A method for efficient collaborative resource utilization of organic waste in the iron and steel industry

Abstract

The present invention relates to the technical field of waste treatment in the iron and steel industry, and particularly relates to a method for efficiently co-resource utilization of organic waste in the iron and steel industry, which includes subjecting the organic waste generated in the iron and steel industry to pyrolysis to obtain pyrolysis slag, non-condensable gas, pyrolysis oil and pyrolysis water for resource utilization; wherein, the organic waste includes waste resin plastics, waste cloth bags, waste oil drums, waste oil, sludge and tar slag. When the present invention conducts pyrolysis treatment on various organic wastes in the iron and steel industry, there is a synergistic effect among the material components, realizing efficient resource utilization.

Description

Technical Field

[0001] The present invention relates to the technical field of steel industry waste treatment, and in particular to a method for efficiently and collaboratively resourcefully treating organic waste from the steel industry. Background Art

[0002] Large steel companies generate most of the solid waste generated during production, such as iron-containing solid waste, carbon-containing solid waste, and slag, which have relatively mature treatment processes and are effectively disposed of through internal recycling or export. However, large steel companies generate more than 30 types of organic waste during production, primarily waste plastics, waste resins, waste woven bags, waste cloth bags, waste oil, oily sludge, tar residue, and other organic wastes. These wastes are diverse and have low yields per type. Existing treatment methods include incineration, landfilling, outsourcing, and designated storage. These methods suffer from high energy consumption, high pollution levels, low resource utilization, high outsourcing costs, and inconsistent and non-standardized treatment methods.

[0003] CN202010820212.X discloses a method for comprehensive utilization of solid waste and hazardous waste resources from the steel industry through thermal cracking, and proposes a method for treating solid waste and hazardous waste from the steel industry using a thermal cracking process. The solid waste and hazardous waste resources are heated in a thermal cracking furnace in an air-tight environment to undergo continuous thermal cracking reactions, ultimately obtaining three resource-utilizable products: ash, combustible gas, and fuel oil. This patent has significant environmental, social, and economic benefits in treating pyrolytic solid waste and hazardous waste resources from the steel industry. However, it does not propose a synergistic relationship between the various materials during thermal cracking, and the thermal cracking materials are not fully utilized. Summary of the invention

[0004] In view of the problem that the existing thermal cracking technology does not fully utilize the materials, the present invention provides a method for efficient and coordinated resource treatment of organic waste from the steel industry. Various organic wastes from the steel industry can be efficiently and collaboratively treated to achieve resource utilization.

[0005] The present invention provides a method for efficiently and collaboratively resource-processing organic waste from the steel industry, comprising thermally cracking the organic waste generated by the steel industry to obtain cracking slag, non-condensable gas, cracking oil and cracking water for resource utilization; wherein the organic waste includes waste resin plastics, waste cloth bags, waste oil drums, waste oil, sludge and tar residue.

[0006] Furthermore, the thermal cracking is carried out in a thermal cracking furnace, and the process conditions of the thermal cracking are: a thermal cracking temperature of 500-550° C., a thermal cracking time of 3 hours, and thermal cracking in an airtight condition.

[0007] Further, the waste resin plastics include one or more of filler, waste lining board, waste woven bag, waste dust suppression net, plastic carpet, waste plastics from circulating water cooling tower, cooling tower nozzles, filter membranes of water treatment reverse osmosis device, ultrafiltration membranes for water treatment, waste water treatment filter elements, oil-containing waste filter elements, PVC dosing pipes, oil-containing filter paper, oil-containing plastic cloth, oilcloth gloves, sealing tapes, and rubber hoses.

[0008] Further, the waste cloth bags include waste dust removal cloth bags.

[0009] Further, the waste oil drums include waste paint buckets.

[0010] Further, the waste oil includes one or more of waste rolling oil, waste cold rolling emulsion, waste grinding fluid, waste grease, waste paint, and high water content waste oil.

[0011] Further, the sludge includes one or more of grinding sludge, water treatment sludge, oil-containing sludge, and gas collecting sump sludge.

[0012] Further, the percentage of each component in the organic waste is as follows: waste resin plastics 20% - 30%, waste cloth bags 1% - 10%, waste oil drums 1% - 10%, waste oil 20% - 40%, sludge 20% - 40%, and tar residue 10% - 30%.

[0013] Further, the waste resin plastics, waste cloth bags, and waste oil drums are all subjected to crushing pretreatment. After the crushing pretreatment, the particle size of the waste resin plastics is ≤ 100 mm, the particle size of the waste cloth bags is ≤ 50 mm, and the particle size of the waste oil drums is ≤ 10 mm. Furthermore, when the waste oil drums are insufficient, iron scale, a by-product of the iron and steel industry, is added to make the total mass of the waste oil drums and iron scale account for 5% - 10% of the total mass of the pyrolysis materials; the waste oil is subjected to oil-water separation pretreatment, and the percentage of water content in the waste oil after oil-water separation is ≤ 30%.

[0014] Further, the pyrolysis water is subjected to biochemical treatment to remove COD and ammonia nitrogen for reuse as reclaimed water.

[0015] The principle of synergistic effect among the component materials during the thermal pyrolysis of the organic waste in the present invention is as follows: The waste resin plastics can act as a skeleton in the pyrolysis furnace. Some of the materials have a cavity structure, and non-condensable gas can be generated during the heating process. The proportion of non-condensable gas products is relatively high, which can promote the heat transfer during the thermal pyrolysis process; the crushed waste oil drums are mainly made of metal materials such as iron and aluminum, and have a catalytic cracking effect on organic substances during the thermal pyrolysis process; the sludge-like organic waste has a relatively high ash content, mainly containing inorganic substances such as Fe, FeO, Fe2O3, Al2O3, and SiO2, which has a certain catalytic effect on the cracking of organic substances during the thermal pyrolysis process, assisting in catalysis and further enhancing the efficiency; the main product after the thermal pyrolysis of the tar residue is pyrolysis residue, and the fixed carbon content exceeds 80%, which can provide a high-quality carbon source for the pyrolysis residue products.

[0016] The pyrolysis residue obtained by pyrolyzing organic waste in the present invention is grayish-black, with a fixed carbon content of 30% - 50%, an ash content of 50% - 70%, a volatile content of 0 - 5%, and a higher heating value of 3500 - 5500 kCal / kg. Among them, the total iron content is 30% - 50%, which can be used as a raw material rich in carbon source and iron source in the processes of sintering and rotary kiln in the iron and steel industry.

[0017] The main component of the pyrolysis gas obtained by pyrolyzing organic waste in the present invention is combustible gas, and the volume ratio of combustible gas exceeds 60%. The lower heating value and higher heating value range from 15 to 30 MJ / Nm 3 , which can be incorporated into the existing coal gas pipeline network of iron and steel enterprises for utilization as high-quality industrial gas.

[0018] The calorific value of the pyrolysis oil obtained by pyrolyzing organic waste in the present invention is 30 - 40 MJ / Kg, and its total sulfur content < 0.3%, which can be used for resource utilization as fuel oil.

[0019] The COD content of the pyrolysis water obtained by pyrolyzing organic waste in the present invention is 3000 - 10000 mg / L, which can be treated by the biochemical treatment system of coking wastewater in the coking plant of iron and steel enterprises. After treatment, the COD is less than 150 mg / L, which can be reused as reclaimed water.

[0020] The beneficial effects of the present invention are as follows:

[0021] (1) The present invention can efficiently co-treat most of the organic waste in the production process of iron and steel enterprises. The pyrolysis residue, pyrolysis gas, and pyrolysis oil obtained after treatment can all be used for resource utilization, and the pyrolysis water can also be reused as reclaimed water after water treatment.

[0022] (2) The present invention can fully utilize the properties of various organic wastes, set up a simple pretreatment method, and through optimization such as raw material ratio, achieve low-energy consumption and rapid pyrolysis treatment. At the same time, the three products of pyrolysis residue, pyrolysis gas, and pyrolysis oil have high resource utilization value.

[0023] (3) The present invention has obvious environmental and economic benefits. While treating the organic waste inside iron and steel enterprises, it can also co-treat the industrial and urban domestic organic waste of surrounding enterprises, promote the integration of production and city, and has high social benefits. Specific embodiments

[0024] To enable those skilled in the art to better understand the technical solutions in the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0025] The waste plastic resin - type organic waste used in the following embodiments includes fillers, waste liners, waste woven bags, waste dust suppression nets, plastic carpets, waste plastics from circulating water cooling towers, cooling tower nozzles, filter membranes of water treatment reverse osmosis devices, ultrafiltration membranes for water treatment, waste - water treatment filter elements, oil - containing waste filter elements, PVC dosing pipes, oil - containing filter papers, oil - containing plastic sheets, oilcloth gloves, sealing tapes, and rubber hoses, etc.

[0026] The waste cloth - bag - type organic waste used in the following embodiments includes waste dust - removal cloth bags, etc.

[0027] The waste oil - barrel - type organic waste used in the following embodiments includes waste paint barrels, etc.

[0028] The waste oil - type organic waste used in the following embodiments includes waste rolling oil, waste cold - rolling emulsion, waste grinding fluid, waste grease, waste paint, highly - water - containing waste oil, etc.

[0029] The sludge - type organic waste used in the following embodiments includes grinding sludge, water - treatment sludge, oil - containing sludge, sludge in gas - collecting sump, etc.

[0030] Example 1

[0031] For pyrolysis treatment of 10 tons of mixed materials of various iron and steel industry organic wastes per furnace, after 3 tons of waste plastic resin - type organic waste is pre - crushed, the size is about 50 mm, and it is evenly distributed into the pyrolysis furnace; 2 tons of tar slag, 2 tons of waste oil, and 2 tons of sludge, these three types of organic wastes are fully stirred evenly in a mixing container and then evenly distributed into the pyrolysis furnace, and the waste oil is pre - treated by oil - water separation; 0.5 ton of waste cloth - bag - type organic waste is pre - crushed, the size is about 30 mm, and it is evenly distributed and added into the pyrolysis furnace; 0.5 ton of waste oil - barrel - type organic waste is pre - crushed, and its size is less than 10 mm, and it is evenly distributed into the pyrolysis furnace.

[0032] Set the pyrolysis temperature at 550 °C and the pyrolysis time at 3 h. Under the condition of air isolation, indirect heating is carried out. The materials are pyrolyzed by heat. After being collected by the material - receiving system, about 4.1 tons of pyrolysis slag products, about 2.1 tons of pyrolysis oil products, about 2.3 tons of pyrolysis gas (converted to standard volume is 3919 Nm 3 ) and about 1.5 tons of pyrolysis water are obtained.

[0033] Among them:

[0034] The physical properties and main components of the pyrolysis residue are as follows: ash content (61.2%), volatile matter (2.13%), higher calorific value (4263 kCal / kg), fixed carbon (36.6%), TFe (41.3%), S (0.29%), SiO2 (1.36%), CaO (4.84%), MgO (0.93%), Al2O3 (1.16%), Cl (0.94%), Cr (0.43%), As (56 mg / kg). It can be used as a raw material rich in carbon source and iron source in the processes such as sintering and rotary kiln in the iron and steel industry.

[0035] The physical properties and the contents of main harmful elements of the pyrolysis oil are as follows: higher calorific value (36.4 MJ / kg), As (0.85 mg / kg), Cl (738 mg / kg).

[0036] The physical properties and the contents of main harmful elements of the pyrolysis gas are as follows: higher calorific value (25.43 MJ / kg), lower calorific value (22.17 MJ / kg), and the volume fraction of combustible gas accounts for 79.1%.

[0037] The main indexes of the pyrolysis water are as follows: COD (7682 mg / l), ammonia nitrogen (573 mg / l). It is treated by the biochemical treatment system of coking wastewater in the coking plant of the iron and steel enterprise. After treatment, the COD is less than 150 mg / L and it can be reused as reclaimed water.

[0038] Example 2

[0039] Carry out pyrolysis treatment on 10 tons of mixed materials of various organic wastes in the iron and steel industry per furnace. After the 2 tons of waste plastic resin organic wastes are pretreated by crushing, the size is about 50 mm, and they are evenly distributed into the pyrolysis furnace; the 1.5 tons of tar slag, 2.5 tons of waste oil, and 3 tons of sludge, these three types of organic wastes are fully stirred evenly in the mixing container and then evenly distributed into the pyrolysis furnace. The waste oil is pretreated by oil-water separation; the 0.3 tons of waste cloth bag organic wastes are pretreated by crushing, the size is about 30 mm, and they are evenly distributed and added into the pyrolysis furnace; the 0.1 tons of waste oil drum organic wastes are pretreated by crushing, the size is less than 10 mm, and 0.7 tons of iron oxide scale is added and evenly distributed into the pyrolysis furnace.

[0040] Set the pyrolysis temperature at 500 °C and the pyrolysis time at 3 h. Indirect heating is carried out under the condition of air isolation. The materials are pyrolyzed by heat. After being collected by the receiving system, about 4.8 tons of pyrolysis residue products, about 1.7 tons of pyrolysis oil products, and about 1.8 tons of pyrolysis gas (equivalent to the standard volume of 3102 Nm 3 ) are obtained, and about 1.7 tons of pyrolysis water are obtained.

[0041] Among them, the physical properties and main components of the cracking residue are: ash content (66.5%), volatile matter (1.06%), gross calorific value (3816 kCal / kg), fixed carbon (32.3%), TFe (45.7%), S (0.26%), SiO2 (2.58%), CaO (3.62%), MgO (1.22%), Al2O3 (1.46%), Cl (0.61%), Cr (0.29%), As (52 mg / kg).

[0042] Physical properties of the cracking oil and contents of main harmful elements: gross calorific value (37.3 MJ / kg), As (0.73 mg / kg), Cl (652 mg / kg).

[0043] Physical properties of the cracking gas and contents of main harmful elements: gross calorific value (26.13 MJ / kg), net calorific value (24.57 MJ / kg), volume fraction of combustible gas 81.3%.

[0044] Main indicators of the cracking water are: COD (7954 mg / l), ammonia nitrogen (553 mg / l).

[0045] Although the present invention has been described in detail by way of preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, those of ordinary skill in the art can make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions should all be within the scope covered by the present invention. / Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, and all of them should be covered within the protection scope of the present invention.

Claims

1. A method for efficiently and synergistically recycling organic waste in the iron and steel industry, characterized in that, It includes the resource utilization of pyrolysis slag, non-condensable gas, pyrolysis oil and pyrolysis water obtained by pyrolyzing organic waste generated in the iron and steel industry; among them, the organic waste includes waste resin plastics, waste cloth bags, waste oil drums, waste oil, sludge and tar slag; the percentage dosage of each component in the organic waste is: waste resin plastics 20% - 30%, waste cloth bags 1% - 10%, waste oil drums 1% - 10%, waste oil 20% - 40%, sludge 20% - 40%, tar slag 10% - 30%; waste resin plastics, waste cloth bags and waste oil drums are all subjected to crushing pretreatment. After crushing pretreatment, the particle size of waste resin plastics is ≤100mm, the particle size of waste cloth bags is ≤50mm, and the particle size of waste oil drums is ≤10mm. When the waste oil drums are insufficient, iron scale, a by-product of the iron and steel industry, is added to make the total mass of waste oil drums and iron scale account for 5% - 10% of the total mass of pyrolysis materials; waste oil is subjected to oil-water separation pretreatment, and after oil-water separation, the water content percentage in the waste oil is ≤30%; pyrolysis is carried out in a pyrolysis furnace, and the process conditions of pyrolysis are: the pyrolysis temperature is 500 - 550°C, the pyrolysis time is 3h, and pyrolysis is carried out under the condition of air isolation; waste resin plastics serve as the skeleton in the pyrolysis furnace. The crushed waste oil drums are mainly made of iron and aluminum metal materials, which have a catalytic cracking effect on organic substances during the pyrolysis process; sludge-like organic waste contains inorganic substances such as Fe, FeO, Fe2O3, Al2O3, and SiO2, which have a certain catalytic effect on the cracking of organic substances during the pyrolysis process and assist in catalysis to further increase efficiency; the main product after the pyrolysis of tar slag is pyrolysis slag, and the fixed carbon content exceeds 80%, providing a high-quality carbon source for the pyrolysis slag product.

2. The method for efficient collaborative resource utilization of organic waste in the iron and steel industry according to claim 1, wherein The waste resin plastics include one or more of filler, waste lining board, waste woven bag, waste dust suppression net, plastic carpet, waste plastics from circulating water cooling towers, cooling tower nozzles, filter membranes of water treatment reverse osmosis devices, ultrafiltration membranes for water treatment, waste water treatment filter elements, oil-containing waste filter elements, pvc dosing pipes, oil-containing filter paper, oil-containing plastic cloth, oilcloth gloves, sealing tapes, and rubber hoses.

3. The method for efficient collaborative resource utilization of organic waste in the iron and steel industry according to claim 1, characterized in that The waste cloth bags include waste dust removal cloth bags.

4. The method for efficiently and collaboratively recycling organic waste in the iron and steel industry according to claim 1, wherein The waste oil drums include waste paint buckets.

5. The method for efficiently and collaboratively recycling organic waste in the iron and steel industry according to claim 1, characterized in that, The waste oil includes one or more of waste rolling oil, waste cold rolling emulsion, waste grinding fluid, waste grease, waste paint, and high-water-content waste oil.

6. The high-efficiency collaborative resource utilization method for organic waste in the iron and steel industry according to claim 1, characterized in that, The sludge includes one or more of grinding sludge, water treatment sludge, oil-containing sludge, and gas collecting sump sludge.

7. The method for efficient collaborative resource utilization of organic waste in the iron and steel industry according to claim 1, characterized in that The pyrolysis water is subjected to biochemical treatment and then reused as reclaimed water.