Investigating the effect of using iron mine tailings as a substitute for cement in cement mortar

Ever since the first Portland cement with its current definition was produced in ۱۸۴۳ by William Spadin, there has been a continuous evolution in the technology of the cement production process. But compared to other industries, it has had a moderate development speed, which can certainly be explained by the huge efforts required to achieve safe and standardized concrete construction [۱]. The cement industry has been looking for ways to effectively reduce the high energy and environmental costs of cement production. One of these methods is the use of alternative materials as a partial replacement for fuel, raw materials or even clinker production. The raw materials for the production of Portland cement are a mixture of minerals (as a fine powder in the dry process) that contains calcium oxide, silicon oxide, aluminum oxide, iron oxide, magnesium oxide, and the addition of clay and limestone, as well as iron ore, which forms the structure of Portland cement. Gives. Raw material as a chemical compound has an important relationship with fuel, furnace performance consumption, clinker formation and cement quality [۲].The main impetus for these developments is provided by the international agreement related to the United Nations Framework Convention on Climate Change to reduce global CO۲. (Kyoto Protocol) Considering that cement production accounts for ۵% of global CO۲ (that is, ۰.۹۵ tons of CO۲ per ton of Portland cement) and also the introduction of the European Union's emission trading system, the cement industry is facing the challenge of reducing CO۲. Portland cement clinker is still the most important composition of modern cement, but the production of Portland cement clinker consumes large amounts of energy (۸۵۰ kcal per kilogram of clinker) and also has significant environmental impacts. These effects include mass extraction of raw materials (limestone, clay, etc.). The cement industry is looking for a solution to these problems and achieving sustainability and complying with the obligations of the Kyoto Protocol. For this reason, the experimental ways to develop cement whose production has less energy and environmental damage and the emission of polluting gases, one of the ways to achieve this goal is to use industrial and mineral waste and by-products as alternative materials for cement production [۳].

کلیدواژه ها:

tailings ، iron tailings ، copper tailings ، recycled materials ، replacement