Chapters authored
Utilization of Iron Ore Mines Waste as Civil Construction Material through Geopolymer Reactions
In India, due to fast pace development there is a drastic growth in the iron and steel industry. As of 2017, India is one of the largest producers of crude steel in the world. This has led to drastic increase in mining activity. Mining activity is responsible for generation of wastes, which can pose threat to the environment and its habitants. However, there is also a great potential for mines wastes to be utilized in construction industry, which can become an important ingredient for sustainable and eco-friendly development. In iron and steel industry, Iron ore tailings (IOT) and slimes utilization is still an area of challenge, because of the low content of iron oxide present in them, which is unsuitable for metal extraction. Usually particle size of slimes below 1 mm is not amenable for further metal extraction through conventional pelletization techniques. In the present study waste from two different iron ore mines have been tried for their utilization as a construction material through geopolymerisation technology. As a primary consideration, shapes made in the form of common bricks were tested for their densification behavior, compressive strength and water absorption. To reduce the cost, industrial wastes like fly ash, ground granulated blast furnace slag, and lime were tried in different batch compositions in addition to sodium silicate and sodium hydroxide. Relationship between compressive strength values with individual ratio of silica to alumina (Si/Al), silica to alumina with iron combined (Si/Al + Fe), and calcium to silica (Ca/Si) were developed. Based on the elemental ratios, critical threshold values were established that showed significant effect on the compressive strength of the final composite.
Part of the book: Geopolymers and Other Geosynthetics
Geopolymer Bricks Using Iron Ore Tailings, Slag Sand, Ground Granular Blast Furnace Slag and Fly Ash
World is pound with million tonnes of industrial wastes such as ground granulated blast furnace slag (GGBS), flyash and mine tailings as a various industrial waste. The best way to make use of these wastes is to incorporate these materials as structural elements, which in turn minimizes the carbon foot print. In this contest, this study focuses on using iron ore tailings and slag sand as a replacement for clay or natural sand for the production of stabilized geopolymer blocks. Also, in this study geopolymer is used as a stabilizer instead of cement. Development of geopolymer binder based bricks using flyash and ground granulated blast furnace slag has been carried out in this research. The study includes mechanical properties of the geopolymer bricks. Sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) solution have been used as alkaline activators. The ratio of alkaline liquid to aluminosilicate solid ratio and percentage of binder had major influence on the strength of brick. The bricks were casted and cured at ambient temperature. The compressive strength was carried out at 7, 14 and 28 days.
Part of the book: Geopolymers and Other Geosynthetics