【摘要】 深海稀土，是指深海盆地中富含稀土元素的沉积物，是继多金属结核、富钴结壳及多金属硫化物之后被发现的第四种深海金属矿产，具有巨大的资源潜力。目前，我国针对深海稀土资源的调查和探测技术研究十分薄弱，缺乏完备的能够实时探测深海沉积物中稀土元素（REY）的技术手段，无法从深海沉积物中准确探测到稀土元素。激光诱导击穿光谱（LIBS）具有原位、实时、连续、非接触等独特优势，近年逐渐应用到水下元素分析中。由此，提出了一种深海稀土探测新方法，即将深海沉积物中的稀土元素通过无机酸浸出，而后利用LIBS的水下分析能力对深海沉积物浸出液中的离子态稀土元素进行探测。深海沉积物经预处理后，进行了不同无机酸种类和浓度、固液比及时间条件的浸出实验，研究了各个条件对稀土元素浸出过程的影响。通过对比各浸出液中稀土元素的浸出率获得最佳浸出条件，即HNO₃浓度1.5 mol·L^-1、液固比2∶1、浸出时间5 min。利用LIBS对浸出液中稀土元素（Y、 La、 Nd）进行分析，光谱经平均处理、波长位移差分算法（WASS）校正后，进行单变量回归（UVR）和偏最小二乘法（PLS）分析。UVR分析获得稀土元素（Y、 La、 Nd）最佳线性回归结果的回归系数分别为0.87、 0.83、 0.80,对应检测限为3.55、 4.09和5.71μg·g^-1; PLS获得了显著优于UVR的回归结果，且获得更好的回归系数，分别为0.97、 0.99、 0.97。分析结果表明，PLS较UVR更适合深海沉积物的定量分析，同时证明了LIBS具有深海原位稀土元素探测的潜能，证实了利用LIBS结合多变量回归分析对深海沉积物中稀土元素进行检测和评价是可行的，为实现LIBS深海稀土探测提供数据支持。更多还原

【Abstract】 Deep-sea rare earth, refers to the sediments rich in rare earth elements in deep-sea basins. It is the fourth deep-sea metal mineral discovered after polymetallic nodules, cobalt-rich crusts, and polymetallic sulfides, and has great resource potential. The research on the investigation and detection technology of deep-sea rare earth resources in China is very weak. There is a lack of complete technical means to detect rare earth elements（REY） in deep-sea sediments in real-time, and rare earth elements cannot be accurately detected from deep-sea sediments. Laser-induced breakdown spectroscopy（LIBS） has unique advantages, such as in-situ, real-time, continuous, and non-contact. In recent years, LIBS has been gradually applied to underwater elemental analysis. Therefore, this paper proposes a new method for deep-sea rare earth detection, that is, the rare earth elements in deep-sea sediments are leached by inorganic acid. Then, the ionic rare earth elements in the leaching solution of deep-sea sediments are detected using LIBS underwater analysis. After the pretreatment of deep-sea sediments, the leaching experiments of different inorganic acid types and concentrations, solid-liquid ratio, and time conditions were carried out, and the effects of various conditions on the leaching process of rare earth elements were studied. By comparing the leaching rate of rare earth elements in each leaching solution, the optimum leaching conditions were obtained, that is, HNO₃ concentration 1.5 mol·L^-1, liquid-solid ratio 2∶1, leaching time 5 min. LIBS was used to analyze the rare earth elements（Y, La, Nd） in the leaching solution. After the spectrum was averaged and corrected by wavelength shift difference algorithm（WASS）, univariate regression（UVR） and partial least squares（PLS） analysis were performed. The regression coefficients of the best linear regression results of rare earth elements（Y, La, Nd） obtained by UVR analysis were 0.87, 0.83, 0.80, respectively, and the corresponding detection limits were 3.55, 4.09, 5.71 μg·g^-1; PLS obtained significantly better regression results than UVR and obtained better regression coefficients, which were 0.97, 0.99, 0.97, respectively. The results show that PLS is more suitable for quantitatively analyzing deep-sea sediments than UVR. It also proves that LIBS can detect deep-sea, in-situ rare earth elements. It is feasible to use LIBS combined with multivariate regression analysis to detect and evaluate rare earth elements in deep-sea sediments and provide data support for LIBS deep-sea rare earth detection.更多还原