With the rapid development of steel industry, the current iron ore resources become tighter, some complex iron ore resources are being vigorously exploited. Storing a large quantity of iron ore containing arsenic in our country, as of 1990, the domestic proven iron ore reserves of 1.88 billion arsenic t. As a harmful element in steel, arsenic has a series of adverse effects on steel properties. For example, under argon-containing steel under normal rolling process conditions, ie, high temperature heating for a long time in an oxidizing atmosphere, surface enrichment layers may occur, causing cracks in the hot-worked surface. It segregates severely in steel, promotes the development of steel ribbon structure, reduces the impact toughness of steel, and easily cracks steel during hot processing. There are special-purpose steels, such as oil drill steel, large generator rotor steel, nuclear industry steel, etc., and even require no arsenic. In addition, arsenic and its compounds are mostly highly toxic substances, and the treatment of arsenic-containing ores can cause serious environmental problems. The research on arsenic removal from arsenic-containing iron ore is of great significance for reducing the harm of arsenic in the smelting system and realizing the comprehensive utilization of arsenic-containing mineral resources. Theoretical analysis and experimental research have shown that arsenic removal can not be achieved in blast furnace slag and steelmaking oxidation. The hot metal pretreatment has high cost for arsenic removal. It is suitable as a deep arsenic removal method. When the arsenic content of molten iron is high, the method is not economical. The arsenic-free iron ore can not be effectively utilized by relying on pretreatment for arsenic removal. Method ore arsenic compounds decompose easily gasified at high temperature, metallurgical workers abroad use of this property, and employs a lot calcined and sintered ore pretreatment removal of arsenic, the arsenic content in the ore has been effectively controlled . Compared with the arsenic removal by hot metal pretreatment, gasification and arsenic removal has the characteristics of low cost, large processing scale and simple process. It is an effective way to develop and utilize arsenic-bearing iron ore resources and reduce the arsenic content in steel. Iron ore gasification and arsenic removal processes mainly include arsenic removal by spheroids, arsenic removal by sintering, and arsenic removal by chlorination. Pellet removal from arsenic: Pellet ore production uses coal as a heat generating agent and has a high production temperature. It is a weak oxidation-reduction atmosphere and has the basic conditions of gasification and arsenic removal. Under reasonable production conditions, it can obtain higher Arsenic removal rate. However, there are some contradictions between the arsenic removal rate of the ore and the compressive strength of the pellets. For example, the strength of pellets increases with the increase of oxygen volume fraction, and the arsenic removal rate is inversely proportional to the oxygen volume fraction; the pellet strength is proportional to the coal blending amount, but if the coal blending amount is too large, the reduction is caused. The sexual atmosphere is too strong, and the rate of arsenic removal is decreasing. Therefore, how to achieve maximum arsenic removal while ensuring the quality of pellets is the key to the process. Sintering and arsenic removal: The sinter production scale is large, and the arsenic-containing iron ore can be processed in a large amount; the temperature of the combustion layer and the cooling layer is very high, the residence time of the high temperature zone of the material layer is long, and the arsenic-containing compound can be fully decomposed; the bottom of the sintering machine With a suction device, the negative pressure operation process is more conducive to the decomposition and gasification of arsenic. In addition, the sintering production can be used with different ores and raw materials, and there are many adjustment methods. However, sintering arsenic removal has some disadvantages in addition to the above advantages. For example, at present, the sintering process generally adopts high alkalinity sintering, which will greatly inhibit sintering and arsenic removal; the sintering process is accompanied by a series of complicated physical and chemical changes, and the various process parameters are closely related and mutually influential, and simulation experiments and industrial tests are difficult to be accurate. The specific influence of each process parameter on sintering and arsenic removal is obtained. In addition, the sintering process belongs to the “black box†model, and it is very difficult to study the mechanism of sintering and arsenic removal. Chloride arsenic removal is a process in which a chlorinating agent is used to convert a target component in a mineral raw material into a gas phase or a condensed phase chloride under a certain temperature and atmosphere to separate and concentrate the target component. Arsenic will be vaporized in the form of low-boiling compound arsenic chloride (AsCl 3 ). When AsCl 3 is at a temperature of 121.4 ° C, the vapor pressure is 105 Pa, and the As 4 O 6 partial pressure reaches 105 Pa, requiring a temperature of 478.8 ° C. Therefore, AsCl 3 is It is more volatile during the roasting process. In addition, AsCl 3 is not easily oxidized at a high temperature, and can effectively prevent the formation of solid arsenic compounds such as calcium arsenate or iron arsenate, and theoretically has a possibility of greatly increasing the arsenic removal rate. Factors affecting the gasification of iron ore by arsenic include reaction temperature, reaction atmosphere, basic oxides in the ore, and reaction time. The elemental As has a melting point of 300 to 320 ° C and a boiling point of 550 to 600 ° C. The arsenic sulfide of As 2 S 2 and the like has a melting point of 300 to 320 ° C and a boiling point of 550 to 600 ° C. The decomposition temperature of FeAsS is 510 to 530 ° C, and the decomposition temperature of FeAsO 4 is 980 to 1050 ° C. As the temperature increases, solid phase arsenic such as As 2 S 2 , FeAsS, FeAsO 4 , As 2 O 5 will gradually decompose. The stability of Fe 2 As, FeAs and FeAs 2 is enhanced with increasing temperature, but it exists only under the conditions of low sulfur potential and low oxygen potential. As 2 S 2 O gas phase system, as the temperature increases, the stability of As 2 S 2 and As 2 S 3 is greatly reduced, and it is easy to react to form As 4 O 6 and SO 2 . The arsenide will be vaporized as As 4 O 6 in an oxidizing atmosphere, but if the oxygen potential is too high, the reaction tends to occur, and the As 2 O 5 and FeAsO 4 solid phase products are formed to lower the arsenic removal rate. Under an oxidizing atmosphere, As 4 O 6 can react with a basic oxide such as CaO to form a stable arsenate and reduce the arsenic removal rate. Under the condition of mixed gas flow rate of 200L/h (air:nitrogen=1:1), coke powder compounding amount of 6%, and reaction temperature of 1100°C, the arsenic removal rate reached over 90% when the reaction progressed to 3 minutes. The prolonged arsenic removal rate continued to increase; the arsenic removal rate was above 95% during the constant temperature period of 8 to 15 minutes, and the arsenic removal rate reached the maximum at 15 minutes; the arsenic removal rate did not increase significantly or decreased after the constant temperature time was greater than 15 minutes. With the depletion of ore and the depletion of resources, it is of great practical significance to increase the development and utilization of arsenic-bearing iron ore in China in line with China's national conditions and the development of steel. At present, by adopting a reasonable arsenic removal process, the arsenic mass fraction in iron ore is controlled to a certain extent, which can basically meet the blast furnace production requirements. However, to further improve the arsenic removal rate of iron ore, it is necessary to study the mechanism of arsenic removal under various process conditions, establish thermodynamics and kinetic theory, especially the research on solid-gas-solid state conversion mechanism of arsenic-containing compounds under different conditions. In addition, arsenic oxide, arsenic chloride, arsenic sulfide and other gasification arsenic removal products are highly toxic gases, and direct emissions will bring serious environmental problems. Therefore, the removal of arsenic from iron ore should also strengthen the research on the harmless treatment and recycling of arsenic-containing waste gas. 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October 30, 2021