本文關(guān)鍵詞： 煤瀝青 改性 機(jī)械振動(dòng) 中間相 半焦 針狀焦　出處：《太原理工大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：針狀焦是一種結(jié)構(gòu)非常有序、性能優(yōu)良的一種焦炭。因其具有熱膨脹系數(shù)小、機(jī)械強(qiáng)度高、導(dǎo)電率高、耗能低和易石墨化等優(yōu)點(diǎn)，工業(yè)上常用做制備高功率(HP)和超高功率(UHP)石墨電極的原料。然而我國生產(chǎn)的針狀焦與發(fā)達(dá)國家生產(chǎn)的相比，存在體積密度大、電阻率高等缺陷。目前，我國的針狀焦仍以進(jìn)口為主，嚴(yán)重制約了我國電爐煉鋼產(chǎn)業(yè)的發(fā)展。所以，如何制備高質(zhì)量的針狀焦對(duì)于我國“富煤貧油少氣”而大力發(fā)展的煤化工產(chǎn)業(yè)有著十分積極的意義。 本實(shí)驗(yàn)研究了中溫煤瀝青經(jīng)過G和D改性后，其喹啉不溶物含量、β樹脂含量、軟化點(diǎn)、結(jié)焦值等理化性質(zhì)的變化，，分析了不同質(zhì)量比下制得的改性煤瀝青（MCTP）的性質(zhì)差異。發(fā)現(xiàn)與未改性的RCTP相比，MCTP的TI含量、β樹脂含量、SP和CV都呈現(xiàn)出先增加后降低的趨勢(shì)，QI含量隨改性劑含量的增加而增多。 對(duì)MCTP做了氫核磁和元素分析，結(jié)果發(fā)現(xiàn)改性后MCTP的H含量增加、C含量減少，相應(yīng)的H/C比值也增加；改性后芳香氫所占比例增大。改性促使稠環(huán)結(jié)構(gòu)增加，相應(yīng)的聚合程度增大，形成更大的芳香族化合物，進(jìn)而促使半焦定向有序結(jié)構(gòu)的形成。通過熱重分析儀、傅立葉紅外光譜儀（FT-IR）對(duì)MCTP化學(xué)結(jié)構(gòu)和熱行為進(jìn)行了分析，發(fā)現(xiàn)MCTP總體產(chǎn)生更強(qiáng)烈的芳香族的C-H伸縮振動(dòng)吸收峰和芳環(huán)骨架振動(dòng)吸收峰。脂肪族的C-H伸縮振動(dòng)吸收峰要弱很多。改性煤瀝青擁有更好的熱穩(wěn)定性。改性劑最佳適量為5%。后將兩種改性劑做了對(duì)比分析，同時(shí)對(duì)兩種改性反應(yīng)可能的機(jī)理進(jìn)行了推測(cè)。 考察了溫度、壓力及機(jī)械振動(dòng)對(duì)中間相微球生成的影響，得出了最佳炭化工藝條件。認(rèn)為增大氣壓可以促使中間相小球生長(zhǎng)速度加快，425℃為中間相最佳制備溫度，適當(dāng)?shù)臋C(jī)械振動(dòng)作用對(duì)于生成大小、分布都較為均勻的中間相微球有積極地促進(jìn)作用。 采用偏光顯微分析儀、XRD比較了機(jī)械振動(dòng)作用對(duì)RCTP、MCTP制取半焦結(jié)構(gòu)的影響。認(rèn)為機(jī)械作用的存在對(duì)半焦的光學(xué)組織產(chǎn)生非常明顯的影響。且施加的機(jī)械振動(dòng)作用強(qiáng)度存在一個(gè)合適的振動(dòng)頻率。在機(jī)械振動(dòng)的基礎(chǔ)上，通過進(jìn)一步D和G改性作用，纖維紋理方向行得到了進(jìn)一步增強(qiáng)；機(jī)械作用和改性的存在能使半焦晶體面間距離減小，軸向晶體有序度增大。石墨化度提高。 采用SEM比較了機(jī)械振動(dòng)作用對(duì)RCTP、MCTP制取針狀焦結(jié)構(gòu)的影響并做了電化學(xué)分析。增加機(jī)械振動(dòng)針狀焦結(jié)構(gòu)有明顯改善，呈現(xiàn)出有序?qū)訝罱Y(jié)構(gòu)。隨著改性劑計(jì)量（超過5%后）的過度增加，反應(yīng)體系過度交聯(lián)，反而破壞了針狀焦線性結(jié)構(gòu)。通過改性和機(jī)械振動(dòng)的作用提高了針狀焦導(dǎo)電率。
[Abstract]:Needle coke is a kind of coke with very ordered structure and excellent performance. It has the advantages of low thermal expansion coefficient, high mechanical strength, high conductivity, low energy consumption and easy graphitization. Industrial applications are often used as raw materials for the preparation of high power HP-) and ultra-high power UHP-) graphite electrodes. However, compared with those produced in developed countries, the needle coke produced in China has many defects, such as high volume density and high resistivity. The needle coke in our country is still mainly imported, which seriously restricts the development of electric furnace steelmaking industry in China. Therefore, how to prepare high quality needle coke is of great significance to the coal chemical industry, which is rich in coal, lean oil and little gas. The physical and chemical properties of medium temperature coal pitch modified by G and D were studied, such as quinoline insoluble content, 尾 resin content, softening point, coking value and so on. The properties of modified coal tar pitch (MCTP) prepared with different mass ratio were analyzed. It was found that compared with the unmodified RCTP, the content of 尾 resin, SP and CV increased first and then decreased, and the content of QI increased with the increase of modifier content. The hydrogen NMR and elemental analysis of MCTP showed that the H content of modified MCTP decreased and the corresponding H / C ratio increased, and the proportion of aromatic hydrogen increased after modification. The corresponding polymerization degree increased to form larger aromatic compounds, which promoted the formation of oriented ordered structure of semi-char. The chemical structure and thermal behavior of MCTP were analyzed by thermogravimetric analyzer and Fourier infrared spectroscopy (FTIR). It is found that the C-H stretching vibration absorption peak and aromatic ring skeleton vibration absorption peak of MCTP are stronger than those of aromatic group. The C-H stretching vibration absorption peak of aliphatic group is much weaker. The modified coal pitch has better thermal stability. After that, the two modifiers were compared and analyzed. At the same time, the possible mechanism of the two modification reactions was speculated. The effects of temperature, pressure and mechanical vibration on the formation of mesophase microspheres were investigated, and the optimum carbonization conditions were obtained. It is considered that increasing the pressure can accelerate the growth rate of mesophase microspheres at 425 鈩

本文編號(hào)：1529132