Lithium Extraction from Carbonate-type Saline Lake by Utilizing of Geothermal Solar Pond in Tibet

1 Introduction The geothermal solar pond is a kind of special solar pond.It is different from traditional solar pond,which high temperature geothermal water can be used to heat brine.When the salt in the brine reaches saturation temperature,it precipitate out and is separated from the brine.Compared with solar pond,the geothermal solar pond does not rely entirely on solar radiation as a heat

Numerical Analysis of the Influence of Buoyancy Ratio and Dufour Parameter on Thermosolutal Convection in a Square Salt Gradient Solar Pond

Revise the abstract as follows:This work aims to investigate numerically the influence of the buoyancy ratio and the Dufour parameter on thermosolutal convection in a square Salt Gradient Solar Pond(SGSP).The absorption of solar radiation by the saline water,the heat losses and the wind effects via the SGSP free surface are considered.The mathematical model is based on the Navier-Stokes equations used in synergy with the thermal energy equation.These equations are solved using the finite volume method and the Gauss algorithm.Velocity-pressure coupling is implemented through the SIMPLE algorithm.Simulations of the SGSP are performed for three values of buoyancy ratio(N=1,2 and 10),three values of Dufour parameter(Df?0,0.2 and 0.8)and some sample meteorological data(Tangier,Morocco).Results show that the highest dimensionless temperature of the storage zone is found for N=10.In the same zone and for the same value of N,the dimensionless salt concentration decreases very slightly versus time(unlike for N=1 or 2).Moreover,increasing Df from 0 to 0.8 causes a decrease in the dimensionless temperature of the SGSP storage zone and this decrease is more pronounced for N=1 and N=2.

Effect of Non-Convective Zone Thickness on Thermal Efficiency of Salt Gradient Solar Ponds

An improved radiation transmission and thermal efficiency model for solar ponds has been proposed based on both the Hull Model and Wang/Seyed-Yagoobi Model in this paper.The new model is more accurate to actual measured conditions because multiple reflections and turbidity effects are included.Absorption penetration,thermal conductivity loss and thermal efficiency under different Non-Convective Zone thicknesses are numerically analyzed and thoroughly discussed.The results show thatΔT/I0 plays a critical role for the thermal efficiency of solar pond.Furthermore,it is found through calculation that there is an optimum thickness of the Non-Convective Zone.When the Non-Convective Zone thickness is less than this critical threshold,both temperature and thermal efficiency are decreased with increasing turbidity.However,when the Non-Convective Zone thickness is greater than this critical threshold,the increasing turbidity within a certain range will be beneficial to improve the thermal efficiency of solar pond.In addition,optimum Non-Convective Zone thickness is also related to the temperature,turbidity,salinity variation and bottom reflectivity.

The Effect of a Liquid Cover on the Thermal Performance of a Salinity Gradient Solar Pond:An Experimental Study

SalinityGradient Solar Ponds(SGSPs)offer the potential to capture and store solar energy for use in a range of domestic and industrial activities in regions with high solar insolation.However,the evaporation of water from these ponds is a significant problem that must be overcome for them to be deployed successfully.Thus,two ponds were constructed in the city of Nasiriya,Iraq.The two ponds were cylindrical with a diameter of 1.4 m and a total depth of 1.4 m.The water body in the two ponds was constructed with layer depths of 0.5,0.75 and 0.1 m for the lower convective zone(LCZ),non-convective zone(NCZ)and the upper convective zone(UCZ)respectively.One of the two ponds was covered with a thin liquid paraffin layer(0.5 cm)to eliminate evaporation from the surface of the UCZ.The behavior of the standard SGSP and that of the covered pond with evaporation suppressed can be straightforwardly compared.The experimental units were run for six months from 1st of February to 31st of July 2019.It was shown in the first instance that by covering the pond with a thin layer of paraffin,that evaporation could be suppressed.The results showed that for the conventional SGSP,the temperature of the LCZ reached a maximum of ca.76℃ while in the covered pond the temperature of the LCZ was consistently lower than that in the uncovered pond by approximately 5-6℃.The results also indicated that the temperature of the UCZ in the covered pond was higher than that in the uncovered pond by about 10℃ in the second half of the study period.However,it was noted that on rainy days the paraffin layer was swept away from the surface;and this could hinder the implementation of thin liquid cover in the large SGSP.

Development of Solar Ponds Optimization Model: Arab Potash Solar System—A Case Study

A steady state optimization model used to define the optimum salt to carnallite ponds area ratio in a solar pond system was developed. The model is based on material balance analysis using a cascade of complete-mix reactors model (cascade of CFSTR, continuous-flow stirred-tank reactor) prepared for the solar pond system. The basic material balance model shall use the basic phase chemistry relations and physical parameters of the solar pond system under optimization. The Arab Potash solar pond system data was used to examine the developed model where the Arab potash solar system was used as a Case Study. In the course of the model development, calibration and validation of the model is performed. Using this steady state model the optimum salt pond to carnallite pond area ratio is deduced. This optimum ratio is defined as the optimum area ratio that maximizes the carnallite production per the total pond system area. This term, which could be expressed as tons per km2, presents the best pond system efficiency. The results show that a 1.88 ratio of salt to carnallite ponds area is the optimum ratio.

Experimental Investigation of a Phase-ChangeMaterial’s Stabilizing Role in a Pilot of Smart Salt-Gradient Solar Ponds

Faced with the world’s environmental and energy-related challenges,researchers are turning to innovative,sustainable and intelligent solutions to produce,store,and distribute energy.This work explores the trend of using a smart sensor to monitor the stability and efficiency of a salt-gradient solar pond.Several studies have been conducted to improve the thermal efficiency of salt-gradient solar ponds by introducing other materials.This study investigates the thermal and salinity behaviors of a pilot of smart salt-gradient solar ponds with(SGSP)and without(SGSPP)paraffin wax(PW)as a phase-change material(PCM).Temperature and salinity were measured experimentally using a smart sensor,with the measurements being used to investigate the stabilizing effects of placing the PCM in the solar pond’s lower convective zone.The experimental results show that the pond with the PCM(SGSPP)achieved greater thermal and salinity stability,with there being a lesser temperature and salinity gradient between the different layers when compared to a solar pond without thePCM(SGSP).The use of the PCM,therefore,helped control the maximum and minimum temperature of the pond’s storage zone.The UCZ has been found to operate approximately 4 degrees above the average ambient temperature of the day in the SGSPP and 7 degrees in SGSP.Moreover,an unstable situation is generated after 5 days from starting the operation and at 1.9 m from the bottom,and certain points have the tendency to be neutral from the upper depths in 1,3 m of the bottom.

Numerical Simulation of Double-diffusive Dynamical Model of a Solar Pond Considering the Effect of Turbidity and Wind

A solar pond, typical double-diffusive system, is a stable heat source that can collect and store the solar energy. When the thermal stable condition is not satisfied at the interface, the upper and lower convective zone （UCZ and LCZ） will erode the middle non-convective zone （NCZ）, resulting in a drop or even a collapse of the thermal performance of solar pond. Wind strongly affects the erosion of NCZ from the entrainment of UCZ. The double-diffusion of heat and salt plays an important role in the erosion of NCZ from the entrainment of the lower-convective zone （LCZ）. The turbidity of saline water in the pond not only could lower the thermal performance of solar pond, but have effect on the entrainment mechanism. In this paper, based on the double-diffusive model along with the wind-driven turbulent entrainment model, the effects of turbidity and external wind etc. on the thermal performance of solar pond and the entrainment mechanism are analyzed with the numerical simulation.

Two-dimensional Modeling of a Salt-gradient Solar Pond with Wall Shading Effect and Thermo-physical Properties Dependent on Temperature and Concentration

In this paper,the behavior of a salt-gradient solar pond with the square cross-section has been studied experimentally and numerically.A small-scale solar pond were designed and built to provide quantitative data.A two-dimensional,transient heat and mass transfer model has been solved numerically by using finite-control-volume method.In this study,all the thermo-physical properties are variable as the function of temperature and salt concentration.Numerical results as obtained for the experimental pond have been satisfactorily compared and validated against measured data.Furthermore,the wall shading effect has been elaborated to improve the agreement between two sets of results.The temperature of the storage zone is predicted well by the model.It also can be observed that the initial concentration profile is preserved with time.The stability of the pond in time has been investigated in order to distinguish the critical zones.Finally,the application of an energy analysis gives an efficiency of about 12%for the pond.

Surface Heat Budget and Solar Radiation Allocation at a Melt Pond During Summer in the Central Arctic Ocean

The heat budget of a melt pond surface and the solar radiation allocation at the melt pond are studied using the 2010 Chinese National Arctic Research Expedition data collected in the central Arctic. Temperature at a melt pond surface is proportional to the air temperature above it. However, the linear relationship between the two varies, depending on whether the air temperature is higher or lower than 0℃. The melt pond surface temperature is strongly influenced by the air temperature when the latter is lower than 0℃. Both net longwave radiation and turbulent heat flux can cause energy loss in a melt pond, but the loss by the latter is larger than that by the former. The turbulent heat flux is more than twice the net longwave radiation when the air temperature is lower than 0℃. More than 50% of the radiation energy entering the pond surface is absorbed by pond water. Very thin ice sheet on the pond surface(black ice) appears when the air temperature is lower than 0℃; on the other hand, only a small percentage(5.5%) of net longwave in the solar radiation is absorbed by such a thin ice sheet.

盐梯度太阳池热性能数值模拟及其供热应用研究

首先,在构建太阳池一维瞬态模型的基础上,利用有限差分法对太阳池在不同结构尺寸和提热速率下的热性能进行数值仿真分析;进一步,结合数值仿真结果设计太阳池集成供热系统,探讨其在普通居民建筑供热方面的供热性能。结果表明,太阳池内温度将会因其结构尺寸的不同而产生差异,且当采用最佳结构尺寸时,系统将获得最高温度和能源效率。同时,为实现太阳池存储热量的有效利用,系统提热量应低于其最大提热速率。对于深度为1.5 m的小型太阳池,其下对流层全年温度在66.68~106.77℃间变化,年均能效为2.52%。同时,当以此小型太阳池为建筑面积200 m^(2)的普通住户供应日常生活所需热能时,应配套太阳池面积至少为250 m^(2)。

溶解性有机质在盐田中的光谱学变化特征

二维相关光谱技术(2D-COS)、三维荧光光谱技术结合平行因子分析(EEM-PARAFAC)具有扩展识别重叠峰,判断不同组分动态变化规律的技术特点。因此,2D-COS和EEM-PARAFAC分析技术可以用来分析溶解性有机质(DOM)结构组成和光谱变化特征。采用溶解性有机碳(DOC)、紫外-可见吸收光谱(UV)和EEM分析技术,借助2D-COS和PARAFAC分析模型,对青藏高原具有代表性的察尔汗盐湖、西台吉乃尔盐湖和马海盐湖中DOM在盐田摊晒过程中的结构组成和光谱学变化特征进行了研究。结果表明,随着日照时间延长,盐田中DOM和有色DOM(CDOM)含量逐渐升高,且DOM的增长倍数明显高于CDOM。在整个盐田摊晒阶段,察尔汗、西台吉乃尔和马海盐田中DOM和CDOM分别增长了1.5 vs.1.0、8.2 vs.5.3和15.7 vs.11.0倍。此外,SUVA254、HIX值在盐田中总体上呈现出逐渐减小的变化趋势。2D UV-COS分析结果表明,在察尔汗、西台吉乃尔和马海盐田中,吸收峰分别在230、217和235 nm处的DOM变动较大,变化顺序分别为228>229>230>231>232 nm&235>234>233>232 nm、200>216>300 nm和201>203>231>232>237>238>281>217 nm。EEM-PARAFAC分析结果表明,盐湖卤水中有5种荧光组分,包括4种类腐殖质荧光组分,分别是类海洋腐殖质C1(Ex/Em:320/400 nm)、类腐殖酸C2(Ex/Em:250/400 nm)和C3(Ex/Em:260/400 nm)、疏水性腐殖酸C5(Ex/Em:280,360/430 nm)和1种类蛋白质组分C4(Ex/Em:280/350 nm)。其中,尤以类腐殖质为主,分别占总荧光组分的84.0%(察尔汗)、87.2%(西台吉乃尔)和93.1%(马海)。随着盐田日晒时间的延长,C1、C2和C5在盐田中逐渐减少直至稳定不变。其中,C2组分在盐田的尾卤阶段基本消失,表明C2组分更加容易降解。C3和C4在察尔汗和马海盐田的前期逐渐减少,后期却略有升高。相对来说,C3和C4性质相对顽固,在盐田中降解程度远小于其他三个组分:6.7%<C3/C4<75.2%vs.52.8%<C1/C2/C5<100%。

Models to predict sunlight-induced photodegradation rates of contaminants in wastewater stabilisation ponds and clarifiers

Two kinetic models were established for conservative estimates of photodegradation rates of contaminants under sunlight irradiation,in particular for wastewater stabilisation ponds and clarifiers in conventional wastewater treatment plants.These two models were designated for(1)contaminants with high photolytic rates or high photolytic quantum yields,whose photodegradation is unlikely to be enhanced by aquatic photosensitisers;and(2)contaminants withstanding direct photolysis in sunlit waters but subjected to indirect photolysis.The effortlessly intelligible prediction procedure involves sampling and analysis of real water samples,simulated solar experiments in the laboratory,and transfer of the laboratory results to realise water treatment using the prediction models.Although similar models have been widely used for laboratory studies,this paper provides a preliminary example of translating laboratory results to the photochemical fate of contaminants in real waters.

内蒙古西部干旱地区煤矿反渗透浓盐水的综合利用

内蒙古西部地区气候干旱,煤炭资源丰富,但矿区地下水和矿井水的矿化度普遍偏高,淡水资源严重短缺。矿区水处理厂利用反渗透技术处理大量的高矿化矿井水,尽管该技术能够解决矿区生活用水的问题和提高矿井水综合利用水平,但是反渗透设备持续产生的浓盐水引发了存放和综合利用的新问题。介绍了反渗透浓盐水的各种处理技术及其优缺点,包括排放入海、蒸发池浓缩、零排放技术、离子提取技术等。以内蒙古西部干旱区上海庙矿区的反渗透浓盐水为例,基于矿区浓盐水水质和水量特征、矿区自然条件和太阳池原理,综合评估了浓盐水离子的回收利用可行性和太阳池的应用前景。研究结果表明:矿区反渗透浓盐水中Na^(+)、K^(+)和Mg^(2+)含量与海水和盐湖中对应离子质量浓度低1~2个数量级,提取钠盐、钾盐、氧化镁技术成熟,但经济可行性较低;反渗透浓盐水中Li离子质量浓度尽管高于海水和浓海水,但与工业提取的最低质量浓度(30 mg/L)和盐湖中锂的质量浓度相差30多倍,浓盐水中锂的回收利用需要未来提取技术的提升;矿区浓盐水中铀的质量浓度同样高于海水和浓海水,但与盐湖中铀的质量浓度相差1个数量级。矿区所在的内蒙古西部属于“太阳能资源丰富带”,年总太阳辐射大于6 300 MJ/m^(2),具有建造太阳池的先天优势,反渗透浓盐水也为太阳池提供足够的盐资源,利用反渗透浓盐水建造太阳池能提供非常可观的热能,经济可行性高。

扎布耶盐湖太阳池中富锂混盐的矿物学与地球化学特征及意义

扎布耶盐湖是全球唯一自然结晶扎布耶石(Li2CO3)的盐湖,该盐湖正在开发利用中,2021年产富锂混盐7790 t。实验所采取的样品是通过“盐梯度太阳池”技术结晶出来的10件富锂混盐,通过对采集的样品进行X射线衍射、扫描电镜、电感耦合等离子质谱法、离子色谱法和滴定法的测试,得到了矿物组成的成分和化学元素组成含量数据。扎布耶盐湖太阳池富锂混盐中的物相组成有扎布耶石、钾石盐、石盐、氯碳钠镁石、天然碱、钾芒硝、菱锰矿、石英这8种,其中菱锰矿是首次从富锂混盐中发现的矿物,扎布耶石的平均含量为62.89%,是富锂混盐中含量最高的矿物,Li+的平均含量为11.90%;K+的平均含量为2.42%;KCl的平均含量为4.63%(工业品位1%),具有巨大的利用价值。扎布耶盐湖二期工程预计年产20000 t碳酸锂,其中利用膜法生产12000 t,利用太阳池技术生产8000 t;预计年产出12700 t的富锂混盐,产出约600 t氯化钾,建议进行综合利用。

太阳池型钾石盐热溶槽底层溶液提取和补充实验

太阳池型钾石盐热溶槽运行稳定后,采取合理方法提取和补充溶液是其实际应用的重要环节,影响其运行效率的主要因素为单次取补液量、取补液速率和补液管位置.为探索取补液最优方法,通过实验考察了单次取补液量、取补液速率和补液管位置对太阳池型钾石盐热溶槽性能的影响.结果表明:太阳池型钾石盐热溶槽运行至第6 d时其密度、盐度与温度处于稳定状态,在15℃左右室温下运行稳定后其最高温度达到36.7℃;单次取补液量越大、取补液速率越快,热溶槽底层溶液温度下降越多,恢复时间越长,对盐梯度层的破坏也越明显.实验得出取补液最优方法:连续操作单次取补液量1 000 mL,间歇操作单次取补液量2 000 mL;取液管位置在热溶槽底部,补液管位置在距热溶槽底部150 mm处;取补液速率1.243 mL/s,太阳池型钾石盐热溶槽能够稳定运行,且单位时间内取补液量较大.

盐田太阳池实验研究

在海边盐田建造了50m2的太阳池,以制盐的废弃液"老卤"灌注太阳池底层,以海水或收集的淡水冲洗水面,进行了太阳池蓄热的实验,测量了太阳池的密度、温度和浊度的分布,对盐田太阳池的运行维护和经济性进行了分析研究.对盐田太阳池特有的问题,如老卤的澄清化处理和卤虫的杀灭进行了实验.研究表明盐田太阳池是一种成本低、用途广泛、适于大规模应用的太阳能集热和蓄热装置.

我国盐田首次产出南极石

南极石是极度干旱且寒冷气候条件下的产物,于1963年在南极首次被发现,并以发现地而被命名为南极石。在我国青海柴达木盆地,也曾有发现南极石的报道。南极石化学式是CaCl2·6H2O,可用来生产融雪剂,干燥剂等,具有广泛的用途。本文在青海省柴达木盆地西部南翼山地区,利用1940 m深处的地下氯化物型富钾油田水进行盐田蒸发试验,于冬季得到了南极石矿物。通过偏光显微镜下鉴定、X光粉晶衍射及化学分析,并参照前人矿物数据,确定为南极石。以前没有关于人工产出南极石的报道,这是首次在野外人工盐田条件下产出南极石,这对认识南极石的自然产出及赋存气候环境条件,对研究地区气候变化,具有重要指示意义。

青海别勒滩干盐湖石盐流体包裹体均一温度分析及地质环境意义

别勒滩位于察尔汗盐湖的最西端,最主要的沉积物为石盐,钾盐矿物主要为杂卤石、光卤石和钾石盐。文章研究了别勒滩区段盐类矿物形成的温度,为确定钾盐的形成条件提供了参考依据。别勒滩地区石盐流体包裹体均一温度呈现出3个或2个温度区段,即低温区段、中温区段和高温区段。低温区段均一温度变化范围为19.5～49.3℃,反映了大多数石盐结晶析出的卤水温度。中温区段均一温度变化范围为50.1～99.3℃,与盐湖底部卤水所达到的最高温度相对应。高温区段均一温度变化范围为100.3～195.6℃,可能为太阳池事件的响应。由太阳池下部对流层中沉积的盐类矿物组合或相关参数计算的古温度只能为其形成时的卤水温度,不能代表当时的气温。在同一样品中,既出现高温流体包裹体,又出现中温或低温流体包裹体,是矿物生长经历太阳池下部对流层环境与中部非对流层环境所致。别勒滩地区在18m以上部位可能出现6次太阳池事件,它们的位置(编号)分别为0.40～1.00m(S6)、1.70～2.90m(S5)、7.90～8.10m(S4)、9.90～10.10m(S3)、10.80～11.00m(S2)、16.39～16.63m(S1)。其中第6次太阳池事件(S6)可能是1989年发生的大水灾在盐湖沉积中的体现。

太阳池灌注卤水净化实验与中试研究

采用化学、物理方法分别对盐田废弃卤水进行净化,降低卤水浊度,用于灌注太阳池,既可节省建池费用,又起到环保的作用。针对卤水的高粘度、高盐度特点,讨论了卤水净化与淡水净化的异同。中试结果,卤水浊度分别降至10.0NTU,5.0NTU以下,符合灌注太阳池要求。

西藏扎布耶盐湖夏季卤水盐田晒制研究

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