Continuous Counter-current Solvent Extraction of Magnesium and Calcium from Lithium-rich Brine

Solvent extraction of calcium and magnesium impurities from a lithium-rich brine (Ca ~ 2,000 ppm, Mg ~ 50 ppm, Li ~ 30,000 ppm) was investigated using a continuous counter-current solvent extraction mixer-settler set-up. The literature review includes a general review about resources, demands and production methods of Li followed by basics of solvent extraction. Experimental section includes batch experiments for investigation of pH isotherms of three extractants; D2EHPA, Versatic 10 and LIX 984 with concentrations of 0.52, 0.53 and 0.50 M in kerosene respectively. Based on pH isotherms LIX 984 showed no affinity for solvent extraction of Mg and Ca at pH ≤ 8 while D2EHPA and Versatic 10 were effective in extraction of Ca and Mg. Based on constructed pH isotherms, loading isotherms of D2EHPA (at pH 3.5 and 3.9) and Versatic 10 (at pH 7 and 8) were further investigated. Furthermore based on McCabe-Thiele method, two extraction stages and one stripping stage (using HCl acid with concentration of 2 M for Versatic 10 and 3 M for D2EHPA) was practiced in continuous runs. Merits of Versatic 10 in comparison to D2EHPA are higher selectivity for Ca and Mg, faster phase disengagement, no detrimental change in viscosity due to shear amount of metal extraction and lower acidity in stripping. On the other hand D2EHPA has less aqueous solubility and is capable of removing Mg and Ca simultaneously even at higher Ca loading (A/O in continuous runs > 1). In general, shorter residence time (~ 2 min), lower temperature (~23 °C), lower pH values (6.5-7.0 for Versatic 10 and 3.5-3.7 for D2EHPA) and a moderately low A/O value (< 1:1) would cause removal of 100% of Ca and nearly 100% of Mg while keeping Li loss less than 4%, much lower than the conventional precipitation in which 20% of Li is lost.

Depth sensors in augmented reality solutions. Literature review

The emergence of depth sensors has made it possible to track – not only monocular cues – but also the actual depth values of the environment. This is especially useful in augmented reality solutions, where the position and orientation (pose) of the observer need to be accurately determined. This allows virtual objects to be installed to the view of the user through, for example, a screen of a tablet or augmented reality glasses (e.g. Google glass, etc.). Although the early 3D sensors have been physically quite large, the size of these sensors is decreasing, and possibly – eventually – a 3D sensor could be embedded – for example – to augmented reality glasses. The wider subject area considered in this review is 3D SLAM methods, which take advantage of the 3D information available by modern RGB-D sensors, such as Microsoft Kinect. Thus the review for SLAM (Simultaneous Localization and Mapping) and 3D tracking in augmented reality is a timely subject. We also try to find out the limitations and possibilities of different tracking methods, and how they should be improved, in order to allow efficient integration of the methods to the augmented reality solutions of the future.

The solutions and tunneling properties for a linear potential and an inverted harmonic oscillator in an infinite well

In this work we look at two different 1-dimensional quantum systems. The potentials for these systems are a linear potential in an infinite well and an inverted harmonic oscillator in an infinite well. We will solve the Schrödinger equation for both of these systems and get the energy eigenvalues and eigenfunctions. The solutions are obtained by using the boundary conditions and numerical methods. The motivation for our study comes from experimental background. For the linear potential we have two different boundary conditions. The first one is the so called normal boundary condition in which the wave function goes to zero on the edge of the well. The second condition is called derivative boundary condition in which the derivative of the wave function goes to zero on the edge of the well. The actual solutions are Airy functions. In the case of the inverted oscillator the solutions are parabolic cylinder functions and they are solved only using the normal boundary condition. Both of the potentials are compared with the particle in a box solutions. We will also present figures and tables from which we can see how the solutions look like. The similarities and differences with the particle in a box solution are also shown visually. The figures and calculations are done using mathematical software. We will also compare the linear potential to a case where the infinite wall is only on the left side. For this case we will also show graphical information of the different properties. With the inverted harmonic oscillator we will take a closer look at the quantum mechanical tunneling. We present some of the history of the quantum tunneling theory, its developers and finally we show the Feynman path integral theory. This theory enables us to get the instanton solutions. The instanton solutions are a way to look at the tunneling properties of the quantum system. The results are compared with the solutions of the double-well potential which is very similar to our case as a quantum system. The solutions are obtained using the same methods which makes the comparison relatively easy. All in all we consider and go through some of the stages of the quantum theory. We also look at the different ways to interpret the theory. We also present the special functions that are needed in our solutions, and look at the properties and different relations to other special functions. It is essential to notice that it is possible to use different mathematical formalisms to get the desired result. The quantum theory has been built for over one hundred years and it has different approaches. Different aspects make it possible to look at different things.

Open source solutions for multiplatform graphics programming

New emerging technologies in the recent decade have brought new options to cross platform computer graphics development. This master thesis took a look for cross platform 3D graphics development possibilities. All platform dependent and non real time solutions were excluded. WebGL and two different OpenGL based solutions were assessed via demo application by using most recent development tools. In the results pros and cons of the each solutions were noted.

The solutions and tunneling properties for a linear potential and an inverted harmonic oscillator in an infinite well

In this work we look at two different 1-dimensional quantum systems. The potentials for these systems are a linear potential in an infinite well and an inverted harmonic oscillator in an infinite well. We will solve the Schrödinger equation for both of these systems and get the energy eigenvalues and eigenfunctions. The solutions are obtained by using the boundary conditions and numerical methods. The motivation for our study comes from experimental background. For the linear potential we have two different boundary conditions. The first one is the so called normal boundary condition in which the wave function goes to zero on the edge of the well. The second condition is called derivative boundary condition in which the derivative of the wave function goes to zero on the edge of the well. The actual solutions are Airy functions. In the case of the inverted oscillator the solutions are parabolic cylinder functions and they are solved only using the normal boundary condition. Both of the potentials are compared with the particle in a box solutions. We will also present figures and tables from which we can see how the solutions look like. The similarities and differences with the particle in a box solution are also shown visually. The figures and calculations are done using mathematical software. We will also compare the linear potential to a case where the infinite wall is only on the left side. For this case we will also show graphical information of the different properties. With the inverted harmonic oscillator we will take a closer look at the quantum mechanical tunneling. We present some of the history of the quantum tunneling theory, its developers and finally we show the Feynman path integral theory. This theory enables us to get the instanton solutions. The instanton solutions are a way to look at the tunneling properties of the quantum system. The results are compared with the solutions of the double-well potential which is very similar to our case as a quantum system. The solutions are obtained using the same methods which makes the comparison relatively easy. All in all we consider and go through some of the stages of the quantum theory. We also look at the different ways to interpret the theory. We also present the special functions that are needed in our solutions, and look at the properties and different relations to other special functions. It is essential to notice that it is possible to use different mathematical formalisms to get the desired result. The quantum theory has been built for over one hundred years and it has different approaches. Different aspects make it possible to look at different things.

Natural freeze crystallization : purification of aqueous Na2SO4 solutions with cold air

The aim of this thesis was to examine efficiency of freeze crystallization and eutectic freeze crystallization in purification of wastewater by imitating natural freezing. In addition, a mathematic model based on heat transfer to determine ice thickness and ice growth rate was examined. Also, the amount of sodium sulfate crystallized at the eutectic point was under investigation. In literature part, advantages and applications of the freeze crystallization are discussed, and possibility to apply it in Northern hemisphere winter weather conditions is under study. Furthermore, main sources of sodium sulfate from Finnish industries are described. The experiments were carried out in modified chest freezer, where a fan was placed in order to obtain laminar air flow inside. Picolog PT-104 data logger was used to monitor temperature changes in the salt-water solution, and constant temperature was maintained in the crystallizer with Lauda RP 850 thermostat. The impurity of formed ice layer was determined by weighing ice samples after experiment and again after 24 hours drying to full dryness in oven. Volume of salt-water solution was also measured after experiment. The highest purity of formed ice layer was obtained with small temperature difference and with long freezing time. On the other hand, the amount of crystallized sodium sulfate was its greatest with long freezing time and higher temperature difference. The results obtained by the mathematic model and empirical results did not differ significantly in most of the experiments. However, the difference increased when salt-water mixture reached its eutectic point, leading to simultaneous ice and salt crystallization. Eutectic point was reached only with the highest salt concentration with one exception. In these cases, calculated values were in many cases greater than the experimental ones. In winter weather conditions freeze crystallization is cost-effective wastewater treatment method and rather simple. Nonetheless, the efficiency and separation rate are strongly depended on ambient temperature and its changes

Oxidation of Aqueous Thiosulfate Solutions by Pulsed Corona Discharge

The aim of this Master’s thesis focused on the oxidation of sodium thiosulfate using non thermal plasma technology as an advance oxidation process (AOP). By using this technology we can degrade certain toxic chemical compounds present in mining wastewaters as pollutants. Different concentrations of thiosulfate and pulse frequencies were used in the PCD experiments and the results in terms of various delivered energies (kWh/m3) and degradation kinetics were compared. Pulsed corona discharge is an energy efficient process compared to other oxidation processes using for the treatment of waste water pollutants. Due to its simplicity and low energy costs make it attractive in the field of waste water treatment processes. This technology of wastewater treatment has been tested mainly on pilot scale level and in future the attempts are to be focus on PCD investigations on larger process scale. In this research work of oxidation of thiosulfate using pulsed corona discharge, the main aim of this research was to study degradation of a studied toxic and not environmental friendly chemical compound. The focus of this research was to study the waste waters coming from the gold mines containing leachate compound thiosulfate. Literature review contained also gold leaching process when cyanide is used as the leachate. Another objective of this work was to compare PCD process with other processes based on their energy efficiencies. In the experimental part two concentrations of sodium thiosulfate, 1000ppm and 400ppm, were used. Two pulse generator frequencies of 833 and 200 pulses per second (pps) were used. The chemical analyses of the samples taken during semi-batch PCD oxidation process were analyzed by ion chromatographic (IC). It is observed after the analyses that among different frequencies and concentrations, the most suitable ones for the process is 200pps and 1000ppm respectively because the pollutants present in the waste water has more time to react with the OH radicals which are the oxidants and the process is energy efficient compared to other frequencies.