(1. 北京科技大學(xué) 金屬礦山高效開采與安全教育部重點(diǎn)實(shí)驗(yàn)室，北京 100083;
2. 北京科技大學(xué) 土木與資源工程學(xué)院，北京 100083；
3. 江西離子型稀土工程技術(shù)研究有限公司，贛州 341000；
4. 國(guó)家離子型稀土資源高效開發(fā)利用工程技術(shù)研究中心，贛州 341000)
摘 要: 為揭示風(fēng)化殼淋積型稀土礦浸出前后孔隙演化規(guī)律，對(duì)重配比礦樣開展室內(nèi)柱浸實(shí)驗(yàn)，分析柱浸過(guò)程溶浸液的滲出速率。基于CT無(wú)損探測(cè)技術(shù)及圖像分析軟件，研究在4%(質(zhì)量分?jǐn)?shù))(NH4)2SO4的條件下風(fēng)化殼淋積型稀土礦顆粒浸出前后孔隙結(jié)構(gòu)微細(xì)觀特征及其演化規(guī)律，得到浸出前后稀土礦體孔隙率在縱截面各分段的變化關(guān)系。結(jié)果表明：浸出液滲流速率與累計(jì)浸出時(shí)間呈負(fù)指數(shù)函數(shù)關(guān)系，滲流速率降幅在累積時(shí)間12 h前最為明顯，之后其幅度減緩，累計(jì)時(shí)間24 h后其值趨于穩(wěn)定，穩(wěn)定速率為7.193×10-4 cm/s。浸出后反應(yīng)器內(nèi)的礦體高度減小0.866 cm，礦體發(fā)生了沉降，且礦物顆粒尺寸有所減小，孔隙不均勻分布程度提高，局部出現(xiàn)“泥化”現(xiàn)象，礦體浸出后孔隙率減小16.35 %。機(jī)制分析認(rèn)為，礦物顆粒遷移和溶液化學(xué)作用是影響風(fēng)化殼淋積型稀土浸礦孔隙結(jié)構(gòu)演化的2個(gè)主要因素。
關(guān)鍵字: 風(fēng)化殼淋積型稀土礦；柱浸；孔隙結(jié)構(gòu)；CT 掃描；圖像處理
（1. Key Laboratory of Ministry of Education for High-Efficient Mining and Safety of Metal, University of Science and Technology Beijing, Beijing 100083, China;
2. School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China;
3. Jiangxi Ionic Rare Earth Engineering Research Co., Ltd., Ganzhou 341000, China;
4. National Engineering Research Center for Ionic Rare Earth, Ganzhou 341000, China）
Abstract:In order to reveal the regularity of pore evolution before and after leaching of weathered crust elution- deposited rare earth ore, laboratory column leaching experiment of reallocated ore sample was carried out, and the infiltration rate of the solution was analyzed. Based on non-destructive detection of CT and image analysis software, the micro-mesoscopic characteristics and evolution of pore structure before and after leaching in the presence of 4% (mass fraction) (NH4)2SO4 were disclosed. The relation of rare earth orebody’s porosity was also obtained in different longitudinal sections. The results show that the infiltration rate of the leaching solution is negatively exponentially related to the cumulative leaching time, and the rate decreases with time. The decrease of the infiltration rate is the most obvious in accumulated time of 12 h, and then the amplitude is slowed down. The seepage rate tends to a stable value after cumulative time of 24 h, and the rate is 7.193×10-4 cm/s. After leaching, the height of the ore body in the reactor reduces by 0.866 cm, the subsidence also occurs in the orebody, the particle size of the minerals is reduced, the uneven distribution of pores increases significantly, and some areas occur “muddy” phenomenon. The porosity decreases by 16.35% after the leaching of ore sample. The mechanism analysis shows that the migration of mineral particles and the chemistry of solution are two main factors influencing the evolution of leaching structure of weathered crust elution-deposited rare earth.
Key words: weathered crust elution-deposited rare earth ore; column leaching; pore structure; CT scanning; image processing
