CN106801145A - A kind of dearsenification from arsenic-containing smoke dust and its method for solidification - Google Patents

Abstract

The invention relates to a method for removing arsenic from arsenic-containing dust and its solidification, including the comprehensive recovery of arsenic, antimony, lead, bismuth and other valuable metals from the smelting dust containing arsenic, antimony and lead, so as to reduce the accumulation of arsenic in the system and make the its harmless. The method provided by the present invention removes the soluble arsenic in the dust through normal pressure alkaline leaching, and after the trivalent arsenic in the leaching solution is catalyzed and oxidized to pentavalent arsenic, a stable arsenic-fixed mineral is synthesized by a controlled growth method, and then the method of stockpiling is adopted The arsenic-fixed minerals are solidified, and the leached slag undergoes washing, reduction smelting, oxidation blowing and other processes to maximize the recovery and utilization of various valuable elements. This method removes arsenic from the dust, and keeps antimony, lead, bismuth, etc. in the arsenic removal slag as much as possible, so that the separation of arsenic and valuable metals can be realized and made harmless. The invention has high resource comprehensive utilization rate, wide range of raw materials, and solves the pollution problem in the extraction process of the traditional process, especially the soot produced in the lead-zinc smelting process. The advantages of the method are more obvious.

Description

A method for removing arsenic from arsenic-containing smoke and its solidification

technical field

The invention belongs to the technical field of metallurgy, and in particular relates to a method for removing arsenic from arsenic-containing fume and solidifying it.

Background technique

In nature, arsenic is usually known as arsenopyrite (FeAsS), arsenopyrhotite (FeAsS ₂ ), arsenite (FeAs ₂ ), arsenite (Cu ₃ AsS ₃ ), realgar (As ₂ S ₃ ), Orpiment (As ₂ S ₃ ) and other minerals are enriched in non-ferrous metal ores such as copper, lead, zinc, nickel, cobalt, gold and silver; in the process of non-ferrous metallurgy, many high-arsenic solid materials are produced, such as roasting and smelting soot. These materials contain arsenic as high as 5-50%, and also contain a large amount of valuable metals, which are directly returned to the smelting process, resulting in the accumulation of arsenic in the system. Therefore, arsenic removal should usually be treated separately. Arsenic is a highly toxic and carcinogenic element, and its application is gradually shrinking. In the face of increasingly stringent environmental protection standards, how to deal with various high-arsenic materials has become a major problem that threatens the survival of the non-ferrous metallurgy industry.

At present, there are two main methods for dealing with arsenic-containing dust, one is fire separation, and the other is wet separation. In fire production, the difference in boiling point between arsenic oxides and other element oxides is mainly used to separate arsenic from other elements. CN103602835A discloses a displacement reduction method to obtain crude arsenic and crude antimony; _CN103602834A discloses a selective oxidation-reduction method to obtain As2O3 and crude antimony with low purity _; method, the purity of the obtained arsenic trioxide can reach more than 97.0%. However, if the soot contains metals (such as antimony) that are close to the properties of arsenic, the purity of the obtained arsenic trioxide is not high. There are three main processes in wet production: water leaching, acid leaching, and alkali leaching, but they can only obtain products such as arsenic trioxide and sodium arsenate with low purity, and no further research has been done on the recovery of valuable metal powder. CN105567983A discloses a water leaching-alkali leaching treatment process for copper smelting dust, which separates arsenic from metal, and the prepared arsenic product has no market, and the arsenic content in the leaching residue is still high. CN104357668A discloses a method of leaching smoke and dust with dirty acid, and removing arsenic by electrowinning, and arsine is easily produced during acid leaching and electrowinning. CN105648226A and CN105648227A disclose a method for separating arsenic and antimony by oxygen pressure alkaline leaching. The separation of arsenic and antimony is relatively thorough, but the sodium arsenate obtained in the process has not been treated, and valuable metals such as tellurium and antimony have not been recovered.

There are many research papers and related patent reports on the removal of arsenic from soot and the extraction of valuable metals, but the comprehensive recovery rate of valuable elements is low, the market for arsenic products is limited, and there are potential safety hazards. Therefore, the prior art still needs to be improved and developed.

Contents of the invention

In order to solve the problems of arsenic removal from arsenic-containing fumes and comprehensive recovery of valuable metals, the present invention proposes a method for removing arsenic from arsenic-containing fumes and solidifying them. The invention has the advantages of environmental protection, economy, energy saving and high resource utilization rate, and realizes the harmlessness of arsenic.

The solution of the present invention is to remove the soluble arsenic in the dust through the leaching method of atmospheric alkaline leaching, and oxidize the trivalent arsenic to pentavalent arsenic by catalytic oxidation, and synthesize the highly stable solid Arsenic minerals and leaching slag undergo fluidized washing, reduction smelting, oxidation blowing and other processes, so that various valuable elements can be recycled. This method removes and solidifies arsenic from the dust, while antimony, lead, bismuth, tin, etc. remain in the arsenic removal slag as much as possible, so as to realize the separation of arsenic and valuable metals and make them harmless. The present invention has high resource comprehensive utilization rate, wide application range of raw materials, and solves the pollution problem in the extraction process of the traditional process, especially the smoke and dust produced in the lead-zinc smelting process. The advantages of the present invention are more obvious.

Specifically, the method provided by the invention comprises the following steps:

(1) Atmospheric pressure alkaline leaching: when the leaching temperature is from room temperature to 100°C, the time is 30 to 240 minutes, the volume-to-mass ratio of liquid to solid is 3:1 to 20:1 (ml:g), and the NaOH concentration is 0.1mol/L to Under the conditions of 6mol/L and a stirring speed of 50-1000r/min, carry out atmospheric pressure alkali leaching treatment on arsenic-containing fumes; filter to obtain leaching liquid and leaching residue; the liquid-solid volume-to-mass ratio refers to ml/g, NaOH solution The volume-mass ratio to the arsenic-containing dust;

(2) Catalytic oxidation of the leach solution: add an oxidizing gas and a catalyst to the leach solution to carry out a catalytic oxidation reaction, so that the arsenic in the arsenic-containing compound is oxidized to pentavalent, and the oxidized solution is obtained;

(3) Solidifying arsenic in the liquid after oxidation: solidifying the arsenic-containing compound in the liquid after oxidation by a controlled growth method to obtain arsenic-fixed minerals; and then further solidifying the arsenic-fixed minerals by means of stockpiling;

(4) Washing of leaching slag: the leaching slag obtained in step (1) is subjected to fluidized washing, so that the soluble arsenic content in the leaching slag is reduced to below 0.1%; after filtering, washing liquid and washing slag are obtained; the washing liquid returns The atmospheric pressure alkaline leaching process is used to prepare the solution;

(5) Recovery of valuable metals from slag washing: After drying the slag washing, add charcoal, coal and an appropriate amount of soda ash, and carry out reduction smelting in the reactor at 900-1200°C under the action of C and CO to form bubbles. slag, lead antimony alloy and soot;

Returning the soot to the reduction smelting or atmospheric alkaline leaching;

Send the foamed slag to lead smelting;

The lead-antimony alloy is oxidized and blown, and air is introduced under the condition of flame insulation at a temperature of 650-800°C to obtain antimony vapor, blowing slag and crude lead; the antimony vapor is oxidized to generate antimony trioxide as antimony white product; returning the blowing slag to the reduction smelting process; sending the crude lead to lead refining.

Use a large amount of heat generated by antimony oxidation to maintain the necessary temperature of the reactor and the temperature of the antimony liquid in the furnace; because the concentration of metal antimony on the surface of the melt is absolutely dominant, the property of metal antimony is more active than that of lead and bismuth, so that the antimony in the alloy liquid is oxidized into three The antimony oxide volatilizes into the dust, while the lead and bismuth remain in the lead at the bottom of the reactor, so that one furnace can be used for two purposes.

The arsenic-containing smoke and dust of the present invention contains the following elements: arsenic, antimony, lead, zinc, copper, tellurium, selenium, bismuth, tin; preferably, in terms of mass percentage, it contains: 1% to 60% of arsenic and 1% of antimony ～55%, lead 0.1%～35%, zinc 0.1%～30%, copper 0.1%～5%, tellurium 0.01%～3%, selenium 0.01%～3%, bismuth 0.01%～3%, tin 0.01%～ 1%.

The leaching described in step (1) is atmospheric pressure alkaline leaching, the NaOH concentration is controlled to be 0.1mol/L-6mol/L, the leaching temperature is room temperature-100°C, the time is 30-240min, and the volume-to-mass ratio of liquid to solid is 3:1 ～20:1(ml:g), the stirring speed is 50～1000r/min.

In step (2) of the present invention, in order to further ensure that the catalytic oxidation reaction can be fully carried out, arsenic is fully oxidized to pentavalent, the oxidizing gas is oxygen, air or oxygen-enriched air, and the flow rate of the oxidizing gas is preferably 1-20 L/min; the catalyst is KMnO ₄ , preferably the molar ratio of arsenic to manganese is 5:1-50:1; the catalytic oxidation temperature is preferably 30°C-120°C.

The regulation and growth method described in step (3) of the present invention is specifically: adjusting the pH value of the oxidized liquid to 1.5-3, adding ferrous salt solution while continuously feeding oxidative gas, at a temperature of 75° C. to 90° C. The reaction is carried out for 5h-24h under certain conditions, and at the same time, a neutralizing agent is added to control the reaction at a pH value of 1.5-3, so that Fe ³⁺ and AsO ₄ ^3- react to form highly stable arsenic-fixing minerals. Preferably, the flow rate of the oxidizing gas is 1-20 L/min; and/or, the molar ratio of the iron element in the ferrous salt solution to the arsenic element in the oxidized solution is 2-5.

The ferrous salt solution can be selected from at least one of ferrous sulfate solution, ferrous chloride solution or ferrous nitrate solution, preferably ferrous sulfate.

The adding speed of the ferrous salt solution is controlled at 3ml/min-20ml/min.

In the processing process of the growth regulation method, a certain concentration of alkaline neutralizer can be added, and the alkaline neutralizer can be selected from at least one of sodium carbonate, sodium bicarbonate or sodium hydroxide, preferably bicarbonate sodium. The adding rate of the alkaline neutralizing agent can be added according to the rate of H ⁺ generated by the reaction to keep the pH value of the system constant during the reaction process. Preferably, the adding rate of the neutralizing agent is controlled at 3ml/min-20ml/min. .

The fluidized washing in the step (4) of the present invention can be performed using a fluidized washing tower; preferably, the number of times of the washing is 2 to 3 times.

The reactors used in the reduction smelting and oxidative blowing described in step (5) of the present invention may specifically be blast furnaces, reverberatory furnaces, bottom-blown furnaces, side-blown furnaces or top-blown furnaces. In this step, charcoal, coal and a small amount of soda ash (Na ₂ CO ₃ ) are added after the slag is washed and dried. Sb, Pb, Bi and other oxides are also reduced under the conditions of 900-1200°C and C and CO. It enters the lead-antimony alloy in the form of simple substance; the ash content of coal and a small amount of arsenic, antimony, lead oxides react with soda ash to form multi-bubble light "bubble slag", which floats on the surface of the antimony liquid; after the reduction is completed, remove Foaming slag, under the condition of oxidative blowing temperature 650℃～800℃ flame insulation, blow the primary air into the antimony liquid to make the antimony volatilize and generate a large amount of antimony vapor, and at the same time pass secondary air into the reactor to oxidize the antimony vapor Generate antimony trioxide, use the large amount of heat generated by antimony oxidation to maintain the necessary temperature of the reactor and the temperature of the antimony liquid in the furnace; because the concentration of metal antimony on the surface of the melt is absolutely dominant, the property of metal antimony is more active than that of lead and bismuth, making the alloy liquid The antimony in the reactor is oxidized into antimony trioxide and volatilizes into the smoke, while the lead and bismuth are left in the lead at the bottom of the reactor, so that one furnace can be used for two purposes.

As a specific embodiment of the present invention, the mass percentage of arsenic in the arsenic-containing dust is 1% to 60%, the mass percentage of antimony is 1% to 55%, and the mass percentage of lead is 0.1% to 35%. The mass percentage content of zinc is 0.1% to 30%, the mass percentage content of copper is 0.1% to 5%, the mass percentage content of bismuth is 0.01% to 3%, and the mass percentage content of tin is 0.01% to 1%. Specifically, it includes the following steps (the process can be Refer to Figure 1):

(1) Atmospheric pressure alkaline leaching process, the leaching temperature is controlled at room temperature to 100°C, the time is 30 to 240 minutes, the liquid-solid volume-to-mass ratio is 3:1-20:1 (ml:g), and the NaOH concentration is 0.1mol/L ～6mol/L, and the stirring speed is 50～1000r/min; the liquid-solid volume-to-mass ratio refers to the volume-to-mass ratio of NaOH solution to arsenic-containing smoke in ml/g.

(2) Catalytic oxidation process, through catalytic oxidation, adding oxidizing gas and catalyst to convert most of As ³⁺ in the leachate into As ⁵⁺ , and the oxidized liquid enters the arsenic fixation process. The oxidizing gas is oxygen, air or oxygen-enriched air, and the catalyst is KMnO ₄ ; the gas flow rate of the oxidizing gas is controlled at 1-20L/min, the molar ratio of As/Mn is controlled at 5:1-50:1, and the catalytic oxidation system is controlled The temperature is controlled between 30°C and 120°C;

(3) The liquid-solid arsenic process after oxidation, the control condition is to adjust the pH value of the liquid after oxidation to 1.5-3, preferably 2, and then raise the temperature to 75-90°C after adjusting to a certain pH value, preferably 90°C After rising to a predetermined temperature, slowly add the ferrous salt solution into the arsenic-containing solution, and at the same time add a neutralizer to regulate the reaction at a pH value of 1.5 to 3, so that Fe ³⁺ and AsO ₄ ^3- react to form high stability arsenic-fixing mineral, and pass through oxidizing gas to oxidize Fe ²⁺ to Fe ³⁺ , the ferrous salt solution is at least one of ferrous sulfate solution, ferrous chloride solution or ferrous nitrate solution, preferably sulfuric acid Ferrous solution, neutralizing agent is at least one in sodium carbonate, sodium bicarbonate or sodium hydroxide, preferably sodium bicarbonate, the adding speed of ferrous salt solution is 3～20ml/min, the adding speed of neutralizing agent 3-20ml/min, oxidizing gas flow rate 1-20L/min, Fe/As molar ratio 1-5, preferably 2-3, reaction time 5-24h;

(4) The leaching slag washing process uses a fluidized washing tower to wash the leaching slag 2 to 3 times at room temperature, so that the content of soluble arsenic in the washing slag is <0.1%;

(5) Comprehensive recovery process of slag washing. After drying slag washing, add charcoal, coal and a small amount of soda ash (Na ₂ CO ₃ ), and oxidize Sb, Pb, Bi, etc. The substance is also reduced into a simple form and enters the lead-antimony alloy; the ash content of coal and a small amount of arsenic, antimony, lead oxides react with soda ash to form a multi-bubble light "foam slag", which floats on the surface of the antimony liquid; reduction After the completion, scrape out the bubble slag, and under the condition of the temperature of 650 ° C ~ 800 ° C under the condition of flame insulation, blow primary air into the antimony liquid to make the antimony volatilize and generate a large amount of antimony vapor, and at the same time, pass secondary air into the reactor to make the antimony Steam oxidation produces antimony trioxide, and the necessary temperature of the reactor and the temperature of the antimony liquid in the furnace are maintained by using a large amount of heat generated by antimony oxidation; since the concentration of metal antimony on the surface of the melt is absolutely dominant, the property of metal antimony is more active than that of lead and bismuth, so that The antimony in the alloy liquid is oxidized into antimony trioxide and volatilizes into the smoke dust, while the lead and bismuth remain in the lead at the bottom of the reactor, so that one furnace can be used for two purposes. The reactors used for reduction smelting and oxidation blowing can be blast furnaces, reverberatory furnaces, bottom-blown furnaces, side-blown furnaces or top-blown furnaces, preferably reverberatory furnaces or bottom-blown furnaces.

Compared with the prior art, the method provided by the invention has the following significant advantages:

First, the present invention adopts the method of normal pressure alkali leaching to remove most of the soluble arsenic in the arsenic dust, the arsenic content of the raw material after the arsenic removal is low, and valuable metals such as antimony, lead, bismuth can be comprehensively recovered, reducing the content of arsenic in the product;

Second, the present invention adopts a catalytic oxidation method to oxidize As ³⁺ into As ⁵⁺ , which solves the difficult problem of difficult oxidation of trivalent arsenic;

Third, on the basis of the prior art, the present invention changes the feeding method, accurately controls the pH value of the synthesis process, and adopts the regulated growth method to synthesize the arsenic-fixed minerals in a stable stockpile under a wide pH range of 2-11 and strong reducing conditions, so that As no longer migrates, it also makes the As in the smelting system have an ideal open path, which is a simple process, resource-saving, and environmentally friendly method;

Fourth, the present invention adopts fluidized washing to further reduce the content of arsenic in the leach slag, which can improve the quality of recycled products;

Fifth, the present invention adopts reduction smelting to recycle valuable metals to maximize the comprehensive recycling of metals.

In a word, the rational process collocation of the present invention and the condition parameters in each process are strictly controlled, so that arsenic can be safely disposed of, and valuable metals such as antimony, lead, and bismuth can be recovered and effectively utilized, achieving environmental protection, economy, energy saving, and high efficiency. The purpose of resource utilization is to realize the harmlessness of arsenic and maximize the utilization of resources. Since the separation of arsenic and other elements adopts a wet process to avoid the large-scale pollution caused by the fire method and the problem of low resource utilization, the whole process basically has no three wastes discharge, all resources are used with maximum efficiency, and the obtained products are all It is convenient for subsequent treatment and processing, so the present invention has the advantages of environmental protection, economy, energy saving and high resource utilization rate.

Description of drawings

Fig. 1 is a schematic flow chart of the method of the present invention.

detailed description

The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

Example 1

Taking arsenic-containing soot from a lead-zinc smelter in China as an example, the main components of the raw materials are Pb 5.26%, As 39.65%, Sn 0.5%, Sb 29.36%, Zn 0.12%, Se 0.04%.

Proceed as follows:

Weigh a certain amount of high arsenic and antimony fumes into the reaction kettle, and carry out the leaching experiment according to the liquid-solid volume mass ratio of 10:1, the stirring speed of 700r/min, the NaOH concentration of 1mol/L, the leaching temperature of 80°C, and the leaching time of 2h. After the leaching, the slurry was removed and separated by filtration. The arsenic leaching rate was 72.36%. The concentration of each element in the leach solution was Pb 86.00ppm, Se 1.80ppm, Zn 20ppm, Sb 1.36g/L, As 28.69g/L;

As ³⁺ is oxidized to As ⁵⁺ by catalytic oxidation method in the leach solution. The control conditions are as follows: the flow rate of oxygen is 5L/min, the molar ratio of As/Mn is controlled at 10:1, and the temperature of the catalytic oxidation system is controlled at 90°C. The results show that , the conversion rate of As ³⁺ is 98.45%;

The oxidized solution is synthesized with high-stable arsenic-fixing minerals by the controlled growth method. The controlled conditions are: adjust the pH value of the oxidized solution to 2, then raise the temperature to 90°C, and then mix the ferrous nitrate solution and sodium carbonate at the same time Slowly add to the arsenic-containing solution, and feed oxygen to oxidize Fe ²⁺ to Fe ³⁺ , the adding speed of ferrous nitrate solution is 5ml/min, the adding speed of sodium carbonate is 5ml/min, and the flow rate of oxygen is 10L/min. The Fe/As molar ratio is 2, and the reaction time is 12 hours to prepare highly stable arsenic-fixing minerals. The synthesized arsenic-fixing minerals meet the requirements of GB5085.3-2007 (Solid Waste Identification Standard-Leach Toxicity Identification) and can be safely stockpiled;

The leached slag was washed twice with a fluidized washing tower according to the liquid-solid volume mass ratio of 5:1, and the leached slag contained 0.1% of soluble arsenic;

Add charcoal, coal and soda ash after washing and drying the slag, and carry out reduction smelting in a reverberatory furnace at 1200°C to produce foam slag, lead-antimony alloy and smoke; The antimony alloy enters the oxidation blowing process; under the flame insulation condition of the oxidation blowing temperature of 700 ° C, the primary air is blown into the alloy, and the secondary air is passed into the reactor at the same time, so that the antimony vapor is oxidized to form antimony trioxide, which forms The antimony trioxide is used as the antimony white product; the blowing slag is returned to the reduction smelting system, and the crude lead after oxidation blowing is sent to the lead refining system; the lead-antimony alloy contains 24.38% of Pb, 70.46% of Sb, and 3.08% of As The generated antimony white powder conforms to the antimony white powder with the brand name Sb ₂ O ₃ 99.00 specified in GB/T 4062-2013; the crude lead contains 97.21% of Pb, 1.08% of Sb and 0.37% of As.

Example 2

Taking arsenic-containing soot from a lead-zinc smelter in China as an example, the main components of the raw materials are Pb 10.39%, As 34.59%, Sn 1.45%, Sb 20.54%, Zn 0.11%, and Se 0.24%.

Proceed as follows:

Weigh a certain amount of high arsenic and antimony fumes into the reactor, and carry out the leaching experiment according to the liquid-solid volume mass ratio of 10:1, stirring speed of 700r/min, NaOH concentration of 3mol/L, leaching temperature of 50°C, and leaching time of 4h. After leaching, remove the slurry and filter and separate, the arsenic leaching rate is 52.06%. The concentration of each element in the leach solution is Pb 87ppm, Se 0.52ppm, Zn 71ppm, Sb1.24g/L, As 18.01g/L;

The leaching solution is oxidized from As ³⁺ to As ⁵⁺ by catalytic oxidation method. The control conditions are as follows: the oxygen flow rate is 10L/min, the As/Mn molar ratio is controlled at 40:1, and the temperature of the catalytic oxidation system is controlled at 30°C. The results show that , the conversion rate of As ³⁺ is 92.31%;

The oxidized solution is synthesized with high-stable arsenic-fixing minerals by the controlled growth method. The controlled conditions are: adjust the pH value of the oxidized solution to 2.5, then raise the temperature to 100°C, and then mix the ferrous nitrate solution and sodium carbonate at the same time Slowly add to the arsenic-containing solution, and feed oxygen to oxidize Fe ²⁺ to Fe ³⁺ , the adding speed of ferrous nitrate solution is 6ml/min, the adding speed of sodium carbonate is 6ml/min, the oxygen flow rate is 20L/min, The Fe/As molar ratio is 4, and the reaction time is 12 hours to prepare high-stable arsenic-fixed minerals. The synthesized arsenic-fixed minerals meet the requirements of GB5085.3-2007 (identification standard for solid waste - leaching toxicity identification), and can be safely stockpiled;

The leached slag was washed twice with a fluidized washing tower according to the liquid-solid volume mass ratio of 5:1, and the leached slag contained 0.1% of soluble arsenic;

Add charcoal, coal and soda ash after washing and drying the slag, carry out reduction smelting in a reverberatory furnace at 1150°C, and smelt to generate foam slag, lead-antimony alloy and smoke; The antimony alloy enters the oxidation blowing process; under the flame insulation condition of the oxidation blowing temperature of 800°C, the primary air is blown into the alloy, and the secondary air is passed into the reactor at the same time, so that the antimony vapor is oxidized to form antimony trioxide, which forms The antimony trioxide is used as antimony white product; the blowing slag is returned to the reduction smelting system, and the crude lead after oxidation blowing is sent to the lead refining system; the lead-antimony alloy contains 29.36% of Pb, 63.89% of Sb, and 4.67% of As The generated antimony white powder conforms to the antimony white powder with the brand name Sb ₂ O ₃ 99.00 specified in GB/T 4062-2013; the crude lead contains 96.14% of Pb, 2.61% of Sb and 0.46% of As.

Example 3

Taking arsenic-containing soot from a lead-zinc smelter in China as an example, the main components of the raw materials are Pb 19.57%, As 24.26%, Sn 1.47%, Sb 30.45%, Zn 0.16%, and Se 0.21%.

Proceed as follows:

Weigh a certain amount of high arsenic and antimony fumes into the reactor, and carry out the leaching experiment according to the liquid-solid volume mass ratio of 5:1, stirring speed of 1000r/min, NaOH concentration of 1mol/L, leaching temperature of 30°C, and leaching time of 2h. After the leaching is completed, remove the slurry and filter and separate it. The arsenic leaching rate is 42.26%. The concentration of each element in the leach solution is Pb 124ppm, Se 0.67ppm, Zn 107ppm, Sb2.02g/L, As 10.25g/L;

The leaching solution is oxidized from As ³⁺ to As ⁵⁺ by catalytic oxidation method. The control conditions are as follows: the flow rate of oxygen is 1L/min, the molar ratio of As/Mn is controlled at 20:1, and the temperature of the catalytic oxidation system is controlled at 120°C. The results show that , the conversion rate of As ³⁺ is 89.36%;

The oxidized solution is synthesized with high-stable arsenic-fixing minerals by the controlled growth method. The controlled conditions are: adjust the pH value of the oxidized solution to 3, then raise the temperature to 100°C, and then mix the ferrous nitrate solution and sodium carbonate at the same time Slowly add to the arsenic-containing solution, and feed in oxygen to oxidize Fe ²⁺ to Fe ³⁺ , the adding speed of ferrous nitrate solution is 6ml/min, the adding speed of sodium carbonate is 5ml/min, and the flow rate of oxygen is 2L/min , the Fe/As molar ratio is 4, and the reaction time is 24 hours to prepare high-stable arsenic-fixing minerals. The synthesized arsenic-fixing minerals meet the requirements of GB5085.3-2007 (identification standard for solid waste - identification of leaching toxicity), and can be safely stockpiled;

The leached slag was washed twice with a fluidized washing tower according to the liquid-solid volume mass ratio of 5:1, and the leached slag contained 0.1% of soluble arsenic;

Add charcoal, coal and soda ash after washing and drying the slag, and carry out reduction smelting in a reverberatory furnace at 1200°C to produce foam slag, lead-antimony alloy and smoke; The antimony alloy enters the oxidation blowing process; under the condition of flame insulation at an oxidation blowing temperature of 650°C, the primary air is blown into the alloy, and the secondary air is passed into the reactor at the same time, so that the antimony vapor is oxidized to form antimony trioxide, which forms The antimony trioxide is used as the antimony white product; the blowing slag is returned to the reduction smelting system, and the crude lead after oxidation blowing is sent to the lead refining system; the lead-antimony alloy contains 27.89% of Pb, 66.96% of Sb, and 4.21% of As The generated antimony white powder conforms to the antimony white powder with the brand name Sb ₂ O ₃ 99.00 specified in GB/T 4062-2013; the crude lead contains 96.69% of Pb, 2.12% of Sb and 0.49% of As.

Although, the present invention has been described in detail with general description, specific implementation and test above, but on the basis of the present invention, some modifications or improvements can be made to it, which will be obvious to those skilled in the art . Therefore, the modifications or improvements made on the basis of not departing from the spirit of the present invention all belong to the protection scope of the present invention.

Claims (10)

1. a kind of method of dearsenification from arsenic-containing smoke dust and its solidification, it is characterised in that in the arsenic-containing smoke dust containing arsenic, antimony and Lead；The described method comprises the following steps：

(1) normal pressure alkali leaching：Extraction temperature be room temperature~100 DEG C, the time be 30~240min, liquid solid product mass ratio be 3:1 ~20:1st, NaOH concentration is 0.1mol/L~6mol/L, mixing speed to enter to arsenic-containing smoke dust under conditions of 50~1000r/min The leaching of row normal pressure alkali is processed；Filter to obtain leachate and leached mud；Liquid solid product mass ratio refer in terms of ml/g, NaOH solution with The volume mass ratio of arsenic-containing smoke dust；

(2) leachate catalysis oxidation：Oxidizing gas and catalyst are added in the leachate carries out catalytic oxidation, makes Arsenic in arsenical is oxidizing to pentavalent, obtains oxidated solution；

(3) the solid arsenic of oxidated solution：Use regulation and control growth method to solidify the arsenical in the oxidated solution in form, obtain Gu arsenic mineral；The solid arsenic mineral is further solidified using mode of storing up again；

(4) leached mud washing：By step (1) gained leached mud by fluidization wash, make the Soluble Arsenic content in leached mud It is down to less than 0.1%；After filtering, washing lotion and washery slag are obtained；The washing lotion returns to the dipped journey of normal pressure alkali；

(5) washery slag reclaims valuable metal：Charcoal, coal and appropriate soda ash are allocated into after the washery slag is dried, in 900 in reactor ~1200 DEG C, have under C, CO conditioning and carry out reduction melting, melting generation bubble slag, lead-antimony alloy and flue dust；

The flue dust is returned into the reduction melting or the leaching of normal pressure alkali；

Lead is sent to smelt the bubble slag；

The lead-antimony alloy is carried out into oxidation blowing, air is passed through under conditions of muffle, antimony vapour, blowing slag and thick is obtained Lead；By antimony vapour oxidation generation antimony oxide, as stibium trioxide product；The blowing slag is returned into reduction melting operation； Lead is sent to refine the lead bullion.

2. method according to claim 1, it is characterised in that following element is included in the arsenic-containing smoke dust：Arsenic, antimony, lead, Zinc, copper, tellurium, selenium, bismuth, tin；

Preferably, by percentage to the quality, comprising：Arsenic 1%~60%, antimony 1%~55%, lead 0.1%~35%, zinc 0.1% ~30%, copper 0.1%~5%, tellurium 0.01%~3%, selenium 0.01%~3%, bismuth 0.01%~3%, tin 0.01%~1%.

3. method according to claim 1 and 2, it is characterised in that step (1) the water logging extraction temperature be room temperature~ 100 DEG C, the time be 30~240min, liquid solid product mass ratio be 3:1~20:1(ml:G), NaOH concentration be 0.1mol/L~ 6mol/L, mixing speed are 50~1000r/min.

4. the method according to claims 1 to 3 any one, it is characterised in that step (2) described oxidizing gas are oxygen Gas, air or oxygen-enriched air, the flow of preferably described oxidizing gas is 1~20L/min；

And/or, the catalyst is KMnO₄, preferably arsenic element and the mol ratio of manganese element is 5:1~50:1.

5. the method according to claim 1 or 4, it is characterised in that the temperature of the catalysis oxidation is 30 DEG C~120 DEG C.

6. method according to claim 1, it is characterised in that step (3) the regulation and control growth method is specially：By the oxygen The pH value of liquid is adjusted to 1.5~3 after change, and ferrous salt solution is added while being continually fed into oxidizing gas, in temperature 75 DEG C~90 5h~24h is reacted under conditions of DEG C, while add nertralizer regulation and control to react being carried out under the conditions of pH value 1.5~3, makes Fe³⁺With AsO₄ ^3-The solid arsenic mineral of reaction generation high stability.

7. method according to claim 6, it is characterised in that be additionally added alkaline neutralization while adding ferrous salt solution Agent；The antalkali is preferably at least one in sodium carbonate, sodium acid carbonate or NaOH.

8. the method according to claim 6 or 7, it is characterised in that the flow for being passed through oxidizing gas is 1~20L/ min。

9. the method according to claim 6~8 any one, it is characterised in that in the heavy arsenic of the ferrous salt ferro element with The mol ratio of arsenic element is 2~5 in oxidated solution.

10. method according to claim 1, it is characterised in that step (4) described fluidization wash uses fluidization wash Tower is washed；It is preferred that the number of times of the washing is 2~3 times.