Selenium is found impurely in metal sulfide ores, copper where it partially replaces the sulfur. Commercially, selenium is produced as a byproduct in the refining of these ores, most often during production. Minerals that are pure selenide or selenate compounds are known, but are rare. The chief commercial uses for selenium today are in glassmaking and in pigments. Selenium is a semiconductor and is used in photocells. Uses in electronics, once important, have been mostly supplanted by silicon semiconductor devices. Selenium continues to be used in a few types of DC power surge protectors and one type of fluorescent quantum dot.
Siman Ltd has started its activities in 1994 as a company for trade and distribution of chemical products. For this period we have been able to establish close collaboration and relationship with our customers and suppliers. While constantly trying to determinate and even predict the actual needs of our partners, we have ever been able to expand the list of the products we are supplying and to improve our service. As an end result of this consequent striving for perfectness we have implemented the system for quality management –ISO 9001:2008, which simply serves to one more time prove our commitment to maintain our highly professional level of customer service.
The main activity of Siman Ltd is trading with chemical products, non ferrous metals and fertilizers over the territory of Bulgaria and worldwide. We have well established partnership network in more than 30 countries around the globe. It’s exactly these relationships that make our main capital, capital that we count on.