Basalt mine-tailings as raw-materials for Portland clinker

Abstract

(limestone, clay, and minor amounts of iron ore and silica). Resulting pellets, known as clinker, are then milled with gypsum (CaSO 4 .5H 2 O) to form the Portland cement.Basalt is widely used as an aggregate for concrete, particularly in regions where quartz-feldspathic rocks are not available, and represents ca. 5% of the market for aggregates in Brazil [4]. Basalt quarries for aggregate production generate two types of large-scale residues: (a) quarry fines produced AbstractLarge volumes of waste materials are produced by crushing of basaltic rocks for aggregate production, which is widely used in regions that lack rocks of granitic or gneissic composition. Two types of waste materials are produced (a) quarry fines, which are in part used as fine aggregates in concrete and (b) vesicular basalt, a porous variety of basalt that is useless as aggregate. This paper presents a procedure to use basaltic mine-tailings as raw-mixtures for Portland cement by adjusting the proportion of the other rawmaterials (limestone, clay, iron ore). It is demonstrated that there is no need for additional fluxes to the basalt-bearing raw-mixtures, since the setting of the chemical parameters is enough to guarantee clinker formation. Two series of experimental clinkers were synthesized with raw-mixtures containing residues from a basalt quarry that produces aggregates for concrete. Experimental clinkers were produced from raw-mixtures with similar lime saturation factors, silica and alumina modules, which were set by adjusting the proportions of limestone, clay and iron ore to the varying proportions of basaltic materials added to them. One series of clinkers was made with basalt quarry fines, which are in part used as fine aggregate, but also accumulate as mine-tailings. Other series was made using vesicular (porous) basalt, a variety not resistant enough to be used as aggregate. It is demonstrated that the basaltic composition is fully compatible with clinker production, and no addition of fluxes or other additions is required. Composition of the raw-mixtures was checked by chemical analysis. Quantitative phase analysis of the clinkers was made by optical microscopy point counting, together with qualitative X-ray diffraction. All mixtures produced clinkers with acceptable proportions of major and minor crystalline phases, inside the range of common industrial Portland clinkers.

Use of basaltic waste as red ceramic raw material

“…Vieira et al [10] describe alkaline oxides fluxes effects, mainly Na 2 O, K 2 O, Fe 2 O 3 , CaO and MgO, which play an important role during firing, reducing the refractory material and promoting liquid phase formation. A number of studies has been developed in order to provide proper destination to such residues such as raw material for Portland cement clinker [21][22][23] and mineral admixture to cement based compounds [20,[24][25][26]. Therefore, this paper aims to study the use of basaltic filler waste as a raw material for red ceramic formulations.…”

Natural pozzolans-like Bahariya basalts used as alternative raw materials for cement clinker Portland

“…Recently, natural basaltic pozzolan substituted about 25 mass% of Portland cement from Saudi Arabia (Khan and Alhozaimy, 2010). Reduction of free lime indicates increase in burnability with increasing basalt contents, confirming that basalts are suitable for clinker production, also lowering of clinker formation temperature and reducing CO2 emissions (Andrade et al, 2010).…”

Sequestering Atmospheric CO2 Inorganically: A Solution for Malaysia’s CO2 Emission

“…Based on the information acquired from operational basalt quarries in Malaysia, clay size fines account for 18-20 wt % of the aggregate production, and are commonly being deposited in large quantities at quarries. Recommendations have been given on suitability of basalt quarry fines for Portland cement production (e.g., [67]); however, where limestone is abundant (as in Malaysia), basalt quarry fines often would not be used as raw material for Portland cement production.…”