20.500.12556/RUL-128349 Reciklaža zlata iz mobilnih telefonov diplomsko delo Recycling of gold from mobile phones diploma work Zlato je gospodarsko in industrijsko pomembna kovina s širokim spektrom uporabnosti. Ta plemenita kovina je nepogrešljiva v zlatarstvu zaradi dobrih fizikalnih lastnosti, kot so dobra električna prevodnost, možnost preoblikovanja in stabilnost, zaradi in odpornosti proti koroziji pa je uporabna tudi v tehnološki uporabi. Ker ima zlato visoko in relativno stabilno vrednost, ima tudi velik monetarni pomen. Ob dejstvu, da je zlata na Zemlji v omejenih količinah in ker zemljine zaloge počasi pojenjajo, ima vedno večji pomen reciklaža zlata. Znanih je več metod raztapljanja zlata. Industrijsko najpomembnejše je raztapljanje v natrijevem (NaCN) in kalijevem (KCN) cianidu. Ker pa so cianidi nevarni in škodljivi za okolje, se bomo v diplomskem delu dotaknili predvsem uporabe zlatotopke. Pri predelavi in reciklaži zlata je pomembno tudi plemenitenje. Za to se uporabljata Millerjeva in Wohlwillova metoda rafinacije. Pri praktičnem delu diplomske naloge smo iz 58 odsluženih mobilnih telefonov reciklirali zlato z uporabo zlatotopke. Delo je obsegalo razstavitev mobilnih telefonov in sortiranje delov, ki so vsebovali zlato. Iz omenjenih delov smo zlato z uporabo mešanice klorovodikove kisline in vodikovega peroksida lužili, ga filtrirali in raztopili v zlatotopki. Iz raztopine smo nato zlato izločili z uporabo natrijevega metabisulfita in čistega cinka; usedline smo stalili v elektro-uporovni komorni peči. Kovinski delec smo nato analizirali z XRF analizo in diferenčno vrstično kalorimetrijo. Gold is an economically and industrially important metal with a wide range of uses. This noble metal is indispensable in jewelry. It is also useful in technological applications due to good physical properties, such as good electrical conductivity, formability, stability, and corrosion resistance. Because gold has a high and relatively stable value, it has also very important monetary significance. Given the fact that the gold on Earth is in limited quantities and that Earth’s reserves are slowly depleting, the recycling of gold is becoming increasingly important. There are several known methods of dissolving gold. The dissolution in sodium (NaCN) and potassium (KCN) cyanide are the most important in the industry. However, since cyanides are dangerous and harmful to the environment, we will focus on the use of aqua regia in the bachelor's thesis. Refining is an important process in the processing and recycling of gold. For that purpose, Miller and Wohlwill methods are used. In the practical part of the bachelor's thesis, we recycled gold from 58 used mobile phones using aqua regia. The thesis involved disassembling mobile phones and sorting parts that contained gold. We separated gold from the mentioned parts using a mixture of hydrochloric acid and hydrogen peroxide. Gold was filtered and dissolved in aqua regia. Gold was then eliminated from the solution using sodium metabisulfite and pure zinc. The sediments were melted in an electric resistance chamber furnace. The metal particle was then analyzed by XRF analysis and differential scanning calorimetry. zlato reciklaža zlatotopka Millerjev proces Wohlwillov proces gold recycling aqua regia Miller process Wohlwill process true false false [B. Bajc] Slovenski jezik Angleški jezik Diplomsko delo/naloga 2021-07-09 09:00:02 2021-07-09 09:00:10 2022-09-07 04:14:37 0000-00-00 00:00:00 2021 0 Ljubljana 0 Ljubljana XIII, 42 str. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 1970-01-01 669 78491 71712771 6975.pdf 6975.pdf 1 5C2F571C1CDA088AE192D785769FE627 d58adef946264a763d326a0993b55b2ff58775678a7e719b0e03d5a8d1111bb6 2a5caddd-e083-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=145061 Naravoslovnotehniška fakulteta 0 0 0