Abstract
KEYWORDS
As, Cd, elimination, melting, vacuum
ABSTRACT
The research work that has been conducted so far, has highlighted the harmful effects of Cd and As upon the health of the workers that are engaged in the elaboration of the antifriction alloys containing Cd and As. Cd, as well as its compounds, is absorbed by human tissues and stored mainly in the lungs, heart, kidneys and blood. As has a low toxicity, but the harmful effects are generated by its compounds. Studies undertaken on groups of workers have clearly shown that Cd, As and their compounds generate different forms of cancer, such as lung cancer, kidney or bladder cancer. In the antifriction alloys the role of Cd and As is to improve their mechanical and tribological characteristics. Although the proportion of Cd and As in these alloys does not surpass 2 per cents they have to be eliminated due to their harmfulness. Moreover, at the time being, a very large amount of wastes containing these elements is to be found worldwide. Therefore the aim of the present paper is to introduce a method that in the authors’ opinion manages to eliminate these two elements successfully. Several methods of eliminating Cd and As have been tested by the authors and the best method has proven to be the vacuum elimination. This method is based on the fact that out of the elements that make up the antifriction alloys (Cu, Ni, Ca, Pb, Zn, Al, etc.), Cd and As have the lowest boiling and respectively sublimation temperatures. These low values lead implicitly to higher pressure values.