本文選題：熱力學(xué) + 反應(yīng)層技術(shù)�。� 參考：《西南科技大學(xué)》2017年碩士論文

【摘要】：窯法磷酸是一種結(jié)合電熱法制黃磷和兩步法熱法磷酸工藝的新型制磷酸工藝,該工藝能夠利用選礦尾礦及高雜質(zhì)含量的中低品位磷礦、不用硫酸、少用電、殘?jiān)衫玫葍?yōu)點(diǎn)。但是由于許多問題仍待解決阻礙了其工業(yè)生產(chǎn),如球團(tuán)中碳燒損、殘?jiān)欧帕看�、需要保護(hù)氣氛及CO難以有效利用等。本課題通過反應(yīng)層技術(shù)制備窯法磷酸工藝中所用的新型反應(yīng)層球團(tuán)以及復(fù)合反應(yīng)層球團(tuán),通過熱分析確定了焦炭以及CO作還原劑還原磷礦時(shí)的快速還原溫度,并通過熱力學(xué)討論了C及CO還原磷礦時(shí)溫度、C/S對(duì)還原反應(yīng)的影響。研究了球團(tuán)結(jié)構(gòu)、C/S、煅燒溫度、空氣通入速率等因素對(duì)磷礦還原率、殘球性能的影響,由此確定了反應(yīng)層技術(shù)下窯法還原磷礦的最佳工藝條件,并在此基礎(chǔ)上對(duì)殘球物相進(jìn)行了分析,同時(shí)測(cè)定了殘球的力學(xué)性能,結(jié)果表明殘球可作輕質(zhì)骨料使用。研究結(jié)果如下:⑴高溫下CO和焦炭都能作為還原劑還原磷礦。隨著煅燒溫度的升高以及Z值的增大(即C/S的減小),C以及CO還原磷礦反應(yīng)的?8)在減小、平衡常數(shù)在增大。而隨著煅燒溫度的升高,C還原磷礦的?8)在逐漸減小,而CO還原磷礦的?8)幾乎不變,且C還原磷礦的?8)是CO還原磷礦的2倍;隨著Z值的增大(即C/S的減小),C以及CO還原磷礦的?8)在逐漸減小。因此,溫度的升高以及C/S的減小都有利于C以及CO還原磷礦的反應(yīng)的進(jìn)行。⑵空氣氣氛下,C/S=0.4的普通球團(tuán)在1300℃下煅燒反應(yīng)3h后其磷礦還原率最高僅為49.76%;N2氣氛下,C/S=0.4的普通球團(tuán)在1275℃下煅燒反應(yīng)3h后其磷礦還原率可達(dá)96.4%。這說明空氣氣氛下普通球團(tuán)雖然有嚴(yán)重的碳燒損問題;而N2保護(hù)氣氛能夠有效地防止普通球團(tuán)中發(fā)生碳燒損。⑶C/S為1.0、造孔材料摻量為8%、碳過剩系數(shù)為1.4的球團(tuán)在1300℃下煅燒3h后(窯內(nèi)氣體流速為500ml/min),球團(tuán)磷礦還原率達(dá)到84.14%。且1250℃煅燒3h后可得到容重為671kg/m3,強(qiáng)度為2.3MPa的空心結(jié)構(gòu)的殘球。⑷C/S=0.4的復(fù)合反應(yīng)層球團(tuán)在1275℃下煅燒3h后,可得到形狀保持完整、具有多孔結(jié)構(gòu)的殘球,此時(shí)球團(tuán)的磷礦還原率可達(dá)86.74%(第一反應(yīng)層磷礦還原率可達(dá)95.44%,第二反應(yīng)層磷礦還原率可達(dá)78.03%);同時(shí)所得殘球的容重為794kg/m3,單�？箟簭�(qiáng)度為1.24MPa,符合國(guó)家標(biāo)準(zhǔn)可作輕骨料使用。
[Abstract]:Kiln phosphoric acid is a new phosphoric acid process combined with electrothermal phosphoric acid process and two-step thermal phosphoric acid process. The process can utilize the advantages of ore dressing tailings and low grade phosphate rock with high impurity content, no sulfuric acid, less electricity consumption and residue utilization. However, many problems still remain to be solved, such as carbon burning in pellets, large residual emissions, need to protect atmosphere, and CO is difficult to be effectively used. In this paper, the new reaction layer pellets and composite reactive layer pellets used in kiln phosphoric acid process were prepared by reactive layer technology. The rapid reduction temperature of coke and CO as reductant for reducing phosphate rock was determined by thermal analysis. The effect of temperature (C / S) on the reduction of phosphate rock by C and CO was discussed by thermodynamics. The effects of pellet structure C / S, calcination temperature and air flow rate on the reduction rate of phosphate rock and the properties of residual ball were studied, and the optimum technological conditions for the reduction of phosphate rock by kiln method under reactive layer technology were determined. On this basis, the phase of the residual ball was analyzed, and the mechanical properties of the remnant ball were measured. The results show that the residual ball can be used as lightweight aggregate. The results are as follows: at high temperature, CO and coke can be used as reductant to reduce phosphate rock. With the increase of calcination temperature and the increase of Z value (that is, the decrease of C / S), the equilibrium constant is increasing. However, with the increase of calcination temperature, the Ca-8) decreased gradually, but the CO reduced Phosphate almost remained unchanged, and the C- 8) of the C-reduced phosphate rock was twice as high as that of the CO reduced phosphate rock. With the increase of Z value (that is, the decrease of C / S) and the decrease of CO reduced phosphate rock, the value of C / S decreases gradually. Therefore, The increase of temperature and the decrease of C / S are beneficial to the reduction of phosphate rock by C and CO. The reduction rate of C / S _ (0.4) ordinary pellets calcined at 1300 鈩，

本文編號(hào)：1881015