Method for co-processing arsenic-containing hazardous waste and application

Abstract

The application discloses a method for treating arsenic-containing hazardous waste and application, and the method comprises the following steps: mixing arsenic-containing hazardous waste, a modifier, a sulfur-increasing agent and a carbonaceous reducing agent to obtain a mixture; and adding the mixture into a CR furnace for treatment to obtain tailings, crude lead, arsenic-iron alloy and matte. The method mainly adopts the CR furnace to treat various arsenic-containing hazardous waste, and simultaneously cooperatively disposes a small amount of copper flotation tailings, pyrite and the like as the modifier and the sulfur-increasing agent, so as to cooperatively dispose the arsenic-containing hazardous waste produced by the non-ferrous smelting industry and comprehensively recover valuable metals such as copper, lead and zinc, and realize large-scale application of arsenic.

Description

Technical Field

[0001] This invention relates to the field of arsenic removal technology, and in particular to a method and application for the co-treatment of arsenic-containing hazardous waste. Background Technology

[0002] Non-ferrous metal smelting processes generate various arsenic-containing hazardous wastes, including black copper sludge, arsenic neutralization slag, and white smoke dust. In particular, the white smoke dust, black copper sludge, and arsenic neutralization slag from copper or lead smelters contain far more metallic arsenic than the market demand, necessitating the stockpiling of arsenic-containing hazardous waste and its byproduct, arsenic trioxide, posing significant safety hazards. This case proposes a collaborative, large-scale treatment of arsenic-containing hazardous waste, producing arsenic-ferroalloys and recovering small amounts of copper and lead resources. This achieves large-scale resource recovery and harmless disposal of arsenic-containing hazardous waste, solving the problem of a severe oversupply in the arsenic market and yielding significant social and environmental benefits.

[0003] Copper electrolysis produces black copper sludge containing elements such as copper, arsenic, nickel, and antimony, with copper content ranging from 10% to 40% and arsenic content from 10% to 30%. White smoke dust, produced during pyrometallurgical copper smelting, contains elements such as copper, lead, zinc, and arsenic, with copper content ranging from 5% to 15%, arsenic from 5% to 20%, lead from 10% to 25%, and zinc from 5% to 20%. Arsenic neutralization slag contains 2% to 15% arsenic and 1% to 2% copper. These solid wastes contain not only valuable metals such as copper, lead, zinc, and nickel, but also a large amount of arsenic, and are classified as hazardous waste. Copper flotation tailings, obtained from copper smelting slag through slag beneficiation, contain 30% to 45% iron, 0.15% to 0.3% copper, 0.5% to 1.5% lead, and 1.5% to 5% zinc. Black copper sludge, arsenic neutralization slag, and white smoke dust are treated together with copper flotation tailings.

[0004] Application No. 202210245273.7 proposes a method for the comprehensive recovery of valuable metals from high-zinc copper smelting dust. This method utilizes wet treatment of high-zinc copper smelting dust, followed by two-stage iron removal using pressure leaching to remove copper, and then evaporation and crystallization using zinc powder to remove cadmium, resulting in zinc sulfate. Metals such as arsenic, iron, and lead are fed into lead slag and then subjected to pyrometallurgical treatment to obtain arsenic-iron alloy.

[0005] Application No. 202110493435.4 proposes a method for the resource utilization of arsenic-containing hazardous waste. The method first adds additives to the high-arsenic hazardous waste for maturation treatment and then performs low-temperature thermal separation to obtain high-purity arsenic trioxide and low-arsenic materials. The low-arsenic materials are mixed with pyrite and smelted to obtain arsenic-iron alloy non-ferrous metal smelting concentrate. The process is relatively short, but the supply of various arsenic products on the market far exceeds the demand.

[0006] Application No. 202111399810.5 proposes a method for efficient separation of arsenic and antimony from high-arsenic flue dust. The method first involves calcining at 300–500℃ for 2–6 hours to solidify antimony and obtain arsenic oxide flue dust; then, the temperature is raised to 500–750℃ for 3–6 hours to further obtain arsenic oxide flue dust, with antimony enriched in the slag.

[0007] Application No. 201711141693.6 discloses a smelting apparatus and method for treating arsenic-containing dust by arsenic matte mixing. This method utilizes an oxygen-enriched side-blown furnace to treat arsenic-containing dust from lead and copper smelting, employing oxygen-enriched pulverized coal as a heat source and simultaneously using pulverized coal as a reducing agent. The smelting temperature is 1300℃, yielding crude lead, arsenic matte, and copper matte. However, the method described in this application fails to comprehensively recover zinc, and the use of an oxygen-enriched side-blown process easily leads to high dust content and high arsenic and lead volatilization rates.

[0008] The high-arsenic hazardous waste produced by the non-ferrous metal smelting industry is mainly used to produce products such as arsenic trioxide dust and metallic arsenic. However, in the current arsenic market, the supply of arsenic trioxide and high-purity arsenic products far exceeds the demand, resulting in poor enthusiasm of enterprises for treating arsenic-containing hazardous waste. They may reduce the amount of arsenic trioxide (arsenic trioxide) products and stockpile them, but this still poses a huge safety hazard to the environment.

[0009] Some companies use blast furnaces to treat arsenic-containing hazardous waste, but blast furnaces have their own drawbacks, such as low arsenic capture rate, need to use coke, and high requirements for raw material properties. Summary of the Invention

[0010] The purpose of this invention is to provide a method for the co-treatment of arsenic-containing hazardous waste. To address the above-mentioned problems, this invention adopts a CR furnace to co-treat copper smelting dust, black copper sludge, arsenic neutralization slag and copper flotation tailings. By utilizing the static molten pool smelting technology of the CR furnace, the arsenic and lead capture rate is improved, and the valuable metals such as copper, lead and zinc in arsenic-containing hazardous waste are deeply recovered. Furthermore, arsenic is captured by metallic iron to obtain a harmless arsenic-iron alloy.

[0011] Currently, industrialized enterprises do not employ the same technological processes. To achieve the above objectives, this invention provides the following technical solution:

[0012] A method for the co-treatment of arsenic-containing hazardous waste, the method comprising,

[0013] Arsenic-containing hazardous waste, conditioning agent, sulfur-increasing agent and carbonaceous reducing agent are mixed to obtain a mixture;

[0014] The mixture is added to a CR furnace for processing to obtain tailings, crude lead, ferroarsenic alloy, and copper matte.

[0015] Furthermore, the method also includes the process of adding the mixture into the CR furnace for processing, and then collecting the flue gas after it is discharged through a dust collector and returned to the CR furnace for recycling.

[0016] Furthermore, the mixture is added directly or after pelletizing to the CR furnace, and the moisture content of the mixture is <15%;

[0017] The mixture forms a pile on top of the smelting slag layer in the CR furnace; the pile is conical with a larger bottom area than the top, wherein the bottom covers the molten slag surface with a coverage ratio of 1 / 2 to 99 / 100.

[0018] Furthermore, the smelting slag type is iron-silicon-calcium slag, wherein the mass fraction ratio of iron-silicon-calcium slag is: Fe / SiO2 = 0.6~1; CaO / SiO2 = 0.4~0.8.

[0019] Furthermore, the carbonaceous reducing agent includes anthracite, bituminous coal, lignite, coke, sawdust, or petroleum coke, and the particle size of the carbonaceous reducing agent is less than 1 mm;

[0020] The conditioning agent includes copper flotation tailings, copper smelting slag, iron ore, silica or quartz sand;

[0021] The sulfur-enhancing agent includes sulfur, gypsum, gypsum slag, pyrite, copper sulfide concentrate, or lead sulfide concentrate.

[0022] Furthermore, the upper part of the CR furnace is provided with feeding ports, the number of which is 1 to 20.

[0023] Furthermore, the CR furnace is supplemented with electrode heating, and the electrodes include graphite electrodes or self-baking electrodes.

[0024] Furthermore, when the mixture is added to the CR furnace for processing, the temperature of the smelting slag in the CR furnace is 1000℃~1300℃, and the thickness of the smelting slag layer is 200mm~1000mm.

[0025] Furthermore, a spray gun is added to the slag layer on the side of the CR furnace. The spray gun adopts a single channel or multiple channels and is used to spray gas, coal, petroleum coke or petroleum.

[0026] The spray gun is positioned at a height of 1 / 10 to 9 / 10 of the slag layer height.

[0027] The present invention also provides the application of the above-described method for the co-treatment of arsenic-containing hazardous waste in arsenic-containing hazardous waste in copper smelters or lead smelters.

[0028] The technical effects and advantages of this invention are as follows:

[0029] This invention employs a newly developed CR (Comprehensive Recovery) furnace for the co-processing of various arsenic-containing hazardous wastes from the non-ferrous smelting industry, achieving comprehensive recovery of valuable metals such as copper, lead, and zinc, and harmless disposal of slag. The co-processing of arsenic-containing hazardous waste allows for the one-step recovery of valuable metals such as copper and lead, enabling large-scale harmless resource application of arsenic. The tailings, generally solid waste, can be used in the building materials industry. This invention solves the following problems: low copper and lead recovery rates in conventional pyrometallurgical processes; long hydrometallurgical processes; low market demand for arsenic used in the production of As₂O₃ or metallic arsenic, while the large volume of arsenic-containing hazardous waste results in a supply far exceeding demand; and the safety hazards associated with tailings storage.

[0030] The method of this invention mainly uses a CR furnace to treat various types of arsenic-containing hazardous waste while simultaneously treating a small amount of copper flotation tailings and pyrite as conditioning and sulfurizing agents. This method enables the co-processing of arsenic-containing hazardous waste produced by the non-ferrous smelting industry and the comprehensive recovery of valuable metals such as copper, lead, and zinc, thereby realizing the large-scale application of arsenic.

[0031] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0032] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] To address the shortcomings of existing technologies, this invention discloses a method for the co-treatment of arsenic-containing hazardous waste, such as... Figure 1 As shown, the method includes mixing arsenic-containing hazardous waste, a conditioning agent, a sulfurizing agent, and a carbonaceous reducing agent to obtain a mixture. The arsenic-containing hazardous waste includes white smoke dust, black copper sludge, and arsenic neutralization slag. The mixture is then added to a CR furnace for treatment to obtain tailings, crude lead, ferroarsine alloy, copper matte, and smoke dust. The smoke dust from the mixture after treatment in the CR furnace is discharged with the flue gas, collected by a dust collector, and returned to the CR furnace for recycling.

[0035] In a specific embodiment of the present invention, a feeding port is arranged at the top of the CR furnace. The furnace body is relatively large, and designing only one port would cause the feeding to be concentrated in one place. The feeding ports for different clinker are set according to the size of the furnace body. Preferably, the number of feeding ports is 1 to 20. The carbonaceous reducing agent is crushed to less than 1 mm. White smoke dust, black copper mud, arsenic neutralization slag, conditioning agent, coal powder, sulfurizing agent, etc. are mixed according to the calculation and directly fed into the CR furnace or pelletized and fed into the furnace. The water content of the mixed material entering the CR furnace is <15%. The amount of reducing agent needs to be calculated based on the amount of metal to be reduced in the material. Taking carbon reduction as an example, the fixed carbon in the reducing agent reacts with the metal oxide to become CO. The sulfurizing agent needs to be calculated based on the required sulfidation element. The mixed material forms a material pile on the top of the slag layer. The material pile exists in a cone shape with the largest bottom area. The bottom covers the surface of the molten slag, and the coverage ratio is 1 / 2 to 99 / 100. After mixing, the materials can be directly fed into the furnace, or they can be pelletized and added into the furnace. A cold material layer is set in the furnace, and the temperature of the flue gas exiting the furnace is 400℃~1000℃.

[0036] Furthermore, the slag layer is the smelting slag layer that already exists inside the CR furnace. The smelting slag as a whole is divided into three layers inside the CR furnace: the arsenic-iron alloy layer obtained from reduction, the metal layer where other metals settle to the bottom, and the slag layer above the alloy layer and the metal layer; wherein, the slag layer refers to the layer after the material has melted, in which part of the slag has completed slag-metal separation, and part has not yet been separated, the difference being the metal layer at the bottom.

[0037] Conditioning agents can be copper flotation tailings, copper smelting slag, iron ore, silica, quartz sand, etc.; sulfur-enhancing agents can be sulfur, gypsum, gypsum slag, pyrite, copper sulfide concentrate, lead sulfide concentrate, etc.; carbonaceous reducing agents can be anthracite, bituminous coal, lignite, coke, sawdust, petroleum coke, etc. The addition of carbonaceous reducing agents mainly utilizes the fixed carbon in them to reduce the oxides of elements such as copper, lead, zinc, arsenic, nickel and antimony in the material into elemental forms, and to reduce some iron oxides into metallic states.

[0038] The CR furnace is heated by electrodes, which can be graphite electrodes, self-baking electrodes, etc. The slag temperature is 1000℃~1300℃, with the preferred temperature being 1150℃~1250℃, and the slag layer thickness is 200mm~1000mm.

[0039] In a specific embodiment of the present invention, the slag temperature is set to 1000℃~1300℃. When the slag temperature is too high, it will lead to energy waste: firstly, under high temperature conditions, it will cause an increase and waste of electrical heating or other energy consumption; secondly, if the temperature is too high, the slag has better fluidity, which will aggravate the erosion of CR furnace dust, increase smelting costs, and increase smelting risks.

[0040] When the slag temperature is too low, firstly, the slag or alloy metals (such as matte) have poor fluidity, leading to poor separation between the alloy metals (such as matte) and the slag, resulting in a low recovery or removal rate of valuable metals. Secondly, when the temperature is too low, the temperature of the slag is also low. Theoretically, the temperature of the matte or other metals or alloys below it is 50 to 150°C lower than the temperature of the slag. In other words, if the slag temperature is low, the temperature of the alloy metals (such as matte) below it will be even lower, resulting in poor overall fluidity. If the lower layers of matte, alloys, or lead are too well separated, it will lead to waste of lead and copper, as well as an increase in lead and copper impurities in the alloy, thus reducing quality.

[0041] In the process of treating high-arsenic waste using a CR furnace, 1 to 100 spray guns can be arranged at a height of 1 / 10 to 9 / 10 of the slag layer. The sprayed gas can be inert, oxidizing, or reducing gases such as nitrogen, compressed air, oxygen, argon, natural gas, blast furnace gas, and coke oven gas; or it can be pulverized coal, petroleum coke, or petroleum.

[0042] In one specific embodiment of the present invention, when treating arsenic-containing hazardous waste such as white smoke dust, black copper sludge, and arsenic neutralization slag from copper or lead smelters, the present invention addresses the issue of valuable metals such as copper, lead, zinc, iron, and arsenic, which mainly exist in oxide form. Under normal circumstances, i.e., when electric heating is sufficient, the cauldron sprays coal, petroleum coke, coke, or natural gas and coke oven gas to reduce the valuable metals existing in oxide form. The valuable metals existing in oxide form are reduced to metallic or sulfide forms and recovered, and separated from the slag containing calcium, silicon, magnesium, aluminum, etc. Since the overall CR furnace is a reducing atmosphere, when electric heating is insufficient or other energy sources are needed, the cauldron sprays oxygen or compressed air and other oxidizing gases to burn with petroleum coke, coal, or natural gas in the heater, releasing heat and thus supplementing the heat of the CR furnace.

[0043] The principle of this invention is to use fixed carbon in a reducing agent to reduce oxides of elements such as copper, lead, zinc, arsenic, nickel, antimony and iron. The theoretical carbon content is 1.0 times the amount of coal required.

[0044] The smelting slag type is iron-silicon-calcium slag, with Fe / SiO2 = 0.6-1 and CaO / SiO2 = 0.4-0.8.

[0045] The products include tailings, crude lead, ferroarsenic alloy, and copper matte; the lead recovery rate exceeds 95%; the arsenic recovery rate exceeds 98%, of which 90% enters the ferroarsenic alloy, and some enters the flue dust. The flue dust is returned to the raw material system for remelting or sold to zinc smelting enterprises.

[0046] The tailings produced are quenched in water to become water-quenched slag, which can be used as general solid waste in the building materials and cement industries.

[0047] The tailings contained Fe / SiO2 ratios of 0.6–1 and CaO / SiO2 ratios of 0.4–0.8. The arsenic, copper, lead, and zinc contents were <0.01%, <0.15%, <0.3%, and <0.5%, respectively. The bottom metal and matte were deposited at temperatures of 1000℃–1100℃. Layering was achieved using density differences to form crude lead (density ≈ 11 t / m³). 3 Arsenic-iron alloy (density ≈ 7t / m³) 3 ), copper matte (density ≈ 5t / m³) 3 ).

[0048] The technology described in this case enables the large-scale harmless application of arsenic in arsenic-containing hazardous waste from non-ferrous smelting enterprises, as well as the harmless application of tailings in building materials. Arsenic ferroalloys, matte, and crude lead are all sold as harmless and valuable products.

[0049] The slag is discharged from the slag discharge port, and the flue gas is discharged with the flue gas. After being collected by the dust collector, it is returned to the raw material system. According to the zinc and arsenic content in the flue gas, if the arsenic content is high, it is returned to the raw material system, and if the arsenic content is low, it can be sold to zinc smelting enterprises.

[0050] Copper matte, ferroarsenic alloy and crude lead are discharged through 1 to 3 outlets. They can be discharged separately or together into a metal liner to utilize density stratification.

[0051] This invention discloses a novel method for the co-processing of arsenic-containing hazardous waste: white smoke dust and black copper sludge. It employs a comprehensive recovery furnace (CR furnace) to treat valuable metals such as copper and lead from copper smelting slag, achieving large-scale, harmless resource utilization of arsenic in the hazardous waste and harmless disposal of tailings. The resulting harmless tailings can be used in the building materials industry, for matte, crude lead, and arsenic-ferroalloys, realizing the comprehensive recovery of valuable metals such as copper and lead and the large-scale, harmless resource utilization of arsenic. Depending on the zinc and arsenic content, the smoke dust can be sold to zinc smelting enterprises or returned to the production system.

[0052] The present invention also provides the application of the above-described method for the co-treatment of arsenic-containing hazardous waste in arsenic-containing hazardous waste in copper smelters or lead smelters.

[0053] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0054] Example 1

[0055] use Figure 1 The process flow diagram shown illustrates the comprehensive recovery of valuable metals such as copper and lead from arsenic-containing hazardous waste generated during non-ferrous smelting, the large-scale harmless application of arsenic, and the harmless treatment of tailings. The process conditions of the unit are as follows:

[0056] The process employed a 1:1:1 ratio of white smoke dust, black copper sludge, and arsenic neutralizing slag, with reducing coal at 1.2 times the theoretical amount. Copper flotation tailings were used as the conditioning agent, and the batching was based on 25% arsenic in the ferroarsenic alloy. The tailings had an iron-silicon ratio of 0.8 and a calcium-silicon ratio of 0.6. Pyrite was used as the sulfur enhancer, and the slag smelting temperature was 1200℃. The resulting tailings contained 0.003% arsenic, 0.1% copper, and 0.2% lead, with a matte grade of 25%. The ferroarsenic alloy contained 26% arsenic, 0.5% copper, and 0.35% lead, respectively. The arsenic capture rate in the alloy was 93%, and the copper and lead recovery rates reached 98% and 98.6%, respectively.

[0057] Example 2

[0058] The processing method is the same as in Example 1, except for the smelting temperature and auxiliary materials, as detailed below:

[0059] The process employed a mixture of white smoke dust, black copper sludge, and arsenic neutralizing slag in a ratio of 1:1:0.5, with reducing coal at 1.2 times the theoretical amount. Iron ore and quartz were used as conditioning agents, and the batching was based on 25% arsenic in the ferroarsenic alloy. The tailings had an iron-silicon ratio of 1 and a calcium-silicon ratio of 0.4. Sulfur was used as the sulfur-enhancing agent, and the slag smelting temperature was 1100℃. The resulting tailings contained 0.02% arsenic, 0.15% copper, and 0.3% lead, with a matte grade of 23%. The ferroarsenic alloy contained 24% arsenic, 1.5% copper, and 0.48% lead, respectively. The arsenic capture rate in the alloy was 90%, and the copper and lead recovery rates reached 96% and 97.2%, respectively.

[0060] Example 3

[0061] The treatment method is the same as in Example 1, except for the reaction kinetic conditions:

[0062] The process employed a 1:1:1 ratio of white flue dust, black copper sludge, and arsenic neutralizing slag, with reducing coal at 1.2 times the theoretical amount. Copper flotation tailings were used as the conditioning agent, and the feedstock was formulated based on 25% arsenic in the ferroarsenic alloy. The tailings had an iron-silicon ratio of 0.8 and a calcium-silicon ratio of 0.6. Pyrite was used as the sulfur enhancer. The slag smelting temperature was 1200℃. Ten side-blowing lances were added to the side of the CR furnace, positioned at half the height of the slag layer. The resulting tailings contained 0.004% arsenic, 0.8% copper, and 0.23% lead, with a matte grade of 24%. The ferroarsenic alloy contained 20% arsenic, 1% copper, and 0.3% lead, respectively. The arsenic capture rate in the alloy was 80%, and the copper and lead recovery rates reached 98% and 91.2%, respectively, indicating that more arsenic and lead entered the flue dust compared to the no-blowing method.

[0063] Example 4

[0064] The treatment method is the same as in Example 1, except for the reducing agent ratio:

[0065] The process employed a 1:1:1 ratio of white smoke dust, black copper sludge, and arsenic neutralizing slag, with reducing coal at 1.0 times the theoretical amount. Copper flotation tailings were used as the conditioning agent, and the batching was based on 25% arsenic in the ferroarsenic alloy. The tailings had an iron-silicon ratio of 0.8 and a calcium-silicon ratio of 0.6. Pyrite was used as the sulfur enhancer, and the slag smelting temperature was 1200℃. The resulting tailings contained 0.05% arsenic, 0.23% copper, and 0.5% lead, with a matte grade of 20%. The ferroarsenic alloy contained 21% arsenic, 1.1% copper, and 0.5% lead, respectively. The arsenic capture rate in the alloy was 91%, and the copper and lead recovery rates reached 93% and 95.2%, respectively.

[0066] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for the co-treatment of arsenic-containing hazardous waste, characterized in that, The method includes, Arsenic-containing hazardous waste, conditioning agent, sulfur-increasing agent and carbonaceous reducing agent are mixed to obtain a mixture; The conditioning agent includes copper flotation tailings, copper smelting slag, iron ore, silica or quartz sand; The sulfur-enhancing agent includes sulfur or pyrite; the mixture is added to a CR furnace for processing to obtain tailings, crude lead, ferroarsenic alloy, and matte, wherein the mixture is added to the CR furnace directly or after pelletizing, and the moisture content of the mixture is <15%. The mixture forms a pile on top of the smelting slag layer in the CR furnace; the pile is conical with a larger bottom area than the top, and the bottom covers the molten slag surface with a coverage ratio of 1 / 2 to 99 / 100; when the mixture is added to the CR furnace for processing, the temperature of the smelting slag in the CR furnace is 1000℃ to 1200℃, and the thickness of the smelting slag layer is 200mm to 1000mm.

2. The method for co-treatment of arsenic-containing hazardous waste according to claim 1, characterized in that, The method also includes adding the mixed material into the CR furnace for processing, and then expelling the flue gas through a dust collector for recycling back into the CR furnace.

3. The method for co-treatment of arsenic-containing hazardous waste according to claim 1, characterized in that, The smelting slag type is iron-silicon-calcium slag, wherein the mass fraction ratio of iron-silicon-calcium slag is: Fe / SiO2 = 0.6~1; CaO / SiO2 = 0.4~0.

8.

4. The method for co-treatment of arsenic-containing hazardous waste according to claim 1, characterized in that, The carbonaceous reducing agent includes anthracite, bituminous coal, lignite, coke, sawdust, or petroleum coke, and the particle size of the carbonaceous reducing agent is less than 1 mm.

5. The method for co-treatment of arsenic-containing hazardous waste according to claim 1, characterized in that, The CR furnace has 1 to 20 feeding ports arranged on its upper part.

6. The method for co-treatment of arsenic-containing hazardous waste according to claim 1, characterized in that, The CR furnace is heated by electrodes, which include graphite electrodes or self-baking electrodes.

7. The method for co-treatment of arsenic-containing hazardous waste according to claim 1, characterized in that, The CR furnace is equipped with a spray gun in the side slag layer. The spray gun is single-channel or multi-channel and is used to spray gas, coal, petroleum coke or petroleum. The spray gun is positioned at a height of 1 / 10 to 9 / 10 of the slag layer height.

8. The application of the method for co-treatment of arsenic-containing hazardous waste as described in any one of claims 1-7 in arsenic-containing hazardous waste from copper smelters or lead smelters.

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