Abstract
Particle size analysis, Atterberg limits, X-ray diffraction, X-ray fluorescence and firing tests were used to determine physico-chemical, mineralogical and technological characteristics of residual lateritic (K1M, Ma2) and alluvial (KB3, KG3) clays from Foumban (West-Cameroon). For technological properties, the samples were pressed and fired over a temperature range of 900d relative high feldspars (20%) and illite contents (10%) in KB3 and MA2; high smectite content in KG3 (up to 20%). Chemical analyses indicate high SiO2 (49% - 77%) and low Al2O3 (14% - 23%) contents in the four samples, with comparatively low contents of iron oxides (4% - 7% in samples KB3 and KG3, 2.5% in MA2 and ~1.5% in sample K1M). The particle size distribution of the alluvial clays (KG3 and KB3) differs considerably: 7% to 37% of clay fraction, 20% to 78% of silt, and 15% to 58% of sand, while residual clays (K1M and MA2) present on average 12% of clay, 51% of silt and 37% of sand. Two raw clays (KB3 and MA2) can be used for bricks/tiles production without beneficiation or addition. K1M requires some flux addition to decrease the sintering temperature while KG3 presents poor properties due to the combined occurrence of smectite and a high clayey fraction (37%). Such mineralogical composition is responsible for very high plasticity (PI: 50), high shrinkage (LS: 5% - 16%), low porosity (OP: up to 21%) and high flexural strength (FS: 16 - 23 N/mm2) above 1050°C. This last clay is therefore less appropriate for bricks and roofing tiles production since degreasers must be added to the raw material.
Highlights
Clays have been used in a wide range of ceramic products as a major component in most ceramic bodies [1]
X-ray diffraction (XRD) patterns of the investigated clays are characterized by the peaks of quartz and kaolinite (Figure 2)
On the basis of semi-quantitative method, kaolinite (31% - 65%) and quartz (35% - 50%) are dominant in Foumban clays but their proportions vary from one sample to another
Summary
Clays have been used in a wide range of ceramic products as a major component in most ceramic bodies [1]. Clays are important raw material for construction such as bricks due to many specific characteristics before (mineralogy, plasticity and particle size distribution) and after firing (mineralogy, porosity, mechanical strength) [2]. The suitability of a clay for fired bricks depends on its behavior during shaping, drying and firing [2]. This behavior determines the final properties of bricks, especially their porosity and durability [1]. Distinct layers associated with different clays can be found in a specific deposit; the mixture of various clays will permit to adjust the properties of both the unfired body and corresponding final product [3]
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Journal of Minerals and Materials Characterization and Engineering
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.