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,我還要感謝魏小磊同學(xué),在試驗(yàn)中得到他的協(xié)助和支持,有時(shí)我們共同探討,在此過程中,讓我學(xué)到了許多知識,在此表示感謝!另外,感謝本論文所引用的所有參考文獻(xiàn)的作者,感謝他們?yōu)楸菊撐牡膶懽魈峁┱鎸?shí)可靠的科學(xué)知識。其次,我要感謝張邦文教授、李解老師、趙瑞超老師,他們在我的實(shí)驗(yàn)過程中也給予我很大的幫助和鼓勵。試驗(yàn)前,我在他的指導(dǎo)下搜集了很多和本論文有關(guān)的專業(yè)方面的資料。因此,用合成的TQ從埃及礦的硫酸鹽浸出液中提取分離鈮時(shí)可行的。實(shí)驗(yàn)室提取試驗(yàn)結(jié)果表明:%,鈮的提取達(dá)到84%。 TQ對干涉元素的萃取從硫酸鹽溶液中TQ提取的主要元素為鈰和銥,提取率分別為63%%。表4的結(jié)果表明。 TQ的載荷能力TQ的載荷能力決定于所接觸的目的溶液。 TQ濃度的影響研究這個(gè)因素,別的條件如A/O定為1/1,接觸時(shí)間15分鐘,%%變化。有可能存在下列反應(yīng)關(guān)系式:Nb2O5+6H2SO4+5/2O2——2NbO2(SO4)3+6H2O (2) 接觸時(shí)間的影響,從一分鐘到三十分鐘。 硫酸濃度的影響、%提取劑TQ后振蕩15分鐘,隨著硫酸濃度的減小,%%。然后用紫外—可見雙射束檢測分析。由蒸餾水、進(jìn)行萃取鈮試驗(yàn)。用電子顯微鏡進(jìn)行礦樣元素分析。接下來,在酒精中有氨基三唑的情況下反應(yīng)六小時(shí),隨后加入結(jié)晶態(tài)的pipredine。為了這個(gè)目的,本實(shí)驗(yàn)就是利用咪唑啉酮化合物從埃及礦硫酸浸出液中提取鈮。這些對提鈮效果顯著地藥劑可以分為兩大類:一類是中性氧化萃取劑,如酮類、TBP、TOPO和亞砜;另一類為含長鏈脂肪族或芳香族的胺類化合物,如TOA、TBA等。鈮應(yīng)用于很多的工業(yè)行業(yè),而且需求很高并且還在增長。L1)Da Effect of TQ concentrationTo study this factor, the TQ concentration in methylene chloride was varied from % up to % while the other extraction conditions were fixed at an A/O ratio of 1/1, contact time 15 min and using the leach liquor of mol/L sulfuric acid. The extraction efficiency increased from % till it reached 84% at the extractant concentration of % and no further extraction occurred by using an excess TQ (%). The logarithmic plot of niobium distribution ratio versus TQ concentration given in yielded a molar ratio of 3/1. Logarithmic plot of Nb distribution ratio lg D vs lg[TQ] Loading capacity of TQThe loading capacity of TQ was determined by contacting the feed solution and % TQ in methylene chloride at an A/O ratio of 1/1 for 15 min. Regarding the molar ratio, the maximum loading capacity was found to be g/L. It is worth to mention that contacting three volumes of the feed solution with one volume of % TQ yielded g/L (Table 3), which is % of the maximum loading capacity. Stripping and precipitation experimentsThe loaded organic phase assaying g/L niobium was shaken with the same volume of the following stripping agents: distilled water, mol/L HF and mol/L HF. The results given in Table 4 showed that mol/L HF stripped % of the loaded niobium. Two volumes of ammonia solution (33%) were mixed with one volume of mol/L HF strip solution to yield % precipitation efficiency. The solid product was filtered and thoroughly washed。 and these may be sold, or further processed to reduce the salts to the respective metals. Niobium is considered to cover the vast majority of material in the industry. Its demand is at all time high and continue to rise. Mining and processing capacity is being increased to satisfy this situation, primarily by CBMM with its further expansion to 185 t/a Nb2O5 scheduled in 2008.Niobium is extracted from the source materials, imported concentrates, and tin slags. A large number of solvent extraction processes using different binations of various organic reagents and mineral acids have been investigated for the extraction and separation of niobium. The reagents that have been shown to be suitable for the extraction and separation of niobium can be grouped broadly into two categories. One includes neutral oxygenated extractants, such as ketones, tributyl phosphate(TBP), triocytlphosphine oxide(TOPO), Noxides, and sulfoxides. The other category includes long chain aliphatic and aromatic amines that contain basic nitrogen capable of forming amine salts。%的鈮留在尾礦中,%。本文使用8M HCl,液固比為6:1,150℃恒溫條件下在高壓反應(yīng)釜中對尾礦進(jìn)行酸浸。 750℃、45min還原礦在不同激磁電流強(qiáng)度下進(jìn)行磁選所得尾礦Nb2O5指標(biāo)I(A)Nb2O5%收率%富集比本文原料中主要有氧化物、鐵酸鹽和硅酸鹽等組分。—:750℃,45min還原,%,%。當(dāng)還原時(shí)間為45min時(shí),%。綜合考慮收率和品位,不同還原時(shí)間時(shí),精礦指標(biāo)均在750℃時(shí)達(dá)到最佳。當(dāng)還原時(shí)間為65min、85min時(shí),還原溫度超過750℃以后,溫度升高,收率開始下降。(a)激磁電流強(qiáng)度對750℃、45min還原鐵精礦指標(biāo)的影響 (b)激磁電流強(qiáng)度對800℃、45min還原鐵精礦指標(biāo)的影響(a)還原溫度對25min還原鐵精礦指標(biāo)的影響,I=(b)還原溫度對45min還原鐵精礦指標(biāo)的影響,I=(a)—(d)。激磁電流越大,磁力越強(qiáng),進(jìn)入精礦中的磁性物質(zhì)就越多,而磁性物質(zhì)以強(qiáng)磁性的磁鐵礦為主,故電流增大,精礦鐵收率隨之增大。(a)(b)表示激磁電流強(qiáng)度對鐵精礦指標(biāo)的影響。該峰代表磁鐵礦,指標(biāo)化的衍射指數(shù)為{311}。這是由于CaF2和SiO2屬衍射表達(dá)能力很強(qiáng)的物相,雖然在原礦和還原礦中的含量很低(<6%),在XRD圖上依然能夠產(chǎn)生較清晰的衍射峰。800℃、45min和850℃、%%,高于理論還原度,表明磁鐵礦可能被進(jìn)一步還原為FeO。故溫度越高,碳的氣化反應(yīng)越高,還原度也越高。700℃的反應(yīng)體系還原度小于20%,明顯低于其它三個(gè)反應(yīng)體系。 實(shí)驗(yàn)結(jié)果及討論 溫度和時(shí)間對還原度的影響 取25min、45min、65min和85min四種還原時(shí)間,分別在700℃、750℃、800℃、850℃四種溫度下進(jìn)行還原。打開真空管式爐開關(guān),在預(yù)先設(shè)定好的時(shí)間和溫度下進(jìn)行還原焙燒?!?300℃、不同保溫時(shí)間條件下合成鈮鐵礦的XRD圖℃不同保溫時(shí)間合成鈮鈣礦的的XRD圖將合成好的鈮鐵礦、鈮鈣礦磨至200目,與200目的、赤鐵礦和稀選尾礦按預(yù)先計(jì)算好的比例稱取,用實(shí)驗(yàn)室用JF810SJ型混料機(jī)混勻。鈮鐵礦、鈮鈣礦的合成在真空碳管電爐(ZT5020型)中進(jìn)行。即,有用組分進(jìn)入溶液,雜質(zhì)和脈石等組分留在渣中,或者是有用組分留在渣中而雜質(zhì)和脈石等進(jìn)入溶液中,從而達(dá)到分離。被磁選礦石進(jìn)入磁性設(shè)備的分選空間后,受到磁力和機(jī)械力(包括重力、離心力、流體阻力等)的共同作用,沿著不同的路徑運(yùn)動,對礦漿分別截取,就可得到不同的產(chǎn)品。R=(WFeO/WTFe)*100(%)式中 R——還原度(%); WFeO——焙燒礦中FeO含量(%); WTFe——焙燒礦全鐵含量(%)。 某稀選尾礦試樣的化學(xué)成分,%元素TFeFeOSiO2PSFK2ONa2O含量元素CaOMgOAl2O3MnOBaONb2O5REO燒減含量 稀選尾礦某試樣的礦相組成,%礦物磁鐵礦赤鐵礦黃鐵礦白云石鈉輝石鈉閃石云母氟碳鈰礦含量礦物獨(dú)居石磷石灰重晶石螢石石英長石鈮礦物其它含量 模擬粗鈮精礦的化學(xué)成分,%元素TFeFeOSiO2PSFK2ONa2OFe2O3含量元素CaOMgOAl2O3MnOBaONb2O5REO燒減 含量第三章 實(shí)驗(yàn)真空碳管電爐 ZT5020型磁選管 SCQS74—Φ50型實(shí)驗(yàn)室用混料機(jī) JF810SJ型壓片機(jī) YP8T型真空烘箱 DZF型高壓反應(yīng)釜 濱海正信儀器廠生產(chǎn)實(shí)驗(yàn)用礦為模擬粗鈮精礦,由200目的合成鈮鐵礦/鈮鈣礦、赤鐵礦和稀選尾礦(、)為原料,配置而成。鑒于上述事實(shí),本課題組提出通過“磁化焙燒—磁選—酸浸”從粗鈮精礦中回收鐵、富集鈮的新工藝。五”科技攻關(guān)項(xiàng)目,組織十余家科研院所和高校進(jìn)行研究攻關(guān),取得了突破性的進(jìn)展,首次在工業(yè)生產(chǎn)條件下,從白云鄂博原礦的生產(chǎn)流程中選出了含鈮(Nb2O5)3%左右的粗鈮精礦。(7) CO/CO2選擇性還原—磁選—酸浸[23 24 ,26]用CO—CO2混合氣體選擇性熱還原含鈮鐵礦, 90%以上的鐵礦物被還原為金屬鐵, 鈮礦物不被還原。二步電爐深還原可得合格鈮鐵合金。溫度、堿度和還原劑是影響鈮熔煉的主要因素。采用選擇性還原—熔分—鈮鐵冶煉流程能夠以較高的回收率綜合提取包頭礦中的鈮、鐵和錳等元素。其中,包鋼采用了弱磁—強(qiáng)磁—浮選稀土進(jìn)行了工業(yè)分流試驗(yàn),首次在工業(yè)生產(chǎn)條件下,%、%的富鈮鐵,%。%,較原礦富集了一倍。(4) 弱磁—強(qiáng)磁—浮選工藝[14 17]中貧氧化礦原礦直接選鈮顯然是經(jīng)濟(jì)上不允許的,必須在選鐵、稀土的同時(shí)實(shí)現(xiàn)鈮的預(yù)先富集,并力求減少鈮富集物中脈石礦物的種類。 (3) 以浮選為主的聯(lián)合流程從包鋼強(qiáng)磁尾礦中回收鈮[1213]采用以浮選為主的聯(lián)合流程,從強(qiáng)磁尾礦中綜合回收稀土和鈮是比較有效地工藝。反浮選作業(yè)中采用水玻璃作鐵礦物、鈮礦物的抑制劑,捕收劑采用氧化石蠟皂,水玻璃用量1kg/t,氧化石蠟