【摘要】：膨潤土是以蒙脫石為主要礦物成分的非金屬礦,蒙脫石是含水鋁硅酸鹽層狀礦物。膨潤土以其優(yōu)良的物理和化學(xué)性能被廣泛地應(yīng)用于工業(yè)、農(nóng)業(yè)、醫(yī)藥和科學(xué)研究等領(lǐng)域。盡管人們對(duì)膨潤土已經(jīng)進(jìn)行了廣泛而深入的研究,但是,由于膨潤土具有很強(qiáng)的吸附性、離子交換性和吸濕性,不同產(chǎn)地的膨潤土的性質(zhì)具有較大的差異性。本文以新疆柯爾堿膨潤土為研究對(duì)象,對(duì)其成分、結(jié)構(gòu)、物化性質(zhì)進(jìn)行表征,對(duì)其所含蒙脫石的熱活化過程及其熱分解動(dòng)力學(xué)進(jìn)行了研究。所做工作對(duì)理解該種膨潤土的物理化學(xué)行為具有重要的理論和實(shí)際意義。本文首先根據(jù)膨潤土的化學(xué)成分推算出其主要礦物成分蒙脫石的化學(xué)結(jié)構(gòu)式為:[(Na,Ca,Mg,K)0.4](Al3+1.58(Fe3+,Fe2+)0.07Mg0.31)Si4O10(OH)2·nH2O。采用比表面積測定儀(BET)、電位測定儀(Zeta電位)、X-射線衍射儀(XRD)、掃描電子顯微鏡(SEM)、紅外光譜儀(FTIR)和熱重-差熱分析儀(TG-DSC)等測試手段對(duì)膨潤土原礦進(jìn)行了結(jié)構(gòu)表征和性質(zhì)測定。然后,采用綜合熱分析儀在動(dòng)態(tài)空氣氣氛條件下,對(duì)新疆柯爾堿膨潤土的熱分解過程進(jìn)行了研究。研究表明,當(dāng)熱處理溫度達(dá)到98℃左右時(shí),蒙脫石開始脫去層間水,直至450℃該過程才完全結(jié)束;當(dāng)溫度達(dá)到500℃左右時(shí),蒙脫石八面體片中的羥基開始脫失,直到750℃該過程完全結(jié)束。最后,根據(jù)綜合熱分析數(shù)據(jù),采用等轉(zhuǎn)化率法,通過迭代計(jì)算獲得了準(zhǔn)確活化能,再將得到的活化能應(yīng)用于Malek方法之中,從而推測熱分解的反應(yīng)機(jī)理,進(jìn)一步計(jì)算求得指前因子A。結(jié)果發(fā)現(xiàn):蒙脫石在98~450℃析出層間水期間,遵循反應(yīng)模型得的微分和積分表達(dá)式分別為:nnf))1(1(-14)(n)(--=ααα,n)-1-1)(Gn=αα)(((式中:α為轉(zhuǎn)化率,反應(yīng)級(jí)數(shù)n=1/2),表觀活化能為32.81kJ/mol,指前因子lg A的范圍為:4.876~4.8821s-。蒙脫石在500~750℃脫去結(jié)構(gòu)羥基水,發(fā)生非晶質(zhì)化,這個(gè)過程遵循化學(xué)反應(yīng)模型的微分和積分表達(dá)式分別為:f(α)=(1-α)n和G(α)=(1-(1-α)1-n)/(1-n)(式中:α為轉(zhuǎn)化率,反應(yīng)級(jí)數(shù)n=2.1),表觀活化能為201.85 kJ/mol,指前因子lgA的范圍為:11.210~11.2311s-
[Abstract]:Bentonite is a non-metallic mineral with montmorillonite as the main mineral composition. Montmorillonite is a layered mineral of aluminosilicate. Bentonites are widely used in industry, agriculture, medicine and scientific research because of their excellent physical and chemical properties. Although bentonites have been widely and deeply studied, the properties of bentonites from different producing areas are quite different because of their strong adsorption, ion exchange and hygroscopicity. In this paper, the composition, structure and physicochemical properties of Xinjiang Kerr base bentonite were characterized, and the thermal activation process and thermal decomposition kinetics of montmorillonite contained in it were studied. The work done is of great theoretical and practical significance to understand the physical and chemical behavior of the bentonite. In this paper, the chemical structure formula of montmorillonite, which is the main mineral component of bentonite, is calculated according to the chemical composition of bentone. the chemical structure formula of montmorillonite is [(Na,Ca,Mg,K) 0.4] (Al3 1.58 (Fe3, Fe2) 0.07Mg0.31) Si4O10 (OH) 2 路nH2O.. The structure and properties of bentonite raw ore were characterized by specific surface area tester (BET), potentiometer (Zeta potential), X-ray diffractometer (XRD), scanning electron microscope (SEM), infrared spectrometer (FTIR) and thermogravimetric differential thermal analyzer (TG-DSC). Then, the thermal decomposition process of Kal alkali bentonite in Xinjiang was studied by using a comprehensive thermal analyzer under the condition of dynamic air atmosphere. The results show that when the heat treatment temperature reaches about 98 鈩，

本文編號(hào)：2497885