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This study presents a methodology for making bricks, in a cost-effective and environmentally friendly manner, using the tailings produced from iron ore mines in Western Australia (WA). The study was based on the geopolymerisation process, which is known to conserve energy by reducing the emission of greenhouse gases. The reduction is accomplished by avoiding the processes of high temperature kiln firing, traditionally utilised when making bricks from sandy soils with high clay content. In this study, the sodium silicate was added to the mine tailings in powder form, as an activator for the formulation of the geopolymer bricks. The effects of the initial setting time, curing temperature, curing time and activator content on the unconfined compressive strength (UCS), water absorption and other durability properties of the bricks were investigated. X-ray diffraction analysis was performed to investigate the phase composition of the geopolymer bricks. The bricks achieved an UCS as high as 50.53 MPa for the optimum values of the parameters. Technically, the geopolymer bricks that were produced met both the American Society of Testing and Materials and the Australian Standards (AS) requirements for bricks. A cost analysis of the geopolymer bricks is also presented, and this shows that the cost of geopolymer bricks is lower than that of the commercial, fired clay bricks

Sustainable handling of iron ore tailings is of prime concern to all stakeholders who are into iron ore mining. This study seeks to add value to the tailings by utilising them as a replacement for aggregates in concrete. A concrete mix of grade 40 MPa was prepared in the laboratory with water-cement ratio of 0.5. The concrete were cured for 1, 2, 3, 7, 14 and 28 days. The properties of the concrete such as workability, durability, density, compressive strength and indirect tensile strength were tested. A controlled mix of concrete was also prepared in similar way using conventional materials and the results were compared with the tailings concrete. It was found that the iron ore tailings may be utilised for complete replacement for conventional aggregates in concrete. The iron ore tailings aggregates concrete exhibited a good mechanical strength and even in the case of compressive strength, there was an improvement of 11.56% over conventional aggregates concrete. The indirect tensile strength did not improve against the control mix due high content of fines in the tailings aggregates but showed 4.8% improvement compared with the previous study where the conventional fine aggregates was partially replaced by 20% with iron ore tailings.

Across the tropical developing countries, smallholder farmers are confronted with various climate related risks that hinge on agricultural activities. Climate change is predicted to impact smallholder farmers and their livelihood, especially within and beyond this century. Several studies have examined the impact of drought and rainfall on smallholder farmers as climate change impact assessment. However, there is limited information on impacts and coping strategies of poor farmers to heat exposure at household and farm level in tropical developing countries. As global temperature is predicted to increase with robust impacts on farmers in African region due to poverty and low adaptive capacity, this study evaluates how farmers in Bawku East of Northern Ghana experience the impacts of heat stress and how they cope with it both at the household level and on the field of cultivation. Using household survey and focus group discussion, the authors elicited impacts and responses of heat exposure from 308 resident farmers in three selected farming communities in Bawku East to gauge their vulnerability to heat exposure. Even though farmers have various impacts and coping strategies to heat exposure, these are ineffective to prevent them from heat related morbidity and mortality at both household and farm level. The study recommends the need for government led intervention to assist farmers in their effort to cope with heat stress as global temperatures will exacerbate heat stress impacts on small holder farmers especially in African region.

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