利用川南硫鐵尾礦制備莫來石晶須的試驗(yàn)研究
發(fā)布時(shí)間：2018-11-28 09:28
【摘要】：川南地區(qū)硫鐵礦儲(chǔ)量巨大,為全國五大硫礦生產(chǎn)基地之一,但粗放型的開采方式,生產(chǎn)者環(huán)保意識薄弱以及相對落后的生產(chǎn)工藝水平等因素造成大量尾礦堆積。數(shù)十年的開采及煉磺所產(chǎn)生的尾礦廢渣被大量堆存于山坡、耕地或排入河流,導(dǎo)致大面積耕地?fù)p失和河流污染,嚴(yán)重影響了當(dāng)?shù)厝嗣竦纳a(chǎn)生活,甚至危及其生命健康。因此,關(guān)于川南硫鐵尾礦綜合開發(fā)利用的研究極具現(xiàn)實(shí)意義。莫來石晶須是運(yùn)用于復(fù)合材料一種性能優(yōu)異的增強(qiáng)補(bǔ)韌材料。在一定條件下,高嶺土可轉(zhuǎn)化為莫來石,而高嶺土正是川南硫鐵尾礦的主要礦物組成,這就為硫鐵尾礦的綜合開發(fā)利用提供了一種可能性。本文以川南硫鐵尾礦的礦物組成及化學(xué)組成分析為基礎(chǔ),驗(yàn)證了以硫鐵尾礦為原料采用熔鹽法在1000℃以下合成莫來石晶須的可行性,并從煅燒溫度、保溫時(shí)間、升溫-冷卻方式、尾礦的成分調(diào)整、雜質(zhì)含量、鋁源及熔鹽介質(zhì)選擇等方面探究了這些因素對制備莫來石晶須的影響,并利用熒光光譜分析(XRF)、等離子體光譜儀(ICP-OES)、 X射線衍射(XRD)、掃描電鏡(SEM)等測試方法對制得產(chǎn)物進(jìn)行表征分析,得出以下結(jié)論：(1)川南硫鐵尾礦的礦物組成以高嶺土為主,主要雜質(zhì)Fe、Ti分別以硫鐵礦、銳鈦礦形式富存于尾礦中,除此之外還存在Ca、K、Mg、C、S及有機(jī)質(zhì)等雜質(zhì)。(2)以川南硫鐵尾礦為原料采用熔鹽法可在800-1000℃內(nèi)成功制備出莫來石晶須。煅燒溫度過低或保溫時(shí)間過短均不利于莫來石晶須的生長,煅燒溫度過高時(shí)則易導(dǎo)致剛玉雜相的生成,而在950℃下煅燒保溫2h,可獲得平均直徑約為45 nm,長度均在500 nm以上,長徑比為10～20的納米級莫來石晶須。因此,煅燒溫度950℃,保溫時(shí)間2h可作為優(yōu)選方案。此外,急速升溫相比于緩慢升溫可形成更多莫來石晶核,這有利于獲得大長徑比的莫來石納米晶須。(3)成分調(diào)整可有效降低川南硫鐵尾礦中Fe、Ca、K和Mg等有害雜質(zhì)元素的含量,但也會(huì)降低有效組分A1203的含量。其中,酸洗過程中酸的濃度及其配比均會(huì)對原料中的化學(xué)組成造成影響。實(shí)驗(yàn)表明,經(jīng)濃度均為25%的硫酸和鹽酸按體積比1：1配置的混合酸酸洗處理和650℃煅燒預(yù)處理的川南硫鐵尾礦的成分組成更有利于制備莫來石晶須。酸洗處理不能明顯減少硫鐵尾礦中TiO2的含量,但一定含量范圍內(nèi)的Ti02有助于莫來石晶須的生長。原料的反應(yīng)活性過低也會(huì)導(dǎo)致最終產(chǎn)品中形成除莫來石以外的物相。(4)在反應(yīng)過程中,能否供給具有高反應(yīng)活性的γ-Al2O3決定了鋁源的優(yōu)劣,以硫鐵尾礦為原料制備莫來石晶須的優(yōu)選鋁源為A12(SO4)3,但若進(jìn)行工業(yè)化大規(guī)模生產(chǎn),選用高品質(zhì)鋁礬土的成本相對較低,將其作為優(yōu)選鋁源。(5)熔鹽介質(zhì)熔點(diǎn)的高低及其液相的粘度大小都會(huì)對莫來石晶須的合成造成影響。Na2SO4的熔點(diǎn)為884℃,且可與A12(SO4)3發(fā)生共融形成液相,該液相在950℃時(shí)的粘度系數(shù)低,而γ-A1203和Si02在該液相中的過飽和度很小,容易析出莫來石晶須,且晶須長徑比大。將K2SO4與Na2SO4質(zhì)量比1：1混合得到的混合熔鹽介質(zhì)可在一定程度上實(shí)現(xiàn)粘度降低,改善晶須形貌,但因K2SO4而產(chǎn)生晶須團(tuán)聚現(xiàn)象不可避免。因而,Na2S04可作為優(yōu)選熔鹽介質(zhì)。
[Abstract]:The reserves of the pyrite in the South Sichuan area are huge, which is one of the five major sulfur ore production bases in the whole country, but the mining method of the extensive type, the weak consciousness of the producer and the relative backward production technology level cause a large number of tailings to accumulate. The decades of exploitation and the tailings waste residue produced by the production of the sulfur are piled up on the hillside, cultivated land or discharged into the river, resulting in large-area cultivated land loss and river pollution, seriously affecting the production and life of the local people, and even endangering the life and health of the local people. Therefore, the research on the comprehensive development and utilization of the sulfur-iron tailings in the south of Sichuan is of great practical significance. Mullite whisker is a kind of reinforced and tough material which is used in the composite material. Under certain conditions, the kaolin can be converted into mullite, and the kaolin is the main mineral composition of the sulfur-iron tailings in the south of Sichuan, which provides a possibility for the comprehensive utilization and utilization of the sulfur-iron tailings. Based on the analysis of the mineral composition and chemical composition of the sulfur-iron tailings in the south of Sichuan, the feasibility of synthesizing the mullite whisker by using the molten salt method at the temperature of 1000 DEG C is verified by using the sulfur-iron tailings as the raw material, and the composition of the tailings is adjusted from the sintering temperature, the heat-insulating time, the temperature-increasing-cooling method, the composition of the tailings, The effects of these factors on the preparation of mullite whiskers were investigated in the aspects of impurity content, aluminum source and molten salt medium selection, and fluorescence spectrum analysis (XRF), plasma spectrometer (ICP-OES) and X-ray diffraction (XRD) were used. The product was characterized by scanning electron microscope (SEM) and other test methods. The following conclusions were drawn: (1) The mineral composition of the sulfur-iron tailings in the South Sichuan is mainly kaolin, and the main impurities, Fe and Ti, are rich in the tailings in the form of pyrite and anatase, and there are also Ca, K, and impurities such as Mg, C, S and organic matters. (2) The mullite whisker can be successfully prepared in the range of 800-1000 DEG C by adopting the molten salt method in the process of using the south Sichuan sulfur iron tailings as the raw material. the sintering temperature is too low or the heat preservation time is too short, which is not beneficial to the growth of the mullite crystal whisker; when the sintering temperature is too high, the generation of the corundum hetero phase is easy to be caused; and the average diameter of the corundum impurity phase can be obtained at the temperature of 950 DEG C for 2h, and the average diameter of the corundum heterophase can be obtained, and the length is more than 500 nm. and the aspect ratio is 10 to 20. Therefore, the sintering temperature is 950 DEG C, and the heat-insulating time 2h can be used as a preferable scheme. in addition, that rapid temperature increase can form more mullite crystal nuclei than the slow temperature rise, which is favorable for obtaining the mullite nano-crystal whisker with large aspect ratio. and (3) the component adjustment can effectively reduce the content of the harmful impurity elements such as Fe, Ca, K and Mg in the sulfur iron tailings of the south Sichuan, but also reduce the content of the active component A1 203. The acid concentration and the ratio of the acid in the pickling process can affect the chemical composition of the raw materials. The experiment shows that the composition of the sulfuric acid and hydrochloric acid with a concentration of 25% and hydrochloric acid at a volume ratio of 1: 1 is more beneficial to the preparation of the mullite whisker. The acid-washing treatment can not obviously reduce the content of TiO2 in the sulfur-iron tailings, but Ti02 in a certain amount can help the growth of the mullite whisker. too low the reaction activity of the feedstock also results in the formation of a phase other than mullite in the final product. (4) In the course of the reaction, it is possible to supply the Al-Al2O3 with high reaction activity to determine the advantages and disadvantages of the aluminum source, and the preferred aluminum source for preparing the mullite whisker by using the sulfur iron tailings as the raw material is A12 (SO4) 3, but if the industrial mass production is carried out, the cost of the high-quality bauxite is relatively low, which is used as a preferred source of aluminium. (5) The melting point of the molten salt medium and the viscosity of the liquid phase affect the synthesis of the mullite whisker. The melting point of Na2SO4 is 884.d egree. C. and can be blended with A12 (SO4) 3 to form a liquid phase, the viscosity coefficient of the liquid phase at 950 DEG C is low, and the supersaturation degree of the Al-A1203 and Si02 in the liquid phase is small, the mullite whisker can be precipitated easily, and the aspect ratio of the crystal whisker is large. The mixed molten salt medium obtained by mixing K2SO4 and Na2SO4 with a mass ratio of 1: 1 can reduce the viscosity to a certain extent, and improve the morphology of the crystal whisker, but the phenomenon of whisker agglomeration due to K2SO4 is inevitable. Thus, Na2S04 can be used as a preferred molten salt medium.
【學(xué)位授予單位】：成都理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TD926.4
本文編號：2362465
[Abstract]:The reserves of the pyrite in the South Sichuan area are huge, which is one of the five major sulfur ore production bases in the whole country, but the mining method of the extensive type, the weak consciousness of the producer and the relative backward production technology level cause a large number of tailings to accumulate. The decades of exploitation and the tailings waste residue produced by the production of the sulfur are piled up on the hillside, cultivated land or discharged into the river, resulting in large-area cultivated land loss and river pollution, seriously affecting the production and life of the local people, and even endangering the life and health of the local people. Therefore, the research on the comprehensive development and utilization of the sulfur-iron tailings in the south of Sichuan is of great practical significance. Mullite whisker is a kind of reinforced and tough material which is used in the composite material. Under certain conditions, the kaolin can be converted into mullite, and the kaolin is the main mineral composition of the sulfur-iron tailings in the south of Sichuan, which provides a possibility for the comprehensive utilization and utilization of the sulfur-iron tailings. Based on the analysis of the mineral composition and chemical composition of the sulfur-iron tailings in the south of Sichuan, the feasibility of synthesizing the mullite whisker by using the molten salt method at the temperature of 1000 DEG C is verified by using the sulfur-iron tailings as the raw material, and the composition of the tailings is adjusted from the sintering temperature, the heat-insulating time, the temperature-increasing-cooling method, the composition of the tailings, The effects of these factors on the preparation of mullite whiskers were investigated in the aspects of impurity content, aluminum source and molten salt medium selection, and fluorescence spectrum analysis (XRF), plasma spectrometer (ICP-OES) and X-ray diffraction (XRD) were used. The product was characterized by scanning electron microscope (SEM) and other test methods. The following conclusions were drawn: (1) The mineral composition of the sulfur-iron tailings in the South Sichuan is mainly kaolin, and the main impurities, Fe and Ti, are rich in the tailings in the form of pyrite and anatase, and there are also Ca, K, and impurities such as Mg, C, S and organic matters. (2) The mullite whisker can be successfully prepared in the range of 800-1000 DEG C by adopting the molten salt method in the process of using the south Sichuan sulfur iron tailings as the raw material. the sintering temperature is too low or the heat preservation time is too short, which is not beneficial to the growth of the mullite crystal whisker; when the sintering temperature is too high, the generation of the corundum hetero phase is easy to be caused; and the average diameter of the corundum impurity phase can be obtained at the temperature of 950 DEG C for 2h, and the average diameter of the corundum heterophase can be obtained, and the length is more than 500 nm. and the aspect ratio is 10 to 20. Therefore, the sintering temperature is 950 DEG C, and the heat-insulating time 2h can be used as a preferable scheme. in addition, that rapid temperature increase can form more mullite crystal nuclei than the slow temperature rise, which is favorable for obtaining the mullite nano-crystal whisker with large aspect ratio. and (3) the component adjustment can effectively reduce the content of the harmful impurity elements such as Fe, Ca, K and Mg in the sulfur iron tailings of the south Sichuan, but also reduce the content of the active component A1 203. The acid concentration and the ratio of the acid in the pickling process can affect the chemical composition of the raw materials. The experiment shows that the composition of the sulfuric acid and hydrochloric acid with a concentration of 25% and hydrochloric acid at a volume ratio of 1: 1 is more beneficial to the preparation of the mullite whisker. The acid-washing treatment can not obviously reduce the content of TiO2 in the sulfur-iron tailings, but Ti02 in a certain amount can help the growth of the mullite whisker. too low the reaction activity of the feedstock also results in the formation of a phase other than mullite in the final product. (4) In the course of the reaction, it is possible to supply the Al-Al2O3 with high reaction activity to determine the advantages and disadvantages of the aluminum source, and the preferred aluminum source for preparing the mullite whisker by using the sulfur iron tailings as the raw material is A12 (SO4) 3, but if the industrial mass production is carried out, the cost of the high-quality bauxite is relatively low, which is used as a preferred source of aluminium. (5) The melting point of the molten salt medium and the viscosity of the liquid phase affect the synthesis of the mullite whisker. The melting point of Na2SO4 is 884.d egree. C. and can be blended with A12 (SO4) 3 to form a liquid phase, the viscosity coefficient of the liquid phase at 950 DEG C is low, and the supersaturation degree of the Al-A1203 and Si02 in the liquid phase is small, the mullite whisker can be precipitated easily, and the aspect ratio of the crystal whisker is large. The mixed molten salt medium obtained by mixing K2SO4 and Na2SO4 with a mass ratio of 1: 1 can reduce the viscosity to a certain extent, and improve the morphology of the crystal whisker, but the phenomenon of whisker agglomeration due to K2SO4 is inevitable. Thus, Na2S04 can be used as a preferred molten salt medium.
【學(xué)位授予單位】：成都理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TD926.4
【參考文獻(xiàn)】
相關(guān)期刊論文 前6條
1 李雪冬;朱伯銓;張少偉;;熔鹽介質(zhì)對合成莫來石晶須的影響[J];稀有金屬材料與工程;2008年S1期
2 蔡舒,孟佳宏,楊正方,袁啟明,陳玉如;柱狀自生長莫來石的制備及顯微結(jié)構(gòu)[J];硅酸鹽學(xué)報(bào);1998年02期
3 葉巧明,劉建,張其春;川南煤系硫鐵礦尾礦高嶺土綜合利用研究[J];礦產(chǎn)綜合利用;2002年01期
4 李智;張其春;葉巧明;;利用硫鐵礦尾礦制備微晶玻璃[J];礦產(chǎn)綜合利用;2007年01期
5 袁建君，劉智恩，，韓玉;莫來石晶須制備新工藝與生長機(jī)理[J];無機(jī)材料學(xué)報(bào);1996年01期
6 曹燁;熊先孝;李響;唐堯;王瑩;;中國硫礦床特征及資源潛力分析[J];現(xiàn)代化工;2013年12期
相關(guān)碩士學(xué)位論文 前1條
1 尹玉成;TiO_2對莫來石結(jié)構(gòu)和性能影響研究[D];武漢科技大學(xué);2006年
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