The effects of the metal temperature and wall thickness on flake graphite layer in ductile iron

This article addresses the effect of mold filling and wall thickness on the flake graphite layer in ductile iron. The research was conducted for castings with different wall thickness (3-8 mm) and using molding sand with furan resin. A thermal analysis has been performed along the length of the castings to determine the initial temperature of the metal in the mold cavity and the contact time of the liquid metal with the mold. Results demonstrated the strong influence of the temperature decrease of the metal in the mold cavity on the occurrence and the thickness of the flake graphite in the surface layer in ductile iron

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

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

Ljevačka industrija – sadašnje stanje i budući razvitak

The casting production is considered as one of the main factors influencing the development of world economy. The state of art and foresight of world’s casting production is discussed in the paper on the basis of the latest statistical data. The progress gained during the last few years in foundry engineering is shown as a way to further development of foundry technology. The last decade brought significant changes in the world map of the greatest casting producers. Globalization and transformation of economic systems is reflected by variations of foundry production in different countries, more over the globalization of economy is regarded not only as a chance but also as a menace for the European foundries.Ljevačka proizvodnja se smatra jednom od glavnih utjecajnih faktora u svjetskom gospodarstvu. Stanje postignuća i predmnijevanje ljevačke proizvodnje na temelju posljednjih statističkih podataka daje se u ovom članku. Polučeni napredak tijekom nekoliko posljednjih godina u ljevačkoj tehnici je prikazan kao putokaz budućeg razvitka ljevačke tehnologije. Posljednja dekada donosi značajne izmjene na svjetskoj karti najvećih proizvođača odljevaka. Globalizacija i tansformacija ekonomskog sustava održavanja se raznolikošću u ljevačkoj proizvodnji različitih država, što više globalizacije gospodarstvo se motri ne samo kao šansa nego i kao ugroz europskih ljevaonica

The state of art and foresight of world’s casting production

The casting production is considered of the main factors influencing the development of World economy. Actual capacity of the world’s casting production, which is about 101 mln metric ton per year (2012), is strongly diversified. The last decade brought significant changes in the World map of the greatest casting producers. Globalization and transformation of economic systems is reflected by variations of foundry production in different countries, moreover the globalization of economy is regarded not only as a chance but also as a menace for European foundries