Faiza Tehseen

Pakistan has huge deposits of copper-gold, which need indigenous copper refining units for extraction of important elements including tellurium, reports WealthPK. Tellurium is a brittle, silvery white metalloid obtained as byproduct during the refining and processing of copper. Pakistan currently exports copper ore in concentrated form depriving it of huge revenue.

Talking to WealthPK about tellurium and its local extraction, Muhammad Yaqub Shah, acting member of the sectoral Council for Marble, Granite, and Minerals, the Ministry of Finance, said this metalloid was present in a ratio of about 0.001PPM in the earth’s crust. “Our rich copper-gold deposits are a great source to get tellurium. We can save hefty foreign exchange through the local extraction of tellurium from the precious copper ore.

Tellurium is primarily hauled out as a consequence of copper refining from hefty tonnage, low-grade copper ore, or porphyry-type copper-gold deposits. Gold and silver form compounds with it, i.e. calaverite or gold telluride,” he said. Yaqub said through an electrolytic process, tellurium was extracted from copper besides other impurities or elements, such as iron (the principal metallic impurity), silver, gold, platinum, and so on.

“The ore mined in Pakistan is mostly of 0.8% viability. It is concentrated through a chemical process and it becomes viable by up to 34% to 35 %, but no further extraction is done,” he said. “Unfortunately, copper is exported in the raw or concentrated form to other countries, where it is further processed to extract industrially important elements, including tellurium.

By spending precious foreign exchange, Pakistan buys these extracted elements, which makes its industrial products a bit pricey. In this way, the country fails to reap the huge socio-economic benefits of copper,” said Yaqub, who is also principal geologist at the Islamabad-based Global Mining Company. “The principal minerals of tellurium are mostly tellurite and sylvanite. Its rock formation is mostly volcanic but chances of occurrence in sedimentary rocks also exist.

However, in Pakistan, their extraction has never been attempted at the government level,” he said. “Copper or copper-gold ore is actively mined in Waziristan district of KP and Balochistan. There are ample deposits of copper-gold in Chiniot city of Punjab, but these are not dynamically mined,” he added. Copper-gold deposits are also found in Gilgit Baltistan (GB) province, but no mining has been done at the government level.

Some people mine it privately and sell it illegally. There are no copper-gold deposits in Sindh. “It is very important for Pakistan to establish copper refineries at any central place to uplift the mining industry,” said the principal geologist. Tellurium is widely used as an important industrial component to manufacture a variety of industrial products, such as rubber vulcanization, rewritable Compact Discs (CDs)/Digital Video Discs (DVDs), glass tinting, and ceramics. It is used as a catalyst to refine oil. In semiconductor applications, it can also be doped with tin, copper, silver, gold, etc. It is a fair electricity conductor but a poor heat conductor. Medically, it is used to treat microbial infections.

To fabricate fiber optics, color ceramics, and pigment production, tellurium dioxide is commonly used. It is frequently used in certain thermoelectric and electronic applications. Considering 2022 as the base year on the basis of its application, the tellurium/telluride market is projected to increase by 83.72 Million Tonnes (MT) up to 2027 at a compound annual growth rate (CAGR) of 3.41%. Keeping in view the future market of precious tellurium and the importance of local copper refining, Pakistan must focus on this issue.

Credit: INP-WealthPk