阅读说明：本技术 一种用于危废处置的污泥衍生燃料制备方法 (Preparation method of sludge derived fuel for hazardous waste disposal ) 是由 张志霄 杨超 马加德 徐剑 樊雪 杨帆 于 2019-10-21 设计创作，主要内容包括：本发明公开了一种用于危废处置的污泥衍生燃料制备方法。污泥衍生燃料给危废处置技术的发展提供了新的发展方向。本发明方法：污泥类危废、工业固废、辅助燃料、调节剂粉、固硫脱酸剂粉和黏结剂粉的接收；污泥和工业固废干化；辅助燃料和工业固废破碎；配伍料暂存；配伍：SDF配伍料由主料和辅料组成,将污泥粉作为主料,辅料包括辅助燃料细粉、工业固废细粉、调节剂粉、固硫脱酸剂粉、黏结剂粉和调湿水；混合、成型、烘干。本发明将危废类污泥作为主料,协同处置其他类别大宗固体废弃物,经过科学配伍制成SDF,供作高温固废热处理设备的原料,实现以废治废,也符合鼓励协同处置的产业政策。(The invention discloses a preparation method of sludge derived fuel for hazardous waste disposal. The sludge derived fuel provides a new development direction for the development of the hazardous waste disposal technology. The method comprises the following steps: receiving sludge hazardous waste, industrial solid waste, auxiliary fuel, regulator powder, sulfur-fixing deacidification agent powder and binder powder; drying sludge and industrial solid waste; crushing auxiliary fuel and industrial solid waste; temporarily storing the compatible materials; compatibility: the SDF compatible material consists of a main material and auxiliary materials, wherein the sludge powder is used as the main material, and the auxiliary materials comprise auxiliary fuel fine powder, industrial solid waste fine powder, regulator powder, sulfur-fixing deacidification agent powder, binder powder and humidity-adjusting water; mixing, forming and drying. According to the invention, the hazardous waste sludge is used as a main material to cooperatively treat other types of bulk solid wastes, and the SDF is prepared by scientific compatibility and used as a raw material of high-temperature solid waste heat treatment equipment, so that the treatment of wastes with processes of wastes against one another is realized, and the industrial policy of encouraging cooperative treatment is also met.)

1. A preparation method of sludge derived fuel for hazardous waste disposal is characterized by comprising the following steps: the method comprises the following specific steps:

firstly, receiving sludge hazardous waste, industrial solid waste, auxiliary fuel, regulator powder, solid sulfur deacidification agent powder and binder powder;

transporting the sludge-type hazardous waste and the industrial solid waste to a disposal plant by a transport vehicle; weighing sludge hazardous wastes which are not powder materials by a weighbridge and then unloading the weighed sludge hazardous wastes into a sludge temporary storage warehouse of a disposal plant, and weighing industrial solid wastes which are not powder materials by the weighbridge and then unloading the weighed industrial solid wastes into an industrial solid waste temporary storage warehouse of the disposal plant; the sludge powder and the industrial solid waste fine powder of the rest powder are respectively weighed by a wagon balance and then directly discharged into a sludge powder bin and an industrial solid waste powder bin of a treatment plant;

transporting the purchased auxiliary fuel to a disposal plant through a transport vehicle, weighing the auxiliary fuel by a wagon balance, and unloading the auxiliary fuel into an auxiliary fuel library of the disposal plant; the auxiliary fuel adopts fire coal or straw or the mixture of the fire coal and the straw, the fire coal is discharged into a coal bunker, and the straw is discharged into a straw bunker;

transporting purchased regulator powder, sulfur-fixing deacidification agent powder and binder powder to a disposal plant by a transport vehicle, weighing by a wagon balance, and respectively unloading into a regulator powder bin, a sulfur-fixing deacidification agent powder bin and a binder powder bin of the disposal plant;

(II) pretreatment;

(1) drying;

conveying the sludge in the sludge temporary storage warehouse to a sludge drier through a transfer conveyor, and drying the wet sludge into sludge powder with the water content of 15-40%; drying industrial solid waste and wet sludge together, or independently arranging an industrial solid waste drying machine for drying and dewatering;

(2) crushing;

conveying the auxiliary fuel in the auxiliary fuel storage to an auxiliary fuel crusher through a transfer conveying machine, and crushing the auxiliary fuel into auxiliary fuel fine powder smaller than 2 mm; when the auxiliary fuel adopts fire coal, the auxiliary fuel crusher adopts a fire coal crusher, and when the auxiliary fuel adopts straw, the auxiliary fuel crusher adopts a straw crusher;

conveying the industrial solid waste in the industrial solid waste temporary storage warehouse to an industrial solid waste crusher through a transfer conveying machine, and crushing the industrial solid waste into industrial solid waste fine powder with the particle size smaller than 2mm by using the industrial solid waste crusher;

(3) temporarily storing the compatible materials;

conveying dried sludge powder to a sludge powder bin, conveying crushed auxiliary fuel fine powder to an auxiliary fuel powder bin, and conveying crushed industrial solid waste fine powder to an industrial solid waste powder bin;

(III) compatibility;

the SDF compatible material consists of a main material and auxiliary materials, wherein the sludge powder is used as the main material, and the auxiliary materials comprise auxiliary fuel fine powder, industrial solid waste fine powder, regulator powder, sulfur-fixing deacidification agent powder, binder powder and humidity-adjusting water; the compatibility process is as follows: analyzing the specific components and heat values of the sludge powder and the industrial solid waste fine powder by a laboratory of a disposal plant, and calculating the proportion of the sludge powder, the industrial solid waste fine powder and the auxiliary fuel fine powder which are compatible for one time according to the respective quantities to be disposed; according to the proportion of pollutants of the compatible materials in the primary compatibility, calculating the corresponding consumption of the sulfur-fixing deacidification agent, calculating the corresponding consumption of the regulator, and calculating the consumption of the adhesive added for the strength required to be achieved in the subsequent forming, thereby obtaining the proportion of the main materials and the auxiliary materials in the secondary compatibility; calculating the humidity-adjusting water consumption according to the water content of the compatible material subjected to the secondary compatibility, and completing the proportion of the main material and the auxiliary material subjected to the tertiary compatibility; checking the scientificity of the third compatibility, and finely adjusting the main materials and the auxiliary materials to obtain an exact production formula; the scientificity of checking the tertiary compatibility is specifically to carry out strength checking, heat value checking, Ca/S checking, ash melting point checking and slag alkalinity checking on the SDF product;

metering devices are arranged below the sludge powder bin, the auxiliary fuel powder bin, the industrial solid waste powder bin, the regulator powder bin, the sulfur-fixing deacidification agent powder bin and the adhesive powder bin; according to the production formula, the compatible materials in the main material bin and various auxiliary material bins are respectively metered and then are conveyed to a buffer bin through a transfer conveying machine;

(IV) mixing;

the materials in the buffer bin are conveyed to a mixer by a transfer conveyor to be fully mixed and uniformly stirred; spraying metered humidity-adjusting water into the mixer to adjust and control the water content; conveying the SDF molding material subjected to mixing and humidifying to a transition bin by a transfer conveyor; controlling the water content of the SDF molding material after full mixing and humidifying to be 15-20%;

(V) forming;

conveying the SDF molding material in the transition bin to a molding machine through a transfer conveyor, and extruding and stirring the SDF molding material to form a molding SDF wet material; screening the formed wet SDF material by a vibrating screen to remove the crushed SDF material, returning the crushed SDF material to the mixer by a transfer conveyor to participate in forming again, rolling the formed wet SDF material into the transfer conveyor through an outlet of the vibrating screen, and drying the wet SDF material by the transfer conveyor;

sixthly, drying;

filling or directly discharging the formed SDF wet material ton bags into a transfer site, and naturally drying the SDF wet material ton bags for recycling; or directly conveying the formed SDF wet material to a dryer through a transfer conveying machine for forced thermal drying; the water content of the dried SDF product is less than 10 percent, and the three-time compatibility scientific checking index of the SDF product is met.

2. The method for preparing sludge derived fuel for hazardous waste disposal according to claim 1, wherein: the industrial solid waste is one or more of non-sludge solid waste listed in the national hazardous waste record and solid waste not listed in the national hazardous waste record.

3. The method for preparing sludge derived fuel for hazardous waste disposal according to claim 1, wherein: the heat source of the sludge drier and the industrial solid waste drier adopts one of electricity, steam, hot water, heat conduction oil, hot air and flue gas; the coal crusher is one or more of a jaw crusher, a back-impact crusher, a roller crusher and a pulverizer; the transfer conveying machinery is one or more of an electric hoist, a bridge crane, a four-wheel loader, a bucket elevator, a belt conveyor, a scraper conveyor, a spiral conveyor and a pneumatic conveyor; the metering device is one of a belt weighing machine, a spiral weighing machine and a weightless scale; the dryer is one of a vertical moving bed hot air dryer, a mesh belt dryer or a flap dryer; the heat source of the dryer adopts one of electricity, steam, hot water, heat conduction oil, hot air and flue gas; the heat source of the dryer is hot air, and the temperature of an air inlet of the dryer is less than or equal to 400 ℃; the mixer choose 2 wheel-mill mixers to operate in series, the compatible mixture is rolled and mixed, 2 double-shaft mixers are connected in series again, and the humidifying water is sent in while mixing.

4. The method for preparing sludge derived fuel for hazardous waste disposal according to claim 1, wherein: the coal is replaced by coke or semi coke, the coke is received by a coke warehouse, the semi coke is received by a semi coke warehouse, and the coke or semi coke is crushed by a crusher which is the same as the coal.

5. The method for preparing sludge derived fuel for hazardous waste disposal according to claim 1, wherein: the regulator powder is one or a combination of a plurality of glass powder, quartz sand powder and borax powder.

6. The method for preparing sludge derived fuel for hazardous waste disposal according to claim 1, wherein: the adhesive is one or a combination of more of bentonite, industrial starch or sodium humate; the sulfur-fixing deacidification agent is one or a combination of limestone powder, quicklime powder or slaked lime powder.

7. The method for preparing sludge derived fuel for hazardous waste disposal according to claim 1, wherein: the SDF compatible material is prepared from the following components in parts by weight: 57 parts of sludge powder, 18 parts of pulverized coal, 1 part of straw powder, 5 parts of rectification residues, 2 parts of waste activated carbon, 5 parts of limestone powder, 1 part of glass powder, 2 parts of binder powder and 9 parts of humidity adjusting water; the sludge powder is formed by drying chemical organic sludge and printing and dyeing sludge until the water content is 15%, and finally consists of 68% by mass of organic sludge, 17% by mass of printing and dyeing sludge and 15% by mass of water; the SDF product has a calorific value of 2100 kcal/kg; the binder powder is bentonite.

8. The method for preparing sludge derived fuel for hazardous waste disposal according to claim 1, wherein: the humidity adjusting water is derived from process wastewater, reclaimed water, softened water and tap water; the method comprises the following steps of arranging 1 or more humidity-adjusting water tanks, wherein outlets at the bottoms of the humidity-adjusting water tanks are connected with humidity-adjusting water pumps through pipelines, outlets of the humidity-adjusting water pumps are connected with humidity-adjusting water metering devices through pipelines, and outlets of the humidity-adjusting water metering devices are connected with a mixer through pipelines; the humidity control water tank contains humidity control water or adhesive solution of several types.

9. The method for preparing sludge derived fuel for hazardous waste disposal according to claim 1, wherein: the shape of the formed SDF wet material is spherical, granular, rod-shaped, flat oval sphere or brick shape; the forming machine selects one or more of a pair of roller ball press machine, a screw rod granulator, a disc granulator, an extrusion granulator and a stirring tooth granulator.

10. The method for preparing sludge derived fuel for hazardous waste disposal according to claim 1, wherein: checking the scientificity of the third compatibility, specifically performing strength checking, heat value checking, Ca/S checking, ash melting point checking and slag alkalinity checking on the SDF product; checking the strength of the SDF product to be greater than a preset minimum value; checking the heat value of the SDF product according to the requirement of the furnace type characteristic of high-temperature solid waste heat treatment equipment on the heat value, wherein the heat value of the SDF product is required to be more than 1800kcal/kg when the high-temperature solid waste heat treatment equipment selects a gasification melting furnace; the Ca/S check of the SDF product is that the Ca/S is 1-3; checking the ash melting point of the SDF product according to the requirement of the furnace type characteristic of high-temperature solid waste heat treatment equipment on the ash melting point, wherein the ash melting point of the SDF product is required to be less than 1400 ℃ when the high-temperature solid waste heat treatment equipment selects a gasification melting furnace; and checking the slag alkalinity of the SDF product to be full alkalinity R which is 0.3-1.5.

Technical Field

The invention belongs to the technical field of environmental protection, relates to a hazardous waste derived fuel preparation technology and hazardous waste disposal pretreatment, and particularly relates to a sludge derived fuel preparation method for hazardous waste disposal.

Background

As the second major economic entity in the world, China has a total domestic production value of 900309.50 hundred million yuan in the 1 st to 4 th quarter in 2018 and a total domestic production value of 450933.20 hundred million yuan in the 1 st to 2 th quarter in 2019, and the year by year is increased by 6.30%; china is a large country with nearly 14 hundred million people, and a large amount of industrial and urban solid wastes are generated every year;

according to the annual newspaper for preventing and treating the solid waste from polluting the environment in the whole big and middle cities in 2018 of the department of ecological environment, in 2017, the generation amount of the general industrial solid waste in 202 big and middle cities reaches 18.1 hundred million tons, the comprehensive utilization amount is 7.7 million tons, the disposal amount is 3.1 million tons, the storage amount is 7.3 million tons, and the dumping and discarding amount is 9.0 million tons. The comprehensive utilization amount of general industrial solid wastes is 42.5%, and the disposal and storage amounts are 17.1% and 40.3%, respectively. From data, the current disposal rate of industrial solid waste is obviously low, and the level needs to be improved urgently;

according to data of national institute of statistics of annual book of China (2018 edition), the national hazardous waste production amount in 2017 is 6936.89 ten thousand tons, the comprehensive utilization amount is 4043.42 ten thousand tons, the disposal amount is 2551.56 ten thousand tons, and the storage amount is 870.87 ten thousand tons. From data, the treatment capacity of hazardous waste in China is also insufficient;

the solid wastes are large in quantity and variety and complex in components, and a plurality of disposal technologies are needed to deal with the social problem together;

particularly, the dehydrated sludge for sewage treatment has large amount and low heat value, and the sludge contains one or more components of heavy metal and sulfur chlorine fluorine, although the drying incineration can achieve the reduction effect to a certain extent, the incineration not only has high cost, but also can generate secondary pollution of dioxin and heavy metal, and the fly ash needs secondary harmless treatment;

municipal sludge and other common solid waste sludge can be made into Sludge Derived Fuel (SDF) by adding auxiliary fuel (coal, straw and the like), the SDF has small heat value fluctuation, and the matched SDF incinerator runs stably, thereby realizing the reduction, harmlessness and reclamation of sludge disposal and providing a new development direction for the development of sludge disposal technology;

although sludge generated by sewage treatment plants for mixing and collecting municipal sewage and industrial sewage, printing sewage treatment plants and other sewage treatment plants is not listed in the list of national hazardous waste records, fly ash generated by sludge drying and incineration belongs to hazardous waste and becomes actual hazardous waste sludge;

the various chemical sludge listed in the national hazardous waste record list is hazardous waste sludge, is used for cooperatively treating other large solid wastes, is prepared into SDF through scientific compatibility, is used as a raw material of high-temperature heat treatment equipment, such as a raw material of a gasification melting furnace, a raw material cooperatively treated by a cement kiln, a raw material of an incineration melting furnace and the like, achieves the purposes of solidifying heavy metal lattices and inhibiting generation of dioxin and fly ash, and is considered to be a hazardous waste pretreatment technology with very development potential.

Disclosure of Invention

The invention aims to disclose a method for preparing sludge derived fuel, in particular to a method for preparing sludge derived fuel for treating hazardous waste, which is characterized in that a hazardous waste sludge main material and a plurality of auxiliary materials are scientifically matched and pressed to form the hazardous waste sludge main material and the auxiliary materials, and the hazardous waste sludge main material and the auxiliary materials are used as raw materials of high-temperature solid waste heat treatment equipment such as an SDF gasification melting furnace and the like; the invention can treat dangerous waste sludge and simultaneously treat other industrial solid wastes, such as medical wastes, pesticide wastes, rectification residues, surface treatment wastes and other non-sludge solid wastes of waste categories listed in national hazardous waste records and common industrial solid wastes such as printing and dyeing sludge, so as to treat wastes with processes of wastes and finally realize the reduction, harmlessness and recycling of industrial solid wastes.

The invention specifically comprises the following steps:

firstly, receiving sludge hazardous waste, industrial solid waste, auxiliary fuel, regulator powder, solid sulfur deacidification agent powder and binder powder;

transporting the sludge-type hazardous waste and the industrial solid waste to a disposal plant by a transport vehicle; weighing sludge hazardous wastes which are not powder materials by a weighbridge and then unloading the weighed sludge hazardous wastes into a sludge temporary storage warehouse of a disposal plant, and weighing industrial solid wastes which are not powder materials by the weighbridge and then unloading the weighed industrial solid wastes into an industrial solid waste temporary storage warehouse of the disposal plant; the sludge powder and the industrial solid waste fine powder of the rest powder are respectively weighed by a wagon balance and then directly discharged into a sludge powder bin and an industrial solid waste powder bin of a treatment plant;

transporting the purchased auxiliary fuel to a disposal plant through a transport vehicle, weighing the auxiliary fuel by a wagon balance, and unloading the auxiliary fuel into an auxiliary fuel library of the disposal plant; the auxiliary fuel adopts fire coal or straw or the mixture of the fire coal and the straw, the fire coal is discharged into a coal bunker, and the straw is discharged into a straw bunker;

the purchased regulator powder, the sulfur-fixing deacidification agent powder and the binder powder are transported to a disposal plant by a transport vehicle, and are respectively unloaded into a regulator powder bin, a sulfur-fixing deacidification agent powder bin and a binder powder bin of the disposal plant after being weighed by a wagon balance.

(II) pretreatment;

(1) drying;

conveying the sludge in the sludge temporary storage warehouse to a sludge drier through a transfer conveyor, and drying the wet sludge into sludge powder with the water content of 15-40%; the industrial solid waste and wet sludge are dried together, or an industrial solid waste drying machine is independently arranged for drying and dewatering.

(2) Crushing;

conveying the auxiliary fuel in the auxiliary fuel storage to an auxiliary fuel crusher through a transfer conveying machine, and crushing the auxiliary fuel into auxiliary fuel fine powder smaller than 2 mm; when the auxiliary fuel adopts fire coal, the auxiliary fuel crusher adopts a fire coal crusher, and when the auxiliary fuel adopts straw, the auxiliary fuel crusher adopts a straw crusher;

industrial solid waste in the industrial solid waste temporary storage warehouse is conveyed to an industrial solid waste crusher through a transfer conveying machine, and the industrial solid waste crusher is used for crushing the industrial solid waste into industrial solid waste fine powder with the particle size smaller than 2 mm.

(3) Temporarily storing the compatible materials;

conveying the dried sludge powder to a sludge powder bin, conveying the crushed auxiliary fuel fine powder to an auxiliary fuel powder bin, and conveying the crushed industrial solid waste fine powder to an industrial solid waste powder bin.

(III) compatibility;

the SDF compatible material consists of a main material and auxiliary materials, wherein the sludge powder is used as the main material, and the auxiliary materials comprise auxiliary fuel fine powder, industrial solid waste fine powder, regulator powder, sulfur-fixing deacidification agent powder, binder powder and humidity-adjusting water; the compatibility process is as follows: analyzing the specific components and heat values of the sludge powder and the industrial solid waste fine powder by a laboratory of a disposal plant, and calculating the proportion of the sludge powder, the industrial solid waste fine powder and the auxiliary fuel fine powder which are compatible for one time according to the respective quantities to be disposed; according to the proportion of pollutants of the compatible materials in the primary compatibility, calculating the corresponding consumption of the sulfur-fixing deacidification agent, calculating the corresponding consumption of the regulator, and calculating the consumption of the adhesive added for the strength required to be achieved in the subsequent forming, thereby obtaining the proportion of the main materials and the auxiliary materials in the secondary compatibility; calculating the humidity-adjusting water consumption according to the water content of the compatible material subjected to the secondary compatibility, and completing the proportion of the main material and the auxiliary material subjected to the tertiary compatibility; checking the scientificity of the third compatibility, and finely adjusting the main materials and the auxiliary materials to obtain an exact production formula; the scientificity of checking the tertiary compatibility is specifically to carry out strength checking, heat value checking, Ca/S checking, ash melting point checking and slag alkalinity checking on the SDF product;

metering devices are arranged below the sludge powder bin, the auxiliary fuel powder bin, the industrial solid waste powder bin, the regulator powder bin, the sulfur-fixing deacidification agent powder bin and the adhesive powder bin; according to the production formula, the compatible materials in the main material bin and various auxiliary material bins are respectively metered and then are conveyed to a buffer bin through a transfer conveying machine.

(IV) mixing;

the materials in the buffer bin are conveyed to a mixer by a transfer conveyor to be fully mixed and uniformly stirred; spraying metered humidity-adjusting water into the mixer to adjust and control the water content; conveying the SDF molding material subjected to mixing and humidifying to a transition bin by a transfer conveyor; and controlling the water content of the SDF molding material after full mixing and humidifying to be 15-20%.

(V) forming;

conveying the SDF molding material in the transition bin to a molding machine through a transfer conveyor, and extruding and stirring the SDF molding material to form a molding SDF wet material; and screening the formed wet formed SDF material by a vibrating screen to remove the crushed SDF material, returning the crushed SDF material to the mixer by a transfer conveyor to participate in forming again, rolling the formed wet formed SDF material into the transfer conveyor through an outlet of the vibrating screen, and conveying the wet formed SDF material into a drying step by the transfer conveyor.

Sixthly, drying;

filling or directly discharging the formed SDF wet material ton bags into a transfer site, and naturally drying the SDF wet material ton bags for recycling; or directly conveying the formed SDF wet material to a dryer through a transfer conveying machine for forced thermal drying; the water content of the dried SDF product is less than 10 percent, and the three-time compatibility scientific checking index of the SDF product is met.

Further, the industrial solid waste is one or more of non-sludge solid waste in the waste category listed in the national hazardous waste list and solid waste not listed in the national hazardous waste list.

Further, the heat source of the sludge drier and the industrial solid waste drier adopts one of electricity, steam, hot water, heat conduction oil, hot air and flue gas; the coal crusher is one or more of a jaw crusher, a back-impact crusher, a roller crusher and a pulverizer; the transfer conveying machinery is one or more of an electric hoist, a bridge crane, a four-wheel loader, a bucket elevator, a belt conveyor, a scraper conveyor, a spiral conveyor and a pneumatic conveyor; the metering device is one of a belt weighing machine, a spiral weighing machine and a weightless scale; the dryer is one of a vertical moving bed hot air dryer, a mesh belt dryer or a flap dryer; the heat source of the dryer adopts one of electricity, steam, hot water, heat conduction oil, hot air and flue gas; the heat source of the dryer is hot air, and the temperature of an air inlet of the dryer is less than or equal to 400 ℃; the mixer choose 2 wheel-mill mixers to operate in series, the compatible mixture is rolled and mixed, 2 double-shaft mixers are connected in series again, and the humidifying water is sent in while mixing.

Furthermore, the fire coal is replaced by coke or semi coke, a coke warehouse is adopted for receiving the coke, a semi coke warehouse is adopted for receiving the semi coke, and a crusher which is the same as the crusher for crushing the coal is adopted for crushing the coke or the semi coke.

Furthermore, the regulator powder is one or a combination of a plurality of glass powder, quartz sand powder and borax powder.

Further, the adhesive is one or a combination of more of bentonite, industrial starch or sodium humate; the sulfur-fixing deacidification agent is one or a combination of limestone powder, quicklime powder or slaked lime powder.

Further, the SDF compatible material is prepared from the following components in parts by weight: 57 parts of sludge powder, 18 parts of pulverized coal, 1 part of straw powder, 5 parts of rectification residues, 2 parts of waste activated carbon, 5 parts of limestone powder, 1 part of glass powder, 2 parts of binder powder and 9 parts of humidity-adjusting water. The sludge powder is formed by drying chemical organic sludge and printing and dyeing sludge until the water content is 15%, and finally consists of 68% by mass of organic sludge, 17% by mass of printing and dyeing sludge and 15% by mass of water; the SDF product has a calorific value of 2100 kcal/kg; the binder powder is bentonite.

Further, the humidity adjusting water is derived from process wastewater, reclaimed water, softened water and tap water; the method comprises the following steps of arranging 1 or more humidity-adjusting water tanks, wherein outlets at the bottoms of the humidity-adjusting water tanks are connected with humidity-adjusting water pumps through pipelines, outlets of the humidity-adjusting water pumps are connected with humidity-adjusting water metering devices through pipelines, and outlets of the humidity-adjusting water metering devices are connected with a mixer through pipelines; the humidity control water tank contains humidity control water or adhesive solution of several types.

Further, the shape of the formed SDF wet material is spherical, granular, rod-shaped, flat oval sphere or brick shape; the forming machine selects one or more of a pair of roller ball press machine, a screw rod granulator, a disc granulator, an extrusion granulator and a stirring tooth granulator.

Further checking the scientificity of the third compatibility, specifically performing strength checking, heat value checking, Ca/S checking, ash melting point checking and slag alkalinity checking on the SDF product; checking the strength of the SDF product to be greater than a preset minimum value; checking the heat value of the SDF product according to the requirement of the furnace type characteristic of high-temperature solid waste heat treatment equipment on the heat value, wherein the heat value of the SDF product is required to be more than 1800kcal/kg when the high-temperature solid waste heat treatment equipment selects a gasification melting furnace; the Ca/S check of the SDF product is that the Ca/S is 1-3; checking the ash melting point of the SDF product according to the requirement of the furnace type characteristic of high-temperature solid waste heat treatment equipment on the ash melting point, wherein the ash melting point of the SDF product is required to be less than 1400 ℃ when the high-temperature solid waste heat treatment equipment selects a gasification melting furnace; and checking the slag alkalinity of the SDF product to be full alkalinity R which is 0.3-1.5.

The invention has the beneficial effects that:

1. the invention takes the dangerous waste sludge listed in the national hazardous waste list as the main material, cooperatively disposes bulk solid wastes of other types, prepares SDF through scientific compatibility and provides the SDF as the raw material of high-temperature solid waste heat treatment equipment, realizes the treatment of wastes with processes of wastes against one another and also conforms to the industrial policy of encouraging cooperative disposal;

2. the auxiliary fuel has wide selection range, and high-heat-value fuels such as fire coal, coke, semi coke, straw and the like can be selected to improve the heat value of the SDF;

3. the invention takes the dangerous waste sludge as the main material, can cooperatively treat non-sludge solid wastes such as medical wastes, pesticide wastes, rectification residues, surface treatment wastes and the like which are listed in the national hazardous waste record, and can also cooperatively treat solid wastes such as printing and dyeing sludge and the like which are not listed in the national hazardous waste record; the distillation residue and the like have higher heat value, and auxiliary fuel can be reduced or not added in the SDF compatible auxiliary materials;

4. compared with the direct treatment of wet sludge and dried sludge powder, the formed SDF is sent into high-temperature solid waste heat treatment equipment such as a gasification melting furnace, and the invention can achieve the following beneficial effects: (1) the dust emission is reduced; (2) the SDF has high energy density, and is beneficial to improving the reaction temperature of a hearth; (3) the lattice solidification of heavy metal is facilitated; (4) inhibiting the generation of dioxin; (5) the flue gas amount is small, and the investment and the operation cost of a flue gas purification facility are reduced; (6) the ventilation in the furnace is facilitated, the high-temperature normal-pressure operation is realized, and the power cost is low;

5. according to the invention, wet sludge with the water content of 50-83% is firstly dried to sludge powder with the water content of 15-40%, the sludge powder is used as a main material to participate in the molding of the SDF, and other industrial solid wastes with high water content are also dried to be used as auxiliary materials to participate in the compatibility and molding of the SDF together, so that the heat value of the SDF is favorably improved, the consumption of auxiliary fuels such as natural gas of high-temperature solid waste heat treatment equipment such as a gasification melting furnace is reduced, the generation of smoke gas is reduced, and the disposal cost of the industrial solid wastes is reduced;

6. according to the invention, the main materials and the auxiliary materials which participate in compatibility are independently provided with the metering devices, so that the performance stability of SDF batch production is achieved, and the SDF batch production is sent into high-temperature solid waste heat treatment equipment such as a gasification melting furnace, so that the operation stability of the heat treatment equipment is facilitated, and the secondary pollution emission is reduced;

7. the invention arranges a buffer bin in front of a mixer and arranges a transition bin behind the mixer; the buffer bin is beneficial to the compatibility continuity of the main materials and the auxiliary materials, and the transition bin is beneficial to the continuity of the SDF forming, so that the SDF forming efficiency is greatly improved, and the SDF forming cost is reduced;

8. SDF molding of various mixtures is always a difficult problem in the industry, and especially the control of the water content is a difficult point; the following measures are taken: (1) drying and dehydrating the wet sludge and the wet industrial solid waste together; (2) the disposal plant sets a laboratory to carry out regular moisture content test on the compatible main materials and auxiliary materials sent into the mixing machine; (3) feeding the humidity-adjusting water into a mixer after metering; the water content of the compatible materials before forming is accurately controlled by three measures, and the forming success rate is improved;

9. the mixer of the invention can select one or more series connection, for example, 2 wheel-grinding type mixers are selected to operate in series, the compatible mixture is fully rolled and mixed, then 2 double-shaft mixers are connected in series, and the humidifying water is fed while stirring and mixing, so that the purpose of 4-level mixing and 4-level humidifying is achieved, and the mixer is a common implementation method configured by the invention;

10. in the method for serially connecting the humidity-regulating water and the multiple mixers, in actual production practice, the humidity-regulating water of the previous mixers in several stages generally adopts low-grade water sources such as process wastewater, intermediate water and the like, so that the discharge of sewage is reduced, and the humidity-regulating water generally comes from drying wastewater, workshop flushing wastewater, initial rainwater, flue gas purification wastewater and the like of solid waste treatment, so that an emission reduction way is provided for realizing zero discharge of sewage;

11. the vibrating screen is arranged behind the forming machine, the formed crushed aggregates are returned to the mixing machine to be formed again, the SDF crushed aggregates are reduced to enter the furnace, the ventilation resistance of high-temperature heat treatment equipment is reduced, the disposal capacity is improved, and the thermal ignition reduction rate of the furnace slag is favorably realized to be less than 5%;

12. the moisture content of the just-formed SDF wet material is 15-20%, if the formed SDF wet material is directly sent to high-temperature solid waste heat treatment equipment for disposal, the strength is low, the temperature of a hearth is unstable, and the amount of generated flue gas is large; for this reason, the invention is directed at small-scale disposal plants, the formed SDF wet material ton bags are contained or directly unloaded into a transfer site, and are recycled after natural drying; aiming at large and medium-sized disposal plants, the formed SDF wet material is directly conveyed to a dryer through a transfer conveying machine for forced thermal drying; the SDF product has the water content of less than 10 percent and meets certain strength and heat value requirements;

13. the SDF compatibility of the invention is provided with three times of scientific checking of compatibility, specifically, the strength checking, the heat value checking, the Ca/S checking, the ash fusion point checking and the slag alkalinity checking of the SDF product are carried out; therefore, a regulator powder bin is specially arranged, one or more combinations of glass, quartz sand and borax are selected, the passing of ash fusion point check and slag alkalinity check is easily achieved, the performance of the SDF product is stable, and the SDF product is suitable for high-temperature solid waste heat treatment equipment and has strong pertinence;

14. the SDF forming method is simple, convenient to operate, flexible in disposal scale and suitable for industrialization.

Drawings

FIG. 1 is a flow chart of the present invention.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

As shown in fig. 1, a method for preparing sludge derived fuel for hazardous waste disposal specifically comprises the following steps:

receiving sludge hazardous waste, industrial solid waste, fire coal, straw, regulator powder, limestone powder and binder powder;

one or more of sludge hazardous waste generally contained in ton bags and industrial solid waste needing to be co-disposed, such as medical waste, pesticide waste, rectification residue, surface treatment waste and the like, which are listed in national hazardous waste records, non-sludge solid waste of waste category and solid waste which is not listed in national hazardous waste records, such as printing and dyeing sludge, are transported to a disposal plant through a transport vehicle; weighing sludge hazardous wastes which are not powder materials by a weighbridge and then unloading the weighed sludge hazardous wastes into a sludge temporary storage warehouse of a disposal plant, and weighing industrial solid wastes which are not powder materials by the weighbridge and then unloading the weighed industrial solid wastes into an industrial solid waste temporary storage warehouse of the disposal plant; the sludge powder and the industrial solid waste fine powder of the rest powder are respectively weighed by a wagon balance and then directly discharged into a sludge powder bin and an industrial solid waste powder bin of a treatment plant;

transporting the purchased fire coal to a disposal plant through a transport vehicle, weighing the fire coal by a wagon balance, and unloading the fire coal into a coal bunker of the disposal plant; the straw is used as another auxiliary fuel, the purchased straw is transported to a disposal plant by a transport vehicle, and is unloaded into a straw warehouse of the disposal plant after being weighed by a wagon balance;

and (3) transporting the purchased regulator powder, limestone powder and binder powder to a disposal plant by a transport vehicle, weighing by a wagon balance, and then respectively unloading into a regulator powder bin, a limestone powder bin and a binder powder bin of the disposal plant.

(II) pretreatment;

(1) drying;

according to the method, the moisture content of the sludge received by a treatment plant is generally between 50 and 83 percent according to different properties of the sludge, different dewatering equipment (such as centrifugal machine dewatering, crawler-type filter press dewatering, screw stacking machine dewatering, plate-and-frame filter press dewatering and the like, which are mature technologies in the industry), different proportions and components of the added dewatering agent and the like, the sludge in a sludge temporary storage warehouse is conveyed to a sludge drier through a transfer conveyor, and the wet sludge is dried to sludge powder with the moisture content of 15 to 40 percent;

according to different sources of industrial solid waste received by the industrial solid waste temporary storage warehouse, the water content of some industrial solid waste is higher, such as waste activated carbon, paint slag and the like, and the industrial solid waste can be dried together with wet sludge or an industrial solid waste drying machine with an applicable model is independently arranged for drying and dewatering;

sludge drying machines and industrial solid waste drying machines are mature technologies in the industry; the type of the drier is divided into the following modes according to the contact mode of a heat medium and sludge or industrial solid waste: direct heating, indirect heating and "direct-indirect" combined heating; the method is divided into the following steps according to the form of equipment: rotary drum, rotary disc type, belt type, spiral type, centrifugal type, fluidized bed type, multiple coil type, film type, slurry plate type, flash evaporation type, spray type, multiple effect evaporation type, microwave type, multiple bed type, etc.; the drying machines of the same type are also characterized by different manufacturers; wherein, the heat source of the sludge drier and the industrial solid waste drier adopts one of electricity, steam, hot water, heat conducting oil, hot air, smoke and the like.

(2) Crushing;

conveying the fire coal in the coal bunker to a fire coal crusher through a transfer conveying machine, and crushing lump coal into pulverized coal smaller than 2mm by using the fire coal crusher; the coal crusher selects one or more combined equipment of a jaw crusher, an impact crusher, a roller crusher and a pulverizer, and is an industry mature technology;

in the coal-fired limited application area, auxiliary fuels such as coke or semi coke can be used for replacing the coal-fired, a coke warehouse is adopted for receiving the coke, a semi coke warehouse is adopted for receiving the semi coke, and a crusher which is the same as the crusher for crushing the coal-fired can be adopted for crushing the coke or the semi coke;

conveying the straws in the straw warehouse to a straw crusher through a transfer conveyor, and crushing the straws into straw powder smaller than 2mm by using the straw crusher; the straw crusher is currently matched with a straw forming and briquetting machine for producing biomass particles, and is mature equipment in the industry;

industrial solid waste in the industrial solid waste temporary storage warehouse is conveyed to an industrial solid waste crusher through a transfer conveying machine, and the industrial solid waste crusher is used for crushing the industrial solid waste into industrial solid waste fine powder with the particle size smaller than 2 mm. According to the characteristics of industrial solid wastes, different crusher equipment is selected, such as crushing of waste ton bags and a woven bag shredder is selected; a plastic bag crusher and the like are selected for crushing waste plastic bags; the industrial solid waste crusher has the selectable crusher of corresponding raw materials in the industry.

(3) Temporarily storing the compatible materials;

conveying the dried sludge powder to a sludge powder bin, conveying the crushed pulverized coal to a pulverized coal bin, conveying the crushed straw powder to a straw powder bin, and conveying the crushed industrial solid waste fine powder to an industrial solid waste powder bin;

according to the treatment needs of a disposal plant, the industrial solid waste can be various industrial solid wastes, such as medical waste, pesticide waste, rectification residue, surface treatment waste and the like, non-sludge solid waste of waste categories listed in the national hazardous waste record and solid waste such as printing and dyeing sludge not listed in the national hazardous waste record can be arranged in a single powder bin or multiple powder bins, and the description of the invention is not influenced;

the transferring and conveying machinery is one or more of an electric hoist, a bridge crane, a four-wheel loader, a bucket elevator, a belt conveyor, a scraper conveyor, a screw conveyor and a pneumatic conveyor.

(III) compatibility;

the SDF compatible material comprises a main material and auxiliary materials, wherein the sludge powder is used as the main material, the auxiliary materials comprise pulverized coal, straw powder, industrial solid waste fine powder, regulator powder, limestone powder, binder powder and humidity-regulating water, and the types and consumption of the auxiliary materials can be adjusted according to the amount and components of the sludge powder to be treated, so that the strength, the heat value, Ca/S, the ash melting point, the slag alkalinity and the like of the auxiliary materials can meet the stability requirement of the in-furnace physicochemical property of high-temperature solid waste heat treatment equipment;

the specific implementation mode of the compatibility is as follows: the sludge powder and the industrial solid waste fine powder which needs to be cooperatively treated are analyzed by a laboratory of a treatment plant to obtain specific components and heat values, and then the mixing ratio of the sludge powder, the industrial solid waste fine powder and auxiliary fuel (one or more combinations of pulverized coal, straw powder, coke, semi coke and the like, wherein the pulverized coal and the straw powder are adopted in the embodiment) which are compatible for one time is calculated according to respective to-be-treated quantities; according to the proportion of the compatible material pollutant (sulfur, chlorine and fluorine) in the primary compatibility, calculating the consumption of the corresponding sulfur-fixing deacidification agent powder (limestone powder is adopted in the embodiment), calculating the consumption of the corresponding regulator powder, and calculating the consumption of the adhesive added for the strength required to be achieved by the subsequent forming, so as to obtain the proportion of the main material and the auxiliary material in the secondary compatibility; calculating the humidity-adjusting water consumption according to the water content of the compatible material subjected to the secondary compatibility, and completing the proportion of the main material and the auxiliary material subjected to the tertiary compatibility; checking the scientificity of the third compatibility, and finely adjusting the main materials and the auxiliary materials to obtain an exact production formula; the scientificity of checking the tertiary compatibility is specifically to carry out strength checking, heat value checking, Ca/S checking, ash melting point checking and slag alkalinity checking on the SDF product;

corresponding metering devices are respectively arranged below the sludge powder bin, the pulverized coal bin, the straw powder bin, the industrial solid waste powder bin (which can be arranged in a single powder bin or a plurality of powder bins), the regulator powder bin, the limestone powder bin and the adhesive powder bin;

according to the production formula, the compatible materials in the main material bin and various auxiliary material bins are respectively metered and then are conveyed to a buffer bin through a transfer conveying machine;

some slurry solid wastes such as rectification residues and the like are generally contained in a barrel, can be directly unloaded into a buffer bin after being weighed and hoisted according to a formula single barrel, and can also be dried together with wet sludge hazardous wastes or industrial solid wastes to participate in compatibility;

the metering device is selected according to the requirements of the quantity, the characteristics and the precision of the medium, and can be selected from a belt weighing machine, a spiral weighing machine, a weightless scale and other metering devices for weighing; the compatible materials with less compatible materials in the formula, which are collectively called small materials, can be measured by common measuring devices such as an electronic scale, a platform scale, a crane special crane scale and the like, and then are transferred and conveyed to a buffer bin manually or by a transfer conveyor;

the regulator is one or more of glass, quartz sand and borax;

the adhesive is a mature forming additive product such as bentonite, industrial starch or sodium humate;

the sulfur-fixing deacidification agent can be one or a combination of limestone powder, quicklime powder or slaked lime powder.

An example of a formulation in actual production practice is given below:

the compatible materials for the hazardous waste gas melting furnace are prepared from the following components in parts by weight: 57 parts of sludge powder, 18 parts of pulverized coal, 1 part of straw powder, 5 parts of rectification residues, 2 parts of waste activated carbon, 5 parts of limestone powder, 1 part of glass powder, 2 parts of binder powder and 9 parts of humidity adjusting water; after the mixture is uniformly mixed and humidified, the moisture content of the mixture is 19%, the formed SDF wet material is dried to an SDF product with the moisture content of 6% by a hot air mesh belt dryer, the three-time compatibility scientific check index of the SDF product can meet the stable operation requirement of the gasification melting furnace, the technical performance index of the gasification melting furnace is qualified, and the pollutant index limit value in the smoke discharged by a smoke purification facility reaches the standard. The sludge powder is formed by drying chemical organic sludge and printing and dyeing sludge until the water content is 15%, and finally consists of 68% of organic sludge by mass fraction, 17% of printing and dyeing sludge by mass fraction and 15% of water by mass fraction; the SDF product has a calorific value of 2100 kcal/kg; the binder powder is bentonite.

(IV) mixing;

materials in the buffer bin are sludge powder, pulverized coal, straw powder, industrial solid waste fine powder, regulator powder, limestone powder, binder powder, SDF (recycled material from a forming machine) and the like which are fed according to the formula, and are conveyed to a mixer by a transfer conveyor to be fully mixed and stirred uniformly;

spraying metered humidity-adjusting water into the mixer to adjust and control the water content; conveying the SDF molding material subjected to mixing and humidifying to a transition bin by a transfer conveyor; the water content of the SDF molding material after full mixing and humidifying is generally 15-20%;

the mixer can be one or the combination of a wheel mill type mixer, a coulter mixer, a double-shaft mixer and a ribbon mixer;

the mixer can be selected from one or more series connection, for example, 2 wheel-grinding type mixers are selected to operate in series connection, the compatible mixture is fully rolled and mixed, then 2 double-shaft mixers are connected in series, and humidifying water is fed while stirring and mixing, so that the purpose of 4-level mixing and 4-level humidifying is achieved, and the method is a recommended implementation method of the invention;

the humidifying water is derived from process wastewater, reclaimed water, softened water and tap water of each process; in the actual production practice, the humidifying water for humidifying is mixed, low-grade water sources such as process wastewater and intermediate water are generally adopted, the sewage discharge is reduced, the humidifying water is generally derived from dried wastewater of solid waste disposal, workshop flushing wastewater, initial rainwater, flue gas purification wastewater and the like, the proportion of impurities relative to compatible main and auxiliary materials is extremely low, the compatibility accuracy is extremely low, and the SDF product is verified to have the scientificity of three-time compatibility, so that the deviation value can be covered; preparing humidity-adjusting water of the adhesive solution, wherein softened water and tap water are generally adopted;

the method comprises the following steps of arranging 1 or more humidity-adjusting water tanks, wherein outlets at the bottoms of the humidity-adjusting water tanks are connected with humidity-adjusting water pumps through pipelines, outlets of the humidity-adjusting water pumps are connected with humidity-adjusting water metering devices through pipelines, and outlets of the humidity-adjusting water metering devices are connected with a mixer through pipelines; the humidity control water tank contains humidity control water or adhesive solution of several types.

(V) forming;

conveying the SDF molding material in the transition bin to a molding machine through a transfer conveyor, and extruding and stirring the SDF molding material to form a molding SDF wet material;

the shape of the formed SDF wet material can be spherical, granular, rod-shaped, flat oval sphere, brick-shaped and the like by adopting a corresponding die according to requirements; the forming machine selects one or a combination of a plurality of pairs of roll ball press machines, screw rod granulators, disc granulators, extrusion granulators, stirring tooth granulators and the like;

compared with powder, the SDF has increased energy density, and is beneficial to improving the reaction temperature of high-temperature solid waste heat treatment equipment; the SDF is uniformly mixed, and multiple compatible materials are fully reacted, so that the vitrification rate is improved;

the forming SDF wet material which is usually used for high-temperature solid waste heat treatment equipment such as a gasification melting furnace and the like is flat elliptic spherical SDF, a roll-to-roll ball press is selected as a forming machine, and rolls with the ball diameter of 10-50 mm can be selected and matched; in order to meet the requirement of the strength of balling, a small amount of SDF raw materials are extruded to the joint of two hemispheres in the balling process, so that the formed SDF wet materials are screened by a vibrating screen to remove the SDF crushed materials which are not balling, the SDF crushed materials are returned to a mixer by a transfer conveyor to participate in forming again, the SDF wet materials which are qualified in balling roll into the transfer conveyor through an outlet of the vibrating screen, and the SDF wet materials are conveyed to a drying step by the transfer conveyor.

Sixthly, drying;

the moisture content of the qualified formed SDF wet material is 15-20%, if the formed SDF wet material is directly sent to high-temperature solid waste heat treatment equipment for disposal, the strength is low, the temperature of a hearth is unstable, and the amount of generated flue gas is large; for this reason, the invention is directed at small-scale disposal plants, the formed SDF wet material ton bags are contained or directly unloaded into a transfer site, and are recycled after natural drying; aiming at large and medium-sized disposal plants, the formed SDF wet material is directly conveyed to a dryer through a transfer conveying machine for forced thermal drying; the water content of the SDF product is less than 10 percent, and the three-time compatibility scientific checking index of the SDF product is met;

the dryer can be one of a vertical moving bed hot air dryer, a mesh belt dryer or a flap dryer;

the heat source of the dryer can adopt one of electricity, steam, hot water, heat conduction oil, hot air, smoke and the like; if the heat source is hot air, the temperature of the air inlet of the dryer is less than or equal to 400 ℃; the heat source such as electricity selection is popularized, the electric power application is simplified, the cost is high, and the heat of 1 kW.h electricity is only about 860 kilocalories.

The strength of the SDF material ball is divided into compressive strength and falling strength; wherein the compression strength is determined by referring to an industrial briquette cold pressing strength determination method MTT748-2007, and the falling strength is determined by referring to an industrial briquette falling strength determination method MTT 925-2004;

checking the scientificity of the third compatibility, specifically performing strength checking, heat value checking, Ca/S checking, ash melting point checking and slag alkalinity checking on the SDF product;

the strength of the SDF product is generally checked to be larger than a preset minimum value;

checking the heat value of the SDF product, which is mainly based on the requirement of the furnace type characteristic of high-temperature solid waste heat treatment equipment on the heat value, if the gasification melting furnace requires that the heat value of the SDF product is more than 1800kcal/kg, the requirement of charging raw materials into the furnace can be basically met;

the Ca/S checking of the SDF product is mainly required for sulfur fixation and deacidification in a furnace of high-temperature solid waste heat treatment equipment, the Ca/S is 1-3 generally, and the numerical value is controlled to be 1.5-2.5, so that the sulfur fixation and deacidification are facilitated and the emission of NOx is reduced;

checking the ash melting point of the SDF product, wherein the ash melting point of the SDF product is mainly required according to the furnace type characteristic of high-temperature solid waste heat treatment equipment, and the ash melting point of the SDF product is less than 1400 ℃ if a gasification melting furnace is required, so that the formation of a glass body is facilitated;

checking the slag basicity of SDF product, wherein the slag basicity R is an index for indicating the slag pH value, and R is (M ═ M)₁+M₂)/(M₃+M₄)；M₁Is the mass of CaO, M₂Is the mass of MgO, M₃Is SiO₂Mass of (A), M₄Is Al₂O₃The mass of (c); r is full alkalinity or quaternary alkalinity, which is generally between 0.3 and 1.5, and the actual operation is generally controlled between 0.9 and 1.2.