本文選題：磷礦 + 稀土　； 參考：《貴州大學(xué)》2015年碩士論文

【摘要】：我國擁有豐富的稀土資源和磷資源,但稀土礦產(chǎn)資源和磷礦礦產(chǎn)資源都是一次性資源,開采使用后永不再生,而稀土和磷是國民經(jīng)濟(jì)和技術(shù)發(fā)展的重要戰(zhàn)略元素,磷礦中伴生稀土的綜合回收顯得尤為重要。因此,本文針對我國典型的含稀土磷礦的礦物學(xué)特征及硫磷混酸浸出過程稀土的分布規(guī)律和浸出機(jī)理進(jìn)行詳細(xì)的研究,為我國含稀土磷礦的綜合開發(fā)利用提供必要的基礎(chǔ)理論依據(jù)。通過對含稀土磷礦的礦物學(xué)性質(zhì)研究,結(jié)果表明,我國典型的含稀土磷礦貴州織金磷礦、河北礬山磷礦、云南磷礦礦物組成和稀土含量有一定差別�？椊鹆椎V以膠磷礦和白云石為主,稀土總量最高,達(dá)到了0.118%;礬山磷礦以磷灰石和透輝石為主,稀土總量為0.093%,而云南磷礦以磷灰石和硅酸鹽為主,稀土含量最低,不足0.03%。三種磷礦石中,稀土均以鈰(CeO2)、鑭(La2O3)、釹(Nd2O3)、釔(Y2O3)為主,占到了稀土總量的85%以上,且均以輕稀土為主,其含量達(dá)到了60%以上,其中礬山磷礦石中輕稀土的含量高達(dá)81.56%。貴州織金磷礦和云南磷礦中稀土主要賦存于含磷礦物中,而河北礬山磷礦中稀土除賦存于磷灰石外,在透輝石、赤鐵礦等脈石礦物中也有一定的賦存。貴州織金磷礦和河北礬山磷礦可能存在稀土的獨立礦物,但數(shù)量很微。通過對含稀土磷礦在硫、磷混酸體系下浸出實驗研究,結(jié)果表明,硫酸和磷酸加入方式影響稀土的浸出率,先加入磷酸充分浸出礦石再加入硫酸生成磷石膏的浸出方式,有利于提高稀土在溶液中的浸出率;浸出過程,較高的溶液初始磷酸濃度、大的浸出液固比、提高浸出溫度以及延長浸出時間,有利于提高稀土的浸出率。實驗獲得的較佳浸出條件為,溶液初始磷酸濃度50%,硫酸過量系數(shù)1,液固比6:1,浸出溫度80℃,反應(yīng)時間180min;在此條件下,P2O5的浸出率達(dá)到90%以上,∑REO的浸出率達(dá)到63.402%。通過對含稀土磷礦在硫、磷混酸浸出體系下的反應(yīng)機(jī)理分析,結(jié)果表明,含磷礦物首先與H3PO4反應(yīng)生成Ca(H2PO4)2,Ca(H2PO4)2再與H2SO4反應(yīng)生成CaSO4·nH2O。先加入H3PO4與磷礦顆粒充分反應(yīng),在磷礦顆粒反應(yīng)界面附近形成的Ca(H2PO4)2產(chǎn)物膜層的可透性好,以類質(zhì)同象形式存在于磷礦中的稀土與H3PO4反應(yīng)生成的可溶性稀土磷酸鹽可透過膜層充分?jǐn)U散到溶液主體,此時再加入H2SO4,雖然溶液中Ca2+與SO42-生成CaSO4·nH2O的核晶速度較快,但硫酸鈣晶體對稀土的包裹作用降低,從而使溶液中稀土的回收率增加。同時,含稀土磷精礦在硫、磷混酸浸出體系下,磷石膏的晶體粒度較細(xì),大多小于10μm,以針狀、板片狀為主,且隨浸出時間的延長,磷石膏的物相有從二水物向半水物轉(zhuǎn)化的趨勢,包裹的稀土有被釋放的可能性,從而有利于提高稀土的浸出率。最后,磷礦石中稀土的賦存狀態(tài)的不一致雖然導(dǎo)致了稀土的浸出效果不同,但稀土在硫磷混酸體系下的反應(yīng)機(jī)理是相同的。
[Abstract]:Our country has abundant rare earth resources and phosphorus resources, but rare earth mineral resources and phosphate mineral resources are one-time resources, and rare earth and phosphorus are important strategic elements in the development of national economy and technology.The comprehensive recovery of associated rare earths in phosphate rock is particularly important.Therefore, the mineralogical characteristics of typical rare earth containing phosphate rock in China, the distribution law and leaching mechanism of rare earth in the process of mixed acid leaching of sulfur and phosphorus are studied in detail in this paper.It provides the necessary basic theoretical basis for the comprehensive development and utilization of rare earth containing phosphate rock in China.The mineralogical properties of rare earth containing phosphate rock are studied. The results show that the mineral composition and rare earth content of the typical rare earth containing phosphate rock Guizhou Zhijin phosphate rock, Hebei Fanshan phosphate rock and Yunnan phosphate rock are different to some extent.The content of rare earth is the lowest in Yunnan phosphate rock and apatite and diopside in Fanshan phosphate rock, while the content of rare earth is the lowest in Yunnan apatite and dolomite, and the content of rare earth is the lowest, which is less than 0.03 in Fanshan apatite and diopside, and is mainly composed of apatite and dolomite, while the mineral in Yunnan is mainly composed of apatite and dolomite.Among the three kinds of phosphate rock, the rare earths are mainly cerium, cerium, lanthanum, lanthanum, neodymium, neodymium, and yttrium yttrium, which account for more than 85% of the total amount of rare earths, and all of them are light rare earths, the content of which is over 60%, and the content of light rare earth in alanshan phosphate rock is as high as 81.56%.The rare earths in Guizhou Zhijin phosphate rock and Yunnan phosphate rock are mainly found in phosphorus bearing minerals, while in Hebei Fanshan phosphate rock, in addition to apatite, diopside, hematite and other gangue minerals also exist.There may be rare earth independent minerals in Zhijin phosphate rock of Guizhou and Fanshan phosphate rock in Hebei province, but the quantity is very small.The leaching experiment of rare earth containing phosphate rock in the system of sulfur and phosphoric acid is carried out. The results show that the addition of sulfuric acid and phosphoric acid affects the leaching rate of rare earths, and the leaching method of phosphorous gypsum is obtained by adding phosphoric acid to leaching the ore fully and then adding sulfuric acid to form phosphogypsum.It is beneficial to increase the leaching rate of rare earths in solution, the leaching process, the higher initial phosphoric acid concentration, the higher leaching liquid / solid ratio, the higher the leaching temperature and the longer the leaching time, so as to improve the leaching rate of rare earths.The optimum leaching conditions are as follows: solution initial phosphoric acid concentration 50, sulfuric acid excess coefficient 1, liquid-solid ratio 6: 1, leaching temperature 80 鈩，

本文編號：1743482