Limestone is found in Alberta along the entire length of the Foothills and Front Ranges trend of the western side of the province as well as within northeastern Alberta in the Fort McMurray area. None of the limestones tested from seven of the nine major localities of accessible outcrops is capable of producing ground calcium carbonate (GCC) paper fillers of acceptable quality due to low brightness characteristics. Two deposits (one at Kananaskis, the other at Windy Point) may be of sufficient quality to be blended in reasonably high proportions with industry standard GCC from outside the province to yield an acceptable filler.
The best possibility for the extensive use of Alberta limestone as paper filler material seems to be through the production of precipitated calcium carbonate (PCC). This material is currently being produced from lime manufactured from limestone quarried by Continental Lime in the Bow Corridor.
A comparison of GCC and PCC products indicates that the latter form of filler will be favoured by the pulp and paper industry in the future. The PCC materials are less expensive to produce, yield a high brightness, may have more consistent fine size ranges, possess high surface area characteristics and demonstrate many other properties favorable to the manufacturing of fine paper. The trend towards establishment of alkaline systems in pulp and paper operations will result in an increased use of calcium carbonate as a paper filler media.
Several deposits of limestone in Alberta may be worthy of further consideration as lime and PCC plant feedstock. As proven by the experience of Continental Lime a rock which has good calcining properties as well as low contents of dolomite, silica, iron oxides, alumina and sulfur may be suitable. Additional work is recommended to further define the quality of Alberta limestones for use as paper filler materials. Tests should be carried out to document lime-making and PCC production capabilities of rock from selected deposits within the province.