How to Choose Arsenic Reduction Furnace?

This series of patented equipment developed by our company in cooperation with Central South University is mainly adopted to treat arsenic alkali slag, arsenic filter cake, and other arsenic contented materials from copper smelter,lead smelter and zinc smelters. The main process is: hydrometallurgy + pyrometallurgy combined to turn the arsenic-containing hazardous wastes into pure arsenic trioxide, and then reduced to metallic arsenic, metallic arsenic can be sold according to local market demand or rigid landfill disposal. The main patented equipment of this process, As2O3 purification furnace and arsenic reduction furnace, is widely praised for its high level of environmental protection, high level of automation, and large treatment capacity during industrial application.

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Arsenic Reduction Furnace is a type of industrial equipment used in metallurgical processes to remove or reduce the arsenic content in ores, concentrates, or other materials. Arsenic is commonly found in copper, lead, and zinc ores and can pose environmental and health hazards if not properly managed. The reduction furnace typically uses high temperatures and specific reducing agents (such as carbon or hydrogen) to convert arsenic compounds (often in the form of arsenic oxide) into more stable or less toxic forms that can be safely captured or neutralized.

Key Components:

Reactor Chamber: The primary area where the thermal reduction process occurs.

Heat Source: Often electric or fuel-based, it provides the necessary temperature to initiate the reduction reactions.

Reducing Agent: Materials like carbon, hydrogen, or other chemicals that assist in breaking down arsenic compounds.

Scrubber or Filter System: Captures or neutralizes the arsenic gas or vapor produced during the process to prevent atmospheric release.

Applications:

Mining and Metallurgy: Commonly used in smelters where copper, lead, or zinc ores are processed, and arsenic is a byproduct.

Environmental Management: Helps reduce the risk of arsenic contamination in the environment by stabilizing arsenic compounds.

具体实施方式Detailed ways

下面对照附图对本发明同时实现脱砷及有价金属的直接还原进行举例说明。The simultaneous realization of arsenic removal and direct reduction of valuable metals in the present invention will be illustrated below with reference to the accompanying drawings.

根据本发明的一种直接还原过程中脱砷的方法包括以下步骤：A method for removing arsenic in a direct reduction process according to the present invention comprises the following steps:

（1）造球：对含砷物料进行研磨，加入还原剂以及粘结剂混匀、造球；（2）烘干：对造球步骤所得的球团进行烘干处理；（3）直接还原：将造球步骤所得的球团置于还原炉内加热至950℃-℃，保温0.5小时-6小时，控制炉内气氛，进行直接还原反应；其中，造球步骤中所得球团直径为1cm-2cm。(1) Pelletizing: Grinding the arsenic-containing material, adding reducing agent and binder, mixing, and pelletizing; (2) Drying: drying the pellets obtained in the pelletizing step; (3) Direct reduction : The pellets obtained in the pelletizing step are placed in a reduction furnace and heated to 950°C-°C, kept for 0.5-6 hours, and the atmosphere in the furnace is controlled to carry out direct reduction reaction; wherein, the diameter of the pellets obtained in the pelletizing step is 1cm-2cm.

在步骤（1）中，球团直径大约为1cm-2cm，如果球团直径小于1cm或大于2cm，则含砷物料与还原剂接触不充分，导致脱砷反应不完全。In step (1), the diameter of the pellets is about 1cm-2cm. If the diameter of the pellets is less than 1cm or greater than 2cm, the contact between the arsenic-containing material and the reducing agent is insufficient, resulting in incomplete arsenic removal reaction.

在步骤（3）中，球团的反应温度范围为950℃-℃，如果含砷物料、还原剂和粘结剂的球团被加热到的温度和/或保温温度低于950℃，则不进行还原反应或反应不完全，若含砷物料、还原剂和粘结剂的球团被加热到的温度和/或保温温度高于℃，则造成能源的浪费。In step (3), the reaction temperature of the pellets ranges from 950°C to °C. If the temperature to which the pellets containing arsenic, reducing agent and binder are heated and/or the holding temperature is lower than 950°C, then If the reduction reaction is not carried out or the reaction is incomplete, if the temperature to which the arsenic-containing material, reducing agent and binder pellets are heated and/or the holding temperature is higher than ° C., energy will be wasted.

在步骤（3）中，球团在还原炉内的保温时间为0.5小时-6小时，若保温时间低于0.5小时，则不进行还原反应或反应不完全，导致砷脱除率偏低，若保温时间高于6小时，则会造成能源的浪费。In step (3), the holding time of the pellets in the reduction furnace is 0.5 hours to 6 hours. If the holding time is less than 0.5 hours, the reduction reaction will not be carried out or the reaction will not be complete, resulting in a low arsenic removal rate. If If the heat preservation time is higher than 6 hours, energy will be wasted.

在直接还原的过程中，在脱砷同时，可以将含砷物料中的有价金属直接还原。In the process of direct reduction, the valuable metals in the arsenic-containing material can be directly reduced while removing arsenic.

根据本发明的一方面，该方法中含砷物料为含砷铁矿、含砷铜渣、含砷镍渣、含砷锰渣、含砷钛渣中的至少一种。根据含砷物料，控制炉内气氛为氧化性或还原性。According to one aspect of the present invention, the arsenic-containing material in the method is at least one of arsenic-containing iron ore, arsenic-containing copper slag, arsenic-containing nickel slag, arsenic-containing manganese slag, and arsenic-containing titanium slag. According to the material containing arsenic, the atmosphere in the furnace is controlled to be oxidizing or reducing.

根据本发明，含砷物料中的砷最终以气体形式存在，砷存在多个价态，含砷物料中As的存在形式不同，经直接还原后，As的存在形式也会出现差别，如As4O6气体或As蒸汽。因此，经直接还原后，气体形式的As与固态或液态的直接还原产物分开，从而实现脱砷的目的。According to the present invention, the arsenic in the arsenic-containing material finally exists in the form of gas, and there are multiple valence states of arsenic. The existence form of As in the arsenic-containing material is different. After direct reduction, the existence form of As will also be different, such as As 4 O 6 gas or As vapor. Therefore, after the direct reduction, the gaseous As is separated from the solid or liquid direct reduction products, thereby achieving the purpose of arsenic removal.

当含砷物料为高砷铁矿石时，As以FeAsO4形式存在，As为正五价，通入还原性气氛，从而发生还原反应，将高价态的砷还原为正三价砷，生成As4O6；当含砷物料为低砷铁矿石时，As以FeAsS形式存在，将炉内气氛控制为氧化性气氛，发生氧化反应，生成As4O6；当含砷物料为铜渣时，As以As2O5形式存在，将炉内气氛控制为还原性气氛，发生还原反应，生成As单质。例如，可以利用N2-CO气体将炉内气氛控制为还原性，可以利用N2-O2气体将炉内气氛控制为氧化性。最后，利用尾气处理装置对含砷尾气进行回收处理。When the arsenic-containing material is high-arsenic iron ore, As exists in the form of FeAsO 4 , and As is positive pentavalent, it is introduced into a reducing atmosphere, so that a reduction reaction occurs, and the high-valent arsenic is reduced to positive trivalent arsenic to generate As 4 O 6 ; when the arsenic-containing material is low-arsenic iron ore, As exists in the form of FeAsS, the atmosphere in the furnace is controlled to be an oxidizing atmosphere, and an oxidation reaction occurs to generate As 4 O 6 ; when the arsenic-containing material is copper slag, As exists in the form of As 2 O 5 , the atmosphere in the furnace is controlled to be a reducing atmosphere, and a reduction reaction occurs to generate As simple substance. For example, N 2 -CO gas can be used to control the furnace atmosphere to be reducing, and N 2 -O 2 gas can be used to control the furnace atmosphere to be oxidative. Finally, the arsenic-containing tail gas is recovered and treated by the tail gas treatment device.

含砷物料中的有价金属在固态还原剂（例如焦粉、煤粉、石油焦、沥青中的至少一种）的还原作用下，从高价态还原到单质态，最终实现了有价金属的回收利用。其中，还原剂的加入量的重量可以是含砷物料重量的10%-30%。Valuable metals in arsenic-containing materials are reduced from a high-valence state to a simple substance state under the reduction of a solid-state reducing agent (such as at least one of coke powder, coal powder, petroleum coke, and pitch), and finally realize the recovery of valuable metals. recycle and re-use. Wherein, the weight of the added amount of the reducing agent can be 10%-30% of the weight of the arsenic-containing material.

在造球的步骤中，可使用的粘结剂为水玻璃、糖浆、粘土、沥青等，其中，粘结剂加入的量的重量可以是含砷物料重量的5～10%。In the step of pelletizing, the binder that can be used is water glass, syrup, clay, asphalt, etc., wherein the weight of the binder can be 5-10% of the weight of the arsenic-containing material.

下面结合附图对根据本发明的一种直接还原过程中脱砷的方法进行举例说明。A method for removing arsenic in a direct reduction process according to the present invention will be illustrated below with reference to the accompanying drawings.

示例1Example 1

含砷物料为高砷铁矿石，TFe的重量百分比为46.70%，As的重量百分比为0.52%，其中As以FeAsO4形式存在。将其研磨制粉，选取100目以下高砷铁矿粉100g，配入20g煤粉混匀，加入8%粘结剂造球，含碳球团直径为1cm-2cm，将造好的球团置于200℃烘箱里，干燥4h以保证绝大部分游离水的脱除。干燥的含碳球团可放入还原炉内随炉升温到850℃，亦可在还原炉到达设定温度850℃后放入，在将球团放入还原炉内的同时通入N2-CO气体以控制炉内的气氛为还原性气氛，打开尾气处理装置以处理还原炉内排出的尾气。在850℃还原2h后取出直接还原后的金属化球团，水冷至常温，再放入200℃烘箱里干燥4h后取样分析。The arsenic-containing material is high-arsenic iron ore, the weight percentage of TFe is 46.70%, and the weight percentage of As is 0.52%, wherein As exists in the form of FeAsO 4 . Grind it to make powder, select 100g of high-arsenic iron ore powder below 100 mesh, mix it with 20g of coal powder, add 8% binder to make pellets, and the diameter of the carbon-containing pellets is 1cm-2cm. Place in an oven at 200°C and dry for 4 hours to ensure most of the free water is removed. The dry carbon-containing pellets can be put into the reduction furnace and the furnace temperature rises to 850°C, or it can be put in after the reduction furnace reaches the set temperature of 850°C, and N 2 - The CO gas is used to control the atmosphere in the furnace as a reducing atmosphere, and the tail gas treatment device is turned on to treat the tail gas discharged from the reduction furnace. After reduction at 850°C for 2 hours, the metallized pellets after direct reduction were taken out, cooled with water to room temperature, dried in an oven at 200°C for 4 hours, and then sampled for analysis.

其中，脱砷机理为：Among them, the mechanism of arsenic removal is:

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4FeAsO4(s)+4CO(g)=2Fe2O3(s)+4CO2(g)+As4O6(g)       (1)4FeAsO 4 (s)+4CO(g)=2Fe 2 O 3 (s)+4CO 2 (g)+As 4 O 6 (g) (1)

其中，铁直接还原机理为：Among them, the iron direct reduction mechanism is:

3Fe2O3(s)+CO(s)=CO2(g)+2Fe3O4(s)                 …(2)3Fe 2 O 3 (s)+CO(s)=CO 2 (g)+2Fe 3 O 4 (s) …(2)

Fe3O4(s)+CO(s)=CO2(g)+3FeO(s)                      (3)Fe 3 O 4 (s)+CO(s)=CO 2 (g)+3FeO(s) (3)

FeO(s)+CO(g)=CO2(g)+Fe(s)                      ……(4)FeO(s)+CO(g)=CO 2 (g)+Fe(s) ……(4)

CO2(g)+C(s)=2CO(g)                             ……(5)CO 2 (g)+C(s)=2CO(g)...(5)

其中，反应（5）中的C为煤粉。Wherein, C in reaction (5) is coal powder.

金属化球团的分析结果为：金属铁重量百分比为46%，砷重量百分比为0.012%。依此计算得到的球团铁金属化率为98.52%，砷脱除率为97.69%。Analysis of the metallized pellets showed 46% by weight metallic iron and 0.012% by weight arsenic. Based on this calculation, the iron metallization rate of the pellets is 98.52%, and the arsenic removal rate is 97.69%.

示例2Example 2

含砷物料为低砷铁矿石，TFe的重量百分比为61.78%，As的重量百分比为0.066%，其中As以FeAsS形式存在。将其研磨制粉，选取100目以下低砷铁矿粉100g，配入20g焦粉混匀，加入8%粘结剂造球，含碳球团直径为1cm-2cm，将造好的球团置于200℃烘箱里，干燥4h以保证绝大部分游离水的脱除。干燥的含碳球团可放入还原炉内随炉升温到℃，亦可在还原炉到达设定温度℃后放入，在将球团放入还原炉内的同时通入N2-O2气体以控制炉内的气氛为氧化性气氛，打开尾气处理装置以处理还原炉内排出的尾气。在℃还原3h后取出直接还原后的金属化球团，水冷至常温，再放入200℃烘箱里干燥4h后取样分析。The arsenic-containing material is low-arsenic iron ore, the weight percentage of TFe is 61.78%, and the weight percentage of As is 0.066%, wherein As exists in the form of FeAsS. Grind it to make powder, select 100g of low-arsenic iron ore powder below 100 mesh, add 20g of coke powder and mix evenly, add 8% binder to make pellets, the diameter of carbon-containing pellets is 1cm-2cm, and the prepared pellets Place in an oven at 200°C and dry for 4 hours to ensure most of the free water is removed. The dry carbon-containing pellets can be put into the reduction furnace and the furnace temperature rises to °C, or it can be put in after the reduction furnace reaches the set temperature of °C, and N 2 - O2 gas controls the atmosphere in the furnace as an oxidative atmosphere, and opens the tail gas treatment device to treat the tail gas discharged from the reduction furnace. After reduction at °C for 3 hours, the metallized pellets after direct reduction were taken out, cooled with water to room temperature, then placed in an oven at 200°C for 4 hours and then sampled for analysis.

其中，脱砷机理为：Among them, the mechanism of arsenic removal is:

4FeAsS(s)+10O2(g)=2Fe2O3(s)+As4O6(g)+4SO2(g)      …(6)4FeAsS(s)+10O 2 (g)=2Fe 2 O 3 (s)+As 4 O 6 (g)+4SO 2 (g) …(6)

铁直接还原机理如示例1中步骤（2）-（5）所示。The mechanism of iron direct reduction is shown in steps (2)-(5) in Example 1.

其中，在本例中，反应（5）中C为焦粉。Wherein, in this example, C in reaction (5) is coke powder.

金属化球团的分析结果为：金属铁重量百分比为58.89%，砷重量百分比为0.006%。依此计算得到的球团铁金属化率为95.32%，砷脱除率为90.9%。The analysis results of the metallized pellets were: metallic iron was 58.89% by weight and arsenic was 0.006% by weight. According to this calculation, the iron metallization rate of the pellets is 95.32%, and the arsenic removal rate is 90.9%.

示例3Example 3

含砷物料为含砷铜渣，其中TFe重量百分比为36.10%，Cu重量百分比为0.68%，As含量为0.14%，其中Cu以CuO形式存在，Fe以Fe2O3形式存在，As以As2O5形式存在。将其研磨，选取100目以下含砷铜渣粉100g，添加30g石油焦，加入8%粘结剂混匀后造球，含碳球团直径为1cm-2cm，将造好的球团置于200℃烘箱里，干燥4h以保证绝大部分游离水的脱除。干燥的含碳球团可放入还原炉内随炉升温到℃，亦可在还原炉到达设定温度℃后放入，在将球团放入还原炉内的同时通入N2-CO气体以控制炉内的气氛为还原性气氛，打开尾气处理装置以处理还原炉内排出的尾气。在℃还原4h后取出直接还原后的金属化球团，水冷至常温，再放入200℃烘箱里干燥4h后取样分析。The arsenic-containing material is arsenic-containing copper slag, in which the weight percentage of TFe is 36.10%, the weight percentage of Cu is 0.68%, and the content of As is 0.14%. Among them, Cu exists in the form of CuO, Fe exists in the form of Fe 2 O 3 , and As exists in the form of As 2 O 5 form exists. Grind it, select 100g of arsenic-containing copper slag powder below 100 mesh, add 30g of petroleum coke, add 8% binder and mix well, and then make pellets. The diameter of the carbon-containing pellets is 1cm-2cm. In an oven at 200°C, dry for 4 hours to ensure that most of the free water is removed. The dry carbon-containing pellets can be put into the reduction furnace and the furnace temperature rises to °C, or it can be put in after the reduction furnace reaches the set temperature of °C, and N 2 - The CO gas is used to control the atmosphere in the furnace as a reducing atmosphere, and the tail gas treatment device is turned on to treat the tail gas discharged from the reduction furnace. After reduction at °C for 4 hours, the metallized pellets after direct reduction were taken out, cooled with water to room temperature, then placed in an oven at 200°C for 4 hours and then sampled for analysis.

其中，脱砷机理为：Among them, the mechanism of arsenic removal is:

As2O5(s)+5CO(g)=2As(g)+5CO2(g)              ……(7)As 2 O 5 (s)+5CO(g)=2As(g)+5CO 2 (g) ……(7)

其中，铜直接还原机理为：Among them, the copper direct reduction mechanism is:

CuO(s)+CO(g)=Cu(s)+CO2(g)                       (8)CuO(s)+CO(g)=Cu(s)+CO 2 (g) (8)

C(s)+CO2(g)=2CO(g)                          ……(9)C(s)+CO 2 (g)=2CO(g)...(9)

其中，铁直接还原机理如示例1中步骤（2）-（5）所示。Wherein, the direct reduction mechanism of iron is shown in steps (2)-(5) in Example 1.

其中，在本例中，反应（5）以及反应（9）中C为石油焦。Wherein, in this example, C in reaction (5) and reaction (9) is petroleum coke.

金属化球团分析结果为：金属铁重量百分比为34.12%，铜重量百分比为0.669%，砷重量百分比为0.006%。依此计算得到的球团铁金属化率为94.52%，铜金属化率为98.46%，砷脱除率为95.68%。The analysis results of the metallized pellets are: the weight percentage of metallic iron is 34.12%, the weight percentage of copper is 0.669%, and the weight percentage of arsenic is 0.006%. Based on this calculation, the iron metallization rate of the pellets was 94.52%, the copper metallization rate was 98.46%, and the arsenic removal rate was 95.68%.