Method for preparing metal arsenic by using composite reducing agent

Abstract

The invention provides a method for preparing metal arsenic through a composite reducing agent. Equipment for preparing metal arsenic through the composite reducing agent is adopted for treatment. The method for preparing the metal arsenic through the composite reducing agent comprises the steps that S11, refined arsenic, zinc powder and carbon powder are obtained through a first reduction furnace, the refined arsenic, the zinc powder and the carbon powder are heated, first arsenic-containing gas is output through a first furnace gas outlet, and zinc-containing carbon tailings are output through a first furnace tailings outlet; s12, the elementary substance arsenic collecting device obtains first arsenic-containing gas and outputs solid elementary substance arsenic; and S13, the second reduction furnace obtains zinc-containing carbon tailings, the zinc-containing carbon tailings are heated, zinc-containing arsenic gas is output through a second furnace gas main outlet and a second furnace gas auxiliary outlet, and solid tailings are output through a second furnace tailings outlet. Wherein the step S11 further comprises the step that the first reduction furnace obtains gas containing zinc and arsenic. According to the method for preparing the metal arsenic through the composite reducing agent, zinc can be recycled, the consumption of the zinc is reduced, and the cost is saved.

Description

Technical Field

[0001] The invention relates to the technical field of preparing metallic arsenic, and in particular to a method for preparing metallic arsenic using a composite reducing agent. Background Art

[0002] Arsenic has important uses in industry and is widely used in alloy smelting, pesticides, medicines, pigments and other industrial fields. Refined white arsenic is highly toxic, and its main component is arsenic trioxide, which is often used as a raw material for preparing elemental arsenic in industrial production. In the prior art, arsenic is generally prepared by carbon thermal reduction. The equipment for preparing metallic arsenic mainly includes a reduction furnace and a crystallizer. The reducing agent carbon powder and refined white arsenic are mixed, and the two are heated in the reduction furnace to obtain gaseous arsenic, and then collected by a crystallizer to obtain solid elemental arsenic. In order to increase the speed of preparing metallic arsenic, a composite reducing agent, such as carbon powder and zinc powder, can be used. However, the method for preparing metallic arsenic has a large consumption of zinc powder and a high cost.

[0003] Therefore, it is necessary to provide a method for preparing metallic arsenic with a composite reducing agent to solve the above technical problems. Summary of the invention

[0004] The invention provides a method for preparing metallic arsenic by using a composite reducing agent, which can recycle zinc, reduce the consumption of zinc and save costs.

[0005] The technical solution of the present invention is:

[0006] A method for preparing metallic arsenic using a composite reducing agent, which uses a composite reducing agent to prepare metallic arsenic equipment for treatment, and reduces refined white arsenic by zinc powder and carbon powder. The composite reducing agent to prepare metallic arsenic equipment comprises:

[0007] The first reduction furnace is provided with a first furnace material inlet, a first furnace gas inlet, a first furnace tailings outlet and a first furnace gas outlet; the first furnace material inlet is used to input refined white arsenic, zinc powder and carbon powder; the first furnace tailings outlet is used to output zinc-containing carbon tailings; the first furnace gas outlet is used to output the first arsenic-containing gas;

[0008] an elemental arsenic collecting device connected to the first furnace gas outlet, the elemental arsenic collecting device being used to collect solid elemental arsenic; and,

[0009] The second reduction furnace is provided with a second furnace material inlet, a second furnace gas main outlet, a second furnace gas secondary outlet and a second furnace tailings outlet; the second furnace material inlet is connected to the first furnace tailings outlet; the second furnace gas main outlet is used to output zinc-arsenic gas, and the second furnace gas main outlet is connected to the first furnace gas inlet; the second furnace gas secondary outlet is used to output zinc-arsenic gas; the second furnace tailings outlet is used to output solid tailings;

[0010] The method for preparing metallic arsenic with a composite reducing agent comprises the following steps:

[0011] S11, the first reduction furnace obtains refined white arsenic, zinc powder and carbon powder, and inputs them into the first reduction furnace through the first furnace material inlet, heats the refined white arsenic, zinc powder and carbon powder, outputs the first arsenic-containing gas through the first furnace gas outlet, and outputs the zinc-containing carbon tailings through the first furnace tailings outlet;

[0012] S12, the elemental arsenic collection device obtains the first arsenic-containing gas and outputs solid elemental arsenic; and,

[0013] S13, the second reduction furnace obtains zinc-containing carbon tailings, and inputs the zinc-containing carbon tailings into the second reduction furnace through the second furnace material inlet, heats the zinc-containing carbon tailings, outputs zinc-arsenic gas through the second furnace gas main outlet and the second furnace gas secondary outlet, and outputs solid tailings through the second furnace tailings outlet;

[0014] Wherein, step S11 also includes that the first reduction furnace obtains zinc-arsenic containing gas and inputs the gas into the first reduction furnace through the first furnace gas inlet.

[0015] In the method for preparing metallic arsenic with a composite reducing agent described in the present invention, step 13 also includes that the ratio of the gas output from the second furnace gas main outlet to the second furnace gas secondary outlet is 8:2.

[0016] In the method for preparing metallic arsenic with a composite reducing agent described in the present invention, in step S11, the refined white arsenic, zinc powder and carbon powder initially added to the first reduction furnace through the first furnace material inlet have a mass ratio of As2O3:C:Zn=10:12:20, and the refined white arsenic, zinc powder and carbon powder subsequently added to the first reduction furnace through the first furnace material inlet have a mass ratio of As2O3:C:Zn=10:12:4.

[0017] In the method for preparing metallic arsenic using a composite reducing agent of the present invention, in step S11, the temperature for heating the refined white arsenic, zinc powder and carbon powder is 800° C.-900° C., and the reaction time is 4 hours.

[0018] In the method for preparing metallic arsenic using a composite reducing agent of the present invention, in step S13, the temperature for heating the zinc-containing carbon tailings is 1100° C.-1200° C., and the reaction time is 1 h-2 h.

[0019] In the method for preparing metallic arsenic using a composite reducing agent according to the present invention, the elemental arsenic collecting device comprises:

[0020] A first high-temperature gas-solid separator is provided with a first separator inlet, a first separator gas outlet and a first separator solid outlet; the first separator inlet is connected to the first furnace gas outlet; the first separator gas outlet is used to output the second arsenic-containing gas; the first separator solid outlet outputs solid impurities; and,

[0021] A crystallization tank is provided with a tank gas inlet, a tank gas outlet and a tank solid outlet; the tank gas inlet is connected to the first separator gas outlet; the tank gas outlet is used to output the third arsenic-containing gas; the tank solid outlet is used to output solid elemental arsenic;

[0022] Step S12 includes the steps of:

[0023] S121, the first high-temperature gas-solid separator obtains a first arsenic-containing gas, and inputs the first high-temperature gas-solid separator through the first separator inlet, the first high-temperature gas-solid separator performs high-temperature filtration on the first arsenic-containing gas, outputs a second arsenic-containing gas through the first separator gas outlet, and outputs solid impurities through the first separator solid outlet; and

[0024] S122, the crystallization tank obtains the second arsenic-containing gas and inputs it into the crystallization tank through the tank gas inlet, the crystallization tank cools down the second arsenic-containing gas, outputs the third arsenic-containing gas through the tank gas outlet, and outputs solid elemental arsenic through the tank solid outlet.

[0025] In the method for preparing metallic arsenic using a composite reducing agent of the present invention, the equipment for preparing metallic arsenic using a composite reducing agent further comprises:

[0026] A second high-temperature gas-solid separator is provided with a second separator inlet, a second separator gas outlet and a second separator solid outlet; the second separator inlet is connected to the second furnace gas auxiliary outlet; the second separator solid outlet is used to output solid impurities; the second separator gas outlet is used to output a fourth arsenic-containing gas; and,

[0027] A condensation chamber, comprising a condensation inlet, a condensation solid outlet and a condensation gas outlet; the condensation inlet is connected to the gas outlet of the second separator; the condensation solid outlet is used to output refined white arsenic; the condensation gas outlet is used to output waste gas;

[0028] The method for preparing metallic arsenic with a composite reducing agent also includes the following steps:

[0029] S14, the second high-temperature gas-solid separator obtains the zinc-arsenic containing gas, and inputs it into the second high-temperature gas-solid separator through the second separator inlet, the second high-temperature gas-solid separator performs high-temperature filtration on the zinc-arsenic containing gas, outputs solid impurities through the second separator solid outlet, and outputs the fourth arsenic containing gas through the second separator gas outlet; and,

[0030] S15, the condensation chamber obtains the fourth arsenic-containing gas and inputs it into the condensation chamber through the condensation inlet, the condensation chamber cools down and condenses the fourth arsenic-containing gas, outputs refined white arsenic through the condensed solid outlet, and outputs waste gas through the condensed gas outlet.

[0031] In the method for preparing metallic arsenic using a composite reducing agent of the present invention, in the elemental arsenic collecting device, the tank gas outlet is connected to the condensation inlet;

[0032] Step S16 also includes that the condensation chamber obtains the third arsenic-containing gas and inputs it into the condensation chamber through the condensation inlet, the condensation chamber cools and condenses the third arsenic-containing gas, outputs refined white arsenic through the condensed solid outlet, and outputs waste gas through the condensed gas outlet.

[0033] In the method for preparing metallic arsenic with a composite reducing agent of the present invention, in the equipment for preparing metallic arsenic with a composite reducing agent, the tank gas outlet is connected to the first furnace gas inlet;

[0034] The method for preparing metallic arsenic with a composite reducing agent further includes step S16, wherein the first reduction furnace obtains a third arsenic-containing gas and inputs the third arsenic-containing gas into the first reduction furnace through the first furnace gas inlet.

[0035] In the method for preparing metallic arsenic with a composite reducing agent of the present invention, in the equipment for preparing metallic arsenic with a composite reducing agent, the first reduction furnace is further provided with a first furnace nitrogen inlet for inputting nitrogen; the second reduction furnace is further provided with a second furnace nitrogen inlet for inputting nitrogen;

[0036] Step S11 also includes: the first reduction furnace obtains nitrogen and inputs the nitrogen into the first reduction furnace through the first furnace nitrogen inlet;

[0037] Step S13 also includes that the second reduction furnace obtains nitrogen and inputs the nitrogen into the second reduction furnace through the second furnace nitrogen inlet.

[0038] Compared with the prior art, the present invention has the following beneficial effects: the method for preparing metallic arsenic using a composite reducing agent of the present invention, by inputting zinc-containing carbon tailings into a second reduction furnace, causes zinc oxide and carbon powder to react to generate gaseous zinc, and the zinc-arsenic gas is input into a first reduction furnace, and the zinc in the zinc-arsenic gas can continue to be used as a reducing agent, thereby recycling the zinc and reducing the consumption of zinc, and the arsenic trioxide in the zinc-arsenic gas can also continue to be reduced, thereby saving the cost of raw materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. The drawings described below are only drawings corresponding to some embodiments of the present invention.

[0040] Figure 1 The main flow chart of the method for preparing metallic arsenic using a composite reducing agent provided in the first preferred embodiment of the present invention.

[0041] Figure 2 This is a schematic structural diagram of a device for preparing metallic arsenic using a composite reducing agent according to a first preferred embodiment of the present invention.

[0042] Figure 3 This is a schematic structural diagram of a device for preparing metallic arsenic using a composite reducing agent according to a second preferred embodiment of the present invention.

[0043] in,

[0044] 11. First reduction furnace, 111. First furnace material inlet, 112. First furnace gas inlet, 113. First furnace tailings outlet, 114. First furnace gas outlet, 115. First furnace nitrogen inlet,

[0045] 12. Arsenic collection device,

[0046] 121, a first high-temperature gas-solid separator, 1211, a first separator inlet, 1212, a first separator gas outlet, 1213, a first separator solid outlet,

[0047] 122, crystallization tank, 1221, tank gas inlet, 1222, tank gas outlet, 1223, tank solid outlet,

[0048] 13. Second reduction furnace, 131. Second furnace material inlet, 132. Second furnace gas main outlet, 133. Second furnace gas secondary outlet, 134. Second furnace tailings outlet, 135. Second furnace nitrogen inlet,

[0049] 141, a second high-temperature gas-solid separator, 1411, a second separator inlet, 1412, a second separator gas outlet, 1413, a second separator solid outlet,

[0050] 142. Condensation chamber, 1421. Condensation inlet, 1422. Condensation solid outlet, 1423. Condensation gas outlet.

[0051] In the figures, structurally similar elements are denoted by the same reference numerals. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0053] The directional terms mentioned in the present invention, such as "up", "down", "front", "back", "left", "right", "inside", "outside", "side", "top" and "bottom", are only for reference to the orientation of the drawings. The directional terms used are used to illustrate and understand the present invention, but not to limit the present invention.

[0054] The terms "first", "second", etc. in the present invention are used for descriptive purposes only and should not be understood as indicating or implying relative importance, and should not be used as a limitation on the order of precedence.

[0055] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] Arsenic is a non-metallic element existing in nature and is widely used in alloy smelting, pesticides, medicines, pigments and other industrial fields. Refined white arsenic is highly toxic, and its main component is arsenic trioxide, which is often used as a raw material for preparing elemental arsenic in industrial production. In the prior art, arsenic is generally prepared by carbon thermal reduction. The equipment for preparing metallic arsenic mainly includes a reduction furnace and a crystallizer. The reducing agent carbon powder and refined white arsenic are mixed, and the two are heated in the reduction furnace to obtain gaseous arsenic, and then collected by a crystallizer to obtain solid elemental arsenic. In order to increase the speed of preparing metallic arsenic, a composite reducing agent, namely carbon powder and zinc powder, can be used. However, the method for preparing metallic arsenic has a large consumption of zinc powder and a high cost.

[0057] The following is a preferred embodiment of a method for preparing metallic arsenic using a composite reducing agent provided by the present invention that can solve the above technical problems.

[0058] Please refer to Figure 1 and Figure 2 , a preferred embodiment of the present invention provides a method for preparing metallic arsenic with a composite reducing agent, which adopts a composite reducing agent to prepare metallic arsenic equipment for treatment. The composite reducing agent to prepare metallic arsenic equipment includes a first reduction furnace 11, a single arsenic collection device 12, and a second reduction furnace 13. The first reduction furnace 11 is provided with a first furnace material inlet 111, a first furnace gas inlet 112, a first furnace tailings outlet 113, and a first furnace gas outlet 114. The first furnace material inlet 111 is used to input refined white arsenic, zinc powder, and carbon powder. The first furnace tailings outlet 113 is used to output zinc-carbon tailings. The first furnace gas outlet 114 is used to output the first arsenic-containing gas. The main reaction chemical formula of the material in the first reduction furnace 11 is:

[0059] 2As2O3+Zn+3C=CO(g)+2CO2(g)+ZnO(s)+As4(g)

[0060] 2As2O3(s)+6C=As4(g)+6CO(g)

[0061] 2As2O3(s)+6CO(g)=As4(g)+6CO2(g)

[0062] Among them, s represents solid state and g represents gas state.

[0063] The elemental arsenic collecting device 12 is connected to the first furnace gas outlet 114 , and the elemental arsenic collecting device 12 is used to collect solid elemental arsenic.

[0064] The second reduction furnace 13 is provided with a second furnace material inlet 131, a second furnace gas main outlet 132, a second furnace gas secondary outlet 133, and a second furnace tailings outlet 134. The second furnace material inlet 131 is connected to the first furnace tailings outlet 113. The second furnace gas main outlet 132 is used to output zinc-arsenic gas, and the second furnace gas main outlet 132 is connected to the first furnace gas inlet 112. The second furnace gas secondary outlet 133 is used to output zinc-arsenic gas. The second furnace tailings outlet 134 is used to output solid tailings. The main reaction chemical formula of the material in the second reduction furnace 13 is:

[0065] ZnO+C=Zn(g)+CO(g)

[0066] ZnO+CO (g) = Zn(g)+CO2 (g)

[0067] Among them, s represents solid state and g represents gas state.

[0068] The method for preparing metallic arsenic using a composite reducing agent comprises the following steps:

[0069] S11, the first reduction furnace 11 obtains refined white arsenic, zinc powder and carbon powder, and inputs them into the first reduction furnace 11 through the first furnace material inlet 111, heats the refined white arsenic, zinc powder and carbon powder, outputs the first arsenic-containing gas through the first furnace gas outlet 114, and outputs the zinc-containing carbon tailings through the first furnace tailings outlet 113;

[0070] S12, the elemental arsenic collecting device 12 obtains the first arsenic-containing gas and outputs solid elemental arsenic; and,

[0071] S13, the second reduction furnace 13 obtains zinc-containing carbon tailings, and inputs them into the second reduction furnace 13 through the second furnace material inlet 131, heats the zinc-containing carbon tailings, outputs zinc-arsenic gas through the second furnace gas main outlet 132 and the second furnace gas secondary outlet 133, and outputs solid tailings through the second furnace tailings outlet 134;

[0072] Wherein, step S11 further includes that the first reduction furnace 11 obtains the zinc-arsenic containing gas and inputs the zinc-arsenic containing gas into the first reduction furnace 11 through the first furnace gas inlet 112 .

[0073] The composite reducing agent preparation method of the present invention is used to mix refined white arsenic, zinc powder and carbon powder and add them into the first reduction furnace 11 through the first furnace material inlet 111, and react at a certain temperature to generate gaseous single substance arsenic, solid zinc oxide and carbon dioxide, and also generate a small amount of zinc arsenate. In addition to gaseous single substance arsenic and carbon dioxide, the first arsenic-containing gas also contains a small amount of gaseous arsenic trioxide, zinc oxide powder and carbon powder. The first arsenic-containing gas is output through the first furnace gas outlet 114 and input into the single substance arsenic collecting device 12, and solid single substance arsenic can be collected. After the reaction is completed, a part of carbon powder and a small amount of unreacted solid arsenic trioxide will remain in the first reduction furnace 11, and the zinc-containing carbon tailings contain a small amount of solid arsenic trioxide and zinc arsenate in addition to zinc oxide and carbon powder.

[0074] The zinc-containing carbon tailings are output through the first furnace tailings outlet 113 and input into the second reduction furnace 13 through the second furnace material inlet 131. At a certain temperature, the zinc oxide and carbon powder in the zinc-containing carbon tailings react to generate gaseous zinc and carbon dioxide, and the solid arsenic trioxide becomes gaseous. Zinc arsenate remains in a solid state and is output together with other solid impurities through the second furnace tailings outlet 134. The zinc-containing arsenic gas contains gaseous zinc, carbon dioxide and a small amount of gaseous arsenic trioxide. The zinc-containing arsenic gas is output through the second furnace gas main outlet 132 and input into the first reduction furnace 11 through the first furnace gas inlet 112. The zinc in the zinc-containing arsenic gas can continue to be used as a reducing agent, and the zinc is recycled, which reduces the consumption of zinc. The arsenic trioxide in the zinc-containing arsenic gas can also continue to be reduced, saving the cost of raw materials.

[0075] In order to avoid excessive carbon dioxide concentration in the first reduction furnace 11, which leads to low carbon monoxide concentration and affects the reaction of carbon monoxide and arsenic trioxide, a small part of the zinc-arsenic gas can also be discharged through the second furnace gas auxiliary outlet 133. Or when the treatment is completed, the first reduction furnace 11 no longer needs zinc, and the zinc-arsenic gas can be completely discharged through the second furnace gas auxiliary outlet 133.

[0076] Step 13 also includes that the ratio of the gas output from the second furnace gas main outlet 132 to the second furnace gas secondary outlet 133 is 8:2, which can not only keep the recycling rate of zinc at a high level, but also prevent the carbon dioxide concentration in the first reduction furnace 11 from being too high.

[0077] In step S11, the refined white arsenic, zinc powder and carbon powder added to the first reduction furnace 11 through the first furnace material inlet 111 for the first time are in a mass ratio of As2O3:C:Zn=10:12:20. This dosage can ensure that almost all of the arsenic trioxide in the first reduction furnace 11 is reduced, and almost all of the zinc is converted into zinc oxide and enters the second reduction furnace 13. After the reaction in the first reduction furnace 11 is completed, a portion of the carbon will enter the second reduction furnace 13, and the amount of this portion of carbon matches the amount of zinc oxide entering the second reduction furnace 13. The refined white arsenic, zinc powder and carbon powder added to the first reduction furnace 11 through the first furnace material inlet 111 are in a mass ratio of As2O3:C:Zn=10:12:4. The zinc input into the first reduction furnace 11 through the second furnace gas main outlet 132 accounts for 80% of the total amount, and the zinc discharged through the second furnace gas secondary outlet 133 accounts for 20% of the total amount, so 80% of the zinc can be recycled, and only 20% needs to be supplemented later.

[0078] In step S11, the temperature for heating the refined white arsenic, zinc powder and carbon powder is 800° C.-900° C., and the reaction time is 4 hours, so that the arsenic trioxide reduction reaction can be fully carried out.

[0079] In step S13, the temperature for heating the zinc-containing carbon tailings is 1100° C.-1200° C., and the reaction time is 1 h-2 h, so that the zinc oxide reduction reaction can be fully carried out.

[0080] The elemental arsenic collecting device 12 includes a first high-temperature gas-solid separator 121 and a crystallizer 122. The first high-temperature gas-solid separator 121 is provided with a first separator inlet 1211, a first separator gas outlet 1212 and a first separator solid outlet 1213. The first separator inlet 1211 is connected to the first furnace gas outlet 114. The first separator gas outlet 1212 is used to output the second arsenic-containing gas. The first separator solid outlet 1213 is used to output solid impurities. The crystallizer 122 is provided with a tank gas inlet 1221, a tank gas outlet 1222 and a tank solid outlet 1223. The tank gas inlet 1221 is connected to the first separator gas outlet 1212. The tank gas outlet 1222 is used to output the third arsenic-containing gas. The tank solid outlet 1223 is used to output solid elemental arsenic. The temperature of the first high-temperature gas-solid separator 121 can be set to 400°C-500°C, and the temperature of the crystallizer 122 can be set to 400°C-450°C.

[0081] Step S12 includes the steps of:

[0082] S121, the first high-temperature gas-solid separator 121 obtains the first arsenic-containing gas, and inputs it into the first high-temperature gas-solid separator 121 through the first separator inlet 1211, the first high-temperature gas-solid separator 121 performs high-temperature filtration on the first arsenic-containing gas, outputs the second arsenic-containing gas through the first separator gas outlet 1212, and outputs the solid impurities through the first separator solid outlet 1213; and,

[0083] S122, the crystallization tank 122 obtains the second arsenic-containing gas and inputs it into the crystallization tank 122 through the tank gas inlet 1221, the crystallization tank 122 cools the second arsenic-containing gas, outputs the third arsenic-containing gas through the tank gas outlet 1222, and outputs solid elemental arsenic through the tank solid outlet 1223.

[0084] After the first arsenic-containing gas enters the first high-temperature gas-solid separator 121, the elemental arsenic, arsenic trioxide and carbon dioxide remain in a gaseous state at a high temperature. The solid impurities (solid zinc oxide, dust, zinc powder and carbon powder) in the first arsenic-containing gas can be filtered out by the first high-temperature gas-solid separator 121, and the gas is converted into a second arsenic-containing gas containing elemental arsenic, arsenic trioxide and carbon dioxide but without solid impurities. Then, the second arsenic-containing gas is cooled at a certain temperature by the crystallization tank 122, so that most of the elemental arsenic becomes solid, while arsenic trioxide and carbon dioxide remain in a gaseous state, forming a third arsenic-containing gas, and solid elemental arsenic can be collected. The elemental arsenic collected by the above structure has a purity of up to 99%.

[0085] The composite reducing agent for preparing metallic arsenic equipment also includes a second high-temperature gas-solid separator 141 and a condensation chamber 142. The second high-temperature gas-solid separator 141 is provided with a second separator inlet 1411, a second separator gas outlet 1412 and a second separator solid outlet 1413. The second separator inlet 1411 is connected to the second furnace gas auxiliary outlet 133. The second separator solid outlet 1413 is used to output solid impurities. The second separator gas outlet 1412 is used to output the fourth arsenic-containing gas. The condensation chamber 142 includes a condensation inlet 1421, a condensation solid outlet 1422 and a condensation gas outlet 1423. The condensation inlet 1421 is connected to the second separator gas outlet 1412. The condensation solid outlet 1422 is used to output refined white arsenic. The condensation gas outlet 1423 is used to output waste gas. The temperature of the second high-temperature gas-solid separator 141 can be set to 400°C-500°C, and the temperature of the condensation chamber 142 can be set to 120°C-300°C.

[0086] The method for preparing metallic arsenic using a composite reducing agent also includes the following steps:

[0087] S14, the second high-temperature gas-solid separator 141 obtains the zinc-arsenic-containing gas, and inputs it into the second high-temperature gas-solid separation through the second separator inlet 1411, the second high-temperature gas-solid separation performs high-temperature filtration on the zinc-arsenic-containing gas, outputs solid impurities through the second separator solid outlet 1413, and outputs the fourth arsenic-containing gas through the second separator gas outlet 1412; and,

[0088] S15, the condensation chamber 142 obtains the fourth arsenic-containing gas and inputs it into the condensation chamber 142 through the condensation inlet 1421. The condensation chamber 142 cools and condenses the fourth arsenic-containing gas, outputs refined white arsenic through the condensation solid outlet 1422, and outputs waste gas through the condensation gas outlet 1423.

[0089] After the zinc-arsenic gas enters the second high-temperature gas-solid separator 141, arsenic trioxide and carbon dioxide remain in a gaseous state at high temperature. The solid impurities (solid zinc oxide, dust, liquid zinc containing dust, and carbon powder) in the zinc-arsenic gas can be filtered out through the second high-temperature gas-solid separator 141, and the zinc-arsenic gas is converted into a fourth arsenic-containing gas containing arsenic trioxide and carbon dioxide but without solid impurities. The fourth arsenic-containing gas is then cooled at a certain temperature through the condensation chamber 142, so that most of the arsenic trioxide becomes solid, while the carbon dioxide remains in a gaseous state. Refined white arsenic with higher purity can be collected and can be subsequently added to the first reduction furnace 11 to improve resource utilization.

[0090] In the composite reducing agent preparation metal arsenic device, the tank gas outlet 1222 is connected to the condensation inlet 1421.

[0091] Step S16 also includes that the condensation chamber 142 obtains the third arsenic-containing gas and inputs it into the condensation chamber 142 through the condensation inlet 1421. The condensation chamber 142 cools and condenses the third arsenic-containing gas, outputs refined white arsenic through the condensation solid outlet 1422, and outputs waste gas through the condensation gas outlet 1423. The third arsenic-containing gas outputted from the tank gas outlet 1222 still contains a small amount of gaseous arsenic trioxide, which is inputted into the crystallization tank 122 through the condensation inlet 1421, and refined white arsenic can be continuously recovered, thereby improving the utilization rate of resources.

[0092] In the equipment for preparing metallic arsenic using a composite reducing agent, the first reduction furnace 11 is further provided with a first furnace nitrogen inlet 115 for inputting nitrogen; the second reduction furnace 13 is further provided with a second furnace nitrogen inlet 135 for inputting nitrogen.

[0093] Step S11 also includes that the first reduction furnace 11 obtains nitrogen and inputs it into the first reduction furnace 11 through the first furnace nitrogen inlet 115, so that the first reduction furnace 11 is close to an oxygen-free atmosphere to prevent oxygen and carbon monoxide from reacting and causing an explosion.

[0094] Step S13 also includes that the second reduction furnace 13 obtains nitrogen and inputs it into the second reduction furnace 13 through the second furnace nitrogen inlet 135, so that the second reduction furnace 13 is close to an oxygen-free atmosphere to prevent oxygen and carbon monoxide from reacting and causing an explosion.

[0095] The method for preparing metallic arsenic with a composite reducing agent according to the first preferred embodiment of the present invention:

[0096] The refined white arsenic, zinc powder and carbon powder are input into the first reduction furnace 11, and nitrogen is input into the first reduction furnace 11 to heat the refined white arsenic, zinc powder and carbon powder at a temperature of 800°C-900°C and a reaction time of 4 hours to generate gaseous elemental arsenic, solid zinc oxide and carbon dioxide. In addition to gaseous elemental arsenic and carbon dioxide, the first arsenic-containing gas also contains a small amount of gaseous arsenic trioxide, zinc oxide powder and carbon powder. In addition to zinc oxide and carbon powder, the zinc-containing carbon tailings also contain a small amount of solid arsenic trioxide and zinc arsenate. The first arsenic-containing gas and the zinc-containing carbon tailings are output separately.

[0097] The zinc-containing carbon tailings are input into the second reduction furnace 13, and nitrogen is input into the second reduction furnace 13 to heat the zinc-containing carbon tailings at a temperature of 1100°C-1200°C for a reaction time of 1h-2h to generate gaseous zinc and carbon dioxide, and solid arsenic trioxide becomes gaseous. The zinc-containing arsenic gas contains gaseous zinc, carbon dioxide and a small amount of gaseous arsenic trioxide. The solid tailings contain zinc arsenate and other solid impurities. The zinc-containing arsenic gas is output through the second furnace gas main outlet 132 and the second furnace gas secondary outlet 133, and the solid tailings are output separately.

[0098] Part of the zinc-arsenic containing gas is fed into the first reduction furnace 11 so that zinc continues to be used as a reducing agent, thereby allowing zinc to be recycled.

[0099] The first arsenic-containing gas is input into the first high-temperature gas-solid separator 121, and the first arsenic-containing gas is filtered at high temperature in the first high-temperature gas-solid separator 121. Elemental arsenic, arsenic trioxide, and carbon dioxide remain in a gaseous state at high temperature, and solid impurities (solid zinc oxide, dust, zinc powder, and carbon powder) in the first arsenic-containing gas can be filtered out by the first high-temperature gas-solid separator 121 to become a second arsenic-containing gas containing elemental arsenic, arsenic trioxide, and carbon dioxide, but without solid impurities. The second arsenic-containing gas and solid impurities are output separately.

[0100] The second arsenic-containing gas is input into the crystallizer 122, which cools the second arsenic-containing gas so that most of the elemental arsenic becomes solid, while arsenic trioxide and carbon dioxide remain in gaseous state to form a third arsenic-containing gas. The third arsenic-containing gas and solid elemental arsenic are output separately.

[0101] Part of the zinc-arsenic containing gas is input into the second high-temperature gas-solid separator 141, and the second high-temperature gas-solid separator 141 performs high-temperature filtration on the zinc-arsenic containing gas, filters out solid impurities (solid zinc oxide, dust, liquid zinc containing dust, and carbon powder) in the zinc-arsenic containing gas, and converts it into a fourth arsenic-containing gas containing arsenic trioxide and carbon dioxide but without solid impurities, and outputs the solid impurities and the fourth arsenic-containing gas separately.

[0102] The third arsenic-containing gas and the fourth arsenic-containing gas are input into the condensation chamber 142, which cools and condenses the third arsenic-containing gas and the fourth arsenic-containing gas, so that most of the arsenic trioxide becomes solid, while the carbon dioxide remains in gaseous state, and the refined white arsenic and waste gas are output respectively.

[0103] This completes the process of preparing metallic arsenic using the composite reducing agent of this preferred embodiment.

[0104] Please refer to Figure 3 , which is a composite reducing agent preparation metal arsenic equipment used in the composite reducing agent preparation metal arsenic method provided in the second preferred embodiment of the present invention. The difference between this embodiment and the first embodiment is that in the elemental arsenic collection device 12, the tank gas outlet 1222 is connected to the first furnace gas inlet 112, and is not connected to the condensation inlet 1421.

[0105] The method for preparing metallic arsenic with a composite reducing agent also includes step S16, the first reduction furnace 11 obtains a third arsenic-containing gas, and inputs it into the first reduction furnace 11 through the first furnace gas inlet 112. Compared with the first embodiment, the third arsenic-containing gas containing arsenic trioxide is directly introduced into the first reduction furnace 11, which can accelerate the reaction speed, and there is no endothermic process from solid to gas. The other steps of this embodiment are similar to those of the first embodiment and are not repeated here.

[0106] The composite reducing agent method for preparing metallic arsenic of the present invention comprises the following steps: inputting zinc-containing carbon tailings into a second reduction furnace, causing zinc oxide and carbon powder to react to generate gaseous zinc; the zinc-containing arsenic gas is input into a first reduction furnace; the zinc in the zinc-containing arsenic gas can continue to be used as a reducing agent, and the zinc is recycled, thereby reducing the consumption of zinc; and the arsenic trioxide in the zinc-containing arsenic gas can continue to be reduced, thereby saving the cost of raw materials.

[0107] To sum up, although the present invention has been disclosed as above in the form of preferred embodiments, the protection scope of the present invention is not limited thereto, and any technician familiar with the technical field can make equivalent substitutions or changes according to the concept of the technical solution of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing metallic arsenic using a composite reducing agent, characterized in that: The composite reducing agent is used to prepare metal arsenic equipment for treatment, and the refined white arsenic is reduced by zinc powder and carbon powder. The composite reducing agent is used to prepare metal arsenic equipment, which includes: The first reduction furnace is provided with a first furnace material inlet, a first furnace gas inlet, a first furnace tailings outlet and a first furnace gas outlet; the first furnace material inlet is used to input refined white arsenic, zinc powder and carbon powder; the first furnace tailings outlet is used to output zinc-containing carbon tailings; the first furnace gas outlet is used to output the first arsenic-containing gas; an elemental arsenic collecting device connected to the first furnace gas outlet, the elemental arsenic collecting device being used to collect solid elemental arsenic; and, The second reduction furnace is provided with a second furnace material inlet, a second furnace gas main outlet, a second furnace gas secondary outlet and a second furnace tailings outlet; the second furnace material inlet is connected to the first furnace tailings outlet; the second furnace gas main outlet is used to output zinc-arsenic gas, and the second furnace gas main outlet is connected to the first furnace gas inlet; the second furnace gas secondary outlet is used to output zinc-arsenic gas; the second furnace tailings outlet is used to output solid tailings; The method for preparing metallic arsenic with a composite reducing agent comprises the following steps: S11, the first reduction furnace obtains refined white arsenic, zinc powder and carbon powder, and inputs them into the first reduction furnace through the first furnace material inlet, heats the refined white arsenic, zinc powder and carbon powder, outputs the first arsenic-containing gas through the first furnace gas outlet, and outputs the zinc-containing carbon tailings through the first furnace tailings outlet; S12, the elemental arsenic collection device obtains the first arsenic-containing gas and outputs solid elemental arsenic; and, S13, the second reduction furnace obtains zinc-containing carbon tailings, and inputs the zinc-containing carbon tailings into the second reduction furnace through the second furnace material inlet, heats the zinc-containing carbon tailings, outputs zinc-arsenic gas through the second furnace gas main outlet and the second furnace gas secondary outlet, and outputs solid tailings through the second furnace tailings outlet; Wherein, step S11 also includes that the first reduction furnace obtains zinc-arsenic containing gas and inputs the gas into the first reduction furnace through the first furnace gas inlet.

2. The method for preparing metallic arsenic using a composite reducing agent according to claim 1, characterized in that: Step 13 also includes that the ratio of the gas output from the second furnace gas main outlet and the second furnace gas secondary outlet is 8:

2.

3. The method for preparing metallic arsenic using a composite reducing agent according to claim 2, characterized in that: In step S11, the refined white arsenic, zinc powder and carbon powder initially added to the first reduction furnace through the first furnace material inlet are in a mass ratio of As2O3:C:Zn=10:12:20, and the refined white arsenic, zinc powder and carbon powder subsequently added to the first reduction furnace through the first furnace material inlet are in a mass ratio of As2O3:C:Zn=10:12:

4.

4. The method for preparing metallic arsenic using a composite reducing agent according to claim 1, characterized in that: In step S11, the temperature for heating the refined white arsenic, zinc powder and carbon powder is 800° C.-900° C., and the reaction time is 4 hours.

5. The method for preparing metallic arsenic using a composite reducing agent according to claim 1, characterized in that: In step S13, the temperature for heating the zinc-containing carbon tailings is 1100° C.-1200° C., and the reaction time is 1 h-2 h.

6. The method for preparing metallic arsenic using a composite reducing agent according to claim 1, characterized in that: The elemental arsenic collection device comprises: A first high-temperature gas-solid separator is provided with a first separator inlet, a first separator gas outlet and a first separator solid outlet; the first separator inlet is connected to the first furnace gas outlet; the first separator gas outlet is used to output the second arsenic-containing gas; the first separator solid outlet outputs solid impurities; and, A crystallization tank is provided with a tank gas inlet, a tank gas outlet and a tank solid outlet; the tank gas inlet is connected to the first separator gas outlet; the tank gas outlet is used to output the third arsenic-containing gas; the tank solid outlet is used to output solid elemental arsenic; Step S12 includes the steps of: S121, the first high-temperature gas-solid separator obtains a first arsenic-containing gas, and inputs the first high-temperature gas-solid separator through the first separator inlet, the first high-temperature gas-solid separator performs high-temperature filtration on the first arsenic-containing gas, outputs a second arsenic-containing gas through the first separator gas outlet, and outputs solid impurities through the first separator solid outlet; and S122, the crystallization tank obtains the second arsenic-containing gas and inputs it into the crystallization tank through the tank gas inlet, the crystallization tank cools down the second arsenic-containing gas, outputs the third arsenic-containing gas through the tank gas outlet, and outputs solid elemental arsenic through the tank solid outlet.

7. The method for preparing metallic arsenic using a composite reducing agent according to claim 6, characterized in that: The composite reducing agent for preparing metallic arsenic equipment also includes: A second high-temperature gas-solid separator is provided with a second separator inlet, a second separator gas outlet and a second separator solid outlet; the second separator inlet is connected to the second furnace gas auxiliary outlet; the second separator solid outlet is used to output solid impurities; the second separator gas outlet is used to output a fourth arsenic-containing gas; and, A condensation chamber, comprising a condensation inlet, a condensation solid outlet and a condensation gas outlet; the condensation inlet is connected to the gas outlet of the second separator; the condensation solid outlet is used to output refined white arsenic; the condensation gas outlet is used to output waste gas; The method for preparing metallic arsenic with a composite reducing agent also includes the following steps: S14, the second high-temperature gas-solid separator obtains the zinc-arsenic containing gas, and inputs it into the second high-temperature gas-solid separator through the second separator inlet, the second high-temperature gas-solid separator performs high-temperature filtration on the zinc-arsenic containing gas, outputs solid impurities through the second separator solid outlet, and outputs the fourth arsenic containing gas through the second separator gas outlet; and, S15, the condensation chamber obtains the fourth arsenic-containing gas and inputs it into the condensation chamber through the condensation inlet, the condensation chamber cools down and condenses the fourth arsenic-containing gas, outputs refined white arsenic through the condensed solid outlet, and outputs waste gas through the condensed gas outlet.

8. The method for preparing metallic arsenic using a composite reducing agent according to claim 7, characterized in that: In the elemental arsenic collection device, the tank gas outlet is connected to the condensation inlet; Step S16 also includes that the condensation chamber obtains the third arsenic-containing gas and inputs it into the condensation chamber through the condensation inlet, the condensation chamber cools and condenses the third arsenic-containing gas, outputs refined white arsenic through the condensed solid outlet, and outputs waste gas through the condensed gas outlet.

9. The method for preparing metallic arsenic using a composite reducing agent according to claim 6, characterized in that: In the composite reducing agent preparation of metallic arsenic equipment, the tank gas outlet is connected to the first furnace gas inlet; The method for preparing metallic arsenic with a composite reducing agent further includes step S16, wherein the first reduction furnace obtains a third arsenic-containing gas and inputs the third arsenic-containing gas into the first reduction furnace through the first furnace gas inlet.

10. The method for preparing metallic arsenic using a composite reducing agent according to claim 1, characterized in that: In the composite reducing agent preparation of metallic arsenic equipment, the first reduction furnace is also provided with a first furnace nitrogen inlet for inputting nitrogen; the second reduction furnace is also provided with a second furnace nitrogen inlet for inputting nitrogen; Step S11 also includes: the first reduction furnace obtains nitrogen and inputs the nitrogen into the first reduction furnace through the first furnace nitrogen inlet; Step S13 also includes that the second reduction furnace obtains nitrogen and inputs the nitrogen into the second reduction furnace through the second furnace nitrogen inlet.

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