CN111115634B - Method for preparing SiC fibers by using silicon wafer cutting waste - Google Patents

Method for preparing SiC fibers by using silicon wafer cutting waste Download PDF

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CN111115634B
CN111115634B CN202010054241.XA CN202010054241A CN111115634B CN 111115634 B CN111115634 B CN 111115634B CN 202010054241 A CN202010054241 A CN 202010054241A CN 111115634 B CN111115634 B CN 111115634B
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李翔
李振强
吉恒松
唐凯
张广清
张梅
夏燏杰
彭海涛
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Abstract

The invention provides a method for preparing SiC fibers by using silicon chip waste, which comprises the steps of firstly removing organic matters in the silicon chip waste through alcohol washing and water washing, then mixing with commercially available quartz powder, generating gas-phase SiO in a high-temperature reactor, and introducing CH 4 Reacting to generate SiC fibers; followed by high temperature, H 2 Roasting in the atmosphere to remove the surplus free carbon in the fiber; and cooling and collecting the high-quality SiC fibers with low carbon content. The raw materials used by the invention are diamond wire cutting silicon chip waste materials in the photovoltaic industry, have wide sources and low price, and do not contain toxic and harmful substances; the preparation method of the high-quality SiC fiber is provided while solving the problem of recycling of the diamond wire-cutting silicon wafer waste, and the recycling of solid waste resources is developed towards the direction of green, high efficiency and high yield.

Description

一种利用硅片切割废料制备SiC纤维的方法A method for preparing SiC fibers from silicon wafer cutting waste

技术领域technical field

本发明涉及半导体材料制备技术领域,具体是一种SiC纤维材料的制备方法,尤其是一种利用硅片切割废料制备SiC纤维的方法。The invention relates to the technical field of semiconductor material preparation, in particular to a method for preparing SiC fiber material, especially a method for preparing SiC fiber by using silicon chip cutting waste.

背景技术Background technique

在制备晶硅型太阳能电池时,必须采用多线切割技术将多晶硅锭或单晶硅棒切割成硅片。由于切割线的直径和硅片的厚度很接近,至少有40%以上的晶硅被切磨成硅粉进入切割液中,而基本上处于闲置或低价值利用状态。目前行业内占主流的金刚石线切割技术产生的废料,其主要成分为Si,少量的C和金属杂质。近年来国内外研究者开展了回收废料中高纯硅的研究,但回收工艺复杂,且回收得到的硅粉的纯度无法满足生产光伏级硅锭的要求,例如公开号为CN102642835A的专利申请“从金刚线切割晶硅产生的废料中回收硅料的方法”。利用晶硅切割废料中制备SiC粉末或耐火材料则存在附加值低等问题,例如公开号为CN107651690B的专利申请“一种金刚线切割废料制备高品质碳化硅的方法”,以及期刊论文“用太阳能级多晶硅切割废料制备Si3N4-SiC复合材料.耐火材料,2017,51(5):390-393.”。因此,寻找晶硅切割废料的高附加值利用途径,成为光伏产业急需解决的问题。When preparing crystalline silicon solar cells, multi-wire cutting technology must be used to cut polycrystalline silicon ingots or monocrystalline silicon rods into silicon wafers. Since the diameter of the cutting line is very close to the thickness of the silicon wafer, at least 40% of the crystalline silicon is cut into silicon powder and enters the cutting fluid, and is basically in a state of idle or low-value utilization. The waste produced by the diamond wire cutting technology, which is currently the mainstream in the industry, is mainly composed of Si, a small amount of C and metal impurities. In recent years, researchers at home and abroad have carried out research on the recovery of high-purity silicon from waste, but the recovery process is complicated, and the purity of the recovered silicon powder cannot meet the requirements for the production of photovoltaic grade silicon ingots. For example, the patent application with publication number CN102642835A "From King Kong A method for recovering silicon material from the waste generated by wire cutting crystal silicon". The use of crystalline silicon cutting waste to prepare SiC powder or refractory materials has problems such as low added value. For example, the patent application with the publication number CN107651690B "A method for preparing high-quality silicon carbide from diamond wire cutting waste", and the journal paper "Using solar energy Preparation of Si 3 N 4 -SiC composites from high-grade polysilicon cutting waste. Refractories, 2017,51(5):390-393.”. Therefore, finding a high value-added utilization method for crystalline silicon cutting waste has become an urgent problem to be solved in the photovoltaic industry.

SiC纤维是以碳和硅为主要组分的一种陶瓷纤维,从形态上分为晶须和连续纤维两种。SiC纤维具有良好的高温性能、高强度、高模量和化学稳定性,抗张强度可达2.5~3.5GPa,弹性模量为200GPa,有良好的耐化学品腐蚀性,线膨胀系数小,约为3.1×10-6K-1,耐辐照、吸波性好,且具有半导体性质。主要用于增强金属和陶瓷,制成耐高温的金属或陶瓷基复合材料。因其具有良好性能,已在尖端科技领域,例如航空航天、火箭发动机、核聚变炉等方面展开应用。此外,随着制备技术的发展,SiC纤维的应用逐渐拓展到高级运动器材、汽车废烟气收尘等民用工业方面。SiC fiber is a kind of ceramic fiber with carbon and silicon as the main components, which can be divided into two types: whisker and continuous fiber. SiC fiber has good high temperature performance, high strength, high modulus and chemical stability, the tensile strength can reach 2.5-3.5GPa, the elastic modulus is 200GPa, it has good chemical corrosion resistance, and the coefficient of linear expansion is about It is 3.1×10- 6 K- 1 , resistant to radiation, good in absorbing waves, and has semiconductor properties. It is mainly used to strengthen metal and ceramics and make high temperature resistant metal or ceramic matrix composites. Because of its good performance, it has been applied in cutting-edge technology fields, such as aerospace, rocket engines, nuclear fusion furnaces, etc. In addition, with the development of preparation technology, the application of SiC fiber has gradually expanded to civilian industries such as advanced sports equipment and automobile exhaust gas dust collection.

SiC纤维制备方法包括化学气相沉积法(例如申请号为CN201810086069.9的专利申请“一种碳化硅纳米线气凝胶及其制备方法”)、先驱体转换法(汤明,余兆菊,兰琳,等.固/液态聚碳硅烷共混制备碳化硅纤维的研究.功能材料,2012,43(16):2267-2272.);超微粉体挤压纺丝法(邱海鹏,陈明伟,谢巍杰.SiC/SiC CMC研究及应用.航空制造技术,2015(4):94-97.)和活性炭纤维转化法(K.Okada,H.Kato,K.Nakajima,Preparation ofSilicon Carbide Fiber from Activated Carbon Fiber and Gaseous SiliconMonoxide.Journal of the American Ceramic Society,1994,Vol.77(6),pp.1691-1693)等方法。这些方法存在着制备工艺复杂,成本高,不利于工业化生产等缺点。此外,为进一步提高碳化硅纤维的使用温度,纤维中的游离碳含量需要进一步降低至2%以下。SiC fiber preparation methods include chemical vapor deposition (such as the patent application CN201810086069.9 "a silicon carbide nanowire airgel and its preparation method"), precursor conversion method (Tang Ming, Yu Zhaoju, Lan Lin, et al. Study on the preparation of silicon carbide fibers by blending solid/liquid polycarbosilane. Functional Materials, 2012,43(16):2267-2272.); Superfine powder extrusion spinning method (Qiu Haipeng, Chen Mingwei, Xie Weijie. SiC /SiC CMC research and application. Aviation Manufacturing Technology, 2015(4):94-97.) and activated carbon fiber conversion method (K.Okada, H.Kato, K.Nakajima, Preparation of Silicon Carbide Fiber from Activated Carbon Fiber and Gaseous SiliconMonoxide .Journal of the American Ceramic Society, 1994, Vol.77(6), pp.1691-1693) and other methods. These methods have the disadvantages of complex preparation process, high cost, and being unfavorable for industrialized production. In addition, in order to further increase the use temperature of silicon carbide fibers, the free carbon content in the fibers needs to be further reduced to below 2%.

发明内容Contents of the invention

针对现有技术中存在的不足,本发明提供了一种利用硅片切割废料制备SiC纤维的方法。所制备的SiC纤维中游离碳含量低,原料来源广泛,成本低,且不含有毒有害物质。本发明在解决金刚线切割硅片废料回收利用问题的同时提供了一种新颖的高质量SiC纤维的制备方法,将固体废弃资源朝着绿色、高效、高收益的方向发展。Aiming at the deficiencies in the prior art, the invention provides a method for preparing SiC fibers by using silicon chip cutting waste. The free carbon content in the prepared SiC fiber is low, the source of raw materials is wide, the cost is low, and no toxic and harmful substances are contained. The invention provides a novel preparation method of high-quality SiC fiber while solving the recycling problem of diamond wire cutting silicon chip waste, and develops solid waste resources towards a green, efficient, and high-yield direction.

一种利用硅片废料制备SiC纤维的方法,其特征在于,包括如下步骤:A method for preparing SiC fibers by utilizing silicon wafer waste, comprising the steps of:

(1)硅片切割废料的清洗,去除硅片废料中的有机物,过滤、干燥后得到洁净的废硅粉;(1) Cleaning of silicon wafer cutting waste, removing organic matter in silicon wafer waste, filtering and drying to obtain clean waste silicon powder;

(2)SiO前驱体的制备:将废硅粉和石英粉按1:2的质量比混合均匀,作为SiO前驱体;(2) Preparation of SiO precursor: Mix waste silicon powder and quartz powder evenly at a mass ratio of 1:2, as a SiO precursor;

(3)SiC纤维制备:将SiO前驱体置于氧化铝坩埚中,装入氧化铝反应器,常压下向氧化铝反应器中通入Ar、H2、CH4混合气体,将此氧化铝反应器缓慢插入预先加热到1550~1650℃的高温炉中,并在高温炉反应60~120min;坩埚中的硅粉和石英粉反应生成气态SiO,随即与混合气体中的CH4反应生SiC纤维;(3) SiC fiber preparation: put the SiO precursor in an alumina crucible, put it into an alumina reactor, and pass a mixed gas of Ar, H 2 , and CH 4 into the alumina reactor under normal pressure, and the alumina The reactor is slowly inserted into a high-temperature furnace preheated to 1550-1650°C, and reacts in the high-temperature furnace for 60-120 minutes; the silicon powder and quartz powder in the crucible react to form gaseous SiO, and then react with CH 4 in the mixed gas to form SiC fibers ;

(4)SiC纤维中富余游离碳的去除:将反应气体切换为纯H2,高温炉内保持1550~1650℃的温度,SiC纤维中富余游离碳与H2反应生成CH4,去除SiC纤维中富余游离碳,反应10~30min后,停止通入气体,并将氧化铝反应器缓慢提出高温炉;充分冷却后,从氧化铝反应器取出氧化铝坩埚,得到低碳含量SiC纤维。(4) Removal of excess free carbon in SiC fibers: switch the reaction gas to pure H 2 , keep the temperature in the high-temperature furnace at 1550-1650°C, the excess free carbon in SiC fibers reacts with H 2 to generate CH 4 , and removes the excess free carbon in SiC fibers. After 10 to 30 minutes of reaction, the gas is stopped, and the alumina reactor is slowly taken out of the high-temperature furnace; after sufficient cooling, the alumina crucible is taken out from the alumina reactor to obtain low-carbon SiC fibers.

进一步地,所述步骤(1)中硅片切割废料中所含有的硅的质量百分比为Si≥97%。Further, in the step (1), the mass percentage of silicon contained in the silicon wafer cutting waste is Si≥97%.

进一步地,所述步骤(2)中细石英粉的粒径为50~500μm。Further, the particle size of the fine quartz powder in the step (2) is 50-500 μm.

进一步地,所述步骤(3)中Ar、H2、CH4混合气体中CH4的含量为2vol%,H2的含量为68vol%,Ar的含量为30vol%。Further, in the step (3), the content of CH 4 in the mixed gas of Ar, H 2 and CH 4 is 2 vol%, the content of H 2 is 68 vol%, and the content of Ar is 30 vol%.

进一步地,所述步骤(4)中得到的低碳含量SiC纤维的直径0.3~0.6μm,长度为50~200μm,游离碳含量小于1.5%。Further, the SiC fiber with low carbon content obtained in the step (4) has a diameter of 0.3-0.6 μm, a length of 50-200 μm, and a free carbon content of less than 1.5%.

进一步地,所述步骤(1)中利用乙醇和去离子水漂洗硅片切割废料。Further, in the step (1), the silicon wafer cutting waste is rinsed with ethanol and deionized water.

本发明首先通过醇洗和水洗去除硅片废料中的有机物,与石英粉混合;混合粉末在高温反应器中反应生成气相SiO;与通入的CH4反应生成SiC纤维。随后在高温下H2气氛中焙烧,能有效去除纤维中的富余游离碳,冷却后收集到低碳含量的高质量SiC纤维。本发明制备的SiC纤维直径0.3~0.6μm,长度为50~200μm,游离碳含量小于1.5%,得到的SiC纤维碳含量低,提高了纤维的耐高温性能,性能优异。The invention first removes the organic matter in the silicon wafer waste by alcohol washing and water washing, and mixes it with quartz powder; the mixed powder reacts in a high-temperature reactor to form gas-phase SiO; and reacts with introduced CH 4 to form SiC fiber. Subsequent calcination in H2 atmosphere at high temperature can effectively remove excess free carbon in the fiber, and high-quality SiC fiber with low carbon content can be collected after cooling. The SiC fiber prepared by the invention has a diameter of 0.3-0.6 μm, a length of 50-200 μm, and a free carbon content of less than 1.5%. The obtained SiC fiber has a low carbon content, improves the high temperature resistance of the fiber, and has excellent performance.

本发明利用光伏产业中金刚线切割硅片废料制备SiC纤维,原料来源广泛,价格便宜,且不含有毒有害物质。在解决金刚线切割硅片废料回收利用问题的同时提供了一种高质量SiC纤维的制备方法,解决了现有技术中金刚线切割硅片废料的回收利用带来的难题,可在硅粉废料回收等领域广泛推广;将固体废弃资源回收利用朝着绿色、高效、高收益的方向发展。The invention utilizes silicon chip waste materials cut by diamond wires in the photovoltaic industry to prepare SiC fibers, and the raw materials have wide source, low price and no poisonous and harmful substances. It provides a high-quality SiC fiber preparation method while solving the recycling problem of diamond wire-cut silicon wafer waste, which solves the problems caused by the recycling of diamond wire-cut silicon wafer waste in the prior art, and can be used in silicon powder waste. Recycling and other fields are widely promoted; the recycling of solid waste resources is developed in the direction of green, efficient and high-yield.

附图说明Description of drawings

图1为本发明所述制备方法中所使用的氧化铝反应器的结构示意图。Figure 1 is a schematic structural view of the alumina reactor used in the preparation method of the present invention.

图2为实施例1所制备的SiC纤维的XRD衍射图。FIG. 2 is an XRD diffraction pattern of SiC fibers prepared in Example 1.

图3为实施例1所制备的SiC纤维的SEM图片。FIG. 3 is a SEM picture of SiC fibers prepared in Example 1.

图4为实施例1所制备的SiC纤维的TEM图片。FIG. 4 is a TEM picture of SiC fibers prepared in Example 1.

附图标记说明:Explanation of reference signs:

1-坩埚,2-氧化铝内管,3-支撑杆,4-SiO前驱体,5-铝合金法兰,6-进气管,7-出气口,8-氧化铝外管。1-crucible, 2-alumina inner tube, 3-support rod, 4-SiO precursor, 5-aluminum alloy flange, 6-intake pipe, 7-gas outlet, 8-alumina outer tube.

具体实施方式Detailed ways

下面结合附图对本发明具体实施方式作进一步详细说明,使本发明所要求保护的技术方案更加清楚、完整。具体实施例是本发明的一部分实施例,而不是全部的实施例,同时本发明的保护范围并不限于所述内容。The specific embodiments of the present invention will be described in further detail below in conjunction with the accompanying drawings, so as to make the technical solutions claimed in the present invention clearer and more complete. The specific embodiments are a part of the embodiments of the present invention, but not all of them, and the protection scope of the present invention is not limited to the content.

本发明所述的利用硅片切割废料制备SiC纤维的方法,首先通过醇洗和水洗去除硅片废料中的有机物,再与粒径为50~500μm的市售石英粉混合,作为SiO前驱体。SiO前驱体在高温反应器中生成气相SiO,与通入的CH4反应生成SiC纤维;此过程中涉及到的化学反应公式为:The method for preparing SiC fibers from silicon chip cutting waste according to the present invention first removes organic matter in the silicon chip waste by alcohol washing and water washing, and then mixes it with commercially available quartz powder with a particle size of 50-500 μm as a SiO precursor. The SiO precursor generates gas-phase SiO in the high-temperature reactor, and reacts with the incoming CH 4 to form SiC fibers; the chemical reaction formula involved in this process is:

Si(s)+SiO2(s)=2SiO(g)Si(s)+SiO2(s)=2SiO(g)

SiO(g)+2CH4(g)=SiC(s)+CO(g)+4H2(g)SiO(g)+2CH 4 (g)=SiC(s)+CO(g)+4H 2 (g)

CH4(g)=C(s)+2H2(g)CH 4 (g)=C(s)+2H 2 (g)

随后在高温、H2气氛中焙烧去除纤维中的富余游离碳;此过程中涉及到的化学反应公式为:Subsequent roasting at high temperature and H2 atmosphere removes excess free carbon in the fiber; the chemical reaction formula involved in this process is:

C(s)+2H2(g)=CH4(g)C(s)+2H 2 (g)=CH 4 (g)

最后,冷却收集到低碳含量的高质量SiC纤维。Finally, cooling collected high-quality SiC fibers with low carbon content.

实施例1Example 1

(1)取25g金刚线切割硅片废料,用乙醇漂洗10分钟,抽滤后再用去离子水漂洗2次。抽滤、干燥后得到洁净废硅粉,其元素组成如表1所示。(1) Take 25g of diamond wire cut silicon wafer waste, rinse it with ethanol for 10 minutes, filter it with suction, and rinse it twice with deionized water. Clean waste silicon powder was obtained after suction filtration and drying, and its elemental composition is shown in Table 1.

表1.金刚线切割硅片废料的元素组分Table 1. Elemental composition of diamond wire sawed silicon wafer scrap

元素element SiSi CC Oo CaCa NiNi KK NaNa MgMg AlAl FeFe 含量(wt%)Content (wt%) 97.3097.30 1.141.14 1.351.35 0.07030.0703 0.05240.0524 0.00850.0085 0.03180.0318 0.03060.0306 0.00870.0087 0.00540.0054

(2)称取步骤(1)清洗干净的废硅粉3克,称取6克市售的粒径为50~500μm的石英粉,混合均匀,得到SiO前驱体。(2) Weigh 3 grams of waste silicon powder cleaned in step (1), weigh 6 grams of commercially available quartz powder with a particle size of 50-500 μm, and mix them uniformly to obtain a SiO precursor.

(3)将步骤(2)的SiO前驱体4倒入氧化铝坩埚1中,将坩埚1置于氧化铝内管中,并放置在两端开口的氧化铝内管2底部的支撑杆3上,然后将氧化铝内管3插入一端开口的氧化铝外管8,并用铝合金法兰5密封氧化铝外管8,如图1所示,所述铝合金法兰5上设有与氧化铝外管8内部连通的出气口7。所述氧化铝内管的上端开口插入进气管6,常压下向氧化铝反应器中通入Ar、H2、CH4的混合气体,其中Ar 30vol%、H2 68vol%、CH4 2vol%,气体流量设置为2L/min。将此氧化铝反应器缓慢插入预先加热到1600℃的高温炉中,反应保温90min。(3) Pour the SiO precursor 4 of step (2) into the alumina crucible 1, place the crucible 1 in the alumina inner tube, and place it on the support rod 3 at the bottom of the alumina inner tube 2 with openings at both ends , then insert the alumina inner tube 3 into the alumina outer tube 8 with an open end, and seal the alumina outer tube 8 with the aluminum alloy flange 5, as shown in Figure 1, the aluminum alloy flange 5 is provided with an alumina The air outlet 7 communicated with the inside of the outer tube 8 . The upper end opening of the alumina inner tube is inserted into the inlet pipe 6, and a mixed gas of Ar, H 2 and CH 4 is passed into the alumina reactor under normal pressure, wherein Ar 30vol%, H 2 68vol%, CH 4 2vol% , the gas flow rate is set to 2L/min. Slowly insert the alumina reactor into a high-temperature furnace preheated to 1600°C, and keep the reaction for 90 minutes.

(4)90min后,将反应气体切换为纯H2,高温炉温度保持在1600℃,并保持20min。接下来停止通入气体,并将氧化铝反应器缓慢提出高温炉。充分冷却后,从氧化铝反应器取出氧化铝坩埚,得到坩埚中的SiC纤维。(4) After 90 minutes, the reaction gas was switched to pure H 2 , and the temperature of the high-temperature furnace was kept at 1600° C. for 20 minutes. Next, the gas flow is stopped, and the alumina reactor is slowly lifted out of the high-temperature furnace. After sufficient cooling, the alumina crucible was taken out from the alumina reactor to obtain SiC fibers in the crucible.

得到的SiC纤维的XRD图谱如图2所示,说明所制备的SiC纤维晶型为β-SiC。根据图3和图4所示SEM图、TEM图,所制备的SiC纤维长度为50~200μm,直径0.3~0.6μm。利用红外碳硫分析仪(温度设定为940℃)测试SiC纤维的游离碳含量平均为1.37%。本发明降低了SiC纤维中游离碳的含量至1.5%以下,提高了耐高温性能。The XRD pattern of the obtained SiC fiber is shown in Fig. 2, which indicates that the crystal form of the prepared SiC fiber is β-SiC. According to the SEM images and TEM images shown in Figure 3 and Figure 4, the prepared SiC fiber has a length of 50-200 μm and a diameter of 0.3-0.6 μm. The average free carbon content of the SiC fiber is 1.37% tested by an infrared carbon-sulfur analyzer (the temperature is set at 940° C.). The invention reduces the free carbon content in the SiC fiber to less than 1.5%, and improves the high temperature resistance performance.

实施例2Example 2

步骤同实施例1,不同之处在于高温炉温度设置为1550℃,在Ar、H2、CH4混合气体气氛中保持120min,在纯H2气氛中保持30min。制备的SiC纤维长度为15~80μm,直径0.3~0.5μm,游离碳含量平均为1.23%。The procedure is the same as that in Example 1, except that the temperature of the high-temperature furnace is set to 1550° C., kept in an Ar, H 2 , and CH 4 mixed gas atmosphere for 120 minutes, and kept in a pure H 2 atmosphere for 30 minutes. The prepared SiC fiber has a length of 15-80 μm, a diameter of 0.3-0.5 μm, and an average free carbon content of 1.23%.

实施例3Example 3

步骤同实施例1,不同之处在于高温炉温度设置为1650℃,在Ar、H2、CH4混合气体气氛中保持60min,在纯H2气氛中保持10min。制备的SiC纤维长度为20~100μm,直径0.3~0.5μm,游离碳含量平均为1.41%。The procedure is the same as that in Example 1, except that the temperature of the high-temperature furnace is set to 1650° C., kept in an Ar, H 2 , and CH 4 mixed gas atmosphere for 60 minutes, and kept in a pure H 2 atmosphere for 10 minutes. The prepared SiC fiber has a length of 20-100 μm, a diameter of 0.3-0.5 μm, and an average free carbon content of 1.41%.

所述实施例为本发明的优选的实施方式,但本发明并不限于上述实施方式,在不背离本发明的实质内容的情况下,本领域技术人员能够做出的任何显而易见的改进、替换或变型均属于本发明的保护范围。The described embodiment is a preferred implementation of the present invention, but the present invention is not limited to the above-mentioned implementation, without departing from the essence of the present invention, any obvious improvement, replacement or modification that those skilled in the art can make Modifications all belong to the protection scope of the present invention.

Claims (5)

1. A method for preparing SiC fibers by using silicon chip waste is characterized by comprising the following steps:
(1) Cleaning silicon wafer cutting waste, removing organic matters in the silicon wafer cutting waste, filtering and drying to obtain clean waste silicon powder;
(2) Preparing an SiO precursor: uniformly mixing waste silicon powder and quartz powder according to the mass ratio of 1;
(3) Preparing SiC fibers: placing the SiO precursor into an alumina crucible, loading the alumina crucible into an alumina reactor, and introducing Ar and H into the alumina reactor at normal pressure 2 、CH 4 Mixing the gas, slowly inserting the alumina reactor into a high-temperature furnace preheated to 1550-1650 ℃, and reacting for 60-120 min in the high-temperature furnace; the silicon powder in the crucible reacts with the quartz powder to generate gaseous SiO, and the gaseous SiO is mixed with CH in the mixed gas 4 Reacting to generate SiC fibers;
(4) Removing the surplus free carbon in the SiC fiber: switching the reaction gas to pure H 2 Keeping the temperature in a high temperature furnace at 1550-1650 ℃, and obtaining the surplus free carbon and H in the SiC fiber 2 Reaction ofGenerating CH 4 Removing the surplus free carbon in the SiC fiber, stopping introducing gas after reacting for 10-30 min, and slowly lifting the alumina reactor out of the high-temperature furnace; and after fully cooling, taking out the alumina crucible from the alumina reactor to obtain the low-carbon SiC fiber, wherein the diameter of the low-carbon SiC fiber is 0.3-0.6 mu m, the length of the low-carbon SiC fiber is 50-200 mu m, and the content of free carbon is less than 1.5%.
2. The method of claim 1, wherein: the mass percentage of silicon contained in the silicon wafer cutting waste in the step (1) is that Si is more than or equal to 97%.
3. The method of claim 1, wherein: the particle size of the fine quartz powder in the step (2) is 50-500 μm.
4. The method of claim 1, wherein: ar and H in the step (3) 2 、CH 4 CH in the mixed gas 4 Content of (2 vol%), H 2 The content of (3) was 68vol%, and the content of Ar was 30vol%.
5. The method of claim 1, wherein: and (2) rinsing the silicon wafer cutting waste by using ethanol and deionized water in the step (1).
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Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101812730A (en) * 2010-04-23 2010-08-25 中南大学 Preparation method of ultralong monocrystal beta-SiC nanowire metal-free catalyst

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Publication number Priority date Publication date Assignee Title
CN101812730A (en) * 2010-04-23 2010-08-25 中南大学 Preparation method of ultralong monocrystal beta-SiC nanowire metal-free catalyst

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Carbothermal Reduction of Quartz in Different Gas Atmospheres;XIANG LI等;《METALLURGICAL AND MATERIALS TRANSACTIONS B》;20150630;1343-1352 *
Synthesis of SiC whiskers by VLS and VS process;Xiang Li等;《Ceramics International》;20151228;2. Experimental,3.2. Carbothermal reduction in H2 atmosphere,3.3. Carbothermal reduction in CH4-H2-Ar gasmixture *
氢气气氛下SiC纤维的热稳定性;王华等;《材料工程》;20091220;1实验方法 *

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