Green sand-to-liquid metal ratios in copper foundries

The metal yield is the ratio of the amount of metal melted to the weight of the finished good castings. Five main factors affect metal yield, i.e. quality requirement choice of mould-box size the extent of runner and feeder systems metal shrinkage scrap casting rate. 

Sector Average metal yield (%) Range of yields reported (%) 

Data were collected through a survey in the UK foundry sector and from the Portuguese foundry association (the latter for steel). A significant number of survey respondents declined to supply yield data, particularly in the aluminium and copper sectors. However, some general comments on metal yield can be made  

A review and study of foundry waste sand quality and composition was performed in Finland. Data were collected from literature and from own experiments [169, Orkas, 2001], 

In several studies, chemical analyses on used foundry sands from various sources were performed. A summary of the most significant results is presented in Table 3.49. The data show that the contents of metallic and organic harmful compounds in used foundry sand are normally low. Generally, the contents of organic and metallic harmful compounds are higher in green sands compared to chemically-bonded sands. Inorganic sands are basically very clean. 

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Figure 3.9 Green sand-to-liquid metal ratios in copper foundries [73, ETSU, 1995]...

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