With the improvement in tailing mining-grade requirements and in mineral processing technology, tailing materials tend to be fine-grained. Under the action of earthquakes, a tailing dam is prone to liquefaction, which endangers the safety and stability of the dam. To further explore the dynamic properties of tailing silt under cyclic stress, through a series of dynamic triaxial experiments, we investigated the growth of the hysteresis curve, the development of pore pressure, and the energy dissipation law of tailing silt. The experimental findings indicated that increasing the density of the sample significantly improves its liquefaction resistance and the pore pressure development curve can be fitted using the BiDoseResp function. At the same cyclic stress ratio, the sample’s anti-liquefaction strength did not rise monotonically with increasing confining pressure but changed variably at values near a specified low confining pressure; when the sample density rose under the same settings, the specific confining pressure reduced. We also further discussed the evolution law of the stress–strain curves of tailing silt. The results further explored the dynamic characteristics of tailing silt, which can provide some reference for the seismic design and reinforcement measures of many fine-grained tailing dams.

基于地震荷载作用下尾砂发生液化现象,本文提出一种增强尾砂抗震液化特性的方法,即玄武岩纤维加筋尾砂.为验证纤维加筋尾砂的抗液化特性效果及其机理,运用动三轴仪对纤维加筋尾粉砂展开一系列动力试验,研究了同质量分数(0.3%)下不同长度(3、6、9、12、15、18 mm)以及相同长度(9 mm)下不同质量分数(0.1%、0.3%、0.5%、0.7%、0.9%)的纤维对尾砂抗液化性能影响.结果表明,纤维加筋尾砂能够有效提升尾砂的抗液化特性.就增强尾砂的抗液化效果而言,纤维存在最优长度和最优掺量分别为9 mm、0.3%.通过SEM发现,玄武岩纤维填充在尾砂颗粒的孔隙与裂隙中,并与尾砂颗粒发生缠绕、包裹等现象,甚至一些被包裹的纤维之间相互弯曲交织,构建成三维网状的"桥梁"纽带.

为了研究软弱夹层在干湿循环条件下的渗透性变化对边坡整体降雨渗流特性产生的影响,结合现场实际,利用GeoStudio有限元软件建立概化模型,模拟了不同干湿循环次数下边坡的降雨渗流,揭示了不同循环次数下边坡体内孔隙水压力的变化规律.结果表明,在初始状态下,由于软弱夹层的弱透水性雨水很难侵入软弱夹层以及下部灰岩,软弱夹层及下部灰岩孔隙水压力几乎没有变化;干湿循环后软弱夹层渗透系数的变大,他不能作为隔水层阻碍雨水的向下入侵,随着循环次数的增加,软弱夹层和下部灰岩受到雨水的浸润,孔隙水压力变大且由于软弱夹层和灰岩的雨水排出能力远小于上部区域,雨水无法及时排出,在边坡体后缘形成的高孔隙水压力区域面积远大于初始状态,雨水入侵对边坡整体稳定性的影响更大.研究结果可为同类型矿山边坡防护提供参考.

Unusual rainfall is the primary cause of the failure of the tailing dams, and overtopping is the most representative model of the tailing dam failure. The upstream tailing dam was selected as the research object to study the whole process of breach extension and the overtopping dam-failure mechanism under the full-scale rainfall condition. The results showed that the significant size grading phenomenon in the front, middle, and end of the tailing pond was obvious due to the flow separation effect, and its average particle diameter was D50. At different moments of rainfall, the height of the infiltration line at different positions of the dam body was different; at the rainfall of 3600 s, the height of the infiltration line lagged behind the height of the tailing pond, and this phenomenon from the tail of pond to the outside of the dam slope became more obvious. After the rainfall of 3600 s, the height of the infiltration line lagging behind the water level in the pond basically disappeared, and the rate of infiltration line rise kept pace with the rate of water level. The process of overtopping dam-failure experienced dam overtopping (gully erosion), formation of a multistepped small "scarp," breach rapid expansion, formation of large "scarp," and burst (fan-shaped formation). The width and depth of the breach showed a positive correlation, and the widening rate of the breach was 3 to 8 times of the deepening rate, especially in the middle of the dam break, widening behavior occupied the dominant factor. The shape of the dam body after failure was parabolic, and the dam body had obvious elevation changes. These results provide the theoretical guidance and engineering application value for improving the theory and early warning model of the upstream tailing dam.

为研究絮团尺寸对全尾砂絮凝沉降效果的影响,采用正交实验和图像颗粒分析相结合的方法,进行多因素耦合条件下全尾砂絮凝沉降实验,基于Giddings函数的沉降速度模型,提出全尾砂絮团图像颗粒分析,探究各时段絮团尺寸的变化规律.研究结果表明:当尾砂浆浓度为15％、絮凝剂溶液浓度为0.25％、絮凝剂单耗为20 g/t,pH值为10时,絮凝沉降效果最佳,最大沉降速度达13.12 mm/s;随着沉降时间的增加,沉降速度随絮团直径、长径比减小而减小,随圆形度增大而减小.研究结果可为实际生产中控制全尾砂絮凝沉降参数、提高沉降速率提供参考.

大屏幕液晶显示器和集成电路等微电子工业的湿法蚀刻和湿法清洗工艺以电子级磷酸为原料,会产生大量含铝离子的磷酸废液.用阳离子交换树脂(Zminw-0705)对该磷酸废液在动态情况下做了处理,研究了动态情况下设备参数和操作参数对吸附效果的影响.采用傅里叶红外光谱法和X射线光电子能谱对吸附前后的树脂做了表征,验证了吸附反应的发生.用模型对动态吸附过程做了拟合,实际吸附量与理论吸附量比较接近,相关系数均在0.92以上.结果表明:在其他条件相同的情况下,150:8为离子交换柱适宜长径比;适宜温度范围为45～55℃;适宜进料流速为4.67 mL/min;废酸的磷酸浓度和铝离子也在适合的操作范围内.

为探索湿法磷酸净化新技术,对新型阳离子交换树脂的再生能力进行研究,考察不同工艺条件下的再生性能与磷回收情况.结果 表明,温度对脱附反应没有明显影响,最优工艺条件为温度50 ℃,w(H2SO4)25％,固液质量比1.0∶1.1,在该条件下,对初始w(Al)为29.05 mg/g的树脂(干基)的脱附率约为43.22％.在磷回收实验中,采用三级逆流水洗能将磷收率提高到98.12％.

云南是我国的富磷省份之一,绝大部分磷矿石适于露天开采.先期开采的浅表风化中高品位磷矿石,P2 O5品位高、MgO含量低、 倍半氧化物高,以1989年云南磷化集团海口磷矿30万t/a擦洗厂的建成投用为标志,采用擦洗分级脱泥的方法,脱除部分泥质,提高矿石品质,使中高品位磷矿石得到了有效利用.随着开采埋藏的加深和风化富矿的不断减少,开采的大量中低品位半风化、 原生矿石,以云南磷化集团有限公司研究开发的中低品位磷矿浮选产业化技术为支撑,2007年云南磷化集团海口200万t/a浮选厂的建成投用为标志,采用浮选法,脱除有害杂质,提高矿石品质,使中低品位磷矿石得到了有效利用.云南胶磷矿的选矿产业化开发利用,有力地支撑了云南磷化工支柱产业的可持续发展.

Animal diets are often over-supplemented with low bioavailability phosphorus (P) sources in China, resulting in unnecessary excretion and loss of P to the environment. The effect of reducing dietary P supplementation and using a highly available P supplement for swine and poultry was determined. Manure collected in feeding trials involving the use of dicalcium phosphate (DCP) or mono-dicalcium phosphates (MDCP) that were < 1 or 17% water soluble, respectively, to increase dietary total P to amounts ranging from approximately 0.39 to 0.68% was analyzed for total P as well as different forms of P (H2O-, NaHCO3-, NaOH-, HCl- and residue-P). Manure total P varied with the amount of P supplemented, ranging from 14.5 to 22.3 g kg(-1) for pigs, 4.7-13.6 g kg(-1) for broilers and ducks, and 8.0-23.5 g kg(-1) for layers. Determined using manure from pigs and birds receiving the highest supplemental amounts, MDCP reduced manure total P by up to 12.1% and H2O-P by up to 18.4% compared to DCP. Manure P extracted by weak NaOH and HCl was up to 9.4% higher for MDCP than DCP. Thus, using MDCP resulted in manure P that was lower in labile fractions than DCP. Soil leaching studies showed that dissolved P collected in leachate from manure was 9.4-32.6% lower when MDCP replaced DCP in the diet of pigs, broilers, ducks, and layers, confirming that MDCP reduced labile P in manure. Minimizing dietary P supplementation and using highly available MDCP as the supplemental source for pigs, broilers, ducks, and layers reduced P excretion and loss potential to the environment. (C) 2019 Elsevier Ltd. All rights reserved.

针对矿山排土空间不足及后期地下开采坑道涌水等问题,提出采坑基底排水及内排设计方案.经技术经济比较,确定的排水方案为底部分层回填碾压+土工布方案,在排土场开始堆置前采用废石分层碾压回填的方式在排土场底部形成南北方向2％的纵坡、东西方向4％的排水反坡.分层碾压回填至设计高程后,在回填体上部满铺一层厚0.3m的黏土隔水层(压实度不低于93％),黏土层上部铺设厚度不小于0.5 rn的大块石滤水层,最后再铺一层透水土工布,才能进行排土场的废石堆置.为保证排土场的整体稳定性,排土场排废一期工程采用高排方式,由南向北逐步堆置;二期排废工程采用分台阶自下而上方式,由北向南堆置.内排设计共分为13个台阶,最低台阶标高2 180 m,最高台阶标高2 370 m.内排设计有效解决了矿山采坑涌水问题,为矿山岩土裂隙水渗漏治理提供了新的思路.

[Objective] Phosphorus (P) is one of the essential mineral elements for animals.It plays an important role in the growth,development and production of livestock.However,the efficiency of P in animal production is very low,a large amount of undigested feed P excreted with manure,and the P enrichment in the environment resulted in serious P pollution,such as eutrophication.Feed P level and phosphate supplementation are closely related to the P use efficiency and manure P excretion.The objective of this study is to determine the status of P level and phosphate application of animal feed in China,and to provide a scientific basis for rational use of feed P resource and reduce the excretion of manure P.[Method] The variance of the P requirement recommended by American feeding standard and Chinese feeding standard,the actual P content and phosphate supplementation in the feed were studied in this research by conducting literature analysis,surveys,and experiments.[Result] For swine,compared to the Chinese standard,the current American standard recommends the P requirements as total P,standardized total tract digestible (STTD) P,and apparent total tract digestible (ATTD) P,with no recommendation for non-phytate P (NPP).For laying hens,broilers,meat ducks,the American standard lists NPP requirements,but not total P requirement.For dairy cattle,the total P requirement recommended by the Chinese standard is 31％,74％,and 26％ higher than the American standard for heifers,milking cows,and dry cows,respectively.Compared to the American standards,the current Chinese feeding standard is higher in the NPP requirement for laying hens (0.32％ vs 0.25％),slaughter chickens (0.35％-0.40％ vs 0.30％-0.35％),and meat ducks (0.35％-0.42％ vs 0.30％-0.40％).The majority of phosphates used in feed in China is dicalcium phosphate (DCP),then the mono-dicalcium phosphate (MDCP) and monocalcium phosphate (MCP).The contents of phosphate,total P and NPP of same feed produced by diffcrent enterprises varied greatly.The use of calcium phosphate in commercial feeds in China was 8.8 kg·t-1 in 2016 on average,decreasing from 12.0 kg.t-1 in 2006.Total P requirement of animals and poultry used by the feed industry in 2016 was similar to that used in 2006 based on surveys,consistent with the Chinese standards.However,the NPP requirement used by the feed industry was higher than recommended by both the Chinese standards and the American standards for laying hens,growing pigs,and finished pigs.[Conclusion] The P requirements of dairy cows,laying hen,later stage of broiler,and meat duck recommended by Chinese feeding standard were higher than the American standard;the use of calcium phosphate in commodity feeds in China was 3.2 kg·t-1 in 2016 lower than in 2006 on average;the NPP requirement used by the feed industry was higher than recommended by both the Chinese feeding standards and the American feeding standards for laying hens,growing pigs,and finished pigs.It is suggested that the study of phosphorus requirement should be carried out based on the animal varieties and feed characteristics in China,and to modify the recommended standards for phosphorus requirement of animals.At the same time,we need to adopt the measures of using the low-phosphorus diets,the high utilization rate of calcium phosphate and addition of phytase in feed to improve the efficiency of feed phosphorus utilization,and to reduce the P excreted with manure.

Cucurbit[n]uril and its derivatives, a new family of macrocyclic hosts comprising n glycoluril units, have gained much attention for their exceptional application in many fields. In this review, we introduced the cucurbituril family and the development of its derivatives, which can be used in the molecular recognition and self-assembled materials such as pseudorotaxane, polyrotaxane. Moreover, cucurbituril provides the possibility to design stimulus–response devices and imitate the life secret at molecule level, such as the molecular devices controlled by pH, photochemistry, thermal and so on.

A novel heterowheel pseudorotaxane comprised of one guest, one cucurbit[7]uril and two cucurbit[6]urils was synthesised and characterised by H-1 NMR, single crystal X-ray diffraction analysis and thermogravimetric analysis. Single crystal X-ray diffraction analysis demonstrates that the heterowheel pseudorotaxane self-assembles into two-dimensional polyrotaxane network with the aid of water molecules and hydrogen bonds. Every four heterowheel pseudorotaxanes self-assemble into a parallelogram, which is the basic unit of the 2D network.[GRAPHICS]A novel heterowheel pseudorotaxane consisting of one guest, one cucurbit[7]uril and two cucurbit[6]urils was synthesised. Single crystal X-ray diffraction analysis demonstrates that the heterowheel pseudorotaxane self-assembles into two-dimensional polyrotaxane network with the aid of water molecules and hydrogen bonds. Every four heterowheel pseudorotaxanes self-assemble into a parallelogram, which is the basic unit of the 2D network.

以晋宁磷矿6号坑为研究对象,采用相似模拟试验方法,对缓倾斜薄至中厚磷矿体采用露天转地下充填法开采后的采场变形规律、破坏方式和边坡稳定性进行了分析研究,结果表明:在地下开采过程中,采空区上方边坡的稳定性会随着开采的推进而逐渐降低,当开采至边坡坡脚附近时,边坡的位移和应力变化比较剧烈,边坡的稳定性下降也相对较大.因此,在地下开采过程中,加强采空区上方边坡的监测对于边坡的稳定和地下采场的安全具有重要意义.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The mining method of the deep slowly inclined-thin to medium thick-soft interlayer ore body is of No. 6 pit in Jingning phosphate mine of Yunnan Phosphate Chemical Group Co.,LTD., has been studied, though the research techniques of field investigation, theoretical analysis and scheme comparison, on basis of the comprehensive analysis of the occurrence characteristics of ore body mining engineering, the technical conditions and the bottom characteristics of surrounding rock. The results show that:(1) the mixed mining way of. seam,. 1 seam and. 2 seam should been carried out, as the ore grade could reach 22.97% and the high resource recovery. (2) for the typical hard-to-mine ore body of No. 6 pit in Jingning phosphate mine, it is very difficult to obtain the ideal economic and technical index by using a single mining method. The section shrinkage-caving method is the right one to take as the mining method to the hanging wall seam, and duo to the seam is thin, for the footwall seam, it should take shallow-hole shrinkage mining as the mining method. The related results provides certain reference for the mining way of the deep mining of Yunnan phosphate group corporation and similar conditions of open pit mining of phosphorus mine.

With the Jianshan Phosphate Mine in Yunnan Phosphate Chemical Group Limited Company engineering back-ground,and in terms of the deformation and instability characteristics of stratified steep dip rock slope, the slope instability process and intrinsic controlling factor have been analyzed by using the cusp catastrophe model. The excavation stability of open-pit slope has been researched with respect to the stress state of the stratified rock slope. The results show as following:(1)With the thickness of strata increasing,lithodeme flexural strength of rock would increase,which could effectively control and prevent from the turn sand twists failure. The rock-soil anchor technology or the step bedding cleaning could reduce risk of this kind of slope instability. (2)With the thickness of bedding slope fixed,the critical slope length would show downward trend with the increase of strata inclination. The thicker the thickness is,the severer the trend becomes. If the inclination is fixed,the critical slope length would show upward trend with the increase of strata thickness. The higher the inclination is,the lower the amplitude becomes. Meanwhile,if the strata inclination is higher than forty degrees,critical slope length increasing amplitude caused by the thicker thickness of strata tends to coincide. The relevant research results provide theoretical and technical guid-ance and advice for the open pit transportation technology of the mine or mining area with similar conditions.

本文研究了4种具有不同链长的叔胺对胶磷矿中石英的浮选行为.研究表明:4种叔胺在pH=6.0～8.0,浓度为0.1 mmol/L的条件下对石英具有较好的捕收能力,且N,N-二甲基十四胺捕收能力最强,其次是N,N-二甲基十二胺,N,N-二甲基十八胺捕收能力最弱,说明捕收剂碳链长度对石英的浮选性能有重要影响.

以硅质及硅酸盐型胶磷矿为研究对象,研究了非离子型和阴离子型表面活性剂与脂肪酸复配在胶磷矿浮选中的应用.研究表明:与空白试验对比,TW-2、TW-4、TW-6、AEO-10、十二烷基硫酸钠、十二烷基磺酸钠和十二烷基苯磺酸钠有明显的增效作用.其中,TW 2在不降低尾矿品位的情况下,可提高精矿品位.十二烷基硫酸钠、十二烷基磺酸钠和十二烷基苯磺酸钠可大幅降低尾矿品位(最低尾矿P2o 5品位为7.47％),表明该类表面活性剂在磷矿浮选中具有较强的增效作用.