稀土萃取分离过程软测量方法的研究

分析了稀土组分含量在线检测技术进展缓慢的原因,分析了稀土萃取分离过程机制,找出影响稀土组分含量检测的主要因素,确定辅助变量。利用从包钢稀土厂采集的数据通过newrb函数创建径向基网络来实现稀土组分含量的软测量。文中通过流程图详细阐述了建模方法,采用50组样本数据对所建立的模型进行计算机仿真验证,仿真结果证明了模型的可行性。     

白云鄂博矿中稀土、铁综合回收的新工艺研究

采用正浮选-弱磁选-反浮选新型联合工艺流程对白云鄂博矿中赋存的稀土、Fe及Sc矿物进行了综合回收试验研究,为白云鄂博矿中Sc矿物的回收利用提供了一种新的研究思路。开路试验结果表明:在-0.074 mm为85%时,原矿经1粗3精正浮选可得到品位46.12%,回收率52.20%的稀土精矿,且研究发现Na OH作p H调整剂要优于Na2CO3;稀土粗选尾矿在磁场强度为160 k A·M-1时经一次磁选即可得到品位63.42%,回收率65.32%的Fe精矿;磁选尾矿经1粗2精反浮选得到品位405×10-6,回收率20.65%的Sc精矿。     

某稀土浮选尾矿高梯度超导磁选富集稀土矿物试验研究

针对某稀土矿选矿厂低品位难选尾矿,采用浮选方法进一步回收稀土时工艺流程长、成本高的技术难题,利用稀土矿物与脉石矿物之间微弱的磁性差异,采用高梯度超导磁选对该稀土尾矿进行富集,以提高稀土浮选入浮品位。研究结果表明,在电磁磁选介质为钢棒介质、磁场强度为0.4 T,高梯度超导磁选介质为钢毛介质、磁场强度为5.0 T时,通过高梯度超导磁选,可由REO品位为2.71%的稀土尾矿,最终获得产率为40.84%, REO品位为4.52%,回收率为67.35%的超导磁选精矿,抛除产率为22.39%, REO品位仅为0.94%的超导磁选尾矿,为后续稀土浮选提供了便利条件。     

基于交互式自模型混合物分析的近红外光谱波长变量优选方法

为了提高近红外光谱定量分析的预测精度和建模效率,提出了一种基于交互式自模型的混合物分析的波长优选方法,根据光谱各波长变量的纯度值和标准差值,选择含有用信息的波长变量,并引入相关权函数解决变量间共线性问题.通过依次迭代选择的变量建立定量校正模型,由交互验证均方根预测误差(RMSECV)确定最佳波长变量个数.应用该波长变量优选方法对具有不同葡萄糖含量的两组(四成分葡萄糖水溶液实验和人体血浆实验)近红外光谱数据进行分析,两组数据中分别只选择了全部变量的0.3%建立定量校正模型,其验证集葡萄糖浓度的均方根预测误差(RMSEP)分别减少为669和15 mg/L.与全谱范围及优选波段建立的定量校正模型比较,本方法能够通过波长变量优选最小化冗余信息、提高预测精度及建模效率.     

基于迭代缩减窗口自助软收缩算法的近红外光谱变量选择方法研究

该文针对近红外光谱因冗余变量导致的标定模型预测性能差的问题,提出了一种迭代缩减窗口自助软收缩（ISWBOSS）算法。该方法使用窗口对变量进行划分,随机抽取窗口并利用其中的变量建立子模型,计算窗口内变量回归系数的归一化并作为权重继续进行加权采样,从而逐步实现变量空间的软收缩。同时在迭代过程中不断缩减窗口大小对特征变量进行精确搜索。通过在玉米数据集上进行验证,并与全谱法、遗传算法、竞争自适应重加权采样法和自助软收缩法建立的偏最小二乘模型对比,结果表明,新方法不论在准确性还是稳定性上都具有显著优势。以玉米蛋白质含量预测为例,与自助软收缩算法相比,ISWBOSS的预测均方根误差从0.041 8降至0.010 3,且达到最优模型所需的迭代次数更少,运算效率更高。该方法对提高近红外光谱标定模型的性能具有一定的指导意义。     

人工神经网络用于连钱草中总黄酮和三萜酸类成分的含量预测

以连钱草的毛细管电泳指纹图谱为输入数据,以总黄酮和三萜酸类成分含量为输出数据,构建了反向传播网络、径向基函数网络和广义回归网络三种人工神经网络模型.采用三种网络模型和两种预测方法对未知样本的总黄酮和三萜酸类成分含量进行了预测,并分别比较了三种网络和两种预测方法的预测结果.另外,结合聚类分析结果和输入数据的相似度,分析了预测误差的来源.结果表明:三种网络对大部分样本的预测值与实际值都比较接近,而广义回归网络的预测效果最优;扣除奇异值后,广义回归网络的两种预测方法对未知样本的总黄酮和三萜酸类成分含量的平均预测误差分别为10.9%和0.00073%.     

白云鄂博矿脱磷选铁及部分回收稀土、铌的新工艺

为了直接利用白云鄂博原矿冶炼钢提供低P的铁精矿,并同时回收其他有价元素。针对含P 1.05%,含Nb 0.19%的原矿进行了反浮选-弱磁选试验,采用油酸钠为捕收剂,在碱性条件下去除大部分磷灰石和稀土矿物,再对反浮选尾矿经弱磁选得到了含P 0.046%品位为68%的低P铁精矿,Fe回收率达80%;从磁选尾矿可回收回收率44.06%品位0.65%的Nb矿。同时从反浮选产品回收相当原矿91.15%,品位12%的稀土矿物。因此本实验提供了一种获得低磷铁精矿,并部分回收稀土、Nb的新工艺。     

电感耦合等离子体原子发射光谱标准加入法测定钼精矿及烟道灰中的铼

1引言铼是一种稀有稀散金属元素,在地壳中含量极低。自然界中的铼主要以类质同相伴生在辉钼矿、铜钼矿中,焙烧钼精矿过程中产生的烟道灰也是回收铼的主要原料。金属铼具有硬度大、耐腐蚀、耐磨、熔点高、强度高以及良好的塑性等特点,广泛应用于石油化工、国防、航空航天、核能及电子工业等领域。铼的稀有分散性和金属铼及其合金的特殊性能,使     

支持向量机方法预测有机物的亨利常数

以有机物摩尔体积V、偶极项π*、氢键给予体的酸性am、氢键接受体的碱性βm等四种理化参数为输入变量,利用支持向量机方法对72种有机物的亨利常数值进行了定量预测研究。研究发现,采用支持向量机方法可以实现使用较少样本数据建模,并达到较好的预测结果。支持向量方法的预测结果远优于线性回归法预测结果。     

包头混合稀土矿清洁冶炼资源综合提取技术研究

研究了烧碱溶液连续焙烧分解包头混合稀土精矿综合提取有价元素制备氯化稀土的工艺。对混合稀土精矿和烧碱溶液的混合矿浆进行了不同温度的连续焙烧,研究了焙烧温度对稀土分解率、铈氧化率和氟、磷溶出行为的影响,考察了该工艺对不同稀土品位精矿的适应性。结果表明:使用56%品位的稀土精矿,300℃以上焙烧时稀土分解率达到97%以上,铈的氧化率达到93%以上。提出了包头混合稀土矿液碱连续焙烧分解、水洗除氟、盐酸分步溶解、萃取回收磷和铁,中和除钍后得到氯化稀土溶液的资源综合提取工艺,精矿中稀土、氟、磷、钙、铁和钍得到综合回收。     

Sulphur removal of iron ore tailings by flotation

Iron ore tailings have become one kind of the most hazardous solid waste. Beneficiation of iron ore tailings is a significant issue in the world steel industries, from the point of view of both pollution control and secondary resources. This investigation addressed the processing of tailings with high sulphur content from an iron ore concentrator to produce pellet feed fines and to prevent acid mine drainage. This study was the lab-scale testing of an integrated method consisting of froth flotation combined with gravity and magnetic separation. Reverse flotation located at the end of the primary treatment circuit (high- and low-intensity magnetic separation) will lower a large amount of the sulphur from magnetic separator concentrate. The effects of various operating parameters such as concentrations of collector, frother, depressant and activator, pH, solid-in-pulp concentration have been studied on the sulphur removal using reverse flotation. According to the data presented in this study, the maximum recovery of total sulphur was obtained when the operational parameters were set to the PAX dosage160?gr/t, MIBC dosage 140?gr/t, CuSo₄ 100?gr/t, air flow rate 10?l/min, pH 8.5, and pulp density 30%. With these optimum parameters, final concentrate with the grade of 63.7% Fe and 0.085% S was obtained. The results of this study indicated that, with this method, a great amount of iron concentrate is produced and, simultaneously, the sulphidic fraction is separated that can later be managed more easily owing to the reduced volume.     

Beneficiation of borax by reverse flotation in boron saturated brine

Flotation is one of the plausible methods for recovering borax fines discharged as fine waste to the tailings dam in the Kirka borax processing plant. A literature review dealing with the flotation behavior of boron minerals reveals that clay minerals in the boron ores coat boron minerals and thus deteriorate the quality of boron concentrates produced by direct flotation. The main objective of this study is therefore to recover borax fines from the tailings of the concentrator by reverse flotation. A three-level-factor experimental design was used to determine the main and interaction effects of variables selected on the metallurgical performance of reverse flotation. An analysis of variance for experimental results indicates that interaction effects of the variables for concentrate quality and recovery of B2O3 is nonsignificant and the most important variable for grade of concentrate and recovery is the collector dosage. It is shown that a concentrate assaying 11.25% B2O3 with 89.90% B2O3 recovery could be produced by means of single-stage (rougher) reverse flotation. Additionally, in order to produce a sufficient-quality concentrate, a multistage reverse flotation scheme involving rougher, scavenger, and two cleaners was devised. A final concentrate containing 23.47% B2O3 with 81.78% B2O3 recovery was obtained from these tests. The reverse flotation method can be thus considered as an important option for the beneficiation of borax fines.     

多谱拟合(MSF)-电感耦合等离子体原子发射光谱法(ICP-OES)测定钼精矿中的磷

受钼精矿基体中铜、钼元素的干扰,电感耦合等离子体原子发射光谱法(ICP-OES)无法直接用于磷(213.617nm)的检测。考察了钼和铜谱线对磷(213.617nm)测定的影响,应用ICP-OES多谱拟合(MSF)法消除铜(213.599nm)、钼(213.606nm)的光谱干扰,建立了适合钼精矿中磷的检测方法。对方法的准确度和精密度进行实验,钼精矿中磷的加标回收率为96.2%~103.7%,RSD为2.6%~6.0%。实验证明,多谱拟合(MSF)电感耦合等离子体原子发射光谱法测定钼精矿中磷的方法是一种较为理想的分析方法,适合钼精矿中磷的测量范围为0.0010%~1%。     

熔融制样–X射线荧光光谱法同时测定铀钼矿中主次成分

采用混合熔剂熔融制样,建立了同时测定铀钼矿中U,Mo,SiO_2,Fe_2O_3,Al_2O_3等的X射线荧光光谱法。以Li_2B_4O_7–LiBO_2作为熔融试剂,NH_4NO_3作为样品的氧化剂,样品与熔剂的质量比为1∶10。除使用铀矿石国家标准物质外,主要选取人工混合校准样品及历年实验室比对的铀钼矿校准样品绘制成工作曲线。采用理论系数法校正样品的基体效应,用Br Kα,Zr Kα,U Lα,Ba Lα,Zn Kα谱线扣除相应元素的谱线重叠干扰。该方法各组分测定结果的相对标准偏差均小于2.0%(n=10);用标准物质验证方法的准确度,测定值相对误差在0.00~8.00%之间,与标准值基本吻合。该法应用于生产实验中,可以满足对铀钼矿准确、快速的测量要求。     

多谱拟合(MSF)电感耦合等离子体发射光谱(ICP-OES)法测定钼精矿中砷

受钼精矿基体效应及钼元素干扰等因数影响,电感耦合等离子体发射光谱(ICP-OES)法无法直接应用于砷的检测。以硝酸、高氯酸分解试样,过滤去除钼酸沉淀,滤液应用ICP-OES多谱拟合(MSF)法消除残余钼对砷的光谱干扰,建立了适合钼精矿中砷的检测方法。对方法的准确度和精密度进行实验,钼精矿中砷的加标回收率为96.0%～104.7%,相对标准偏差RSD为3.4%～5.2%。实验证明,方法简化了分析流程,具有准确性和重现性均好的优点,方法检出限0.045μg/mL,满足各品级钼精矿中砷的测定。     

The effect of polymer adsorption on the wetting properties of partially hydrophobized magnetite

Upon reverse flotation of iron ore, the surface of the iron ore concentrate may become partially hydrophobized due to adsorption of flotation collector, which is facilitated by the calcium ions present in the process water. Hydrophobic areas on the concentrate surface may introduce problems in subsequent pelletization of the concentrate. A possible way to restore the wettability of the surface could be by modifying the surface with a hydrophilic polymer. The effect of hydrophilic polymers of different types, viz. cationic, anionic, and non-ionic, on the wettability of the magnetite surface after adsorption of a surfactant was investigated. Although all the polymers could adsorb on magnetite at pH 8.5, the contact angle measurements revealed that only anionic ammonium polyacrylate could decrease the contact angle of synthetic magnetite after surfactant adsorption to a level close to that of as-synthesized magnetite. Such effect was probably achieved due to shielding of the hydrophobic surfactant chains from the aqueous phase by hydrophilic polyacrylate molecules. The fact that polyacrylate adsorption on magnetite occurred via calcium ions makes polyacrylate suitable for application in calcium-rich process water. The results presented in this work illustrate that ammonium polyacrylate could be successfully used to improve the wettability of magnetite after adsorption of surfactants.     

Adsorbing colloid flotation separation and polarographic determination of Mo(VI) in water

A method is described for the flotation and determination of Mo(VI) in water at ng/ml levels. Mo(VI) is preconcentrated and separated by adsorbing colloid flotation employing aluminium(III) hydroxide as collector and sodium lauryl sulphate as surfactant at pH 5.3 ± 0.1. The molybdenum content in the froth is estimated by using the catalytic wave of Mo(VI) in the presence of nitrate by charging current compensated d.c. polarography (CCCDCP) or differential pulse polarography (DPP). The effect of variables such as pH, ionic strength, concentration of collector and surfactant, time of stirring and gas flow-rate on the recovery of Mo by flotation is reported. The effects of various cations and anions on the flotation and determination of Mo are studied. This method is employed for the determination of molybdenum in natural fresh water samples.     

Isotope pattern vector based tandem mass spectral data calibration for improved peptide and protein identification

Tandem mass spectra contain noisy peaks which make peak picking for peptide identification difficult. Moreover, all spectral peaks can be shifted due to systematic measurement errors. In this paper, a novel use of an isotope pattern vector (IPV) is proposed for denoising and systematic measurement error prediction. By matching the experimental IPVs with the theoretical IPVs of candidate fragment ions, true ionic peaks can be identified. Furthermore, these identified experimental IPVs and their corresponding theoretical IPVs are used in an optimization process to predict the systematic measurement error associated with the target spectrum. In return, the subsequent spectral data calibration based on the predicted systematic measurement error enhances the data quality. We show that such an integrated denoising and calibration process leads to significantly improved peptide and protein identification. Different from the commonly employed chemical calibration methods, our IPV‐based method is a purely computational method for individual spectra analysis and globally optimizes the use of spectral data. Copyright © 2009 John Wiley & Sons, Ltd.     

Estimation of tungsten in complex matrices using toluene 3,4-dithiol and thiocyanate

 A rapid less labour-intensive procedure for complete decomposition of tungsten bearing complex matrices by potassium pyrosulphate and its determination using toluene 3,4-dithiol and thiocyanate is reported. The analytical results of various standard reference materials are presented (Jasperoid GXR-1, Deposit GXR-3, copper mill head GXR-4, tin-tungsten ore IGS-26, Mo-W ore IGS-27, tungsten concentrate SRM-277, scheelite ore SRM-2430, reference tungsten ore TLG-1, CT-1, BH-1 and Mo-W ore MP-2) along with two manganese nodules (GSPN-2 and GSPN-3) recently introduced by the Chinese Academy of Geological Sciences and one Polish soil sample (SRM-2710). For most of the samples the agreement between the observed value and the published data have been found to be extremely good. Derivations have been noted in some samples where published concentrations are indicative values only, indicating that more data are still required to upgrade the status from proposed/unspecified to the certified level. Results of various statistical analyses (intermethod comparison, F-test and regression analysis) reveal that the methods are matrix dependent. Separation of tungsten from molybdenum is straightforward, hence can be used for a quality control programme and in the evaluation of reference materials. Received: 30 December 1996 / Revised: 12 March 1997 / Accepted: 15 March 1997     

改进的人工神经网络在传感器阵列信号处理中的应用

本文提出传感器阵列信号处理的人工神经网络模型，以Cu^ 2/Ca^ 2系统为研究对象．尝试了神经网络方法的效果。其最大相对误差不超过5．％，最大相对预测误差不超过2．4％，结果表明，该方法性能良好，在各种传感器阵列的信号处理方面有广泛的应用前景。