Arsenic-calcium slag harmless treatment equipment

Abstract

The utility model provides harmless treatment equipment for arsenic-calcium slag. The harmless treatment equipment comprises a mixer, a medium-temperature volatilization furnace, a high-temperature decomposition furnace and a tail gas purification device, the mixer is provided with a mixed material inlet and a mixed material outlet, and the mixed material inlet is used for inputting arsenic-calcium slag and pyrite. The medium-temperature volatilization furnace is provided with a volatilization furnace material inlet, a volatilization furnace gas inlet, a volatilization furnace gas outlet and a volatilization furnace tailing outlet. And the volatilization furnace material inlet is connected with the mixed material outlet. The high-temperature decomposing furnace is provided with a decomposing furnace material inlet, a decomposing furnace gas inlet, a decomposing furnace gas outlet and a decomposing furnace tailing outlet. The material inlet of the decomposing furnace is connected with the tailing outlet of the volatilization furnace. The tail gas purification device is provided with a purification inlet and a purification outlet, and the purification inlet is connected with the volatilization furnace gas outlet and the decomposition furnace gas outlet. The harmless treatment equipment for the arsenic-calcium slag can effectively remove arsenic in the arsenic-calcium slag, avoid arsenic pollution, improve the utilization rate of pyrite and save cost and heat.

Description

Technical Field

[0001] The utility model relates to the technical field of solid waste treatment equipment, in particular to a harmless treatment equipment for arsenic-calcium slag. Background Technique

[0002] Arsenic-calcium slag contains calcium arsenate and arsenic trioxide. To avoid the risk of environmental arsenic pollution caused by the release of arsenic in arsenic-calcium slag, the arsenic-calcium slag needs to be further stabilized. At present, the main method for stabilizing arsenic-calcium slag is the cement solidification stabilization technology. The cement solidification stabilization technology mainly improves the stabilization of arsenic-calcium slag by mixing and solidifying arsenic-calcium slag and cement. However, this technology not only produces a large amount of secondary arsenic-containing solid waste, but also has the problem of high cost. In addition, the iron-arsenic coprecipitation technology can also be used for the stabilization treatment of arsenic-calcium slag. This method uses a large amount of iron salts to fix arsenic through the coprecipitation and adsorption mechanisms, and finally forms iron arsenate with arsenic. However, this method requires a large amount of iron salts, and the molar ratio of iron to arsenic needs to reach more than 14, which not only increases the cost of fixing arsenic, but also leads to an increase in the amount of slag and generates secondary pollution.

[0003] Therefore, it is necessary to provide a harmless treatment equipment for arsenic-calcium slag to solve the above technical problems. Summary of the Utility Model

[0004] The utility model provides a harmless treatment equipment for arsenic-calcium slag, which can effectively remove arsenic from arsenic-calcium slag, avoid arsenic pollution, and at the same time improve the utilization rate of pyrite, save costs and heat.

[0005] The technical solution of the utility model is as follows:

[0006] A harmless treatment equipment for arsenic-calcium slag, wherein the arsenic-calcium slag contains calcium arsenate and arsenic trioxide, and the harmless treatment equipment for arsenic-calcium slag includes:

[0007] A mixer, which is provided with a mixing inlet and a mixing outlet; the mixing inlet is used for inputting arsenic-calcium slag and pyrite, and the mixing outlet is used for outputting a mixed material including arsenic-calcium slag and pyrite;

[0008] A medium-temperature volatilization furnace, which is provided with a volatilization furnace material inlet, a volatilization furnace gas inlet, a volatilization furnace gas outlet and a volatilization furnace tail slag outlet; the volatilization furnace material inlet is connected with the mixing outlet and is used for inputting the mixed material; the volatilization furnace gas inlet is used for inputting nitrogen; the volatilization furnace gas outlet is used for outputting a first tail gas containing arsenic trioxide; the volatilization furnace tail slag outlet is used for outputting a first tail slag containing calcium arsenate and pyrite;

[0009] Pyrolysis furnace, which is provided with a pyrolysis furnace material inlet, a pyrolysis furnace gas inlet, a pyrolysis furnace gas outlet and a pyrolysis furnace tail slag outlet; the pyrolysis furnace material inlet is connected to the volatilization furnace tail slag outlet for inputting the first tail slag; the pyrolysis furnace gas inlet is used for inputting air; the pyrolysis furnace gas outlet is used for outputting the second tail gas containing arsenic oxide and sulfur dioxide; the pyrolysis furnace tail slag outlet is used for outputting the second tail slag containing calcium oxide and iron tetroxide; and,

[0010] Tail gas purification device, which is provided with a purification inlet and a purification outlet, and the purification inlet is connected to both the volatilization furnace gas outlet and the pyrolysis furnace gas outlet for inputting the first tail gas and the second tail gas.

[0011] In the arsenic-calcium slag harmless treatment equipment of the present utility model, the arsenic-calcium slag harmless treatment equipment further includes a paddle-type preheating feeder, and its inner tank is provided with a feeder material inlet, a feeder gas outlet and a feeder material outlet; the feeder material inlet is connected to the mixing outlet for inputting the mixed material; the feeder gas outlet is used for outputting water vapor; the feeder material outlet is used for outputting the dehydrated mixed material, which is connected to the volatilization furnace material inlet.

[0012] In the arsenic-calcium slag harmless treatment equipment of the present utility model, the arsenic-calcium slag harmless treatment equipment further includes:

[0013] High-temperature gas-solid separator, which is provided with a separator inlet, a separator solid outlet and a separator gas outlet; the separator inlet is connected to both the volatilization furnace gas outlet and the pyrolysis furnace gas outlet for inputting the first tail gas and the second tail gas; the separator solid outlet is used for outputting impurities; the separator gas outlet is used for outputting the third tail gas containing arsenic oxide and sulfur dioxide; and,

[0014] Condensing arsenic collection chamber for collecting refined white arsenic, which is provided with an arsenic collection chamber inlet and an arsenic collection chamber gas outlet; the arsenic collection chamber inlet is connected to the separator gas outlet for inputting the third tail gas; the arsenic collection chamber gas outlet is used for outputting the fourth tail gas containing sulfur dioxide, which is connected to the purification inlet.

[0015] In the arsenic-calcium slag harmless treatment equipment of the present utility model, the arsenic-calcium slag harmless treatment equipment further includes a discharge heat exchanger, and the inner tank of the discharge heat exchanger is provided with a heat exchanger material inlet and a heat exchanger material outlet; the heat exchanger material inlet is connected to the pyrolysis furnace tail slag outlet for inputting the second tail slag; the heat exchanger material outlet is used for outputting the cooled second tail slag.

[0016] In the arsenic-calcium residue harmless treatment equipment of the present utility model, an inlet for hot oil of the feeder and an outlet for cold oil of the feeder are further provided on the outer casing of the paddle-type preheating feeder; an inlet for cold oil of the heat exchanger and an outlet for hot oil of the heat exchanger are further provided on the outer casing of the discharge heat exchanger; the outlet for hot oil of the heat exchanger is connected to the inlet for hot oil of the feeder.

[0017] In the arsenic-calcium residue harmless treatment equipment of the present utility model, the inlet for cold oil of the heat exchanger is connected to the outlet for cold oil of the feeder.

[0018] In the arsenic-calcium residue harmless treatment equipment of the present utility model, the inlet for cold oil of the heat exchanger is arranged adjacent to the outlet for the material of the heat exchanger, and the outlet for hot oil of the heat exchanger is arranged adjacent to the inlet for the material of the heat exchanger.

[0019] In the arsenic-calcium residue harmless treatment equipment of the present utility model, the inlet for hot oil of the feeder is arranged adjacent to the outlet for the material of the feeder, and the outlet for cold oil of the feeder is arranged adjacent to the inlet for the material of the feeder.

[0020] In the arsenic-calcium residue harmless treatment equipment of the present utility model, the arsenic-calcium residue harmless treatment equipment further includes a condenser, which is provided with a condensation inlet and a condensation outlet, and the condensation inlet is connected to the gas outlet of the feeder.

[0021] In the arsenic-calcium residue harmless treatment equipment of the present utility model, both the medium-temperature volatilization furnace and the high-temperature decomposition furnace are electrically heated furnaces or flue gas indirectly heated furnaces.

[0022] Compared with the prior art, the beneficial effects of the present utility model are as follows: For the arsenic-calcium residue harmless treatment equipment of the present utility model, arsenic-calcium residue and pyrite are first mixed in a mixer to ensure sufficient subsequent reaction; then the mixed material containing arsenic-calcium residue and pyrite is input into a medium-temperature volatilization furnace, so that arsenic oxide in the mixed material becomes gaseous and is separated from the first tailing residue containing calcium arsenate and pyrite. The medium-temperature volatilization furnace is in a nitrogen atmosphere, which can prevent arsenic oxide from reacting with oxygen to generate solid arsenic pentoxide, increasing the difficulty of subsequent treatment; then the first tailing residue is input into a high-temperature decomposition furnace, where calcium arsenate and pyrite in the first tailing residue undergo a chemical reaction in an oxygen-containing atmosphere, so that arsenic exists in the form of gaseous arsenic oxide and is separated from the second tailing residue containing calcium oxide and magnetite. Finally, the obtained second tailing residue does not contain arsenic, and the first tail gas and the second tail gas are treated by a tail gas purification device to avoid arsenic pollution. At the same time, through medium-temperature treatment in the medium-temperature volatilization furnace first and then high-temperature treatment in the high-temperature decomposition furnace, pyrite in the medium-temperature volatilization furnace will not react with arsenic oxide, so that all pyrite reacts with calcium arsenate in the high-temperature decomposition furnace, improving the utilization rate of pyrite and saving costs; arsenic oxide in the arsenic-calcium residue first becomes gaseous and is discharged in the medium-temperature volatilization furnace, so that only calcium arsenate remains in the arsenic-calcium residue in the high-temperature decomposition furnace, which can also shorten the treatment time in the high-temperature decomposition furnace and save heat. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following briefly introduces the drawings required to be used in the embodiments. The drawings described below are only the corresponding drawings of some embodiments of the present utility model.

[0024] Figure 1 FIG. 1 is a schematic structural diagram of the arsenic-calcium residue harmless treatment equipment provided by a preferred embodiment of the present utility model.

[0025] Among them,

[0026] 11. Mixer, 111. Mixing inlet, 112. Mixing outlet,

[0027] 12. Medium-temperature volatilization furnace, 121. Volatilization furnace material inlet, 122. Volatilization furnace gas inlet, 123. Volatilization furnace gas outlet, 124. Volatilization furnace tailing residue outlet,

[0028] 13. High-temperature decomposition furnace, 131. Decomposition furnace material inlet, 132. Decomposition furnace gas inlet, 133. Decomposition furnace gas outlet, 134. Decomposition furnace tailing residue outlet,

[0029] 14. Tail gas purification device, 141. Purification inlet, 142. Purification outlet,

[0030] 15. Blade-type preheating feeder, 151. Feeder material inlet, 152. Feeder gas outlet, 153. Feeder material outlet, 154. Feeder hot oil inlet, 155. Feeder cold oil outlet,

[0031] 16. High-temperature gas-solid separator, 161. Separator inlet, 162. Separator solid outlet, 163. Separator gas outlet,

[0032] 17. Condensation arsenic recovery chamber, 171. Arsenic recovery chamber inlet, 172. Arsenic recovery chamber gas outlet,

[0033] 18. Discharge heat exchanger, 181. Heat exchanger material inlet, 182. Heat exchanger material outlet, 183. Heat exchanger cold oil inlet, 184. Heat exchanger hot oil outlet,

[0034] 19. Condenser, 191. Condensation inlet, 192. Condensation outlet.

[0035] In the figure, units with similar structures are denoted by the same reference numerals. Detailed implementation manners

[0036] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without making creative efforts belong to the protection scope of the present utility model.

[0037] The directional terms mentioned in the present utility model, such as "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "side", "top" and "bottom" and other words, are only references to the orientation of the accompanying drawings. The directional terms used are for explaining and understanding the present utility model, rather than for limiting the present utility model.

[0038] The terms "first", "second" and other words in the terms of the present utility model are only for descriptive purposes, and cannot be understood as indicating or implying relative importance, nor as a limitation on the order of precedence.

[0039] In the present utility model, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0040] The arsenic-calcium residue contains calcium arsenate and arsenic trioxide. To avoid the risk of environmental arsenic pollution caused by the release of arsenic from the arsenic-calcium residue, the arsenic-calcium residue needs to be further stabilized. At present, the main method for stabilizing the arsenic-calcium residue is the cement solidification stabilization technology. The cement solidification stabilization technology mainly improves the stabilization of the arsenic-calcium residue by mixing and solidifying the arsenic-calcium residue and cement. However, this technology not only produces a large amount of secondary arsenic-containing solid waste, but also has the problem of high cost. In addition, the iron-arsenic coprecipitation technology can also be used for the stabilization treatment of the arsenic-calcium residue. This method uses a large amount of iron salts to solidify arsenic through the coprecipitation and adsorption mechanisms, and finally forms iron arsenate with arsenic. However, the dosage of iron salts in this method is very large, and the molar ratio of iron to arsenic needs to reach more than 14. This not only increases the cost of solidifying arsenic, but also leads to an increase in the amount of slag and generates secondary pollution.

[0041] The following is a preferred embodiment of an arsenic-calcium residue harmless treatment device provided by the present utility model that can solve the above technical problems.

[0042] Please refer to Figure 1 , a preferred embodiment of the present utility model provides an arsenic-calcium residue harmless treatment device. The arsenic-calcium residue contains calcium arsenate and arsenic trioxide. The arsenic-calcium residue harmless treatment device includes a mixer 11, a medium-temperature volatilization furnace 12, a high-temperature decomposition furnace 13, and a tail gas purification device 14.

[0043] The mixer 11 is provided with a mixing inlet 111 and a mixing outlet 112. The mixing inlet 111 is used to input the arsenic-calcium residue and pyrite, and the mixing outlet 112 is used to output the mixed material including the arsenic-calcium residue and pyrite.

[0044] The medium-temperature volatilization furnace 12 is provided with a volatilization furnace material inlet 121, a volatilization furnace gas inlet 122, a volatilization furnace gas outlet 123, and a volatilization furnace tail slag outlet 124. The volatilization furnace material inlet 121 is connected to the mixing outlet 112 and is used to input the mixed material. The volatilization furnace gas inlet 122 is used to input nitrogen. The volatilization furnace gas outlet 123 is used to output the first tail gas containing arsenic trioxide. The volatilization furnace tail slag outlet 124 is used to output the first tail slag containing calcium arsenate and pyrite.

[0045] The high-temperature decomposition furnace 13 is provided with a decomposition furnace material inlet 131, a decomposition furnace gas inlet 132, a decomposition furnace gas outlet 133, and a decomposition furnace tail slag outlet 134. The decomposition furnace material inlet 131 is connected to the volatilization furnace tail slag outlet 124 and is used to input the first tail slag; the decomposition furnace gas inlet 132 is used to input air. The decomposition furnace gas outlet 133 is used to output the second tail gas containing arsenic trioxide and sulfur dioxide. The decomposition furnace tail slag outlet 134 is used to output the second tail slag containing calcium oxide and iron tetroxide. The reaction chemical formula of calcium arsenate and pyrite is:

[0046] Ca3(AsO4)2 + 3FeS2 + 7O2(g) = As2O3(g) + 3CaO + 6SO2(g) + Fe3O4;

[0047] The tail gas purification device 14 is provided with a purification inlet 141 and a purification outlet 142. The purification inlet 141 is connected to both the volatile furnace gas outlet 123 and the decomposition furnace gas outlet 133, and is used to input the first tail gas and the second tail gas.

[0048] For the arsenic-calcium residue harmless treatment equipment of the present utility model, first, the arsenic-calcium residue and pyrite are mixed in the mixer 11 to make the subsequent reaction sufficient; then, the mixed material containing the arsenic-calcium residue and pyrite is input into the medium-temperature volatile furnace 12, so that the arsenic oxide in the mixed material becomes gaseous and is separated from the first tail residue containing calcium arsenate and pyrite. The medium-temperature volatile furnace 12 is in a nitrogen atmosphere, which can avoid the reaction of arsenic oxide with oxygen to generate solid arsenic pentoxide, resulting in increased difficulty in subsequent treatment; then, the first tail residue is input into the high-temperature decomposition furnace 13, and in an oxygen-containing atmosphere, the calcium arsenate and pyrite in the first tail residue undergo a chemical reaction, so that arsenic exists in the form of gaseous arsenic oxide and is separated from the second tail residue containing calcium oxide and iron tetroxide. The finally obtained second tail residue does not contain arsenic, and the first tail gas and the second tail gas are treated by the tail gas purification device 14 to avoid arsenic pollution. At the same time, first, medium-temperature treatment is carried out in the medium-temperature volatile furnace 12, and then high-temperature treatment is carried out in the high-temperature decomposition furnace 13, so that pyrite in the medium-temperature volatile furnace 12 will not react with arsenic oxide, and all pyrite reacts with calcium arsenate in the high-temperature decomposition furnace 13, improving the utilization rate of pyrite and saving costs; the arsenic oxide in the arsenic-calcium residue first becomes gaseous and is discharged in the medium-temperature volatile furnace 12, so that only calcium arsenate remains in the arsenic-calcium residue in the high-temperature decomposition furnace 13, which can also shorten the treatment time in the high-temperature decomposition furnace 13 and save heat.

[0049] The arsenic-calcium residue harmless treatment equipment further includes a paddle-type preheating feeder 15, and its inner tank is provided with a feeder material inlet 151, a feeder gas outlet 152 and a feeder material outlet 153. The feeder material inlet 151 is connected to the mixing outlet 112 and is used to input the mixed material. The feeder gas outlet 152 is used to output water vapor; the feeder material outlet 153 is used to output the dehydrated mixed material, which is connected to the volatile furnace material inlet 121. The paddle-type preheating feeder 15 can turn the moisture in the mixed material into water vapor and discharge it, improving the treatment efficiency of the subsequent medium-temperature volatile furnace 12. The temperature of the paddle-type preheating feeder 15 is much lower than that of the medium-temperature volatile furnace 12, so heat is also saved.

[0050] The arsenic-calcium residue harmless treatment equipment further includes a high-temperature gas-solid separator 16 and a condensation arsenic collection chamber 17.

[0051] The high-temperature gas-solid separator 16 is provided with a separator inlet 161, a separator solid outlet 162, and a separator gas outlet 163. The separator inlet 161 is connected to both the volatile furnace gas outlet 123 and the decomposition furnace gas outlet 133, and is used for inputting the first tail gas and the second tail gas. The separator solid outlet 162 is used for outputting impurities. The separator gas outlet 163 is used for outputting the third tail gas containing arsenic trioxide and sulfur dioxide. The high-temperature gas-solid separator 16 can keep arsenic trioxide and sulfur dioxide in a gaseous state at high temperature, and filter out the solid impurities through the membrane tube.

[0052] The condensation arsenic collection chamber 17 is used for collecting refined white arsenic, and is provided with an arsenic collection chamber inlet 171 and an arsenic collection chamber gas outlet 172. The arsenic collection chamber inlet 171 is connected to the separator gas outlet 163 and is used for inputting the third tail gas. The arsenic collection chamber gas outlet 172 is used for outputting the fourth tail gas containing sulfur dioxide, which is connected to the purification inlet 141. The condensation arsenic collection chamber 17 can keep sulfur dioxide in a gaseous state, turn arsenic trioxide into a solid powder for collection to obtain refined white arsenic, and improve the resource utilization rate.

[0053] The arsenic-calcium slag harmless treatment equipment further includes a discharge heat exchanger 18. The inner tank of the discharge heat exchanger 18 is provided with a heat exchanger material inlet 181 and a heat exchanger material outlet 182. The heat exchanger material inlet 181 is connected to the decomposition furnace tail slag outlet 134 and is used for inputting the second tail slag. The heat exchanger material outlet 182 is used for outputting the cooled second tail slag. The second tail slag is cooled by the discharge heat exchanger 18, which is convenient for stacking and storing the second tail slag.

[0054] The outer tank of the paddle-type preheating feeder 15 is further provided with a feeder hot oil inlet 154 and a feeder cold oil outlet 155. The outer tank of the discharge heat exchanger 18 is further provided with a heat exchanger cold oil inlet 183 and a heat exchanger hot oil outlet 184. The heat exchanger hot oil outlet 184 is connected to the feeder hot oil inlet 154. The high-temperature second tail slag in the inner tank of the discharge heat exchanger 18 will conduct heat to the heat-conducting oil in the outer tank of the discharge heat exchanger 18, and the hot heat-conducting oil output from the heat exchanger hot oil outlet 184 is transported to the outer tank of the paddle-type preheating feeder 15 through the feeder hot oil inlet 154, which can provide a heat source to heat the mixed materials in the inner tank of the paddle-type preheating feeder 15, effectively saving and utilizing heat.

[0055] The heat exchanger cold oil inlet 183 is connected to the feeder cold oil outlet 155. The heat of the cold heat-conducting oil located in the outer tank of the paddle-type preheating feeder 15 is transferred to the first mixture located in the inner tank of the paddle-type preheating feeder 15, and the cold heat-conducting oil output from the feeder cold oil outlet 155 is input into the outer tank of the discharge heat exchanger 18 through the heat exchanger cold oil inlet 183, which can effectively cool the second tail slag.

[0056] The cold oil inlet 183 of the heat exchanger is arranged adjacent to the material outlet 182 of the heat exchanger, and the hot oil outlet 184 of the heat exchanger is arranged adjacent to the material inlet 181 of the heat exchanger. In the outer shell of the discharge heat exchanger 18, in the direction from the material inlet 181 of the heat exchanger to the material outlet 182 of the heat exchanger, the temperature of the heat-conducting oil gradually decreases, which can gradually cool the second tailings residue. That is, by adopting the method of countercurrent heat exchange, the cooling effect of the second tailings residue is effectively improved.

[0057] The hot oil inlet 154 of the feeder is arranged adjacent to the material outlet 153 of the feeder, and the cold oil outlet 155 of the feeder is arranged adjacent to the material inlet 151 of the feeder. In the outer shell of the paddle-type preheating feeder 15, in the direction from the material inlet 151 of the feeder to the material outlet 153 of the feeder, the temperature of the heat-conducting oil gradually increases, which can gradually heat the mixed material. That is, by adopting the method of countercurrent heat exchange, it helps the evaporation of moisture.

[0058] The arsenic-calcium residue harmless treatment equipment further includes a condenser 19, which is provided with a condensation inlet 191 and a condensation outlet 192, and the condensation inlet 191 is connected to the gas outlet 152 of the feeder. The condenser 19 can turn water vapor into liquid water, which is convenient for transportation to a wastewater treatment plant for treatment, avoiding environmental pollution.

[0059] Both the medium-temperature volatilization furnace 12 and the high-temperature decomposition furnace 13 are electrically heated, and the temperatures of the medium-temperature volatilization furnace 12 and the high-temperature decomposition furnace 13 can be accurately and conveniently controlled. The medium-temperature volatilization furnace 12 and the high-temperature decomposition furnace 13 can also be indirectly heated by flue gas, which can make full use of the high-temperature flue gas discharged from other treatment equipment in the factory, effectively saving energy.

[0060] The working process of the arsenic-calcium residue harmless treatment equipment in the preferred embodiment of the present utility model:

[0061] Obtain arsenic-calcium residue and pyrite, and input the two into the mixer 11 through the mixing inlet 111. After mixing the arsenic-calcium residue and pyrite, output the mixed material through the mixing outlet 112;

[0062] Obtain the mixed material, input it into the paddle-type preheating feeder 15 through the material inlet 151 of the feeder, heat the mixed material, the heating temperature is 150°C - 200°C, the heating duration is 60 min - 120 min, discharge water vapor through the gas outlet 152 of the feeder, and output the dehydrated mixed material through the material outlet 153 of the feeder;

[0063] Obtain the dehydrated mixed material, input it into the medium-temperature volatilization furnace 12 through the volatilization furnace material inlet 121, and input nitrogen into the medium-temperature volatilization furnace 12 through the volatilization furnace gas inlet 122 to conduct medium-temperature heating on the mixed material. Output the first tail gas containing arsenic trioxide through the volatilization furnace gas outlet 123, and output the first tail residue containing calcium arsenate and pyrite through the volatilization furnace tail residue outlet 124;

[0064] Obtain the first tail residue, input it into the high-temperature decomposition furnace 13 through the decomposition furnace material inlet 131, and input air into the high-temperature decomposition furnace 13 through the decomposition furnace gas inlet 132 to conduct high-temperature heating on the first tail residue. Output the second tail gas containing arsenic trioxide and sulfur dioxide through the decomposition furnace gas outlet 133, and output the second tail residue containing calcium oxide and magnetite through the decomposition furnace tail residue outlet 134;

[0065] Obtain the second tail residue, input it into the discharge heat exchanger 18 through the heat exchanger material inlet 181 to cool down the second tail residue, and output the cooled second tail residue through the heat exchanger material outlet 182;

[0066] Obtain the hot heat transfer oil output from the heat exchanger hot oil outlet 184, and input it into the outer tank of the paddle-type preheating feeder 15 through the feeder hot oil inlet 154;

[0067] Obtain the cold heat transfer oil output from the feeder cold oil outlet 155, and input it into the outer tank of the discharge heat exchanger 18 through the heat exchanger cold oil inlet 183;

[0068] Obtain the first tail gas and the second tail gas, input the two into the high-temperature gas-solid separator 16 through the separator inlet 161, output impurities through the separator solid outlet 162, and output the third tail gas containing arsenic trioxide and sulfur dioxide through the separator gas outlet 163;

[0069] Obtain the third tail gas, input it into the condensation arsenic collection chamber 17 through the arsenic collection chamber inlet 171 to collect refined white arsenic, and output the fourth tail gas containing sulfur dioxide through the arsenic collection chamber gas outlet 172;

[0070] Obtain the fourth tail gas, input the fourth tail gas into the tail gas purification device 14 through the purification inlet 141, and discharge the purified tail gas through the purification outlet 142;

[0071] Obtain water vapor, input it into the condenser 19 through the condensation inlet 191, then output wastewater through the condensation outlet 192, and transport the wastewater to the sewage treatment plant.

[0072] In this way, the working process of the arsenic-calcium residue harmless treatment equipment in this preferred embodiment is completed.

[0073] The harmless treatment equipment for arsenic-calcium slag of the present utility model first mixes arsenic-calcium slag and pyrite in a mixer to ensure sufficient subsequent reactions; then inputs the mixed material containing arsenic-calcium slag and pyrite into a medium-temperature volatilization furnace, making the arsenic oxide in the mixed material become gaseous and separating from the first tail slag containing calcium arsenate and pyrite. The medium-temperature volatilization furnace is in a nitrogen atmosphere, which can avoid the reaction of arsenic oxide with oxygen to generate solid arsenic pentoxide, increasing the difficulty of subsequent treatment; then inputs the first tail slag into a high-temperature decomposition furnace, where calcium arsenate and pyrite in the first tail slag undergo chemical reactions in an aerobic atmosphere, making arsenic exist in the form of gaseous arsenic oxide and separating from the second tail slag containing calcium oxide and magnetite. The finally obtained second tail slag does not contain arsenic, and the first tail gas and the second tail gas are treated through a tail gas purification device to avoid arsenic pollution. At the same time, through medium-temperature treatment in the medium-temperature volatilization furnace first and then high-temperature treatment in the high-temperature decomposition furnace, the pyrite in the medium-temperature volatilization furnace will not react with arsenic oxide, enabling all pyrite to react with calcium arsenate in the high-temperature decomposition furnace, improving the utilization rate of pyrite and saving costs; the arsenic oxide in the arsenic-calcium slag first becomes gaseous and is discharged in the medium-temperature volatilization furnace, leaving only calcium arsenate in the arsenic-calcium slag in the high-temperature decomposition furnace, which can also shorten the treatment time in the high-temperature decomposition furnace and save heat.

[0074] In summary, although the present utility model has been disclosed above with preferred embodiments, the protection scope of the present utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present utility model, according to the concept of the technical solution of the present utility model, makes equivalent substitutions or changes, and should be covered within the protection scope of the present utility model.

Claims

1. An arsenic-calcium residue harmless treatment device, the arsenic-calcium residue contains calcium arsenate and arsenic trioxide, and is characterized in that, The arsenic-calcium slag harmless treatment equipment includes: A mixer, which is provided with a mixing inlet and a mixing outlet; the mixing inlet is used for inputting arsenic-calcium slag and pyrite, and the mixing outlet is used for outputting a mixed material including arsenic-calcium slag and pyrite; A medium-temperature volatilization furnace, which is provided with a volatilization furnace material inlet, a volatilization furnace gas inlet, a volatilization furnace gas outlet and a volatilization furnace tail slag outlet; the volatilization furnace material inlet is connected to the mixing outlet for inputting the mixed material; the volatilization furnace gas inlet is used for inputting nitrogen; the volatilization furnace gas outlet is used for outputting a first tail gas containing arsenic trioxide; the volatilization furnace tail slag outlet is used for outputting a first tail slag containing calcium arsenate and pyrite; A high-temperature decomposition furnace, which is provided with a decomposition furnace material inlet, a decomposition furnace gas inlet, a decomposition furnace gas outlet and a decomposition furnace tail slag outlet; the decomposition furnace material inlet is connected to the volatilization furnace tail slag outlet for inputting the first tail slag; the decomposition furnace gas inlet is used for inputting air; the decomposition furnace gas outlet is used for outputting a second tail gas containing arsenic trioxide and sulfur dioxide; the decomposition furnace tail slag outlet is used for outputting a second tail slag containing calcium oxide and magnetite; and A tail gas purification device, which is provided with a purification inlet and a purification outlet, and the purification inlet is connected to both the volatilization furnace gas outlet and the decomposition furnace gas outlet for inputting the first tail gas and the second tail gas.

2. The arsenic-calcium residue harmless treatment equipment according to claim 1, characterized in that, The arsenic-calcium slag harmless treatment equipment further includes a paddle-type preheating feeder, the inner tank of which is provided with a feeder material inlet, a feeder gas outlet and a feeder material outlet; the feeder material inlet is connected to the mixing outlet for inputting the mixed material; the feeder gas outlet is used for outputting water vapor; the feeder material outlet is used for outputting the dehydrated mixed material, which is connected to the volatilization furnace material inlet.

3. The arsenic-calcium residue harmless treatment equipment according to claim 2, wherein, The arsenic-calcium slag harmless treatment equipment further includes: A high-temperature gas-solid separator, which is provided with a separator inlet, a separator solid outlet and a separator gas outlet; the separator inlet is connected to both the volatilization furnace gas outlet and the decomposition furnace gas outlet for inputting the first tail gas and the second tail gas; the separator solid outlet is used for outputting impurities; the separator gas outlet is used for outputting a third tail gas containing arsenic trioxide and sulfur dioxide; and A condensation arsenic collection chamber for collecting refined white arsenic, which is provided with an arsenic collection chamber inlet and an arsenic collection chamber gas outlet; the arsenic collection chamber inlet is connected to the separator gas outlet for inputting the third tail gas; the arsenic collection chamber gas outlet is used for outputting a fourth tail gas containing sulfur dioxide, which is connected to the purification inlet.

4. The arsenic-calcium residue harmless treatment equipment according to claim 2, characterized in that, The arsenic-calcium slag harmless treatment equipment further includes a discharge heat exchanger, the inner tank of which is provided with a heat exchanger material inlet and a heat exchanger material outlet; the heat exchanger material inlet is connected to the decomposition furnace tail slag outlet for inputting the second tail slag; the heat exchanger material outlet is used for outputting the cooled second tail slag.

5. The arsenic-calcium residue harmless treatment equipment according to claim 4, characterized in that, The outer tank of the paddle-type preheating feeder is further provided with a feeder hot oil inlet and a feeder cold oil outlet; the outer tank of the discharge heat exchanger is further provided with a heat exchanger cold oil inlet and a heat exchanger hot oil outlet; the heat exchanger hot oil outlet is connected to the feeder hot oil inlet.

6. The arsenic-calcium residue harmless treatment equipment according to claim 5, characterized in that The cold oil inlet of the heat exchanger is connected to the cold oil outlet of the feeder.

7. The arsenic-calcium residue harmless treatment equipment according to claim 5, characterized in that, The cold oil inlet of the heat exchanger is arranged adjacent to the material outlet of the heat exchanger, and the hot oil outlet of the heat exchanger is arranged adjacent to the material inlet of the heat exchanger.

8. The arsenic-calcium residue harmless treatment equipment according to claim 5, characterized in that, The hot oil inlet of the feeder is arranged adjacent to the material outlet of the feeder, and the cold oil outlet of the feeder is arranged adjacent to the material inlet of the feeder.

9. The arsenic-calcium residue harmless treatment device according to claim 2, wherein The arsenic-calcium residue harmless treatment equipment further includes a condenser, which is provided with a condensation inlet and a condensation outlet, and the condensation inlet is connected to the gas outlet of the feeder.

10. The arsenic-calcium residue harmless treatment equipment according to claim 1, characterized in that, Both the medium-temperature volatilization furnace and the high-temperature decomposition furnace are electrically heated flue gas indirect heating furnaces.

Images