Displaying items by tag: fly ash

US: Novel concretes developer Greencraft has made a patent application for a new method of CO₂ mineralisation using a microporous material containing mineral oxides, like slag. Global Warming Focus News has reported that the method also works for natural hyaloclastite, bottom ash, fly ash, volcanic ash and lava.

Greencraft said that its method marks an ‘improvement’ in current techniques for sequestering CO₂ in alternative materials.

Australia: Alternative cement and concrete producers have welcomed a new Australian civil engineering standard that allows builders to use reduced-CO₂ geopolymer concrete in infrastructure projects. Wagners, which produces Earth Friendly Concrete (EFC), said that the revision has removed one if its key barriers to wider market acceptance. EFC replaces 100% of cement with supplementary cementitious materials, including ground granulated blast furnace slag (GGBFS) and pulverised fly ash, by virtue of its binder technology. Wagners previously supplied EFC for the London Power Tunnels project in the UK, based on local technical approval-based building codes. The producer now expects a new standard like the Australian one to follow in the EU.

Japan: A team at the University of Tokyo has developed cement-free alternative concrete from ultra-fine sand and fly ash. NHK has reported that the process uses recyclable alcohols and has lower CO₂ emissions compared to concrete production using ordinary Portland cement. Research with industrial partners into possible construction sector applications is underway. Partnerships with Japanese ready-mixed concrete producers are reportedly also under discussion.

Further information is available from Yuzo Tobisaka, an independent Japanese consultant in the cement and ready-mixed concrete industry, at yuzo.tobisaka@gmail.com.

Namibia: Ohorongo Cement Namibia has supplied 3000m³ of cement to the site of NamPower's upcoming Sekelduin power plant in Swakopmund. Ohorongo Cement used 730t of its CEMIR cement, which contains 30% fly ash, combined with an additional 30% fly ash in the concrete mixer. The producer said that the extra ash increases the finished product's density, reducing permeability.

Ohorongo Cement said that the project is 'near completion,' having begun in mid-2021.

Canada: Lafarge Canada has signed an agreement with power provider TransAlta to recover and process fly ash from the site of the latter's decommissioned Edmonton coal-fired power plant. The project will use Ash-TEK's Ponded Ash Beneficiation System (PABS) fly ash beneficiation technology. The processed ash will then be able to replace up to 25% of cement in low-CO₂ concrete production.

TransAlta previously secured with Lafarge Canada for the supply of renewable power to its Exshaw, Alberta, cement plant in February 2022.

India: Three new Indian concrete companies have separately secured agreements for the use of Finland-based Betolar’s Geoprime alkali-activated slag and fly ash additive. Reuters News has reported that the companies are Balaiji Cement Products, Shiv Tiles and SNEH Precast. Engineering company Godrej & Boyce has also signed a letter of intent with the supplier for pilot production of concrete blocks, paving slabs and other elements.

Betolar expects producers to achieve global concrete production volumes of 250,000t/yr of concrete containing Geoprime by 2023.

Vietnam: Trung Hieu Development Corporation has secured a five-year contract to use Betolar’s alkali-activated slag and fly ash-based concrete additive Geoprime. Trung Hieu Development Corporation plans to source the materials for Geoprime from local industrial side streams. Dow Jones Institutional News has reported that the move will eliminate 80% of raw materials CO₂ emissions across its 120,000t/yr-worth precast concrete production capacity.

Betolar's Head of Asia Juha Pinomaa said "Vietnam is the world's third largest cement producer and fourth largest cement consumer, with 85Mt/yr. We estimate that the Vietnamese market represents significant commercial potential for us in the coming years due to the huge potential for cement replacement.” He concluded “We can promote the local circular economy and accelerate Vietnam's sustainable development efforts by directly offering cement-free alternatives. The Vietnamese steel and energy industry generates large amounts of steel slag and fly ash as side streams, which can be used for Geoprime-based concrete."