Automobilski otpad rabljen kao materijal za taline u metalurškim procesima

Increased content of automotive scrap in metallurgical charge raises the content of zinc and lead in the dust from melting installations. Every year 1.2 mln tons of zinc-coated scrap comes to the market to be recycled. The cost of the waste dumping will be systematically growing, this comes refers to both the dumping fee and costs of transport from the plant to the dumping ground. The dust collected in the process of melting is, on one hand, a valuable raw material while, on the other, special processes are required for its effective management. Zinc-containing dust can be processed by two methods: hydrometallurgical refining and pyrometallurgical refining.Povećana količina automobilskog otpada u metalurškim talinama podiže sadržaj cinka i olova u prašini metalurških postrojenja. Svake godine 1.2 mln tona otpada presvučenog cinkom dolazi na tržište radi recikliranja. Troškovi prikupljanja otpada rasti će sustavno. To se odnosi i na troškove spremanja i troškove prijevoza od pogona do mjesta odlaganja. Prašina sakupljana tijekom procesa taljenja, s jedne strane, vrijedan sirovinski materijal, s druge strane, potrebni su posebni postupci za uspješno upravljanje tim otpadom. Prašina koja sadrži cink, može se obraditi na dva načina: hidrometalurškim rafiniranjem i pirometalurškim rafiniranjem

Mogućnost formiranja deoksina i furana u metalurškim procesima kao i metode njihova smanjivanja

The metallurgical industry, among others, generates various kinds of wastes: gaseous, dusts, wastes and sewage. Special attention of the European Union is directed towards the elimination or significant reduction of the gaseous-dust contamination emissions including the most hazardous compounds, such as dioxins and furans. In the article the sources of dioxins and furans in metallurgical industry are described along with the reduction methods of these pollutants. Particularly the activities recommended as the Best Available Techniques (BAT) in order to reduce the PCDD/PCDF emission from sintering processes, non-ferrous metallurgy and foundry engineering have been presented.Metalurška industrija, između ostalih, proizvodi različite vrste otpadaka: plinovite, prašinaste, jalovinu i mulj. Posebna pozornost Europske unije usmjerena je prema eliminiranju i znatnom smanjenju plinovito-prašinaste emisijske kontaminacije uključujući najopasnije spojeve, kao što su deoksini i furani. U članku su opisani izvori deoksina i furana u metalurškoj industriji zajedno s metodama smanjenja tih polutanata. Posebno su prikazane aktivnosti koje se preporučuju kao najdostupnije metode (BAT) radi smanjenja emisije PCDD/PCDF iz procesa sinteriranja, obojene metalurgije i ljevaoničkog inženjerstva

Assessment Method of Overheating Degree of a Spent Moulding Sand with Organic Binder, After the Casting Process

A proper management of sand grains of moulding sands requires knowing basic properties of the spent matrix after casting knocking out. This information is essential from the point of view of the proper performing the matrix recycling process and preparing moulding sands with reclaimed materials. The most important parameter informing on the matrix quality - in case of moulding sands with organic binders after casting knocking out - is their ignition loss. The methodology of estimating ignition loss of spent moulding sands with organic binder - after casting knocking out - developed in AGH, is presented in the paper. This method applies the simulation MAGMA software, allowing to determine this moulding sand parameter already at the stage of the production preparation

Obnavljanje uporabljenog pijeska pri proizvodnji odljevaka

The scope and purpose of the present study is to contribute to the research of reclamation processes by investigating factors and conditions allowing replacement of fresh quartz sand consumption in foundry production by the recovered sand. Actually gained experience by the foundries on this field confirmed that reclamation of moulding used sands is regarded as an effective way of saving and protecting of the natural silica sand deposits.Opseg i svrha ove studije je doprinos razvoju istraživanja procesa obnavljanja pijeska pri pronalaženju okolnosti i uvjeta koji omogućuju zamjenu svježeg kvarcnog pijeska u proizvodnji odljevaka. Na tom polju stvarno stečeno iskustvo u ljevaonicama potvrđuje da se obnavljanje pijeska korištenog za izradu kalupa smatra djelotvornim načinom čuvanja i zaštite postojećeg prirodnog silicijskog pijeska