Prediction of leaching rate in heap leaching process by grey dynamic model GDM(1,1)

The method of developing GM（1,1） model is extended on the basis of grey system theory. Conditions for the transfer function that improve smoothness of original data sequence and decrease the revert error are given. The grey dynamic model is first combined with the transfer function to predict the leaching rate in heap leaching process. The results show that high prediction accuracy can be expected by using the proposed method. This provides a new approach to realize prediction and control of the future behavior of leaching kinetics.

Assessment of Biofouling Using Leaching Rate of Antifouling Agents and Bioluminescent Assay

The authors investigated the leaching rate of antifouling agents from marine paint using an instrument that allows direct measurement from the flat bottom of ship hulls shortly after dry dock. A similar procedure was also used for painted flat panels that were immersed in the ocean. The relationship between leaching rate and fouling condition was considered by quantifying the amount of ATP （adenosine triphosphate） on the surface of immersed flat panel using fluorescence spectroscopy. The leaching rate results from ship hulls showed good agreement with the value by reporting of leaching rate of antifouling agents. The fluorescence spectroscopy results showed that the amount of ATP on the surface of the panel increased over time as the leaching rate fell, which implies an inverse relationship between leaching rate and fouling index. Fluorescence spectroscopy was also seen to be a simple method for evaluating the relationship between biofouling indexes and leaching rate.

Factors Research on the Influence of Leaching Rate of Nickel and Cobalt from Waste Superalloys with Sulfuric Acid

Unlike the reported leaching technologies of waste superalloys, the process of the “atomized spray-sulfuric acid leaching nickel and cobalt” technology was put forward in the present work according to the compositions of waste superalloys. The effects of sulfuric acid temperature, concentration, leaching time, stirring speed and size of superalloys on leaching of Ni and Co from waste superalloys have been mainly investigated, and the optimum leaching conditions were determined and reported. The leaching rates for nickel and cobalt were 96.68% and 96.63%, respectively, and the contents of nickel and cobalt in leaching slag were 6.77% and 0.96%, respectively. The obtained leaching solution containing Ni and Co could be used for production of Ni and Co products after removal.

Numerical analysis of aerated heap bioleaching with variable irrigation and aeration combinations

Forced aeration is an effective way to accelerate the heap bioleaching process.To reveal the effects of different irrigation and aeration combinations on bioleaching performance of copper sulfides,numerical simulations with COMSOL were carried out.Results showed the oxygen concentration is the highest at the bottom with forced aeration,the airflow transports spherically from the aeration pipeline to the slope,and the horizontal diffusion distance is further than vertical value.When the irrigation-to-aeration ratio is higher,the average heap temperatures are mainly decided by aeration rates;otherwise,temperature distributions are the equilibrium of mineral reaction heat,the livixiant driven heat and the airflow driven heat.When the aeration rate is higher than 0.90 m3/(m2·h),oxygen concentration is no longer a limiting factor for mineral dissolution.Additionally,on the premise of sufficient oxygen supply,Cu recovery rate is higher at the bottom with low irrigation rate;while it is higher at upper regions with high irrigation rate.The numerical analysis uncovered some insights into the dynamics and thermodynamics rules in bioleaching of copper sulfides with forced aeration.

STUDY ON GREY FORECASTING MODEL OF COPPER EXTRACTION RATE WITH BIOLEACHING OF PRIMARY SULFIDE ORE

A model GM （grey model） （1,1） for forecasting the rate of copper extraction during the bioleaching of primary sulphide ore was established on the basis of the mathematical theory and the modeling process of grey system theory. It was used for forecasting the rate of copper extraction from the primary sulfide ore during a laboratory microbial column leaching experiment. The precision of the forecasted results were examined and modified via ＂posterior variance examination＂. The results show that the forecasted values coincide with the experimental values. GM （1,1） model has high forecast accuracy; and it is suitable for simulation control and prediction analysis of the original data series of the processes that have grey characteristics, such as mining, metallurgical and mineral processing, etc. The leaching rate of such copper sulphide ore is low. The grey forecasting result indicates that the rate of copper extraction is approximately 20% even after leaching for six months.

Effects of microwave pretreatment on zinc extraction from spent catalyst saturated with zinc acetate

A new technology for microwave pretreatment of spent catalyst on Zn extraction by HCl leaching was proposed and the temperature-change curve of spent catalyst under microwave irradiation was measured.The influence of microwave pretreatment temperature and microwave irradiation time on zinc extraction was investigated and the mechanism of microwave pretreatment for spent catalyst was analyzed.The results show that microwave pretreatment can greatly enhance the leaching rate of Zn.The Zn extraction reaches 96.58%under the conditions of microwave pretreatment temperature of 950℃and the microwave irradiation time of 12 min.The blocked pores of spent catalyst can be opened through microwave pretreatment,increasing the contact area of leaching reagent and zinc.

A rate-based method for dynamic analysis and optimal design of reactive extraction: n-Hexyl acetate esterification as an example

The dynamic analysis and optimal design of reactive extraction are challenging due to high nonlinearity of model equations and tough decision of judging criteria. In this work, a dynamic rate-based method is developed on g PROMS platform to get easy access to the solutions of reactive extraction with phase splitting. Based on rigorous criteria, dynamic analysis from initial state to final equilibrium(e.g., evolution of phase composition, mass transfer rate and reaction rate) and optimal design of operating conditions(e.g., extractant dosage and feed molar ratio) are achieved. To illustrate the method, the esterification of n-hexyl acetate is taken as an example. The approach proves to be reliable in the analysis and optimization of the exemplified system, which provides instructive reference for further process design and simulation of reactive extraction.

Comparing a small gravel-less perforated pipe leach fields (GPPLF) to a medium one in treating domestic sewage

There were obvious differences between a medium gravel-less perforated pipe leach fields and a small system in the treatment of demestic sewage with the change of influent quality. In small system, COD removal rate was 91%, ammonia nitrogen removal rate was 90%, total nitrogen was 58%. In medium system, COD removal rate was 86.07%, ammonia nitrogen removal rate was 45.3%, and total nitrogen was 48.2%. This paper studied on the differences. Its main reasons were as follows: differences in opening rate (perforated area account of the total area in infiltration pipe), air flow conditions, exterior environment, and wastewater distribution. Considering those problems, Solutions and applications for the development of GPPLF are given.

Line-of-sight rates extraction of roll-pitch seeker under anti-infrared decoy state

In this paper,the method of extracting guidance information such as the line-of-sight(LOS)rates under the anti-infrared decoy state for the roll-pitch seeker is researched.Coordinate systems which are used to describe the angles transform are defined.The LOS angles reconstruction model of the roll-pitch seeker in inertial space is established.A Kalman filter model for extracting LOS rates of the roll-pitch seeker is proposed.In this model,the target performs constant acceleration(CA)model maneuvers.The error model of LOS rates extraction under infrared decoy state is established.Several existing methods of extracting LOS rates under anti-infrared decoy state are listed in this paper.Different from the existing methods,a novel method that uses extrapolated values of target accelerations as filter measurements is proposed to solve the guidance information extraction problem under the anti-infrared decoy state.Numerical simulations are conducted to verify the effectiveness of the proposed method under different target maneuvering models such as the CA model,the CA extended model and the singer model.The simulation results show that the proposed method of extracting guidance information such as LOS rates for the rollpitch seeker under the anti-infrared decoy state is effective.

Recovery of indium by acid leaching waste ITO target based on neural network

The optimized leaching techniques were studied by technical experiment and neural network optimization for improving indium leaching rate. Firstly, effect of single technical parameter on leaching rate was investigated experimentally with other parameters fixed as constants. The results show that increasing residual acidity can improve leaching rate of indium. Increasing the oxidant content can obviously increase leaching rate but the further addition of oxidant could not improve the leaching rate. The enhancement of temperature can improve the leaching rate while the further enhancement of temperature decreases it. Extension leaching time can improve the leaching rate. On this basis, a BPNN model was established to study the effects of multi-parameters on leaching rate. The results show that the relative error is extremely small, thus the BPNN model has a high prediction precision. At last, optimized technical parameters which can yield high leaching rate of 99.5%were obtained by experimental and BPNN studies：residual acidity 50-60 g/L, oxidant addition content 10%, leaching temperature 70 ℃ and leaching time 2 h.

岩巷综掘面抽尘参数影响粉尘污染扩散规律研究

抽尘系统是岩巷综掘面长压短抽通风方式中控除粉尘污染的重要组成部分,而确定适宜的抽尘参数是实现有效除尘的关键。利用Solidworks软件对某矿632岩巷综掘面进行了物理建模,并进行了ICEM-CFD网格划分,通过网格无关性检验确认了后续所用的网格模型,运用FLUENT计算流体力学软件对不同抽尘位置Dn(n分别为0、1/4、1/2、3/4、1)与抽风量(300~350 m^(3)/min)影响粉尘污染扩散状况进行了数值模拟,并通过仿真试验验证了数值模拟结果的准确性。结果表明:抽尘位置为D0、D1/4、D1/2、D3/4时,巷道内风流整体均处于较为紊乱的状态,粉尘污染经风流运载最终均扩散至整个巷道;抽尘位置为D1时,在抽风与压风协同作用下,距迎头4.6~6 m范围内形成了风向指向迎头、流动均匀且覆盖巷道全断面的有效控尘风幕,粉尘污染被风幕控制在掘进机司机与迎头之间的封闭空间内。抽风量在330 m^(3)/min及以上时,在司机处均形成了有效控尘风幕。为了在有效控尘的前提下尽可能降低能耗,最优抽风量选取最小值330 m^(3)/min。

4种提取方法对对虾肌原纤维蛋白提取率、空间结构和热稳定性的影响

【目的】获取提取率高且结构完整的凡纳滨对虾(Litopenaeus vannamei)肌原纤维蛋白。【方法】通过0.5 mol/L KCl、53 kHz超声辅助0.5 mol/L KCl、53 kHz超声辅助质量分数5%十二烷基硫酸钠(SDS)和RIPA裂解液这4种提取方法提取对虾肌原纤维蛋白,以肌原纤维蛋白提取率和结构完整性为评价指标,采用光谱学和凝胶电泳生化,评价四种提取方法对对虾肌原纤维蛋白提取率、空间结构和热稳定性的影响。【结果】53 kHz超声辅助0.5 mol/L KCl、0.5 mol/L KCl、53 kHz超声辅助5%SDS和RIPA裂解液4种方法所得提取率分别为(87.99±3.08)%、(53.76±3.90)%、(75.59±0.95)%和(95.46±4.49)%。53 kHz超声辅助0.5 mol/L KCl提取的蛋白中肌钙蛋白和原肌球蛋白蛋白丰度较高,0.5 mol/L KCl和53 kHz超声辅助质量分数5%SDS提取的肌球蛋白重链和肌动蛋白蛋白丰度较高;相较于0.5 mol/L KCl,超声辅助提取可最大限度保持肌原纤维蛋白天然结构,α-螺旋结构保留完好;0.5 mol/L KCl提取可较好维持肌原纤维蛋白的酰胺Ⅰ带结构。RIPA裂解液提取对肌原纤维蛋白二级结构有明显破坏,热稳定性仅为原蛋白的(60.63±4.46)%。【结论】综合提取率、空间结构和热稳定性结果,采用53 kHz超声辅助5%SDS提取可获得质量最佳的凡纳滨对虾肌原纤维。本研究可为后续深入解析冷藏对虾品质劣变和开发高效控制技术提供高质量的肌原纤维蛋白。

不同螯合剂对褐煤中金属离子浸出效果的实验研究

螯合剂种类的不同,其对金属离子浸出效果也存在差异,为分析螯合剂对贵州地区褐煤中金属离子的浸出效果,选取ASDA,DTPA,IDS和GLDA等共4种螯合剂,开展了浸出效果对比实验,利用电感耦合等离子体质谱仪(ICP)和扫描电子显微镜(SEM)对实验结果进行了表征。结果表明:螯合剂能够将煤体中矿物质解络为游离态,煤体表面孔隙呈现从微孔、小孔向大孔变化的趋势,煤体表面矿物质呈现颗粒数量减少、颗粒体积变小、颗粒形态圆润的特点;ASDA对该煤样中Mg,Al,Fe,Ca,Cu离子具有最佳浸出效果,DTPA对K,Pb离子具有最佳浸出效果。

多指标响应面优化枸杞提取工艺研究

枸杞中含有丰富的枸杞多糖和枸杞黄酮,均具有较高的药用价值。选取提取方法、提取时间、料液比、提取次数、提取温度、浸泡时间进行单因素试验,根据单因素结果选取3个影响较大的因素,结合响应面法中的Box-Behnken试验设计对枸杞总多糖和总黄酮的提取工艺进行优化,得到优化提取工艺条件为:加热回流法,浸泡1.0h,提取时间55min,料液比1∶12(g∶m L),提取温度81℃,提取2次。总多糖提取率能够达到45.36%,总黄酮提取率达到0.29%。该方法提取率高、重复性好,高效环保。为枸杞中总多糖和总黄酮的提取方法提供参考依据。

新疆制种玉米生产机械化技术——去雄

新疆是我国重要的制种玉米种植区,玉米母本的雄穗去除是制种玉米种植的关键环节之一。受种植模式和去雄技术要求的影响,不同地区在去雄方法、机械去雄使用情况上存在不同。人工去雄可以根据雄穗的生长情况,选择性的去除,整个去雄期需要进行5~6次抽雄。机械去雄采用直接抽雄或者先切顶然后抽雄两种方法,抽净率为80%~95%,机械去雄对叶片的损伤较大,机械去雄后需要人工检查并对未去雄玉米母本再次抽雄。为了全面推广应用机械去雄技术,应进一步规范和提高适于机械化作业的种植模式、机械抽雄技术以及去雄机的整机性能。

吉林省某金矿石氰化浸出试验研究

吉林省某金矿具有嵌布粒度较细、包裹金含量较高的特点,矿石工艺类型为少硫化物石英脉型含金矿石,氰化浸出试验分别研究了磨矿细度、氧化钙用量、碱处理时间、氰化钠用量、浸出时间、矿浆浓度对该矿石浸出指标的影响。试验结果表明:当磨矿细度为-0.045 mm质量分数90%,氧化钙用量2.5 kg/t,碱处理时间1 h,氰化钠用量1 kg/t,浸出时间24 h,浸出浓度40%,氰化浸渣品位0.50 g/t,金浸出率可达到92.10%。

柠檬酸钠对电石渣中钙离子的浸取研究

电石渣是以氢氧化钙为主要成分的工业废渣,若不采取合理的治理措施,不仅占用土地资源,还会污染环境。文章以柠檬酸钠为浸取剂浸取电石渣中钙离子,探索其资源化利用。实验探究了用水量、柠檬酸钠用量、反应时间、反应温度等浸取条件对钙离子浸取率的影响,并通过浸取液和滤渣的成分分析,分析柠檬酸钠浸取除杂效果。结果表明,当电石渣用量15 g,用水量1500 mL,柠檬酸钠用量70 g,反应时间40 min,反应温度25℃时,浸取率达到最佳,为81.62%。以柠檬酸钠为浸取剂,浸取液较高的pH值和柠檬酸根的络合作用,可能导致Al、Fe、Mg不能除尽,滤渣中的主要成分为炭黑、碳酸钙、水铝钙石。

氯化铵浸取电石渣中钙离子的研究

电石渣是工业生产乙炔气过程中电石水解后产生的废渣,主要成分是Ca(OH)_(2)。文章以氯化铵为浸取剂,提取电石渣中的钙离子,以达到提纯钙和资源化利用的目的。实验探究了不同用水量、氯化铵用量、反应温度及反应时间下Ca^(2+)浸取率,探讨了氯化铵浸取机理,同时对浸取液和滤渣的成分进行了详细分析。结果表明,当浸取温度25℃,浸取时间40min,电石渣∶氯化铵∶用水量=5∶6∶35时,电石渣中的Ca^(2+)浸取率最高,为76.58%。经氯化铵浸取,电石渣中的Mg、Al、Fe、C等杂质被去除,Ca^(2+)纯度达到98%,滤渣中的主要成分为炭黑、碳酸钙、水铝钙石、钙矾石。

山楂多糖酶解法和水提法的工艺优化和比较

研究酶解法和水提法对山楂多糖提取率的影响,为进一步开发利用山楂多糖提供技术依据。分别对酶解法和水提法进行优化,选择最佳条件提取山楂多糖。结果表明,酶解法提取山楂多糖的最适条件为酶用量3‰、酶解温度50℃、酶解时间1.0 h、酶解pH=8、料液比1∶10,多糖提取率为11.72%;水提法提取山楂多糖的最适条件为提取次数3次、提取时间120 min、料液比1∶10,多糖提取率为9.47%。酶解法提取率高,优于水提法。结论:山楂中多糖含量较高,通过酶解法可进行高效提取,方法简便,实用性强。

前胡药材产地干燥加工方法研究

目的比较产地不同干燥加工方法对前胡药材质量的影响,筛选其最佳产地干燥加工方法。方法分别采用传统晒干、自然阴干和电热恒温鼓风干燥、真空干燥、红外干燥和真空冷冻干燥等干燥加工方法对前胡药材进行处理,以折干率、含水量、浸出物含量、颜色色度值以及4种香豆素类成分含量为指标,采用逼近理想解排序法进行综合质量评价。结果不同干燥加工方法下,12份前胡药材样品的折干率为31.56%~40.10%,含水量为6.96%~8.58%,浸出物含量为27.56%~43.10%,红绿度值为1.80~7.50,黄蓝度值为19.90~30.20,明度值为46.90~59.90;伞形花内酯、白花前胡甲素、白花前胡乙素、白花前胡E素的含量分别为≤0.05、3.70~14.05、0.72~2.37、0.81~3.90 mg/g,总含量为5.47~19.65 mg/g;40℃电热恒温鼓风干燥下的前胡药材综合得分最高。结论40℃电热恒温鼓风干燥是前胡药材最佳的产地干燥加工方法。