CN108017064B - Method and device for impurity removal and activation of industrial silicon micro-silicon powder - Google Patents
Method and device for impurity removal and activation of industrial silicon micro-silicon powder Download PDFInfo
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Abstract
The invention discloses a method and a device for impurity removal and activation of industrial silicon micro-powder, wherein the method comprises the steps of preheating micro-silicon powder separated and collected from industrial silicon smelting flue gas to 560-650 ℃, then roasting the preheated micro-silicon powder at high temperature of 720-1100 ℃ in an oxygen-rich atmosphere in a static or dynamic mode, discharging, cooling and separating after roasting for 15-90 minutes to obtain the impurity removal and activation micro-silicon powder. The device is used for realizing impurity removal and activation of industrial silicon micro-silicon powder and comprises a first dust removal unit, a preheating heat exchange unit, a roasting unit, a cooling heat exchange unit, a second dust removal unit, a micro-silicon powder storage unit and an air heating unit. According to the invention, the influence of the organic volatile matters such as coal tar, carbon and the like in the micro silicon powder on the production and quality of subsequent products is avoided by removing the organic volatile matters such as coal tar, carbon and the like, and the density and the granularity of the micro silicon powder are adjusted under the condition of ensuring the reaction activity of the micro silicon powder so as to be beneficial to the reaction and the filtration of the subsequent products, thereby realizing the industrial production of the subsequent water glass products.
Description
Technical Field
The invention belongs to the technical field of solid waste recycling, and particularly relates to a method and a device for removing impurities and activating industrial silicon micro-silicon powder.
Background
The micro silicon powder is silicon-containing industrial micro dust which is formed by escaping SiO and Si gases generated in an ore-smelting electric furnace, rapidly oxidizing and cooling the SiO and Si gases by air in the production process of industrial silicon or ferrosilicon alloy, is micron-sized fine powder with high silicon dioxide content, is greatly harmful to human bodies after being inhaled by people, and belongs to solid waste. Along with the enhancement of national environmental protection, the micro silicon powder in the flue gas of industrial silicon production enterprises begins to be collected through environment-friendly cloth bag dust removal equipment so as to reach the emission standard.
The quality index conditions of the micro silicon powder collected by industrial silicon smelting are as follows through detection: SiO 22 91～95.2％、Fe2O30.08～0.42％、Al2O3 0.09～0.55％、CaO 0.12～1.0％、MgO 0.08～0.45％、K2O 0.16～0.9％、Na20.18-1.21% of O and 1.62-4.78% of volatile matter, wherein the main components of the volatile matter are coal tar and carbon powder, which is also micro silicon powderThe main reason for the grey and grey-black appearance; the density of the micro silicon powder is 0.3-0.6 g/ml; the median particle size is 5-10 μm, and the powder is powdery and has poor fluidity.
The micro silicon powder can be theoretically used for concrete raw materials and refractory materials, and has better corrosion resistance, insulativity, wear resistance, impermeability, frost resistance and high temperature resistance; it can also be used as a filler for organic compounds such as rubber and resin. In recent years, various industries have made many application attempts on such silica fume, but due to frequent and large fluctuations of negative pressure in the furnace and temperature of the fume during the production of industrial silicon, the quality of the silica fume in the fume is very unstable, and finally, due to unstable and poor mechanical properties of direct application, the actual addition proportion of the silica fume is very small, the effect is not obvious, the actual application amount is very limited, a large amount of silica fume is accumulated, and the market digestion is difficult, so that the application is a great obstacle for restricting the clean and environment-friendly production of industrial silicon enterprises.
In order to convert the microsilica into more valuable products, the microsilica is analyzed and found to be in an amorphous state in structure and high in activity. Enterprises utilize the characteristic of the micro silicon powder, and try to convert the micro silicon powder into liquid sodium silicate with wide application by reacting liquid caustic soda with the micro silicon powder through a liquid phase method. But finally, the industrialization can not be smoothly realized due to the low concentration and difficult filtration of the reacted water glass liquid, and the product has peculiar smell and is dark yellow or brownish red in color, thereby also seriously influencing the product quality and the subsequent application of the water glass.
Therefore, no industrial application or success of the method is reported at present.
Disclosure of Invention
In order to solve the problems in the prior art, the invention aims to provide a method and a device for impurity removal and activation of industrial silicon micro-powder, which can avoid the influence of coal tar, carbon and other organic volatile matters in the micro-powder on the production and quality of subsequent products by removing the coal tar, the carbon and other organic volatile matters, and can adjust the density and the granularity of the micro-powder under the condition of ensuring the reaction activity of the micro-powder so as to be beneficial to the reaction and the filtration of the subsequent products, thereby realizing the industrial production of the subsequent sodium silicate products by utilizing the industrial silicon micro-powder.
The invention provides an impurity removal and activation method for industrial silicon micro-silicon powder, which comprises the steps of preheating micro-silicon powder separated and collected from industrial silicon smelting flue gas to 560-650 ℃, roasting the preheated micro-silicon powder at 720-1100 ℃ in an oxygen-rich atmosphere in a static or dynamic mode, discharging, cooling and separating after roasting for 15-90 minutes to obtain impurity removal and activation micro-silicon powder.
According to one embodiment of the method for impurity removal and activation of the industrial silicon micro silicon powder, the micro silicon powder separated and collected from the industrial silicon smelting flue gas is low-temperature micro silicon powder continuously separated and collected from an industrial silicon tail gas system through a first dust removal unit, wherein the temperature of the low-temperature micro silicon powder is 180-220 ℃, and the first dust removal unit is a bag-type dust remover or a cyclone dust remover.
According to one embodiment of the method for impurity removal and activation of the industrial silicon micro silicon powder, the micro silicon powder separated and collected from the industrial silicon smelting flue gas is preheated to 560-650 ℃ by using a preheating heat exchange unit.
According to one embodiment of the method for impurity removal and activation of industrial silicon micro-silicon powder, the preheated micro-silicon powder is continuously fed into a roasting unit for roasting, and is continuously discharged after roasting, oxygen-enriched air or pure oxygen is continuously introduced during the roasting process to form an oxygen-enriched atmosphere, wherein the micro-silicon powder is preferably roasted in a continuously fed dynamic mode.
According to one embodiment of the method for impurity removal and activation of the industrial silicon micro-silicon powder, the roasting unit is a fluidized bed roaster, a rotary roaster or a microwave roaster, and a heat source of the roasting unit is natural gas, coal, electricity or microwave.
According to one embodiment of the method for removing impurities and activating the industrial silicon micro-silicon powder, the roasting temperature in the roasting unit is preferably controlled to be 850-1100 ℃, and the roasting time is 15-50 minutes; more preferably, the roasting temperature in the roasting unit is controlled to be 900-1000 ℃, and the roasting time is controlled to be 18-40 minutes; most preferably, the roasting temperature in the roasting unit is controlled to be 920-950 ℃, and the roasting time is controlled to be 20-30 minutes.
According to one embodiment of the method for removing impurities and activating the industrial silicon micro-silicon powder, the high-temperature roasted micro-silicon powder is cooled by using the cooling heat exchange unit, and then the cooled micro-silicon powder is separated by using the second dust removal unit to obtain the impurity-removed and activated micro-silicon powder.
According to one embodiment of the method for impurity removal and activation of the industrial silicon micro-silicon powder, cold air is introduced into the cooling heat exchange unit to exchange heat with high-temperature micro-silicon powder to obtain preheated air, the preheated air is introduced into the air heating unit to be heated to obtain high-temperature hot air, the high-temperature hot air is introduced into the preheating heat exchange unit to preheat the micro-silicon powder separated and collected from industrial silicon smelting flue gas, and heat exchange tail gas discharged by the preheating heat exchange unit is mixed with the preheated air and then introduced into the air heating unit to be heated to obtain the high-temperature hot air.
According to one embodiment of the method for removing impurities and activating the industrial silicon micro silicon powder, the method comprises the following steps of: SiO 22 94.4～98.2％、Fe2O3 0.1～0.42％、Al2O3 0.11～0.61％、CaO 0.15～1.2％、MgO 0.1～0.6％、K2O 0.2～1.1％、Na20.22-1.42% of O; the density of the impurity-removed activated micro silicon powder is 0.6-0.8 g/ml, and the median particle size is 45-70 μm.
The invention provides a device for removing impurities and activating industrial silicon micro-silicon powder, which is used for removing impurities and activating the industrial silicon micro-silicon powder according to the method for removing impurities and activating the industrial silicon micro-silicon powder and comprises a first dust removal unit, a preheating heat exchange unit, a roasting unit, a cooling heat exchange unit, a second dust removal unit, a micro-silicon powder storage unit and an air heating unit;
the flue gas inlet of the first dust removal unit is connected with an industrial silicon tail gas system, the tail gas outlet is communicated with a desulfurization and denitrification device, and the dust outlet is connected with the material inlet of the preheating heat exchange unit;
a material outlet of the preheating heat exchange unit is connected with a material inlet of the roasting unit, a high-temperature hot air inlet is connected with a high-temperature hot air outlet of the air heating unit, and a heat exchange tail gas outlet is connected with a preheating air inlet of the air heating unit;
the material outlet of the roasting unit is connected with the material inlet of the cooling heat exchange unit, the cold air inlet of the cooling heat exchange unit is communicated with the atmosphere, the preheated air outlet is connected with the preheated air inlet of the air heating unit, the material outlet is connected with the material inlet of the second dust removal unit, and the material outlet of the second dust removal unit is connected with the micro silicon powder storage unit.
Compared with the prior art, the method and the device for impurity removal and activation of the industrial silicon micro silicon powder remove organic volatile matters such as coal tar, carbon powder and the like in the micro silicon powder, and avoid the influence of the organic volatile matters on the quality of subsequent products; the structure, density and granularity of the micro silicon powder are adjusted, and the activity of the reaction is kept; meanwhile, the concentration of the subsequent water glass product, the filtering efficiency of the subsequent water glass product and the quality of the subsequent water glass product are improved, and the subsequent water glass product is easy to realize industrial production.
Drawings
Fig. 1 shows a process flow diagram of a method for impurity removal and activation of industrial silicon micro-silicon powder according to an exemplary embodiment of the invention.
Fig. 2 is a block diagram illustrating a structure of an apparatus for impurity removal and activation of industrial silicon micro-silicon powder according to an exemplary embodiment of the present invention, wherein a single arrow indicates a material flow direction, and a double arrow indicates an air flow direction.
Detailed Description
All of the features disclosed in this specification, or all of the steps in any method or process so disclosed, may be combined in any combination, except combinations of features and/or steps that are mutually exclusive.
Any feature disclosed in this specification may be replaced by alternative features serving equivalent or similar purposes, unless expressly stated otherwise. That is, unless expressly stated otherwise, each feature is only an example of a generic series of equivalent or similar features.
The industrial silicon micro-silicon powder treated by the invention is silicon-containing industrial micro-dust which is formed by escaping SiO and Si gases generated in an ore-smelting electric furnace, rapidly oxidizing by air and cooling in the production process of industrial silicon or ferrosilicon alloy.Specifically, the micro silicon powder collected by industrial silicon smelting is detected, and the quality indexes are as follows in percentage by mass: SiO 22 91～95.2％、Fe2O3 0.08～0.42％、Al2O3 0.09～0.55％、CaO 0.12～1.0％、MgO 0.08～0.45％、K2O 0.16～0.9％、Na20.18-1.21% of O and 1.62-4.78% of volatile matters, wherein the main components in the volatile matters are coal tar and carbon powder; the density of the micro silicon powder is 0.3-0.6 g/ml, the median particle size is 5-10 μm, and the micro silicon powder is powdery and has poor fluidity.
The experimental analysis shows that the root causes of difficult filtration, peculiar smell, color and low concentration of the water glass prepared by directly using the micro silicon powder liquid phase reaction are two points: the micro silicon powder contains 1.62-4.78% of volatile matters (including coal tar and carbon powder), the volatile matters enable a layer of oily gel to be formed in liquid after reaction, filtering resistance is increased, and the oily gel is partially dissolved in liquid water glass to enable the water glass to be colored; and secondly, the particle size of the micro silicon powder is too fine, so that the water distribution amount of a reaction system is large, otherwise, the reaction system has high viscosity and is not beneficial to reaction, so that the final liquid concentration is low, and meanwhile, unreacted micro silicon powder, coal tar and carbon powder form more compact precipitates which are difficult to filter.
Aiming at the problems, the invention provides a method for removing volatile matters (mainly coal tar and carbon powder) in the micro silicon powder by an oxygen-enriched roasting method, and sintering the micro silicon powder at high temperature to increase the density and granularity of the micro silicon powder. Effectively reduces the water consumption for the subsequent reaction, improves the concentration of the final reaction liquid, and greatly improves the filtration efficiency of the liquid under the condition of ensuring the reaction activity. Most importantly, after the micro silicon powder is subjected to impurity removal and activation in the above mode, the reacted and filtered water glass liquid is transparent, colorless and tasteless, and low in impurity content, so that a foundation can be laid for subsequent wide application and high-end market application of products.
The method and apparatus for removing impurities and activating industrial silicon micropowder of the present invention will be described in detail below.
According to an exemplary embodiment of the invention, the method for removing impurities and activating the industrial silicon micro-silicon powder specifically comprises the following steps:
preheating the micro silicon powder separated and collected from the industrial silicon smelting flue gas to 560-650 ℃, then performing high-temperature roasting on the preheated micro silicon powder at 720-1100 ℃ in an oxygen-rich atmosphere in a static or dynamic mode, discharging, cooling and separating after roasting for 15-90 minutes to obtain the impurity-removed activated micro silicon powder. The static mode refers to a state that the micro silicon powder is kept still in the roasting process, and the dynamic mode refers to a state that the micro silicon powder keeps a certain degree of movement or moves at a certain speed in the roasting process. The method can be realized by any device or system which can be realized as long as the high-temperature roasting for a certain time under the oxygen-enriched atmosphere can be realized.
Fig. 1 shows a process flow diagram of a method for impurity removal and activation of industrial silicon micro-silicon powder according to an exemplary embodiment of the invention.
As shown in fig. 1, first, the first dust removing unit 10 is used to separate and collect the fine silicon powder from the industrial silicon smelting flue gas, the fine silicon powder is low-temperature fine silicon powder with a temperature of 180-220 ℃, and preferably, the low-temperature fine silicon powder is directly and continuously heated by the preheating heat exchange unit 20 to preheat the temperature of the fine silicon powder to 560-650 ℃, but the cooled fine silicon powder may also be preheated, which is not particularly limited in the present invention. As most of coal tar components and coal almost have ignition points in the temperature range of 560-650 ℃, the preheating aims to preheat the micro silicon powder to the temperature capable of burning volatile matters such as coal tar, coal dust and the like. Wherein, the first dust removing unit 10 may be a bag-type dust remover or a cyclone dust remover.
The preheated microsilica is then continuously fed into the roasting unit 30 for roasting and continuously discharged after roasting, in which oxygen-enriched air or pure oxygen is continuously fed to form an oxygen-enriched atmosphere, wherein the microsilica is preferably roasted in a continuously fed dynamic manner. Therefore, the dynamic silica fume can be fully and uniformly contacted with oxygen-enriched air or pure oxygen continuously introduced, volatile matters such as coal tar, carbon powder and the like in the silica fume are rapidly combusted and decomposed in the oxygen-enriched high-temperature environment, heat energy is released, the heat energy is favorable for keeping high temperature in the roasting unit, and partial heating energy is properly saved. And the temperature in the roasting unit is controlled to be 720-1100 ℃ through an external heat source, and the roasting time is controlled to be 15-90 minutes, so that the full decomposition of volatile matters is realized. According to the preferred embodiment of the present invention, the roasting temperature in the roasting unit 30 is preferably controlled to be 850-1100 ℃, and the roasting time is preferably controlled to be 15-50 minutes; more preferably, the roasting temperature in the roasting unit 30 is controlled to be 900-1000 ℃, and the roasting time is 18-40 minutes; the roasting temperature in the roasting unit 30 is controlled to be 920-950 ℃ most preferably, and the roasting time is controlled to be 20-30 minutes.
The roasting unit 30 may be a fluidized bed roaster, a rotary roaster, or a microwave roaster, and the heat source of the roasting unit 30 may be natural gas, coal, electricity, or microwave.
The micro silicon powder is roasted under the temperature and time conditions and the dynamic conditions, so that organic volatile matters such as coal tar, carbon and the like in the micro silicon powder can be fully combusted and decomposed, and fine micro silicon powder particles can be sintered while being roasted at high temperature, so that the particle size is coarsened and the density is increased.
And then cooling the high-temperature micro silicon powder roasted at the high temperature by using a cooling heat exchange unit 40, separating the cooled micro silicon powder by using a second dust removal unit 50 to obtain impurity-removed activated micro silicon powder, and preferably storing the obtained impurity-removed activated micro silicon powder for later use. The cooling heat exchange unit 40 may be a tubular heat exchange cooling pipe, and the second dust removal unit 50 may be a bag-type dust remover and/or a cyclone dust remover.
According to the preferred embodiment of the invention, cold air is introduced into the cooling heat exchange unit 40 to exchange heat with the high-temperature silica fume to obtain preheated air, the preheated air is introduced into the air heating unit 60 to be heated by a heat source to obtain high-temperature hot air, the high-temperature hot air is introduced into the preheating heat exchange unit 20 to preheat the silica fume separated and collected from the industrial silicon smelting fume, and the heat exchange tail gas part discharged from the preheating heat exchange unit 20 is mixed with the preheated air discharged from the cooling heat exchange unit 40 and then introduced into the air heating unit 60 to be heated by the heat source again to obtain the high-temperature hot air. The heat source quantity can be effectively saved by the cyclic utilization of the air.
The impurity-removed activated micro silicon powder obtained by the method has no volatile components and comprises the following components in percentage by mass: SiO 22 94.4～98.2％、Fe2O3 0.1～0.42％、Al2O3 0.11～0.61％、CaO 0.15～1.2％、MgO 0.1～0.6％、K2O 0.2～1.1％、Na20.22-1.42% of O; the density of the impurity-removed activated micro silicon powder is 0.6-0.8 g/ml, and the median particle size is 45-70 μm.
The water glass produced by the reaction of the impurity-removed activated silica fume and the caustic soda liquid phase method has high filtering efficiency, the filtered liquid is colorless and tasteless, the modulus of the water glass reaches more than 3.0, the concentration of the water glass is also improved from 10% to more than 20%, and the industrial production of the silica fume water glass can be smoothly realized.
The invention also provides a device for removing impurities and activating the industrial silicon micro-silicon powder, which is preferably adopted to remove impurities and activate the industrial silicon micro-silicon powder according to the method for removing impurities and activating the industrial silicon micro-silicon powder.
Fig. 2 is a block diagram illustrating a structure of an apparatus for impurity removal and activation of industrial silicon micro-silicon powder according to an exemplary embodiment of the present invention. As shown in fig. 2, the apparatus includes a first dust removing unit 10, a preheating heat exchange unit 20, a baking unit 30, a cooling heat exchange unit 40, a second dust removing unit 50, a micro silicon powder storage unit 70, and an air heating unit 60.
The flue gas inlet of the first dust removal unit 10 is connected with the industrial silicon tail gas system, the tail gas outlet is communicated with the desulfurization and denitrification device, and the dust outlet is connected with the material inlet of the preheating heat exchange unit 20. Therefore, the industrial silicon smelting flue gas directly enters the first dust removal unit 10 to be separated to obtain low-temperature silica fume and tail gas, the tail gas is discharged into the atmosphere through a tail gas outlet, and the low-temperature silica fume enters the preheating heat exchange unit 20 to be preheated.
The material outlet of the preheating and heat exchanging unit 20 is connected with the material inlet of the roasting unit 30, the high-temperature hot air inlet is connected with the high-temperature hot air outlet of the air heating unit 60, and the heat exchanging tail gas outlet is connected with the preheating air inlet of the air heating unit 60. Therefore, high-temperature hot air from the air heating unit 60 enters the preheating heat exchange unit 20 to heat the low-temperature micro silicon powder and is discharged as heat exchange tail gas after heat exchange for circulation, and the micro silicon powder preheated in the preheating heat exchange unit 20 directly enters the roasting unit 30 to be roasted at high temperature in an oxygen-rich atmosphere.
The material outlet of the roasting unit 30 is connected to the material inlet of the cooling heat exchange unit 40, the cold air inlet of the cooling heat exchange unit 40 is communicated with the atmosphere, the preheated air outlet is connected to the preheated air inlet of the air heating unit 60, the material outlet is connected to the material inlet of the second dust removal unit 50, and the material outlet of the second dust removal unit 50 is connected to the micro-silicon powder storage unit 70. Therefore, the high-temperature roasted silicon micro powder enters the cooling heat exchange unit 40 to be subjected to heat exchange cooling with cold air, the cooled roasted silicon micro powder is separated by the second dust removal unit 50 to obtain impurity-removing activated silicon micro powder and tail gas, the impurity-removing activated silicon micro powder is sealed and stored for later use by the silicon micro powder storage unit 70, and the tail gas is discharged into the atmosphere.
The method and apparatus for removing impurities and activating industrial silicon micropowder according to the present invention will be further described with reference to the following specific examples.
Example 1:
separating and collecting the obtained grey black micron-sized micro silicon powder (185 ℃) from the industrial silicon smelting flue gas by a bag-type dust collector; preheating the micro silicon powder to 580 ℃ through a heat pipe exchanger; feeding the preheated micro silicon powder into an electric heating high-temperature rotary roasting unit with three-stage temperature of 850 ℃, 880 ℃ and 920 ℃, introducing oxygen-enriched air, and keeping the micro silicon powder to turn radially and move axially in the furnace by adjusting the revolution of the rotary roasting furnace and controlling the length of the rotary roasting furnace, so as to ensure that the micro silicon powder is fully contacted with the oxygen-enriched air, and controlling the time from the entry of the micro silicon powder into the rotary roasting furnace to the exit of the micro silicon powder to be 23 minutes; discharging after dynamic high-temperature roasting, and cooling in an air cooler; and then the impurity-removed activated silica fume sample 1 is obtained by separation through a bag-type dust collector. The whole process keeps continuous feeding and discharging.
Example 2:
separating and collecting the obtained grey black micron-sized micro silicon powder (194 ℃) from the industrial silicon smelting flue gas by a bag-type dust collector; preheating the micro silicon powder to 600 ℃ through a heat pipe exchanger; then sending the preheated micro silicon powder into a 880 ℃ natural gas heating high-temperature rotary roasting furnace; introducing pure oxygen, keeping the micro silicon powder to turn radially and move axially in the furnace by adjusting the revolution of the rotary roasting furnace and controlling the length of the rotary roasting furnace, ensuring that the micro silicon powder is fully contacted with oxygen-enriched air, and controlling the time from the entry of the micro silicon powder into the rotary roasting furnace to the discharge of the micro silicon powder to be 28 minutes; discharging after dynamic high-temperature roasting, and cooling in an air cooler; and then the impurity-removed activated silica fume sample 2 is obtained by separation through a bag-type dust collector. The whole process keeps continuous feeding and discharging.
Example 3:
separating and collecting the obtained grey black micron-sized micro silicon powder (202 ℃) from the industrial silicon smelting flue gas by a bag-type dust collector; preheating the micro silicon powder to 650 ℃ through a heat pipe exchanger; then sending the preheated micro silicon powder into a 950 ℃ natural gas heating high-temperature rotary roasting furnace; introducing oxygen-enriched air, keeping the micro silicon powder to turn over in the radial direction and move in the axial direction in the furnace by adjusting the revolution of the rotary roasting unit and controlling the length of the rotary roasting furnace, ensuring the micro silicon powder to be fully contacted with the oxygen-enriched air, and controlling the time from the micro silicon powder entering the rotary roasting furnace to the micro silicon powder leaving the furnace to be 20 minutes; discharging after dynamic high-temperature roasting, and cooling in an air cooler; and then the impurity-removed activated silica fume sample 3 is obtained by separation through a bag-type dust collector. The whole process keeps continuous feeding and discharging.
Comparative example 1:
separating and collecting the obtained grey black micron-sized micro silicon powder (188 ℃) from the industrial silicon smelting flue gas through a bag-type dust collector; preheating the micro silicon powder to 400 ℃ by a heat pipe exchanger; sending the preheated micro silicon powder into an electric heating high-temperature rotary roasting unit with three-section temperature of 580 ℃, 600 ℃ and 650 ℃, introducing oxygen-enriched air, keeping the micro silicon powder to turn radially and move axially in the furnace by adjusting the revolution of the rotary roasting furnace and controlling the length of the rotary roasting furnace, ensuring that the micro silicon powder is fully contacted with the oxygen-enriched air, and controlling the time from the entry of the micro silicon powder into the rotary roasting furnace to the exit of the micro silicon powder to be 80 minutes; discharging after dynamic high-temperature roasting, and cooling in an air cooler; and then the impurity-removed activated silica fume is separated by a bag-type dust collector to obtain a reference sample 1. The whole process keeps continuous feeding and discharging.
Comparative example 2:
separating and collecting the obtained grey black micron-sized micro silicon powder (190 ℃) from the industrial silicon smelting flue gas by a bag-type dust collector; preheating the micro silicon powder to 480 ℃ through a heat pipe exchanger; then sending the preheated micro silicon powder into a 680 ℃ natural gas heating high-temperature rotary roasting furnace; introducing pure oxygen, keeping the micro silicon powder to turn radially and move axially in the furnace by adjusting the revolution of the rotary roasting furnace and controlling the length of the rotary roasting furnace, ensuring that the micro silicon powder is fully contacted with oxygen-enriched air, and controlling the time from the entry of the micro silicon powder into the rotary roasting furnace to the discharge of the micro silicon powder to be 70 minutes; discharging after dynamic high-temperature roasting, and cooling in an air cooler; and then the impurity-removed activated silica fume sample 2 is obtained by separation through a bag-type dust collector. The whole process keeps continuous feeding and discharging.
Comparative example 3:
separating and collecting the obtained grey black micron-sized micro silicon powder (185 ℃) from the industrial silicon smelting flue gas by a bag-type dust collector; preheating the micro silicon powder to 550 ℃ by a heat pipe exchanger; then sending the preheated micro silicon powder into a 700 ℃ natural gas heating high-temperature rotary roasting furnace; introducing oxygen-enriched air, keeping the micro silicon powder to turn over in the radial direction and move in the axial direction in the furnace by adjusting the revolution of the rotary roasting unit and controlling the length of the rotary roasting furnace, ensuring the micro silicon powder to be fully contacted with the oxygen-enriched air, and controlling the time from the micro silicon powder entering the rotary roasting furnace to the micro silicon powder leaving the furnace to be 80 minutes; discharging after dynamic high-temperature roasting, and cooling in an air cooler; and then the impurity-removed activated silica fume sample 3 is obtained by separation through a bag-type dust collector. The whole process keeps continuous feeding and discharging.
Table 1 shows the results of the tests of the samples prepared in the above three examples and three comparative examples. As can be seen from Table 1, below the preheating temperature, the roasting temperature and the roasting time of the present application, the roasting is not thorough, and the residual organic volatile matters still bring quality influence on the subsequent production. If the time is further prolonged, comparative example 3 may be such that no volatile matter remains, but the treatment efficiency is seriously affected. Therefore, the comprehensive treatment effect and efficiency factors are treated according to the roasting treatment parameter range and the method determined by the invention, and the influence of organic matters in the micro silicon powder on the production and quality of subsequent products can be thoroughly eliminated.
TABLE 1 examination results of samples prepared in examples 1 to 3 and comparative examples 1 to 3
In conclusion, the method and the device for impurity removal and activation of the industrial silicon micro silicon powder remove organic volatile matters such as coal tar, carbon powder and the like in the micro silicon powder, and avoid the influence of the organic volatile matters on the quality of subsequent products; the structure, density and granularity of the micro silicon powder are adjusted, and the activity of the reaction is kept; meanwhile, the concentration of the subsequent water glass product, the filtering efficiency of the subsequent water glass product and the quality of the subsequent water glass product are improved, and the subsequent water glass product is easy to realize industrial production.
The invention is not limited to the foregoing embodiments. The invention extends to any novel feature or any novel combination of features disclosed in this specification and any novel method or process steps or any novel combination of features disclosed.
Claims (8)
1. The method for impurity removal and activation of industrial silicon micro-silicon powder is characterized in that a preheating heat exchange unit is used for preheating micro-silicon powder obtained by separating and collecting industrial silicon smelting flue gas to 560-650 ℃, the micro-silicon powder obtained by separating and collecting industrial silicon smelting flue gas is low-temperature micro-silicon powder obtained by continuously separating and collecting the micro-silicon powder from an industrial silicon tail gas system through a first dust removal unit, the temperature of the low-temperature micro-silicon powder is 180-220 ℃, and the first dust removal unit is a bag-type dust remover or a cyclone dust remover;
roasting the preheated silica fume at high temperature of 720-1100 ℃ in an oxygen-rich atmosphere in a dynamic mode, discharging after roasting for 15-90 minutes, cooling and separating to obtain impurity-removed activated silica fume, wherein the impurity-removed activated silica fume is free of volatile matters, the preheated silica fume is continuously fed into a roasting unit for roasting, and continuously discharged after roasting, oxygen-rich air or pure oxygen is continuously introduced during the roasting process to form the oxygen-rich atmosphere, and the oxygen-rich atmosphere is formed by mass percentThe impurity removal and activation micro silicon powder comprises the following components: SiO 22 94.4～98.2％、Fe2O30.1～0.42％、Al2O3 0.11～0.61％、CaO 0.15～1.2％、MgO 0.1～0.6％、K2O 0.2～1.1％、Na20.22-1.42% of O; the density of the impurity-removed activated micro silicon powder is 0.6-0.8 g/ml, and the median particle size is 45-70 μm.
2. The method for impurity removal and activation of industrial silicon micro-powder according to claim 1, wherein the roasting unit is a fluidized bed roaster, a rotary roaster or a microwave roaster, and the heat source of the roasting unit is natural gas, coal, electricity or microwaves.
3. The method for impurity removal and activation of industrial silicon micro-silicon powder according to claim 1, wherein the roasting temperature in the roasting unit is controlled to be 850-1100 ℃, and the roasting time is 15-50 minutes.
4. The method for impurity removal and activation of industrial silicon micro-silicon powder according to claim 1, wherein the roasting temperature in the roasting unit is controlled to be 900-1000 ℃, and the roasting time is controlled to be 18-40 minutes.
5. The method for impurity removal and activation of industrial silicon micro-silicon powder according to claim 1, wherein the roasting temperature in the roasting unit is controlled to be 920-950 ℃, and the roasting time is controlled to be 20-30 minutes.
6. The method for removing impurities and activating industrial silicon micropowder according to claim 1, wherein the high-temperature silicon micropowder roasted at high temperature is cooled by a cooling heat exchange unit, and the cooled silicon micropowder is separated by a second dust removal unit to obtain the removed and activated silicon micropowder.
7. The method for impurity removal and activation of industrial silicon micro-powder as claimed in claim 6, wherein cold air is introduced into the cooling heat exchange unit to exchange heat with high-temperature micro-powder to obtain preheated air, the preheated air is introduced into the air heating unit to be heated to obtain high-temperature hot air, the high-temperature hot air is introduced into the preheating heat exchange unit to preheat the micro-powder separated and collected from the industrial silicon smelting flue gas, and the heat exchange tail gas discharged from the preheating heat exchange unit is mixed with the preheated air and then introduced into the air heating unit to be heated to obtain the high-temperature hot air.
8. The device for removing impurities and activating the industrial silicon micro-silicon powder is characterized by comprising a first dust removal unit, a preheating heat exchange unit, a roasting unit, a cooling heat exchange unit, a second dust removal unit, a micro-silicon powder storage unit and an air heating unit, wherein the first dust removal unit, the preheating heat exchange unit, the roasting unit, the cooling heat exchange unit, the second dust removal unit, the micro-silicon powder storage unit and the air heating unit are adopted;
the flue gas inlet of the first dust removal unit is connected with an industrial silicon tail gas system, the tail gas outlet is communicated with a desulfurization and denitrification device, and the dust outlet is connected with the material inlet of the preheating heat exchange unit;
a material outlet of the preheating heat exchange unit is connected with a material inlet of the roasting unit, a high-temperature hot air inlet is connected with a high-temperature hot air outlet of the air heating unit, and a heat exchange tail gas outlet is connected with a preheating air inlet of the air heating unit;
the material outlet of the roasting unit is connected with the material inlet of the cooling heat exchange unit, the cold air inlet of the cooling heat exchange unit is communicated with the atmosphere, the preheated air outlet is connected with the preheated air inlet of the air heating unit, the material outlet is connected with the material inlet of the second dust removal unit, and the material outlet of the second dust removal unit is connected with the micro silicon powder storage unit.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5213497A (en) * | 1975-07-24 | 1977-02-01 | Chisso Corp | Method for production of white silica powder |
| CN102849751A (en) * | 2012-10-17 | 2013-01-02 | 安徽理工大学 | Method for desorbing residual carbon in siliceous dust by means of oxygen-enriched calcination and device therefor |
| CN106219550A (en) * | 2016-07-25 | 2016-12-14 | 刘成成 | A kind of method utilizing industrial waste SILICA FUME to prepare industrial silicon and production system |
-
2017
- 2017-12-27 CN CN201711439350.8A patent/CN108017064B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5213497A (en) * | 1975-07-24 | 1977-02-01 | Chisso Corp | Method for production of white silica powder |
| CN102849751A (en) * | 2012-10-17 | 2013-01-02 | 安徽理工大学 | Method for desorbing residual carbon in siliceous dust by means of oxygen-enriched calcination and device therefor |
| CN106219550A (en) * | 2016-07-25 | 2016-12-14 | 刘成成 | A kind of method utilizing industrial waste SILICA FUME to prepare industrial silicon and production system |
Non-Patent Citations (1)
| Title |
|---|
| 固定床富氧气氛煅烧脱除硅灰中残碳的研究;付敏等;《广州化工》;20130630;第41卷(第11期);第127页左栏第1-2行以及第128页左栏第4-6行 * |
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