A comprehensive recovery method of high-arsenic multi-metal hazardous waste

Abstract

The application discloses a comprehensive recovery method of high-arsenic multi-metal hazardous waste, and comprises the following steps: after high-arsenic multi-metal hazardous waste and a reducing agent and a sulfuration agent are proportioned according to a predetermined ratio, a mixture is obtained; the mixture is added into a top-blown furnace to perform reduction sulfuration smelting, so that first furnace slag, mixed matte, crude lead and first waste gas are obtained, wherein the mixed matte comprises sulfides of arsenic, lead, copper and iron; the first furnace slag and the crude lead are discharged, the first waste gas is treated and then discharged; the mixed matte is subjected to oxygen-enriched blowing in the top-blown furnace, so that second furnace slag, crude copper and second waste gas are obtained; after arsenic trioxide in the second waste gas is recovered, the second waste gas is treated and then discharged. The method is suitable for treating arsenic-containing multi-metal materials, and can also be used for treating industrial wastes without arsenic; the top-blown furnace adopts periodical operation, is very suitable for small-scale hazardous waste disposal production systems, and can save investment and reduce cost.

Description

Technical Field

[0001] This invention relates to the field of harmless treatment technology for arsenic-containing hazardous waste, and in particular to a comprehensive recycling method for high-arsenic polymetallic hazardous waste. Background Technology

[0002] Materials produced by smelters, such as white smoke dust, Kaldor furnace dust, precious lead furnace dust, acid sludge, purified liquor residue, and lead matte, contain multiple metals including copper, lead, zinc, gold, and silver. These raw materials have a high arsenic content, typically ranging from 1% to 10%. Currently, the treatment of arsenic-containing polymetallic industrial solid waste, primarily composed of oxides, commonly employs a blast furnace reduction smelting process. However, because arsenic readily reacts with lead, copper, and iron to form arsenic matte, and the blast furnace lance position is relatively fixed, it cannot penetrate the diaphragm layer, easily leading to furnace sludge formation and operational difficulties. Pretreatment of the raw materials is necessary to remove arsenic and copper to a certain extent before adding them to the furnace. A typical treatment process involves initial water leaching, secondary acid leaching, copper removal from iron filings, and iron and arsenic removal from the smoke dust. Valuable metals are recovered and reused in the form of sponge copper and zinc sulfate, respectively. The underflow is pumped to a filter press for filtration. The filter cake is slurry washed and then pumped back to the filter press for further filtration. The resulting slag is lead slag with a high lead content. Lead slag contains high levels of lead and bismuth, as well as some arsenic and copper. After drying and brick-making, it is added to a blast furnace for reduction smelting to recover crude lead and ferroarsenic alloy. This process is lengthy, involves many steps, and has high processing costs. Furthermore, the ferroarsenic alloy is miscible with copper and lead, resulting in low recovery rates of valuable metals and impacting economic efficiency.

[0003] Currently, there are also processes that use side-blown furnaces to replace blast furnaces, but these still require pretreatment of the raw materials. The problems are similar to those of the blast furnace process.

[0004] The reduction smelting process using a blast furnace (or side-blown furnace) to treat high-arsenic polymetallic hazardous waste has the following problems: direct processing of materials easily leads to the formation of arsenic matte; the position of the side-blown spray gun is relatively fixed, making it impossible to blow through the diaphragm layer, resulting in poor heat transfer and fluidity of the molten pool, affecting metal separation; the raw materials require pretreatment to remove copper and arsenic, and the resulting waste acid and wastewater treatment is complex; arsenic-iron alloys are miscible with copper and lead, making them difficult to separate and resulting in low metal recovery rates; the process flow is long, the investment is large, and the processing cost is high; the product, arsenic-iron alloy, lacks industry standards, resulting in low market sales value. Summary of the Invention

[0005] The purpose of this invention is to provide a comprehensive recycling method for high-arsenic polymetallic hazardous waste. To achieve the above objective, this invention provides the following technical solution:

[0006] This invention provides a comprehensive recycling method for high-arsenic polymetallic hazardous waste, the method comprising:

[0007] High-arsenic polymetallic hazardous waste, reducing agent, and sulfiding agent are mixed in a predetermined ratio to obtain a mixture.

[0008] The mixture is added to a top-blown furnace for reduction sulfidation smelting to obtain a first slag, mixed matte, crude lead and a first waste gas, wherein the mixed matte includes sulfides of arsenic, lead, copper and iron.

[0009] The first batch of slag and crude lead is discharged, and the first batch of waste gas is treated before being discharged.

[0010] The mixed copper matte is subjected to oxygen-enriched blowing in a top-blown furnace to obtain a second slag, crude copper, and a second waste gas.

[0011] After recovering arsenic trioxide from the second waste gas, the second waste gas is treated and then discharged.

[0012] Optionally, the high-arsenic polymetallic hazardous waste, reducing agent, and sulfiding agent are mixed in a predetermined ratio to obtain a mixture comprising:

[0013] After the high-arsenic polymetallic hazardous waste, the first reducing agent, and the sulfiding agent are mixed for the first time, the mixture is humidified and granulated to obtain granular material.

[0014] The granular material is mixed with a second reducing agent and other hazardous waste materials in a second batch to obtain a mixture.

[0015] The ratio of the high-arsenic polymetallic hazardous waste to the first reducing agent and the sulfiding agent is 100:(1-5):(1-5).

[0016] The other hazardous waste materials include blowing slag, and the ratio of the granular material to the second reducing agent and other hazardous waste materials is 100:(10-20):(1-5).

[0017] Optionally, the first reducing agent comprises pulverized coal;

[0018] The second reducing agent includes lump coal or coke;

[0019] The sulfiding agent includes one of pyrite, gypsum slag, CaSO4, or copper concentrate.

[0020] Optionally, the moisture content of the granular material is controlled at 8-12%.

[0021] Optionally, the mixture is added to a top-blown furnace for reduction sulfidation smelting, including,

[0022] After the mixture is added into the furnace, natural gas and oxygen-enriched air are injected into the furnace through a top-blown spray gun to control the temperature of the molten pool at 1250℃~1550℃, so that the mixture in the furnace can react fully to generate slag, crude lead, mixed matte and the first waste gas.

[0023] Optionally, the first slag is sold as waste slag;

[0024] The crude lead was sold as a product.

[0025] The mixed copper matte remains inside the top-blown furnace.

[0026] Optionally, the first exhaust gas is discharged after treatment, including:

[0027] After the first waste gas is fully combusted, it is discharged after passing through a waste heat boiler to recover waste heat, a quench tower to cool down, and desulfurization and denitrification treatment.

[0028] Optionally, the oxygen-enriched blowing of the mixed copper matte in a top-blown furnace includes,

[0029] Inject oxygen-rich air into the furnace to control the molten pool temperature at 1200℃~1250℃;

[0030] Quartzite and mixed matte are added in a predetermined ratio and subjected to oxygen-enriched blowing to obtain second slag, crude copper, and second waste gas.

[0031] Optionally, the crude copper ingots may be sold externally;

[0032] The second slag is added back into the top-blown furnace for reduction sulfidation smelting to recover lead.

[0033] Optionally, the second exhaust gas is treated before being discharged, including,

[0034] The second waste gas is treated with a dry arsenic recovery process to obtain arsenic trioxide.

[0035] The second waste gas after recovering arsenic trioxide is discharged after desulfurization and denitrification treatment to meet the standards.

[0036] The technical effects and advantages of this invention are as follows:

[0037] (1) This method is applicable to the treatment of arsenic-containing polymetallic materials, and can also be used in conjunction with the treatment of arsenic-free industrial waste;

[0038] (2) The raw materials do not need to be pretreated and can be directly put into the top blown furnace for pyrometallurgical reduction smelting. The furnace membrane layer can be penetrated by raising and lowering the gun position, so that the materials in the furnace can react fully.

[0039] (3) The diameter and height of the top-blown furnace are related to the smelting scale and need to be determined according to the processing scale;

[0040] (4) The grade of mixed copper matte / crude lead / crude copper and the smelting slag / blowing slag type can be flexibly adjusted according to different working conditions and needs;

[0041] (5) The top-blown furnace adopts a periodic operation mode, which is very suitable for small-scale hazardous waste disposal production systems. It saves investment and reduces costs.

[0042] (6) The top-blown furnace uses spray gun A and spray gun B for reduction smelting and oxygen-enriched blowing respectively, which provides good production flexibility and strong risk resistance.

[0043] (7) The flue gas of the first and second cycles is treated separately. The flue gas of the second cycle with high arsenic content is treated by dry cooling and arsenic recovery technology to recover arsenic trioxide and achieve the reduction of hazardous waste.

[0044] 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

[0045] Figure 1 This is a process flow diagram of the present invention;

[0046] Figure 2 This is a schematic diagram of the main apparatus in a specific embodiment of the present invention.

[0047] In the diagram: 1-Top blown furnace, 2-Spray gun A, 3-Spray gun B, 4-Slag outlet, 5-Metal discharge outlet. Detailed Implementation

[0048] 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.

[0049] To address the shortcomings of existing technologies, this invention discloses a comprehensive recycling method for high-arsenic polymetallic hazardous waste, such as... Figure 1 As shown, the method includes,

[0050] Step 1: The high-arsenic polymetallic hazardous waste (high-arsenic polymetallic material) and the first reducing agent (crushed coal) and sulfiding agent are initially mixed. Then, the mixture is added to a granulator for humidification and granulation (or pelletizing) to obtain granular material. The water content of the granular material generated after granulation is controlled to be 8-12%. The ratio of the high-arsenic polymetallic hazardous waste to the first reducing agent and sulfiding agent is 100:(1-5):(1-5).

[0051] Step 2: The granular material is mixed with the second reducing agent (lump coal or coke), blowing slag and other hazardous waste materials for the second time to obtain a mixture; the ratio of the granular material to the second reducing agent and other hazardous waste materials is 100:(10-20):(1-5);

[0052] Step 3: The mixture is transported to the top-blown furnace plant via a belt conveyor and added into the top-blown furnace through the top feeding port. The top-blown furnace processes high-arsenic polymetallic materials in cycles: the first cycle involves material preparation and reduction sulfidation smelting; the second cycle involves oxygen-enriched blowing operations.

[0053] Step 4: The mixture is added to a top-blown furnace for the first cycle of melting and reduction sulfidation smelting. The process is as follows: After the mixture is added to the furnace, natural gas and oxygen-enriched air are blown into the furnace through a top-blown lance A to melt the material and carry out reduction and sulfidation reactions. By adjusting the insertion depth of the lance, the material in the furnace is fully reacted, resulting in the first slag, mixed matte, crude lead, and the first waste gas. The mixed matte includes sulfides of arsenic, lead, copper, and iron. After the reaction is completed, the top-blown lance A is removed, the slag and crude lead are discharged, and the mixed matte remains in the furnace.

[0054] Further, after the reduction smelting is completed, the slag is discharged from the slag outlet located above the molten pool and subjected to slag flushing and crushing, and is either stockpiled as waste slag or sold. Crude lead is discharged from the vent located at the bottom of the hearth. The mixed matte molten metal remains in the furnace as raw material for the second-cycle oxygen-enriched blowing. The reduction sulfidation process generates a large amount of CO, which is fully combusted by introducing secondary and tertiary air at the furnace and boiler inlet, respectively. The boiler inlet flue gas temperature is controlled between 1150℃ and 1250℃. After recovering waste heat in the waste heat boiler and cooling in the quench tower, the flue gas is sent for desulfurization and denitrification treatment, and the tail gas is discharged in compliance with standards.

[0055] Step 5: Switch the top-blown furnace to the blowing operation mode and carry out the second cycle of oxygen-enriched blowing operation. The specific steps are as follows:

[0056] Top-blown lance A is removed from the furnace, and lance B is inserted. Oxygen-enriched air is injected into the furnace through lance B, and a certain proportion of quartz is added through the top charging port. The molten pool temperature is controlled at 1200℃~1250℃. The mixed matte reacts with the oxygen-enriched air and quartz in the furnace for blowing operations, deeply removing impurities such as lead, iron, and arsenic. The molten metal in the furnace forms a second slag and crude copper two-phase. Most of the sulfur and arsenic are oxidized in the furnace to form sulfur dioxide and arsenic trioxide, which enter the gas phase for removal and are then recycled with the flue gas dust collection system. Lead and iron are oxidized and slag with quartz, entering the slag phase. After the second cycle, crude copper is obtained and sold as ingots. The second slag is rich in lead and is returned to the first cycle for lead recovery as cold material. Arsenic is oxidized and enters the flue gas dust, where it can be recovered as arsenic trioxide with a purity of over 90% through a dry flue gas arsenic recovery process.

[0057] In one specific embodiment of the present invention, during the second cycle of oxygen-enriched blowing operation, when mixing copper matte (arsenic copper matte) in the blowing furnace, other high-copper materials such as purchased copper matte and lead copper matte can be added and blown together.

[0058] In one specific embodiment of the present invention, the flue gas temperature at the boiler inlet in the second cycle is 900℃~1100℃. An electrostatic precipitator, a quench tower, and a bag filter are installed after the boiler to recover arsenic trioxide from the flue gas. The white arsenic contains 90~95% As2O3. The boiler gas is then discharged after desulfurization treatment to meet the standards.

[0059] In one specific embodiment of the present invention, the method of the present invention is applicable to the treatment of arsenic-containing polymetallic materials, and can also be used in conjunction with the treatment of arsenic-free industrial waste;

[0060] In a specific embodiment of the present invention, the raw materials of the present invention do not require pretreatment and can be directly put into the top blown furnace for pyrometallurgical reduction smelting. The furnace membrane layer can be penetrated by raising and lowering the position of the spray gun.

[0061] In one specific embodiment of the present invention, the diameter and height of the top-blown furnace in the method of the present invention are related to the smelting scale and need to be determined according to the processing scale;

[0062] In one specific embodiment of the present invention, the raw materials processed by this process can be arsenic-containing hazardous waste, copper-containing hazardous waste, nickel-containing hazardous waste, or copper-free industrial sludge, copper-containing solid waste, solid or semi-solid organic waste, spent activated carbon, spent catalysts, etc. In another specific embodiment of the present invention, secondary batching can be performed by appropriately adding auxiliary materials such as quartz and hematite to adjust the slag profile, depending on the composition of the raw materials.

[0063] In one specific embodiment of the present invention, the reducing agent may be a carbon-based material such as coke, carbon concentrate, granular coal, or spent activated carbon. The first reducing agent includes crushed coal; the second reducing agent includes lump coal or coke; and the sulfiding agent includes one of pyrite, gypsum slag, CaSO4, or copper concentrate.

[0064] In one specific embodiment of the present invention, organic waste minerals can be injected into the top-blown furnace as fuel for co-processing, providing heat to the furnace.

[0065] In one specific embodiment of the present invention, the mixing grade of copper matte / crude lead / crude copper and the smelting slag / blowing slag type can be flexibly adjusted according to different operating conditions and needs. The top-blown furnace adopts a periodic operation mode, which is very suitable for small-scale hazardous waste treatment production systems, saving investment and reducing costs. The top-blown furnace uses spray gun A2 and spray gun B3 for reduction smelting and oxygen-enriched blowing, respectively, which provides good production flexibility and strong risk resistance. The flue gas of the first and second cycles is treated separately. The flue gas with high arsenic content in the second cycle is treated with dry quenching arsenic recovery technology to recover arsenic trioxide, thereby achieving hazardous waste reduction.

[0066] The technical solution and significance of the present invention will be explained below with reference to specific embodiments.

[0067] like Figure 2The figure shows a schematic diagram of the main device used in the embodiment of the present invention. The figure includes a top-blown furnace 1, a spray gun A2, a spray gun B3, a slag outlet 4, and a metal discharge outlet 5. Spray gun A2 and spray gun B3 are respectively arranged above the top-blown furnace 1 and inserted into the top-blown furnace 1 from above. The slag outlet 4 and the metal discharge outlet 5 are respectively arranged on the lower sides of the top-blown furnace 1.

[0068] In one specific embodiment of the present invention, a ring of side-blowing spray guns can be installed along the circumferential direction in the reaction zone of the furnace body to blow oxygen-enriched air into the furnace, thereby improving the dynamic reaction of the furnace body;

[0069] In one specific embodiment of the present invention, the melt operating temperature and flue gas temperature may vary depending on the raw materials.

[0070] In one specific embodiment of the present invention, the composition of matte, crude lead and smelting slag may vary depending on the raw materials.

[0071] Example 1

[0072] 1. Ingredient preparation and granulation

[0073] Primary batching and granulation: White smoke dust, Kaldor furnace dust, and precious lead furnace dust with a moisture content of 2% are weighed and metered using a weighing screw feeder, and batched at a mass ratio of 3:2:2 to form a high-arsenic polymetallic mixture. Crushed coal and a sulfiding agent are also added. The mixed material is fed onto a belt conveyor and transported to a disc granulator (or briquetting machine). The mixture is moistened by spraying water and then granulated (or briquetized) to form spherical materials with a moisture content of 8-10%. The mass ratio of the high-arsenic polymetallic mixture, crushed coal, and sulfiding agent is 100:2:2.5.

[0074] Secondary batching: Lump coal and blowing slag are fed into the furnace via a quantitative feeder and then mixed with spherical materials. The mixture is then fed into the top-blown furnace via a conveyor belt. The mass ratio of the high-arsenic polymetallic mixture, lump coal, and blowing slag is 100:15:3.5.

[0075] 2. Reduction sulfidation smelting (first cycle)

[0076] The top-blown furnace operates in cycles. The granulated spherical material, along with lump coal and blown slag, is added into the furnace through the top-blown furnace feed port. The top-blown nozzle A is inserted 250mm into the molten pool, and 450Nm of natural gas is injected into the furnace through nozzle A. 3 / h and oxygen-enriched air 1500Nm 3The oxygen-enriched air contains 65% O2, and the molten pool temperature is controlled at 1420℃. After melting in the furnace, the material undergoes reduction sulfidation smelting and separates into three phases: slag, mixed matte, and crude lead. The mixed matte is composed of sulfides of arsenic, lead, copper, and iron. After reduction smelting, the slag is discharged from the slag outlet located at the top of the molten pool and subjected to slag flushing and water-crushing. It is then stored as waste slag or sold. The water-crushed slag contains 0.7% Cu. Crude lead is discharged from the discharge port located at the bottom of the hearth, containing 97.5% Pb. The mixed matte melt remains in the furnace as raw material for the second-cycle oxygen-enriched blowing. The mixed matte contains 45% Cu, 15% Pb, and 16% As. The reduction sulfidation process generates a large amount of CO. Secondary and tertiary air are blown into the furnace and boiler inlet to ensure complete combustion of CO in the flue gas. The O2 content in the boiler outlet flue gas is controlled at 5%, and the boiler inlet flue gas temperature is controlled at 1160℃. The furnace gas is sent to desulfurization and denitrification treatment after waste heat recovery in the waste heat boiler and cooling in the quench tower, and the exhaust gas meets the emission standards.

[0077] 3. Oxygen-enriched blowing (second cycle)

[0078] The top-blown furnace enters its second cycle operation. Top-blown nozzle A is removed from the furnace, and nozzle B is inserted. Oxygen-enriched air (containing 25% O2) is injected into the furnace through nozzle B at a rate of 8500 Nm³. 3 / h. Quartz stone of a certain proportion is added through the top charging port of the furnace, with a mass ratio of quartz to mixed copper matte of 2.5:100. The molten pool temperature is controlled at 1200℃. The mixed matte reacts with oxygen-enriched air and quartz stone in the furnace for blowing operations, forming two phases of slag and crude copper in the furnace melt. After the second cycle, crude copper product is obtained, and the crude copper ingots are sold. The crude copper temperature is 1200℃, and the crude copper contains 98.5% copper, 0.15% As, and 0.18% Pb. The flue gas from the second cycle is treated by an electrostatic precipitator, a quench tower, and a bag filter after the boiler to recover arsenic trioxide from the flue gas. The white arsenic contains 90% As2O3. The furnace gas is desulfurized and discharged after meeting the standards. The blowing slag contains 7.5% lead and is returned to the first cycle for lead recovery as cold feed.

[0079] Example 2

[0080] 1. Ingredient preparation and granulation

[0081] Primary batching and granulation: White smoke dust, Kaldor furnace dust, and precious lead furnace dust with a moisture content of 2.5% are weighed and metered using a weighing screw feeder, and batched at a mass ratio of 3:3:1 to form a high-arsenic polymetallic mixture. Crushed coal and a sulfiding agent are also added simultaneously. The mixed material is fed onto a belt conveyor and transported to a disc granulator (or briquetting machine). The mixture is moistened by spraying water and then granulated (or briquetized) to form spherical materials with a moisture content of 8-12%. The mass ratio of the high-arsenic polymetallic mixture, crushed coal, and sulfiding agent is 100:2:2.

[0082] Secondary batching: Lump coal and blowing slag are fed in via a quantitative feeder, and after secondary batching with spherical materials, they are added together to the top-blown furnace via a feeding belt conveyor. The mass ratio of high-arsenic polymetallic mixture, lump coal, and blowing slag is 100:12:3.

[0083] 2. Reduction sulfidation smelting (first cycle)

[0084] The top-blown furnace operates in cycles. The granulated spherical material, along with lump coal and blown slag, is added into the furnace through the top-blown furnace feed port. The top-blown nozzle A is inserted 200mm into the molten pool, and 500Nm³ of natural gas is injected into the furnace through nozzle A. 3 / h and oxygen-enriched air 1600Nm 3 The oxygen-enriched air contains 65% O2, and the molten pool temperature is controlled at 1400℃. After melting in the furnace, the material undergoes reduction sulfidation smelting and separates into three phases: slag, mixed matte, and crude lead. The mixed matte is composed of sulfides of arsenic, lead, copper, and iron. After reduction smelting, the slag is discharged from the slag outlet located at the top of the molten pool and subjected to slag flushing and water-crushing. It is then stored as waste slag or sold. The water-crushed slag contains 0.65% Cu. Crude lead is discharged from the discharge port located at the bottom of the hearth, containing 97.6% Pb. The mixed matte melt remains in the furnace as raw material for the second-cycle oxygen-enriched blowing. The mixed matte contains 48% Cu, 13% Pb, and 18% As. The reduction sulfidation process generates a large amount of CO. Secondary and tertiary air are blown into the furnace and boiler inlet to ensure complete combustion of CO in the flue gas. The O2 content in the boiler outlet flue gas is controlled at 5.5%, and the boiler inlet flue gas temperature is controlled at 1180℃. The furnace gas is sent to desulfurization and denitrification treatment after waste heat recovery in the waste heat boiler and cooling in the quench tower, and the exhaust gas meets the emission standards.

[0085] 3. Oxygen-enriched blowing (second cycle)

[0086] The top-blown furnace enters its second cycle operation. Top-blown nozzle A is removed from the furnace, and nozzle B is inserted. Oxygen-enriched air (containing 25% O2) is injected into the furnace through nozzle B at a rate of 8000 Nm³. 3 / h. Quartz stone of a certain proportion is added through the top charging port of the furnace, with a mass ratio of quartz to mixed copper matte of 2.5:100. The molten pool temperature is controlled at 1210℃. The mixed matte reacts with oxygen-enriched air and quartz stone in the furnace for blowing operations, forming two phases of slag and crude copper in the furnace melt. After the second cycle, crude copper product is obtained, and the crude copper ingots are sold. The crude copper temperature is 1210℃, and the crude copper contains 98.6% copper, 0.1% As, and 0.12% Pb. The flue gas from the second cycle is treated by an electrostatic precipitator, a quench tower, and a bag filter after the boiler to recover arsenic trioxide from the flue gas. The white arsenic contains 90% As2O3. The furnace gas is desulfurized and discharged after meeting the standards. The blowing slag contains 8% lead and is returned to the first cycle for lead recovery as cold feed.

[0087] Example 3

[0088] 1. Ingredient preparation and granulation

[0089] Primary batching and granulation: White smoke dust, Kaldor furnace dust, and precious lead furnace dust with a moisture content of 3% are weighed and metered using a weighing screw feeder, and batched at a mass ratio of 4:2:1 to form a high-arsenic polymetallic mixture. Crushed coal and a sulfiding agent are also added. The mixed material is fed onto a belt conveyor and transported to a disc granulator (or briquetting machine). The mixture is moistened by spraying water and then granulated (or briquetized) to form spherical materials with a moisture content of 8-10%. The mass ratio of the high-arsenic polymetallic mixture, crushed coal, and sulfiding agent is 100:2.5:2.

[0090] Secondary batching: Lump coal and blowing slag are fed in via a quantitative feeder, and after secondary batching with spherical materials, they are added together to the top-blown furnace via a feeding belt conveyor. The mass ratio of high-arsenic polymetallic mixture, lump coal, and blowing slag is 100:18:3.

[0091] 2. Reduction sulfidation smelting (first cycle)

[0092] The top-blown furnace operates in cycles. The granulated spherical material, along with lump coal and blown slag, is added into the furnace through the top-blown furnace feed port. The top-blown nozzle A is inserted 280mm into the molten pool, and 550Nm³ of natural gas is injected into the furnace through nozzle A. 3 / h and oxygen-enriched air 1800Nm 3 The oxygen-enriched air contains 65% O2, and the molten pool temperature is controlled at 1500℃. After melting in the furnace, the material undergoes reduction sulfidation smelting and separates into three phases: slag, mixed matte, and crude lead. The mixed matte is composed of sulfides of arsenic, lead, copper, and iron. After reduction smelting, the slag is discharged from the slag outlet located at the top of the molten pool and subjected to slag flushing and water-crushing. It is then stored as waste slag or sold. The water-crushed slag contains 0.75% Cu. Crude lead is discharged from the discharge port located at the bottom of the hearth, containing 97.8% Pb. The mixed matte melt remains in the furnace as raw material for the second-cycle oxygen-enriched blowing. The mixed matte contains 50% Cu, 12% Pb, and 20% As. The reduction sulfidation process generates a large amount of CO. Secondary and tertiary air are blown into the furnace and boiler inlet to ensure complete combustion of CO in the flue gas. The O2 content in the boiler outlet flue gas is controlled at 6%, and the boiler inlet flue gas temperature is controlled at 1220℃. The furnace gas is sent to desulfurization and denitrification treatment after waste heat recovery in the waste heat boiler and cooling in the quench tower, and the exhaust gas meets the emission standards.

[0093] 3. Oxygen-enriched blowing (second cycle)

[0094] The top-blown furnace enters its second cycle operation. Top-blown nozzle A is removed from the furnace, and nozzle B is inserted. Oxygen-enriched air, containing 25% O2, is injected into the furnace through nozzle B at a rate of 7800 Nm³. 3 / h. Quartz stone of a certain proportion is added through the top charging port of the furnace, with a mass ratio of quartz to mixed copper matte of 2.5:100. The molten pool temperature is controlled at 1220℃. The mixed matte reacts with oxygen-enriched air and quartz stone in the furnace for blowing operations, forming two phases of slag and crude copper in the furnace melt. After the second cycle, crude copper product is obtained, and the crude copper ingots are sold. The crude copper temperature is 1220℃, and the crude copper contains 98.7% copper, 0.08% As, and 0.1% Pb. The flue gas from the second cycle is treated by an electrostatic precipitator, a quench tower, and a bag filter after the boiler to recover arsenic trioxide from the flue gas. The white arsenic contains 92% As2O3. The furnace gas is desulfurized and discharged after meeting the standards. The blowing slag contains 8.5% lead and is returned to the first cycle for lead recovery as cold feed.

[0095] 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 comprehensive recycling method for high-arsenic polymetallic hazardous waste, characterized in that, The method includes, High-arsenic polymetallic hazardous waste, reducing agent, and sulfiding agent are mixed in a predetermined ratio to obtain a mixture; wherein, the high-arsenic polymetallic hazardous waste, reducing agent, and sulfiding agent are mixed in a predetermined ratio to obtain a mixture comprising: After the high-arsenic polymetallic hazardous waste, the first reducing agent, and the sulfiding agent are mixed for the first time, the mixture is humidified and granulated to obtain granular material. The granular material is mixed with a second reducing agent and other hazardous waste materials in a second batch to obtain a mixture. The ratio of the high-arsenic polymetallic hazardous waste to the first reducing agent and the sulfiding agent is 100:(1-5):(1-5); The ratio of the granular material to the second reducing agent and other hazardous waste materials is 100:(10-20):(1-5); the other hazardous waste materials include blowing slag. The mixture is added to a top-blown furnace, and natural gas and oxygen-enriched air are blown into the furnace through the top-blown lance A for reduction sulfidation smelting. By adjusting the insertion depth of the lance, the temperature of the molten pool is controlled at 1250℃~1550℃ to ensure that the mixture in the furnace reacts fully, resulting in the first slag, mixed matte, crude lead and the first waste gas. The mixed matte includes sulfides of arsenic, lead, copper and iron. The first batch of slag and crude lead is discharged, and the first batch of waste gas is treated before being discharged. Top-blown lance A is removed from the furnace, and lance B is inserted into the furnace. Oxygen-enriched air is injected into the furnace through lance B to perform oxygen-enriched blowing on the mixed copper matte, resulting in a second slag, crude copper, and a second waste gas. The oxygen-enriched blowing of the mixed copper matte in the top-blown furnace includes... Inject oxygen-rich air into the furnace to control the molten pool temperature at 1200℃~1250℃; Quartzite and mixed matte are added in a predetermined ratio and subjected to oxygen-enriched blowing to obtain second slag, crude copper and second waste gas. After recovering arsenic trioxide from the second waste gas, the second waste gas is treated and then discharged.

2. The comprehensive recycling method for high-arsenic polymetallic hazardous waste according to claim 1, characterized in that, The first reducing agent includes crushed coal; The second reducing agent includes lump coal or coke; The sulfiding agent includes one of pyrite, gypsum slag, CaSO4, or copper concentrate.

3. A comprehensive recycling method for high-arsenic polymetallic hazardous waste according to any one of claims 1 or 2, characterized in that, The moisture content of granular materials should be controlled between 8% and 12%.

4. A comprehensive recycling method for high-arsenic polymetallic hazardous waste according to any one of claims 1 or 2, characterized in that, The first batch of slag was sold as waste slag. The crude lead was sold as a product. The mixed copper matte remains inside the top-blown furnace.

5. A comprehensive recycling method for high-arsenic polymetallic hazardous waste according to any one of claims 1 or 2, characterized in that, The first waste gas, after treatment, is discharged, including: After the first waste gas is fully combusted, it is discharged after passing through a waste heat boiler to recover waste heat, a quench tower to cool down, and desulfurization and denitrification treatment.

6. The comprehensive recycling method for high-arsenic polymetallic hazardous waste according to claim 1, characterized in that, The crude copper ingots were sold externally. The second slag is added back into the top-blown furnace for reduction sulfidation smelting to recover lead.

7. The comprehensive recycling method for high-arsenic polymetallic hazardous waste according to claim 6, characterized in that, The second waste gas is treated before being discharged, including, The second waste gas is treated with a dry flue gas arsenic recovery process to obtain arsenic trioxide. The second waste gas after arsenic trioxide recovery is then treated for desulfurization and denitrification to meet the standards before being discharged.

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