Cerro Colorado enters feasibility stage in Panama

Toronto-based Tiomin Resources (TIO-T) has awarded a contract to an independent engineering firm to study the feasibility of developing its Cerro Colorado porphyry copper deposit in Panama.

Kvaerner Metals (Davy Nonferrous Division) of California will determine the capital and operating costs of mining the deposit’s reserves of 1.4 billion tonnes grading 0.78% copper by open-pit methods. Processing would be carried out by a combination of heap-leaching, solvent extraction-electrowinning (SX-EW) and conventional sulphide milling.

In its earlier, in-house prefeasibility study, Tiomin recommended the ore be processed in two successive phases. In the first phase, SX-EW was recommended for the first few years of operations, during which time annual production of cathode copper would range from 50 million to 60 million lb. This would then be replaced by a 50,000-Tonne-per-day sulphide milling operation for the remainder of the mine’s expected life of 45 years. Annual production during this second phase was projected at 300 million lb. of copper concentrate. For the first phase, cash costs were pegged at 47 cents per lb.; for the second, they were estimated to fall to 30 cents per lb.

To assist Kvaerner with the new study, Tiomin has hired several additional consultants. Each firm will focus on an individual aspect, with Kvaerner acting as overall project co-ordinator.

These other requirements include an environmental base line study, metallurgical and laboratory work, auditing of reserve estimates, mine design, geotechnical assessment and design of pit slopes.

The study is expected to be finished by March 1998. Cerro Colorado is the 12th-largest porphyry copper deposit in the world. The total resources there, including reserves, are estimated at 4.5 billion tonnes grading 0.45% copper, equivalent to 45 billion lb.

Copper mineralization occurs in a supergene and underlying primary-sulphide zone, in the form of chalcocite, covellite, cuprite and chalcopyrite.

Tiomin holds a 100% interest in the operation. Upon repayment of capital expenditures to lenders, its interest will fall to 71%, and, thereafter, by 1% per year to a final interest of 51%.

In other developments, Tiomin is undergoing a prefeasibility study at its titanium-bearing mineral sands project on the coast of Kenya.

The study, which is expected to be completed in mid-June, will incorporate four separate, but nearby, heavy-Mineral zones. The company says additional infill drilling is required for total resource estimates, and drill results are currently awaited from one of the zones.

Titanium is used as a pigment in the manufacture of paints, plastics and paper. In Kenya, titantium mineralization takes the form of ilmenite (FeTiO3) and rutile (TiO2). The project also contains quantities of zircon (ZrSiO4), which is used in the ceramics industry.