizes the high-temperature oxidation of metal elements and is wrapped by silicon oxide adhesion, so that the heavy metal elements return to the natural state of the initial metal oxide ore and are not dissolved in underground water any more, and the problem of solid waste pollution is solved. The finished product after roasting treatment has high strength, and can be used as building sandstone substitutes, thermal insulation material aggregates, lightweight concrete aggregates, gardening ceramsite, urban water-absorbing and water-retaining materials and the like. In addition, the invention has the advantages of large treatment capacity and unlimited variety of solid wastes, and the device and the method can treat solid wastes, including municipal sludge, river and lake dredging, red mud, tailings, fly ash, coal gangue, metallurgical solid wastes, waste plastics, paper mill black liquor drying, crushed straws or wood chips, and have wide application range.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

FIG. 1 is a structural diagram of a high-temperature roasting solid waste treatment device in an embodiment of the invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

Examples

Fig. 1 is a structural diagram of a high-temperature roasting solid waste treatment device in an embodiment of the present invention, and as shown in fig. 1, the high-temperature roasting solid waste treatment device provided by the present invention includes: the device comprises a conveying device, a drying device 8, a heating device 11, a roasting device 15, a homogenizing device 19, a first cooling device, a second cooling device, a third cooling device, a first tail gas treatment device, a second tail gas treatment device, a third tail gas treatment device, an emptying device 44, a first explosion-proof device, a second explosion-proof device, a third explosion-proof device, a first storage bin 6 and a second storage bin 7.

The drying device, the heating device, the roasting device, the homogenizing device, the first cooling device, the second cooling device and the third cooling device are sequentially arranged along the conveying direction of the conveying device. A solid waste treatment finished product particle layer covers on the conveying device, and a particle layer to be subjected to solid waste treatment covers on the solid waste treatment finished product particle layer; the conveying device sequentially passes the particles to be treated by the solid waste through the drying device, the heating device, the roasting device, the homogenizing device, the first cooling device, the second cooling device and the third cooling device to obtain finished particles for treating the solid waste. The homogenizing device is used for homogenizing the particles treated by the roasting device.

The roasting device is connected with the first cooling device through an air pipe 17; the first cooling device is used for introducing cold air into the homogenized particles from the bottom of the conveying device and then conveying the heat-exchanged air to the roasting device. The first cooling device specifically includes: a first fan 23, a first cooling windbox 16 and a first combustion device 18. The first fan is connected with the bottom end of the first cooling air box through an external air pipe 22 and used for blowing cold air into the first cooling air box; one end of the first combustion device is connected with the top end of the first cooling air box, the other end of the first combustion device is connected with the top end of the roasting device, and the first combustion device is used for heating air output from the top end of the first cooling air box; the temperature in the roasting device is 1000-1450 ℃.

The heating device is connected with the second cooling device through an air pipe 13; the second cooling device is used for introducing cold air into the particles cooled by the first cooling device from the bottom of the conveying device, and then conveying the air subjected to heat exchange to the heating device. The second cooling device specifically includes: a second fan 24, a second cooling windbox 12, and a second combustion device 14. The second fan is connected with the bottom end of the second cooling air box through an external air pipe 21 and used for blowing cold air into the second cooling air box; one end of a second combustion device is connected with the top end of the second cooling air box, the other end of the second combustion device is connected with the top end of the heating device, and the second combustion device is used for heating air output from the top end of the second cooling air box; the temperature in the heating device is 800-1000 ℃. The first combustion device and the second combustion device are gas burners.

The drying device is connected with a third cooling device through an air pipe 9, the third cooling device is used for introducing cold air into the particles cooled by the second cooling device from the bottom of the conveying device, and then conveying the air subjected to heat exchange to the drying device. The third cooling device specifically includes: a third fan 25 and a third cooling windbox 10. The third fan is connected with the bottom end of the third cooling air bellow through an external air pipe 20, and the third fan is used for blowing cold air into the third cooling air bellow; the top end of the third cooling air box is connected with the top end of the drying device; the temperature in the drying device is 300-500 ℃.

One end of the first tail gas treatment device is connected with the bottom end of the roasting device through an air pipe 26, and the other end of the first tail gas treatment device is connected with the emptying device through an air pipe 43; the first tail gas treatment device is used for purifying gas generated in the roasting device; the emptying device is a chimney. The first exhaust gas treatment device includes a dry exhaust gas purification device 31 and a fan 34.

One end of the second tail gas treatment device is connected with the bottom end of the heating device through an air pipe 27, and the other end of the second tail gas treatment device is connected with the emptying device through an air pipe 42; the second tail gas treatment device is used for purifying the gas generated in the heating device; the second tail gas treatment device comprises a dry tail gas purification device 32 and a fan 35.

One end of the third tail gas treatment device is connected with the bottom end of the drying device through an air pipe 28, and the other end of the third tail gas treatment device is connected with the emptying device through an air pipe 39; the third tail gas treatment device is used for purifying the gas generated in the drying device. The third tail gas treatment device comprises a dry tail gas purification device 33 and a fan 36.

The first explosion-proof device is arranged between the first tail gas treatment device and the roasting device; the first explosion-proof device includes an explosion-proof valve 30 and an explosion-proof air duct 40. The second explosion-proof device is arranged between the second tail gas treatment device and the heating device; the second explosion-proof device comprises an explosion-proof valve 29 and an explosion-proof air pipe 41. The third explosion prevention device is arranged between the third tail gas treatment device and the drying device; the third explosion-proof device comprises an explosion-proof valve 37 and an explosion-proof air pipe 38.

The first bin and the second bin are sequentially arranged along the conveying direction; the first bin is positioned above the conveying device, solid waste treatment finished product particles 4 are arranged in the first bin, and the solid waste treatment finished product particles are arranged on the conveying device through a discharge hole of the first bin. The second feed bin is located conveyer top, and the first feed bin is built-in to wait to give up useless granule 5 admittedly, waits to give up useless granule through second feed bin drain hole to on the useless finished product granule of handling admittedly.

The conveying device comprises a heat-insulation protective steel belt 1, a driving wheel 2 and a driven wheel 3, wherein the conveying steel belt is provided with punched holes, and the speed regulation range of the steel belt 1 is 0.3-1.2 m/min. The steel belt 1 is wound on the driving wheel 2 and the driven wheel 3, and the driving wheel 2 is driven by the variable frequency motor to operate.

The invention also provides a solid waste treatment method, which comprises the following steps:

1) carrying out mixing, ball milling, filtering and granulation treatment on the solid waste and auxiliary materials to obtain particles to be treated for solid waste with the preset size of 12 mm, and placing the particles to be treated for solid waste with the preset size of 12 mm on a conveying device paved with finished particles for solid waste treatment.

Mixing the solid waste and the auxiliary material without bentonite according to the dry basis weight proportion, sending the mixture to a ball mill, adding water, and carrying out ball milling to obtain slurry, wherein the solid granularity in the slurry is more than 80% and minus 200 meshes;

sending the slurry to a filter for filtering treatment to obtain a filter cake with the water content not exceeding 9 percent of the first water content;

feeding the filter cake into a strong mixer, adding water, and stirring to obtain a mixture with a second water content of 10%; while adding water and stirring, bentonite is added or not added according to the dry weight proportion of the bentonite;

and (3) sending the mixture to a roller granulator for granulation, screening out particles to be subjected to solid waste treatment with the preset size of 12 mm, sending the particles with the size of 12 mm smaller than the preset size to the roller granulator for continuous granulation, and sending the particles with the size of 12 mm larger than the preset size to the roller granulator for granulation after crushing.

2) And drying the particles placed on the conveying device to obtain dried particles.

3) And (4) carrying out heating treatment on the dried particles to obtain the heated particles. The temperature of the drying treatment is 300-500 ℃.

4) And roasting the heated particles to obtain roasted particles. The temperature of the heating treatment is 800-1000 ℃.

5) And homogenizing the roasted particles to obtain homogenized particles. The temperature of the roasting treatment is 1000-1450 ℃.

6) And carrying out cooling treatment on the homogenized particles for three times to obtain solid waste treatment finished product particles.

Specifically, the process method for treating the solid waste comprises the following steps:

(1) the solid wastes and the auxiliary materials are respectively placed in respective bins, and the process steps have the following requirements: all solid waste is fine particles with a particle size of less than 1 mm.

(2) The lower part of the solid waste and auxiliary material bin is provided with a weighing disk feeder, and a material conveying belt is arranged below the disk feeder. According to different solid wastes, a certain formula in a formula table is selected, the disc feeder below each bin continuously dries the solid wastes, coke powder or coal dust or blue carbon powder or straw powder or waste plastic scraps or oil sludge or coal gangue powder or black liquor of a paper mill respectively according to the prescription of the formula, and each component is weighed and is put on a conveying belt below the disc feeder according to the prescribed weight. The formula of the solid wastes and the auxiliary materials is shown in table 1.

Table 1 formula table

(3) The prepared materials are continuously conveyed to a wet ball mill by a conveying belt under a disk feeder, and the mixture is ground into slurry with the granularity of minus 200 meshes and 80 percent.

(4) And filtering the slurry by using a filter to form a filter cake with the water content of less than 9%.

(5) And (3) feeding the filter cake into a powerful mixer, adding bentonite according to the formula proportion (certain formulas do not need to be added), and adding water to adjust the water content of the mixture to 10% in the process of continuously and powerfully stirring by the powerful mixer.

(6) The mixed material is continuously conveyed to a roller granulator by a belt conveyor to produce granules, and the technical requirement emphasized here is that the roller granulator is required to be adopted, a disc granulator is not required to be adopted, and the disc granulator does not meet the process requirement.

(7) The drum granulator continuously produces raw granules with different sizes from bulk materials containing 10% of water from a powerful mixer, the raw granules with different sizes are screened by a roller screen arranged below the drum granulator, only the raw granules 5 with the diameter of 12 mm are qualified raw granules and enter the next process, the raw granules with the diameter of less than 12 mm are conveyed back to the drum granulator by a belt for granulation, and the raw granules with the diameter of more than 12 mm are crushed by paired rollers and then conveyed back to the drum granulator by a belt conveyor for granulation. The invention requires the use of roller screens for screening.

(8) As shown in figure 1, raw granules 5 (granules to be treated with solid waste) which pass through a roller granulator and a roller screen and have the diameter of 12 mm and the water content of 10 percent are continuously arranged on a flexible steel belt 1 which enters a steel belt furnace by a shuttle belt conveyor in a back-and-forth motion, and the thickness of the steel belt is 4 mm.

(9) The steel strip 1 is provided with perforations which allow process gas to pass through the steel strip 1.

(10) Before the green pellets 5 are applied to the steel strip 1, finished cooked pellets 4 (solid waste disposal finished pellets) having a diameter of 12 mm and a thickness of 200 mm are applied to the steel strip 1, and the finished cooked pellets 4 having a thickness of 200 mm serve as heat-insulating protective material for the steel strip 1, corresponding to heat-insulating refractory material having a thickness of 200 mm, to prevent the steel strip 1 from being burnt by high-temperature gas passing through the material bed.

(11) The thickness of the raw particles 5 on the bedding material cooked particles 4(200 mm thick) is 250 mm, the bedding material is below, the raw particles 5 are on the upper part, the material layer with the thickness of 450 mm moves along with the steel belt 1 with the punched holes, the moving speed of the steel belt 1 is 0.7 m/min, and the speed regulating range of the steel belt 1 is 0.3-1.2 m/min.

(12) The steel strip 1 carries 450 mm thick granules to enter the first section of the steel strip furnace, namely the drying section 8 (drying device), the temperature of the section is in the range of 300-500 ℃, the time of the material layer passing through the section is 10 minutes, and the time is adjustable along with the speed of the steel strip 1. The hot air in the drying section 8 is recovered from the cooling three sections 10 (third cooling bellows) by an air pipe 9, and enters the material layer from the upper part of the material layer to heat the raw granules 5 and take away the moisture in the raw granules. After hot air passes through the material layer particles of the drying section and then passes through the perforated steel belt 1, the blast pipe 28 enters the tail gas purification device 33, and the tail gas is purified and then pumped to the air pipe 39 by the fan 36 to be exhausted through the chimney 44. For explosion protection, an explosion protection valve 37 and an explosion protection air duct 38 are provided in the drying section 8.

(13) Then the steel strip 1 sends the material layer to the next stage, namely a heating section 11, the temperature is 800-1000 ℃, the time of the material layer passing through the section is 8 minutes, and the time is adjustable along with the speed of the steel strip 1. In the heating section 11 (heating device), the fuel in the raw particles 5, such as coke powder, coal powder, blue carbon powder, straw powder, wood chips, waste plastic chips, oil sludge, coal gangue powder or black liquor in a paper mill, is dried and begins to burn, the silicon oxide in the raw particles 5 begins to be in a molten state and to adhere heavy metal particles in the raw particles 5, and viruses and bacteria in the raw particles 5 are killed. The hot air in the heating section 11 is recovered from the cooling section 12 (second cooling air box) through an air pipe 13, the hot air enters the material layer from the upper part of the material layer, if the temperature of the hot air is not up to the set value between 800 and 1000 ℃, a gas burner 14 is arranged on the air pipe 13, the gas can be coal gas, natural gas or methane, and the gas burner 14 raises the temperature of the hot air to the set value between 800 and 1000 ℃. After passing through the material layer particles of the heating section 11 and the perforated steel strip 1, the hot air enters the dry-method tail gas purification device 32 through the air pipe 27, and the tail gas is purified and then pumped to the air pipe 39 through the fan 35 and is exhausted through the chimney 44. The metal oxides such as lead oxide and zinc oxide in the off-gas are collected at the dry off-gas cleaning unit 32 and recycled as raw materials for the nonferrous smelting plant. For explosion protection, an explosion-proof valve 29 and an explosion-proof air duct 41 are provided in the heating section 11.

(14) The steel strip 1 then feeds the layer into the next stage, i.e. the baking stage 15 (baking device), at a temperature of 1000 and 1450 ℃, where the layer resides for 8 minutes, the time being adjustable with the speed of the steel strip 1. In the roasting section 15, the heavy metal elements in the raw particles are oxidized, the silicon oxide in the raw particles is fully melted and wraps the particles of the heavy metals and the oxides thereof in the raw particles, and the viruses, bacteria or other microorganisms in the raw particles are thoroughly killed. The hot air in the roasting section 15 is recovered from the cooling section 16 (the first cooling wind box) through an air pipe 17, the hot air enters the material layer from the upper part of the material layer, if the temperature of the hot air does not reach the set value of 1000-. After passing through the material layer particles of the roasting section 15 and the porous steel strip 1, the hot air enters the dry-method tail gas purification device 31 through the air pipe 26, and the tail gas is purified and then pumped to the air pipe 38 through the fan 34 to be evacuated through the chimney 44. Metal oxides such as lead oxide and zinc oxide in the tail gas are collected in the dry tail gas purification device 31 and are recycled as raw materials of the nonferrous smelting plant; for explosion protection, an explosion protection valve 30 and an explosion protection air duct 40 are provided in the roasting section 15.

(15) The steel strip 1 then feeds the layer into the next stage, i.e. the homogenization section 19 (homogenization apparatus), where the layer takes 5 minutes, the time being adjustable as a function of the speed of the steel strip 1. In the homogenizing section 19, no additional energy is input, no steam flow is input, the high-temperature material layer is remained and calmed for a period of time, and the silicon oxide in the molten state in the interior of the material layer particles still in the high-temperature state can still flow and adhere to other solid phases under the action of gravity, so that the homogenization of the internal tissues of the particles is realized. The homogenization section is necessary, and high-temperature particles which do not pass through the homogenization section directly enter the cooling section, so that cracks can occur, and the bearing strength of the particles is reduced.

(16) The strip 1 then feeds the layer into the next stage, i.e. cooling 16, where the layer resides for 8 minutes, the time being adjustable with the speed of the strip 1. Cold air is sucked from an external air duct 22 by a fan 23 and blown from the lower side of the steel strip 1, after passing through the steel strip and the cooked particle 4 layer, the cold air meets the high-temperature finished particle layer and exchanges heat, and the cold air is changed into hot air and is sent to the roasting section 15. After the high-temperature material layer particles are cooled for a period of time, the temperature is reduced to 1000-800 ℃.

(17) The steel strip 1 then feeds the layer into the next stage, the cooling second stage 12 (second cooling windbox), where the layer resides for 8 minutes, the time being adjustable with the speed of the steel strip 1. Cold air is sucked from an external air pipe 21 by a fan 24 and blown from the lower part of the steel strip 1, after the cold air passes through the steel strip and the cooked particle 4 layer, the cold air meets the high-temperature finished particle layer and exchanges heat, and the cold air is changed into hot air and is sent into the heating section 11. After the high-temperature material layer passes through the cooling section 12, the temperature is reduced to 500-600 ℃.

(18) The steel strip 1 then feeds the layer into the next stage, i.e. the cooling of three sections 10 (third cooling windboxes), where the layer resides for 8 minutes, the time being adjustable with the speed of the steel strip 1. Cold air is sucked from an external air pipe 20 by a fan 25 and blown from the lower part of the steel strip 1, after the cold air passes through the steel strip 1 and the cooked particle 4 material layer, the cold air meets the high-temperature finished product particle material layer and exchanges heat, and the cold air is changed into hot air and is sent into the drying section 8. After the hot bed has been cooled through three sections 10, the temperature drops to about 100 ℃. So far, after the whole process stage is finished, the solid wastes are roasted at high temperature to form hard particles with the diameter of 12 mm and the strength of 1000-2000 Newton, and the hard particles can replace building sandstone materials.

(19) A part of the finished pellets was returned to the steel belt as undercoated pellets 4 having a thickness of 200 mm. The rest is sold as a product. The whole process does not generate solid waste, and realizes clean production of zero solid waste.

The device and the method have the advantages that:

the energy consumption is low, the solid waste is granulated, and the process comprises seven process steps of drying, heating, roasting, homogenizing, cooling I, cooling II and cooling III, wherein hot air for cooling I, cooling II and cooling III is completely recovered, so 70% of energy in the process is recovered and recycled, the energy consumed by cooling burners in the first and second hot air recovery flues only accounts for about 5-7% of the total energy at the maximum temperature of 1450 ℃, and the rest energy is derived from organic matters and matched fuel in the solid waste. The advantage of low energy consumption is low cost.

The process temperature is high, the temperature field is uniform, the solid waste particles do not rub against each other and are in a static state, the maximum roasting temperature can reach 1450 ℃, and at the temperature, viruses, bacteria and microorganisms contained in the solid waste are all killed and killed; lead and zinc in the solid waste are volatilized to enter tail gas, so that the lead and zinc are collected and recycled; the acidic or basic substance is cracked; harmful metal elements are oxidized again, and are adhered and wrapped by the re-melted silicon oxide, so that the harmful metal elements are not released into the nature; the finished product particles have high-temperature roasting strength, and can be used as a substitute of building sandstone materials or aggregate used as a light heat-insulating material.

The treatment capacity is large, the total annual treatment solid waste amount can reach millions of tons, the occupied area is small, the one-time investment is low, and the operation cost is low.

The variety of solid wastes to be treated is not limited, the process can treat all solid wastes, and municipal sludge, river and lake dredging, red mud, tailings, fly ash, coal gangue, metallurgical solid wastes, waste plastics, paper mill black liquor drying, crushed straws or wood chips can be treated by the process.

According to the analysis of the basic principle, the method provided by the invention is to oxidize the metal elements at high temperature and wrap the metal elements by using silicon oxide adhesion, so that the metal elements return to the natural state of the initial metal oxide ore and are not dissolved in underground water any more, and therefore, pollution is not generated.

The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In summary, this summary should not be construed to limit the present invention.

Claims

1. A solid waste treatment device, comprising:

2. The solid waste treatment apparatus of claim 1, further comprising:

3. The solid waste treatment apparatus of claim 2, further comprising:

4. The solid waste treatment apparatus of claim 3, further comprising:

5. The solid waste treatment apparatus of claim 4,

the first cooling device specifically includes:

the first fan, the first cooling air box and the first combustion device;

the second cooling device specifically includes:

a second fan, a second cooling windbox, and a second combustion device;

the third cooling device specifically includes:

a third fan and a third cooling windbox;

6. A solid waste treatment method is characterized by comprising the following steps:

drying the particles placed on the conveying device to obtain dried particles;

heating the dried particles to obtain heated particles;

roasting the heated particles to obtain roasted particles;

homogenizing the roasted particles to obtain homogenized particles;

7. The solid waste treatment method according to claim 6, wherein the solid waste and auxiliary materials are subjected to mixing, ball milling, filtering and granulation treatment to obtain particles to be treated for solid waste meeting a preset size, and the method specifically comprises the following steps:

8. The solid waste treatment method according to claim 6,

the temperature of the drying treatment is 300-500 ℃;

the temperature of the heating treatment is 800-1000 ℃;

the temperature of the roasting treatment is 1000-1450 ℃.

9. The solid waste treatment method according to claim 7,

the preset size is 12 mm;

the first water content is 9%;

the second water content is 10%.

10. The method according to claim 7, wherein the particle size of the solid in the slurry is 80% or more and minus 200 mesh.