【正文】
io of niobium increased by increasing volume ratio of aqueous phase over the organic phase, thus the maximum Nb loading was occurred at ratio of 3/1.Table 3 Effect of A/O ratio upon extracting niobium by % TQ from aqueous solution of mol/L sulfuric acid and 15 min contact timeA/O ratio1/41/31/21/12/13/1Concentration in aquor (gL1)Concentration in organics/ (gL1)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。 then it was ignited at 900 ℃. The analysis by SEM showed that its purity reached %。 and it was mainly contaminated with sulfur, calcium and yttrium ().Table 4 Stripping of niobium from loaded extractant % TQ at O/A ratio of 1/1 for 15 minStripping agentH2O mol/L HF mol/L HFStripping efficiency/% Elemental position of precipitate formed from stripsolution as analyzed by scanning electron microscope Interfering elements extracted by TQThe major elements extracted by TQ from the sulfate leach liquor were cerium and yttrium with efficiency of 63% and %, respectively. Both elements were stripped with 20% sodium hydroxide. The extraction process was also interfered by % calcium, which was detected in the final product. Only % tantalum was transferred to the extractant while 4% uranium and % iron were extracted but none of the mentioned elements were stripped with mol/L HF.4 ConclusionsThis study demonstrated the potentiality of TQ in the extraction of niobium from sulfate leach liquor of Egyptian ore sample. The results of the bench scale extraction experiments showed that 84% of niobium was extracted by shaking equal volumes of % TQ in methylene chloride with leach liquor of [NbO2(SO4)3]3 in the organic phase. The mol/L HF was used to strip % niobium, which was precipitated by ammonium hydroxide with efficiency of %. The purity of the final product reached %.Thus, it is possible to utilize the synthesized TQ as an extractant in hydrometallurgical processes for separating niobium from sulfate liquor of Egyptian ore sample.用咪唑啉酮化合物從埃及礦硫酸浸出液中提取鈮1 緒論自然界中,鈮和鉭總是以復雜的氧化物共存,脈石礦物主要為結(jié)晶花崗巖。鈮礦一般用物理或化學方法粉碎礦石后形成鹽類或氧化物然后進入市場;還有就是進一步加工減少鹽類后形成金屬單質(zhì)。鈮應用于很多的工業(yè)行業(yè),而且需求很高并且還在增長。采選能力跟隨這種形式也在增加,尤其是巴西礦冶公司計劃在2008年年處理鈮礦量達到185噸。鈮一般來源于自然鈮礦物、進口或者錫渣。用不同的有機試劑或無機酸進行溶劑萃取來分離提取鈮的研究正在進行。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。以酮類和TBP為基礎(chǔ)的處理方法在鈮提取工業(yè)化上深受喜愛。唑類化合物作為重要的環(huán)狀系因為他們的生物性能的多樣二受到重視。目前的工作就是試驗多齒雜環(huán)含氮化合物。為了這個目的,本實驗就是利用咪唑啉酮化合物從埃及礦硫酸浸出液中提取鈮。2 試驗 萃取劑以β二元酮1,3環(huán)己烷為原料制作的雜環(huán)氮化合物被用來作為提鈮萃取劑。1,3雜環(huán)二酮的懸浮液在有DMF、DMA的情況下加熱三小時。冷卻到室溫,烯胺酮從其中結(jié)晶出來。接下來,在酒精中有氨基三唑的情況下反應六小時,隨后加入結(jié)晶態(tài)的pipredine。殘渣在酒精中用蒸餾水處理,過濾,然后再DMF/水中再結(jié)晶從而得到TQ。 礦石性質(zhì)本實驗所用礦樣為埃及東部Kadabora礦山得來,此礦山的礦為典型的復雜氧化礦。將礦樣磨至74μm并且用X射線檢測。用電子顯微鏡進行礦樣元素分析。表1為礦樣的所含元素及其賦存狀態(tài)。 鈮的回收率,所得懸浮液在150℃下攪拌兩個小時,不溶殘渣過濾,所得濾液的化學成分在表2中給出。把有機溶劑TQ溶入二氯甲烷中作為稀釋劑然后進行萃取試驗。由蒸餾水、進行萃取鈮試驗。最后一步是用33%的氫氧化銨從溶液中沉淀鈮礦物。最后得到的產(chǎn)物用SEM分析其中的化學組成和純度。鈮的濃縮決定于浸出液、萃余液和由連苯三酚組成的剝離劑。然后用紫外—可見雙射束檢測分析。3 結(jié)果及討論 提取試驗在硝酸銨存在下,曾用環(huán)己酮從硫酸鹽浸出液中提取70%的鈮礦物。本次試驗將檢驗1,3環(huán)己酮對提鈮的效果,其浸出率不超過5%。β—二元酮被用來合成TQ,%后用來研究在不同浸出情況下從硫酸鹽中提取鈮的浸出率。 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,%%。這可能是因為提取劑TQ對不同濃度酸的能力不同。值得提的是高度解離的礦對試驗時有好處的。圖1為lgD對lg[H2SO4]的關(guān)系。有可能存在下列反應關(guān)系式:Nb2O5+6H2SO4+5/2O2——2NbO2(SO4)3+6H2O (2) 接觸時間的影響,從一分鐘到三十分鐘。結(jié)果表明隨著接觸時間的延長,浸出率并沒有明顯的變化,而且15分鐘已經(jīng)出現(xiàn)了最大值,%。 A/O的影響,在不同油水度(從1/4—3/1)下振蕩15分鐘。如表3所示,隨著A/O比值的增大,鈮的分布律也在增加,并且在3/1處出現(xiàn)最大值。 TQ濃度的影響研究這個因素,別的條件如A/O定為1/1,接觸時間15分鐘,%%變化。%%時的最高值84%。當TQ濃度再增加時浸出率沒有明顯的變化。表2為鈮的分布率與TQ濃度的對數(shù)關(guān)系。 TQ的載荷能力TQ的載荷能力決定于所接觸的目的溶液。對于摩爾濃度。%TQ以體積比3/1,%。 剝離和沉淀試驗、。表4的結(jié)果表明。兩體積33%。所得濾渣洗滌過濾,然后加熱到900℃干燥。%,其中主要含硫、鈣和銥。 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%%。兩種元素用20%氫氧化鈉洗滌剝離,%鈣的影響。當4%%的鐵被提取時,%的鉭也被提取。4 結(jié)論本實驗證明TQ從硫酸鹽浸出液中提取鈮元素具有很大的潛力。實驗室提取試驗結(jié)果表明:%,鈮的提取達到84%。鈮和TQ在有機相中形成TQ[Nb2(SO4)3]3。,%。%。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可行的。致謝此次畢業(yè)論文是對我大學四年學習結(jié)果的一個整理總結(jié),是把我所學的書本知識轉(zhuǎn)化為實踐,指導并順利完成試驗。本論文所研究的內(nèi)容和書寫是在許多老師以及同學們的幫助下才得以順利進行的,在此,我要衷心的感謝他們!首先,我要感謝我的指導老師布林朝克老師。他在我的整個試驗和論文書寫的過程中給予了我很多很大的幫助和支持。試驗前,我在他的指導下搜集了很多和本論文有關(guān)的專業(yè)方面的資料。試驗中,他細心的指導我,讓我養(yǎng)成了親自動手的好習慣。試驗后他又耐心的指導我書寫論文。他那嚴謹?shù)闹螌W態(tài)度給我留下了很深的印象。其次,我要感謝張邦文教授、李解老師、趙瑞超老師,他們在我的實驗過程中也給予我很大的幫助和鼓勵。我還要感謝我們礦物加工系的屈啟龍、李俠等老師,是他們教會了我選礦的專業(yè)知識,給我做本次試驗打下了牢固的專業(yè)知識。再次,我還要感謝魏小磊同學,在試驗中得到他的協(xié)助和支持,有時我們共同探討,在此過程中,讓我學到了許多知識,在此表示感謝!另外,感謝本論文所引用的所有參考文獻的作者,感謝他們?yōu)楸菊撐牡膶懽魈峁┱鎸嵖煽康目茖W知識。最后,感謝所有幫助我人,他們在我人生路上給予我的幫助將是我一生的財富,祝愿他們身體健康,工作順利!謝謝!