Scientists proved that municipal sewage sludge contains many dangerous pathogens, toxic heavy metals, endocrine disruptors, drains, storm water runoff, hospitals, and industrial plants. Sewage sludge represents an extremely high ecological hazard to the environment. Due to the increasing amount of sludge generated from the wastewater treatments plants a strong demand for environmentally and effective safe reuse has arisen. One potential use of that waste is its incorporation in the production of ceramic tiles. The main aim of present work was to study the possibility of usage of this hazardous waste in floor ceramic tiles industry. A dried sludge waste was added in percentages from 5% up to 35% to a standard floor tile mix, molded, pressed uniaxially at 30 MPa and then fired at temperatures reaching 1150°C for 15 min soaking time. The properties of both green and fired tiles were investigated as function of percent waste added. The vitrification parameters, which are linear firing shrinkage, water absorption, apparent porosity, and mechanical property, were determined and compared with ISO standards. Fired samples of the proposed mixtures were investigated by scanning electron microscope (SEM). It was possible to obtain tiles that abided by ISO standards for maximum addition of 7% sludge fired at 1150°C (for water absorption < 10%), and 10% sludge or 5% sludge for tiles fired at 1150°C and 1100°C, respectively (for water absorption > 10%), which are recommended for both their economic and environmental benefits.

The merit of this study is manufacturing cheaper roof tiles using fluxed waste material such as granulated iron slag, in addition to the environmental benefit of decreasing the cost and negative impact of their disposal and landfilling. Waste water-cooled granulated iron slag was ground and added in proportions ranging from 0 to 30 wt.% to kaolin clay to prepare roof tiles for the economic purpose of decreasing the production cost by incorporating cheap waste and to serve sustainability. The raw materials were characterized by XRD, XRF, and particle size analysis. The specimens were shaped using a rectangular mould with dimensions of 150 × 30 × 30 mm3 under an axial pressure of 10 MPa and then dried in a dryer at 110°C. The firing of the dried specimens was carried out at 900, 1000, and 1100°C. The characteristics of fired specimens were determined by their linear firing shrinkage, water absorption, compressive strength, and freezing-thawing resistance. Results showed that samples containing 20% slag waste and fired at 1000°C displayed a cold water absorption of 12% and a saturation coefficient of 0.82, both values being lower than the maximum value recommended by standards. Also, the recorded breaking strength of 5040 N was much higher than the minimum standard value. These samples were also subjected to 50 freeze-thawing cycles, which they passed without the appearance of any cracks. It was concluded that samples containing 20% slag waste and fired to 1000°C or 1100°C fulfilled the requisites of ASTM C1167 for grade 3 normal duty roof tiles.

This research investigated the reuse potential of pomegranate peels waste (PPW) in the production of fired clay bricks with improved thermo-physical and mechanical properties. PPW was used as a substitute for natural clay with different replacement ratios ranging from 0 to 12.5% with a stride of 2.5 wt%. The impact of adding PPW on compressive strength, total porosity, water absorption, bulk density, thermal conductivity and microstructure characteristics has been assessed for bricks fired at 900, 1000 and 1100 °C. With the increase of PPW replacement ratio, the bulk density, thermal conductivity and compressive strength decreased. The obtained results confirm the possibility of using PPW as a sustainable pore forming agent in brick industry. The incorporation of 12.5 wt% PPW showed the lowest bulk density (1230 kg/m3), the lowest thermal conductivity (0.2 W/mK), the lowest compressive strength (5.5 MPa), the highest water absorption (38%), and the highest total porosity (48%) for bricks fired at 1000 °C. The obtained compressive strength satisfies the minimum acceptable requirements for clay bricks. The contribution of the newly developed bricks to the energy consumption performance of a building model has been evaluated by using DesignBuilder energy simulation software. A considerable reduction in the annual energy consumption by about 23.3% has been attained as compared to the traditional bricks.

A large amount of granite sludge waste (GSW) is produced during the granite quarry processing that has a negative impact on the environment. The main aim of this study to investigate the possibility of partial replacement of brick clay by GSW and silica fume (SF) due to the similarity of the mineralogical composition of GSW and clay. Five different series of clay to SF to GSW proportions were tried, which

Mill scale is a valuable waste material that contains high amount of iron, little impurities and also is chemically stable composition. It is produced from the hot rolling processing in steel industry. The second waste is El-Dekheila pellets fine waste that produced as the results of handling in the El-Dekheila plant, West of Alexandria on the Northern coast of Egypt. This paper studies the recycling of mill scale and El-Dekheila pellets fine waste in iron and steel industries by reduction using coke breeze in the form of pellets. Characterization of raw materials were performed which are XRF, XRD and screen analysis. Reduction of pellets consisting of El-Dekheila pellets fine waste and different percentage of mill scale was investigated with 4 stoichiometric coke breezes using thermo-balance. The reduction increases with increasing coke breeze. The kinetics of reduction of these pellets were studied using different percentage of mill scale (20,60 and 80%) and at different temperatures ranging from 900 to 1050oC. The results displayed that the reduction process was controlled by Avrami and Erofeev involving nucleation of reduced phases followed by grain growth. Also, that the maximum reduction 80% can be reached after 125 minutes using 20% mill scale. The activation energies of reduced 20, 60 and 80% mill scale were found to be 112 kJ.mol-1 , 81 kJ.mol-1 and 107.8 kJ.mol-1 respectively

Most of the research of building materials companies at present focuses on recycling waste to minimize the cost of their products and for the safe disposal of these wastes. In this work, the by-pass cement kiln dust (BCKD), the dust that is discarded from the kiln system was used for the preparation of roof tiles. It is partially used to substitute clay in percentages from 5 % up to 25 %. to prepare roof tiles abiding by ASTM C1167 for two objectives, the safe disposal of waste and the production of low-cost roof tiles. The raw materials were assessed by particle size analysis, XRD, and XRF. The mud was poured into moulds with dimensions of 150 * 30 * 25 mm3 and pressed under a pressure of 10 MPa then dried. The dried samples were fired to temperatures 1000, 1100, and 1150℃ with a soaking time of one hour for each temperature. The linear firing shrinkage, water absorption, bulk density, and breaking strength were measured to determine the properties of the fired specimens. The initial rate of absorption and runoff properties were also determined for the optimal samples. The results showed that samples containing 8% and 12% of BCKD waste that fired at 1100°C and 1150°C had cold water absorption of 14% and a saturation coefficient of 0.85, both of which were below the maximum values of the standard limits. Furthermore, the measured breaking strength of about 2700 N was much higher than the necessary minimum value. The results showed that samples met the requirements of ASTM 1167 for clay-type roof tiles containing 8% BCKD waste and fired to 1100℃. For economic and environmental benefits, 1100℃ firing temperature is recommended than 1150℃. The initial rate of absorption was found to be 2.8 kg.m-2 and the runoff properties were found to be 0.02 mg.L-1, 7.53, 110.5 mg.L-1 for total dissolved solids, pH and total solids respectively.