FABRICATION OF CERAMIC ARTICLES FROM MINING WASTE MATERIALS

Mining waste materials (tailings) are generated in immense and often environmentally unacceptable proportions. This note details the results of research having the objectives of elucidating viable chemical methods of economically bonding these particulate materials, fabrication of potentially useful products and relevant property testing. The tailings were derived from phosphate mine overburden and contained primarily 85% quartz, 6% Ca3(PO4)2 and 6% clay. The particle size was moderately large with 95 wt% within a-14, + 100 screen size range. The separate additions of limestone taken from quarries in the vicinity of the tailings or sodium carbonate to the - 100 mesh tailings was integrated with a search for inexpensive highway aggregate. Property tests showed that skid resistant highway aggregate may be fabricated using Na2CO3 to produce a water insoluble glass bond and controlled porosity in an unpressed mixture of silicate particles.