Displaying items by tag: coal fly ash

Philippines: A recent study from Cebu, Philippines presents a method for reducing greenhouse emissions in the cement industry. The research, supported by the Department of Science & Technology (DOST) of the Philippines, focuses on partially substituting cement with coal fly ash (CFA). According to the University of San Carlos researchers, CFA's efficacy as a cement substitute depends on its source, with variations in quality, performance, and water requirements when used in paste and mortar formulations.

The study evaluated CFA from a Philippine power plant, examining its use as a partial cement substitute. Researchers designed paste and mortar mixtures with different CFA-to-binder ratios and water-to-binder ratios. The study revealed that increasing the amount of CFA in cement up to 20% by weight could enhance compressive strength, ‘outperforming’ pure cement mixtures.

The study concluded that substituting a portion of cement with CFA not only reduces greenhouse gas emissions but also improves the compressive strength of the resultant material.

Indonesia: Indonesia Power says that it has processed coal fly ash and bottom ash from its Adipala power plant into building materials, including cement-free ready-mix concrete, concrete blocks, paving slabs and refractory casts. The energy company also supplies ash to mine reclamation and water neutralisation projects, according to LKBN Antara News. In total, it reused 135,000t of ash by-products in 2021. The company generates 85,000t/yr fly ash and bottom ash.

Sinar Tambang Arthaestari has previous targeted Indonesia Power’s ash products for use in its cement production.

US: Charah Solutions has secured a contract with energy supplier Entergy for provision of environmental services to three coal-fired power plants in Louisiana and Arkansas. The gives Charah Solutions the right to dispose of or market 0.9Mt/yr of coal combustion residuals (CCR), including to cement producers in the region for use as a cement additive.

US: The Environmental Protection Agency (EPA) has announced the first national regulations to provide for the safe disposal of coal ash from coal-fired power plants. The ruling establishes safeguards to protect communities from coal ash impoundment failures and establishes safeguards to prevent groundwater contamination and air emissions from coal ash disposal.

"The EPA is taking action to protect our communities from the risk of mismanaged coal ash disposal units and putting in place safeguards to help prevent the next catastrophic coal ash impoundment failure, which can cost millions for local businesses, communities and States," said EPA Administrator Gina McCarthy.

The new federal regulations include:

• The closure of surface impoundments and landfills that fail to meet engineering and structural standards and will no longer receive coal ash;
• Reducing the risk of catastrophic failure by requiring regular inspections of the structural safety of surface impoundments;
• Restrictions on the location of new surface impoundments and landfills so that they cannot be built in sensitive areas such as wetlands and earthquake zones;
• Protecting groundwater by requiring monitoring, immediate clean up of contamination and closure of unlined surface impoundments that are polluting groundwater;
• Protecting communities using fugitive dust controls to reduce windblown coal ash dust;
• Requiring liner barriers for new units and proper closure of surface impoundments and landfills that will no longer receive coal combustion residues.

In response to feedback on the proposal, the ruling clarifies the technical requirements for coal ash landfills and surface impoundments under Subtitle D of the Resource Conservation and Recovery Act (RCRA), the country's primary law for regulating solid waste. Implementation of the technical requirements will be reported through disclosure to States, and communities. Examples of this include power plants providing information to the public and States and new transparency requirements, including recordkeeping and reporting requirements, as well as the requirement for each facility to post specific information to a publicly-accessible website. This final rule also supports the responsible recycling of coal ash by distinguishing safe, beneficial use from disposal.

US: VHSC Cement has announced the commercial release of Pozzoslag 1.2, a cementitious material made using coal fly ash as a raw material. VHSC promotes its product as a partial replacement to Ordinary Portland Cement (OPC), offering early set times, greater long-term strength and enhanced concrete durability. Users are also able to reduce their chemical additive packages and lower the total amount of cementitious binder material.

"Pozzoslag 1.2 is created using a patented process that was introduced into commercial operations in November of 2012. This new product uses raw fly ash as a base material to produce a cementitious blend of material that meets grade 120 slag strengths based on ASTM 989 testing protocols. Using Pozzoslag in concrete allows very high durability at routine replacement factors in the 55-65% range," said Buddy Pike, president of VHSC Cement.

VHSC Cement developed Pozzoslag to overcome the early set time issues that have historically hindered the use of higher volumes of fly ash and slag in many cement applications. Currently this process is used to produce materials that are currently being used in ready mix concrete, highways, roads, building foundations and precast and concrete products.

Pozzoslag 1.2 from the Limestone facility in Texas meets ASTM C989 performance specifications as a Ground Granulated Blast Furnace Slag (GGBFS). These products meet Grade 120 slag requirements.