White Mountain Test Work Succeeds in Recovery of Feldspar From Rutile Flotation Tailings
White Mountain Titanium Corporation reports that it has successfully completed flotation test work to recover feldspar from natural rutile (titanium dioxide) flotation tailings. The test work program was carried out at SGS Lakefield (“SGS”) in Ontario, Canada. The aim of the program was to produce a low iron, feldspar concentrate from waste stream tailings acceptable for possible use as a flux or in the glass and ceramic industries.
Working on rutile flotation tailings derived from the Stage 2 pilot plant and previous locked cycle test work programs, SGS examined various operating procedures to extract feldspar minerals. These procedures included the adjustment of pH conditions in the circuit, the use of fresh and sea water as the aqueous medium and the choice of flotation reagents. Following several trials, SGS were able to develop a process flow sheet that successfully recovered a low iron (Fe2O3), sodium (Na2O) rich feldspar concentrate.
The principal steps in the process flow sheet involve desliming the rutile tailings, muscovite (mica) pre-flotation and preferential flotation of sodium feldspars. All test work was carried out in an acidic environment (pH 3.5 to 5.5) – very similar to pH conditions previously used in the flotation of rutile. This is an important achievement as it obviates the need to undertake major pH adjustment from the rutile to the feldspar flotation circuit. A sodium feldspar concentrate assaying 9.07% Na2O and 0.37% Fe2O3 was produced using fresh water as the aqueous medium and minimal addition of flotation reagents. Comparable concentrate grades were obtained using sea water as the aqueous medium.
“Completion of the flotation test work to recover feldspar is an important component of the Cerro Blanco development program,” said Michael Kurtanjek, the Company’s President and CEO. “The latest results are a considerable improvement on earlier test work where iron impurity levels in excess of 1% were recorded. Given the high feldspar content in source rock planned for the processing plant and now the demonstrated ability to produce a low iron, sodium feldspar concentrate from rutile flotation tailings, the possible sale of feldspar concentrate may have a significant impact on the economics of the project. We now see the possibility of co-producing both rutile and feldspar concentrates, the latter derived from a plant waste stream.”