Crushing energy measurements on the field : master’s thesis

Ovaj rad prikazuje rezultate terenskog mjerenja energije drobljenja na eksploatacijskom polju „Očura“. Hipoteza rada je da smanjenjem veličine čestica raste energija potrebna za njihovo sitnjenje. Na separacijskom postrojenju eksploatacijskog polja „Očura“ uzorci su drobljeni u čeljusnoj (primarnoj), konusnoj (sekundarnoj) i udarnoj (tercijarnoj) drobilici. Pomoću mjernog sustava mjerena je potrošnja električne energije elektromotora prilikom drobljenja u pojedinim drobilicama. U čeljusnoj drobilici izdrobljeno je 16 pojedinačnih uzoraka te je određivana njihova specifična energija. U konusnoj i udarnoj drobilici izdrobljen je materijal iz čeljusne drobilice, ali odjednom. Uspoređivana je specifična energija drobljenja u čeljusnoj, konusnoj i udarnoj drobilici. Statističkom analizom utvrđivana je ovisnost između mase uzorka, specifičnoj energiji drobljenja, prosječnoj snazi drobljenja i maksimalnoj snazi tijekom drobljenja.This thesis shows the results of crushing energy measurements on the field on „Očura“ surface mine. The hypothesis of the thesis is that lowering the particle size raises the energy needed for their comminution. Samples of rock were crushed in jaw (primary), cone (secondary) and impact (tertiary) crushers on the „Očura“ processing plant. Electrical energy consumption of the crushers motor was measured with the measuring system during sample crushing. In the jaw crusher, 16 individual samples were crushed and their specific crushing energy was calculated. In the cone and impact crushers the material form the jaw crusher was crushed all at once. Specific crushing energy of jaw, cone and impact crushers was compared. Dependence between samples mass, specific crushing energy, average crushing power and maximum crushing power was determined by statiscial data processing

Crushing energy measurements on the field : master’s thesis

Ovaj rad prikazuje rezultate terenskog mjerenja energije drobljenja na eksploatacijskom polju „Očura“. Hipoteza rada je da smanjenjem veličine čestica raste energija potrebna za njihovo sitnjenje. Na separacijskom postrojenju eksploatacijskog polja „Očura“ uzorci su drobljeni u čeljusnoj (primarnoj), konusnoj (sekundarnoj) i udarnoj (tercijarnoj) drobilici. Pomoću mjernog sustava mjerena je potrošnja električne energije elektromotora prilikom drobljenja u pojedinim drobilicama. U čeljusnoj drobilici izdrobljeno je 16 pojedinačnih uzoraka te je određivana njihova specifična energija. U konusnoj i udarnoj drobilici izdrobljen je materijal iz čeljusne drobilice, ali odjednom. Uspoređivana je specifična energija drobljenja u čeljusnoj, konusnoj i udarnoj drobilici. Statističkom analizom utvrđivana je ovisnost između mase uzorka, specifičnoj energiji drobljenja, prosječnoj snazi drobljenja i maksimalnoj snazi tijekom drobljenja.This thesis shows the results of crushing energy measurements on the field on „Očura“ surface mine. The hypothesis of the thesis is that lowering the particle size raises the energy needed for their comminution. Samples of rock were crushed in jaw (primary), cone (secondary) and impact (tertiary) crushers on the „Očura“ processing plant. Electrical energy consumption of the crushers motor was measured with the measuring system during sample crushing. In the jaw crusher, 16 individual samples were crushed and their specific crushing energy was calculated. In the cone and impact crushers the material form the jaw crusher was crushed all at once. Specific crushing energy of jaw, cone and impact crushers was compared. Dependence between samples mass, specific crushing energy, average crushing power and maximum crushing power was determined by statiscial data processing

Električna svojstva elektrohemijski kopolimerizovanog anilina i sulfanilne kiseline

Electrochemical synthesis of poly(aniline-co-(sulfanilic acid)) was performed on a graphite electrode with constant current densities from an aqueous electrolyte containing 1.0 mol dm-3 H2SO4 and 0.25 mol dm-3 monomers with different ratios of aniline and sulfanilic acid. Optimal conditions for copolymerization were set to the current density of 0.75 mA cm-2 and the electrolyte containing 0.15 mol dm-3 aniline and 0.10 mol dm-3 sulfanilic acid. Electrochemical characterization of the poly(aniline-co-(sulfanilic acid)) electrode was performed using cyclic voltammetry and galvanostatic charge/discharge techniques. Electrical properties such as specific power and specific energy at different discharge currents were also determined. Based on the Ragon plot, it was observed that the poly(aniline-co-(sulfanilic acid)) electrode exhibited battery features at low discharge currents. In contrast, it was possible to achieve specific power of supercapacitors at high discharge currents. Moreover, after 4000 cycles of charge/discharge poly(aniline-co-(sulfanilic acid)), capacity retention exceeding 90 % was obtained.Elektrohemijska kopolimerizacija anilina i sulfanilne kiseline ostvarena je u galvanostatskim uslovima različitim gustinama struje na grafitnoj elektrodi. Kao elektrolit korišćen je vodeni rastvor 1.0 mol dm-3 H2SO4 sa dodatkom 0.25 mol dm-3 monomera različitog odnosa anilina i sulfanilne kiseline. Izabrani su optimalni uslovi za sintezu u pogledu gustine struje polimerizacije od 0.75 mA cm-2 i sastava elektrolita koji je sadržavao 0.15 mol dm-3 anilina i 0.10 mol dm-3 sulfanilne kiseline. Za elektrohemijsku karakterizaciju elektrode na bazi kopolimera anilina i sulfanilne kiseline korišćene su tehnike ciklične voltametrije i snimanja hronopotenciometrijskih krivih punjenja/pražnjenja. Na osnovu krivih pražnjenja procenjene su električne karakteristike ove elektrode: specifična energija i specifična snaga. Na osnovu Ragonovog dijagrama pokazano je da elektroda na bazi kopolimera anilina i sulfanilne kiseline poseduje baterijska svojstva pri niskim strujama pražnjenja, dok se pri visokim strujama pražnjenja ponaša kao elektroda superkondenzatora. Takođe, ova elektroda je nakon 4000 ciklusa punjenja i pražnjenja zadržala preko 90 % početnog kapaciteta

Electrochemical and Electrical Performances of High Energy Storage Polyaniline Electrode with Supercapattery Behavior

Polyaniline (PANI), due to its highly reversible electrochemistry with superior energy storage and delivery characteristics, is considered as an electrode material in batteries, capacitors, and hybrid systems. We used a facile electrochemical synthesis for the formation of the PANI electrode using galvanostatic polymerization of aniline on the graphite electrode at the current density of 2.0 mA cm−2 from the aqueous electrolyte containing 0.25 mol dm−3 aniline and 1.0 mol dm−3 H2SO4. Electrochemical and electrical characterization suggested excellent energy storage features of the PANI electrode in a three-electrode system with specific energy up to 53 Wh kg−1 and specific power up to 7600 W kg−1. After 2000 successive charge/discharge cycles at 9.5 Ag−1, the PANI electrode retained 95% of the initial capacity, with practically unaltered Coulombic efficiency of nearly 98%, providing a good base for future studies and practical applications

Crushing energy measurements on the field : master’s thesis

Ovaj rad prikazuje rezultate terenskog mjerenja energije drobljenja na eksploatacijskom polju „Očura“. Hipoteza rada je da smanjenjem veličine čestica raste energija potrebna za njihovo sitnjenje. Na separacijskom postrojenju eksploatacijskog polja „Očura“ uzorci su drobljeni u čeljusnoj (primarnoj), konusnoj (sekundarnoj) i udarnoj (tercijarnoj) drobilici. Pomoću mjernog sustava mjerena je potrošnja električne energije elektromotora prilikom drobljenja u pojedinim drobilicama. U čeljusnoj drobilici izdrobljeno je 16 pojedinačnih uzoraka te je određivana njihova specifična energija. U konusnoj i udarnoj drobilici izdrobljen je materijal iz čeljusne drobilice, ali odjednom. Uspoređivana je specifična energija drobljenja u čeljusnoj, konusnoj i udarnoj drobilici. Statističkom analizom utvrđivana je ovisnost između mase uzorka, specifičnoj energiji drobljenja, prosječnoj snazi drobljenja i maksimalnoj snazi tijekom drobljenja.This thesis shows the results of crushing energy measurements on the field on „Očura“ surface mine. The hypothesis of the thesis is that lowering the particle size raises the energy needed for their comminution. Samples of rock were crushed in jaw (primary), cone (secondary) and impact (tertiary) crushers on the „Očura“ processing plant. Electrical energy consumption of the crushers motor was measured with the measuring system during sample crushing. In the jaw crusher, 16 individual samples were crushed and their specific crushing energy was calculated. In the cone and impact crushers the material form the jaw crusher was crushed all at once. Specific crushing energy of jaw, cone and impact crushers was compared. Dependence between samples mass, specific crushing energy, average crushing power and maximum crushing power was determined by statiscial data processing

A novel method of preparing the silver chloride cathode for the magnesium seawater activated primary cell

The novel method based on the inexpensive and fast modified successive ion layer adsorption and reaction (SILAR) method of preparing silver chloride cathode on the carbon felt is developed. The electrochemical behavior of the silver chloride cathode in the combination with magnesium alloy AZ63 anode is investigated, as the seawater activated primary cell. Under the discharge rate of the cell of 1C, 157 mA g(-1) of active materials, the voltage discharge plateau of similar to 1.25 V-0.9 V; specific capacity of 130 mAh g(-1); specific energy of 145 mWh g(-1), and specific power of 175 mW g(-1) are obtained

Kapacitivna svojstva elekrode na bazi elektrohemijski formiranog polianilina

Intrinsically conducting polymers, especially polyaniline (PANI), are widely investigated in the field of energy storage and conversion due to the highly reversible electrochemistry of doping/dedoping. These reactions are responsible for PANI’s high capacitance, often reported as pseudocapacitance. In this work, PANI electrodes were obtained by electrochemical polymerization of aniline monomer, with different polymerization charges ranging between 0.125 and 1.0 mA cm-2, on a graphite electrode, at the constant current density of 2.0 mA cm-2. The electrolyte used in this study consisted of 1.0 mol dm-3 H2SO4 and 0.2 mol dm-3 aniline. Electrochemical characterization of the PANI electrode involved cyclic voltammetry, chronopotentiometric charge/discharge and electrochemical impedance spectroscopy at constant potentials. Specific capacitance was determined from these techniques following the procedure for pseudocapacitive electrodes. After 250 cycles of charge/discharge with the current density of 10 mA cm-2, only 7 % of the capacitance was lost, indicating good stability of PANI that likely originates from its structure comprising a shared divalent sulfate ion between two monomer units.Elektroprovodni polimeri, prvenstveno polianilin (PANI), su intenzivno proučavani u oblasti konverzije i skladištenja električne energije, zahvaljujući visokoj reverzibilnosti reakcije dopovanja/dedopovanje. Ove reakcije su odgovorne za visoku specifičnu kapacitivnost PANI koja se često u literaturi označava kao pseudokapacitivnost. U ovom radu, elektrode na bazi PANI dobijene su oksidativnom elektrohemijskom polimerizacijom anilina različitim kapacitetima polimerizacije u opsegu od 0,125 do 1,0 mA cm-2 na elektrodi od grafita u galvanostatskim uslovima gustinom struje od 2,0 mA cm-2. Kao elektrolit korišćen je vodeni rastvor 1,0 mol dm-3 H2SO4 uz dodatak 0,2 mol dm-3 anilina. Za elektrohemijsku karakterizaciju elektrode na bazi PANI korišćene su tehnike ciklične voltametrije, hronopotenciometrijskog snimanja krivih punjenja/pražnjenja i spektroskopija elektrohemijske impedanse na konstantnom potencijalu. Specifična kapacitivnost PANI elektrode određivana je na način uobičajen za pseudokapacitivne elektrode. Na osnovu 250 sukcesivnih ciklusa punjenja i pražnjenja gustinom struje od 10 mA cm-2, utvrđeno je gubitak kapacitivnosti od svega 7%, što se verovatno može dovesti u vezu sa povećanom stabilnošću PANI usled strukture koja podrazumeva deljenje dvovalentnog sulfatnog jona između dve jedinice monomera