Faiza Tehseen

Pakistan can unlock a sizable treasure chest of valuable minerals by reprocessing waste rocks. This transformation is vital for the country’s socio-economic benefits and environmental safety, Abdul Bashir, Chief Geologist of Balochistan-based Koh-e-Daleel Minerals (Pvt) Ltd, told WealthPK. “With smart modern methods, old mining waste can be turned into an asset, which was earlier impossible using the old methods or conventional techniques. Basically, waste rocks are not the ore but a covering toward the mine. They are also called sidoberg, warp or wall-rock. To access the ore deposit in the mine (whether it is open pit or the underground/tunnel mine), the waste rocks need first to be mined,” he said. In the past, during mining operations, waste rocks were usually removed with overburden. Owing to the absence of sophisticated technology, practically, they were considered having low concentration for economic recovery. Mostly, the waste rock consists of crushed, coarse, or blocky material covering a range of sizes including large boulders, fine sand particles, and dust.

The sizes depend upon the nature of formation or the employed mining method. “Practically, all the minerals in waste rocks cannot have a good financial gain except the most valuable ones including, gold, copper, lead, zinc, or rare earths. Gold enriched ores usually remain 5% or less with the tailings. Ten percent of valuable sulphide ores (lead, zinc, and copper) stay in the residual material”. He said some minerals considered valueless in the past and left with tailings were demanding items today. For example, phosphorus containing iron oxide concentrate is high in demand for blast furnaces. In tailings, rare earth bearing mineral apatite is considered of high value. Usually, apatite contains an average of 0.1% to 0.8% of rare earth oxides. So, other than the need for blast furnaces, it can be beneficial to recover for other industrial and strategic needs. Talking to WealthPK about the reovery of metals/ minerals from the waste rock in Pakistan, miner and geologist Imran Babar said, “Other than the conventional methods, modern echnology is more efficient to perform this operation.

Besides extraction of valuable minerals from the waste rock, the number of disposal places will also decrease after the mining operation. Otherwise, the waste rocks or mine tailings occupy a large area without any further use.” He said with the increasing demand for metals and minerals in the global market, reuse or recovery of valuable minerale from the waste rock was becoming increasingly important. Only the smart technilogy is making the matters easy. For example, in the past, normal gold recovery through the conventional methods was around 35 to 60% but the sophisticated technology has increased this ratio up to 92% to 97% approximately. Imran emphasized the need to introduce the modern technology in the country. He said awareness campaigns about mining techniques, new equipment, and technology were also necessary for the investors and miners so that they may take quick decisions and the mining sector in Pakistan may be strengthened.

Credit: INP-WealthPk