Research Highlight: Acid Extraction of Valuable Resources in Fly Ash and Various Utilizations of Acid Slag

- Beijing, China

Aluminium and rare earth mineral extraction was a well-explored topic at AsianCAA’s latest Coal Ash Asia event, in Beijing, last July.   Vice Professor Li Fang Fei, from JiLin University, shared her research pertaining to acid leaching in order to extract precious rare earth minerals. Jilin University is a key collaborator with the China Building Materials Academy (CBMA), and the Institute for Technical Information for the Building Materials Industry, our co-hosts of Coal Ash Asia. The university's chemistry department contributes essential research to the topic of waste utilization and management.  Below is Professor Li Fang Fei’s abstract, discussing her latest research.

Abstract: Fly ash is the main solid waste of power plants. After combustion, the aluminum, rare earth and other valuable resources in the raw coal are further enriched in the fly ash. That makes the high Al2O3 content in the fly ash of Inner Mongolia region (up to 50 wt % ). Aluminum, iron, gallium, and other rare earth resources in fly ash could be extracted by acid leaching process. And followed by resin separation, enrichment leaching, and crystallized purification process, various valuable resources could be successfully separated and purified to an ideal level. Such leaching method is not only applicable to the high-active CFB fly ash, but also suitable for the OF fly ash whose amount is much larger than the former. In addition, the amount of acid leaching slag of fly ash is very small, which is composed of porous SiO2 with ideal purity and highly reactivity. Such "white mud" could be produced as building materials, artificial zeolites, inorganic fibers, catalyst carriers, and other useful products, which promotes the governance and comprehensive utilization of fly ash.

Jilin University will be returning contributors to Coal Ash Asia 2018. For more information, or to register, please follow the links below. If you would like to be sent an information package regarding our event, please input your email below.

For more information on other papers from Professor Li Fang Fei, click below:

Research Highlight: Synthesis of High Quality Zeolites from Coal Fly Ash

- Perth, Australia

Dr. Kevin Li (Gang Li), participated in CAA2017 on behalf of the Centre for Energy, School of Mechanical & Chemical Engineering at the University of Western Australia in Perth, Australia. Dr. Li, a returning speaker to Coal Ash Asia, focused his presentation on synthesizing zeolites and necessary related conditions. The below abstract is an overview of the research presented at the conference. For more of Dr. Li’s publications and research, please click the link at the bottom of the abstract.

Abstract: Coal fly ash is a hazardous industrial waste generated from coal combustion and has been considered as an appropriate raw material for zeolite synthesis. In this study, synthesis of a high-quality type A zeolites (471m /g surface area) from fly ash at high conversion rate (98.2% aluminium and 96.5% silicon) has been achieved via a two-step alkali fusion and hydrothermal procedure. Furthermore, in preparation for production in commercials scale, up scaling of the developed synthesis process has been undertaken by using 150L reactor. More importantly, we tracked the migration of elements and quantified their distribution from fly ash to product zeolites and waste water throughout the synthesis process. Metalloid elements including arsenic and selenium, and those with strong amphoteric properties such as molybdenum were found highly mobile and mostly collected in the waste water. In comparison, less than 20% of heavy metal elements of weak amphoteric nature including copper, chromium and lead originated from the fly ash went to the waste water; the rest of these three heavy metals along with almost all of the cadmium, iron and nickel were fixed into the product zeolites. Despite the accumulation of hazardous elements in product zeolites, none of them was leachable under various harsh conditions, ensuring safe applications of such zeolites.

If you are interested in attending Coal Ash Asia 2018 in Shuozhou, please click the "CAA2018" link to register, and our event team will assist you in finding the participation that's right for you.

Fly Ash Use in Road and Embankment Construction: A Goa Workshop

- Panaji, Goa

Another successful workshop, organized by AsianCAA and hosted by our friends at ALCON (Anil Counto Enterprises) took place in Goa, India during the globally prestigious CoalTrans India conference.

The speaker, Mr. Bill Martin, is an experienced operations, sales and marketing executive with decades of experience in the construction materials industry. Bill’s expertise covers raw materials procurement, supply chain management, new business development and manufacturing operations in cement, masonry and concrete products.

Bill has held positions at the ADAA (Ash Development Association of Australia) and the Concrete Masonry Association of Australia.

A regular at the annual Asian Coal Ash Association’s Coal Ash Asia conferences, Bill and the team at CAS (Coal Ash Solutions) team offer complimentary introductions, translation and business matching to all international guests in attendance.

The Workshop:

Explored in “Fly Ash Use in Road and Embankment Construction” were some of the technical, environmental and operational requirements for achieving maximum benefits from fly ash in road and embankment construction.

In attendance at the workshop were ash managers, construction and engineering firms, government officials including the Department of Transport and the Ministry of Environment. 

The group examined the many benefits of incorporating fly ash and bottom ash into Portland Cement/Concrete. Extensive research and countless highway and bridge construction projects have indisputably proven the following facts about the use of fly ash in construction:
1. Higher ultimate strength

2. Improved workability

3. Lowered costs

4. Reduced bleeding

5. Reduced heat of hydration

6. Reduced permeability

7. Increased sulfate attack resistance

8. Increased resistance to ASR

9. Reduced shrinkage

10. Increased durability.

AsianCAA hosts and organizes multiple workshops and conferences throughout the year. To find out more about our next event, enter your email below and we will send you more information.

AsianCAA to Attend and Participate in Coaltrans India 2018

- Goa, India

Asian Coal Ash Association Chairman, Mr. David Harris, and fellow AsianCAA members will be in attendance at this year’s CoalTrans India conference this February 12-14, 2018 at the Hyatt Goa in Goa, India.  

Mr. Harris will host a panel on international ash trade during the conference that will be attended by the conference's over 600 guests, from India and around the world. Attendees will review and exchange knowledge surrounding domestic production and competitive green alternatives. India’s Coal sector has been under scrutiny and vast reform for many years and is confronting an era of change.

For more information on Coaltrans India 2018 or information on upcoming Asian Coal Ash Association hosted or supported events, please click the links below.

Autoclaved Aerated Concrete: CCPs Growth in Asia Pacific

Between 2015 and 2021, the global autoclaved aerated concrete market is expected to increase by just under $2 billion USD.  AAC is increasing in industry wide use due to its light weight and versatility. The construction material consists of fly ash and gypsum, both biproducts of burning coal to make energy, and much less costly than their alternatives, sand and anhydrite.  The material also consists of lime, cement, and aluminum powder. Construction companies are increasing their use of this material as it is not only more cost efficient, but also provides wider durability to seismic fluctuation, intense heat, and pests. The material itself also saves the manufacturer or construction company in water and energy usage.  Autoclaved aerated concrete is widely used in Europe and North America.

AAC materials can either be used instead of or to repair common building materials. Application can be seen in most real estate areas including residential, industrial and commercial. However, the majority of the AAC market has been residential since its inception, and continuing throughout 2017 with a third of the overall market. The product types of autoclaved aerated concrete are distributed into tiles, panels, blocks, lintels and others.

The growing market is propelled by elements such as the increased importance of utilizing green building materials, the use of recycled materials themselves (fly ash, etc), and its superiority to commonly used materials for the same purpose.

Currently, limited adoption is due to high start up costs associated with AAC, and because manufacturing facilities are not yet commonplace, resourcing and logistics becomes problematic.

As adaptation grows however, and infrastructure is set in place, the forecast for AAC paneling is projected to grow almost 8% in the next 5 years.

Globally, Europe has lead in market consumption. However, the Asia Pacific region, including countries like China, Thailand, Malaysia, Singapore and Indonesia are expected to increase consumption by over 10%, also within the next 5 years.

Opportunities in the AAC market are real as there is strong interest in China, India and other densely populated regions who would benefit from disaster resistant structures made from coal combustion products (CCPs).

To read more about autoclaved aerated concrete construction, trends, and forecasts for investment and integration, please read Orbis Research’s report:  Global Autoclaved Aerated Concrete (AAC) Market-Segmented by Type, Application (Construction), and Geography-Trends and Forecasts (2017-2022). Follow the link in the text for more information.

To learn more about global trends and research on AAC and CCPs, join us at Coal Ash Asia 2018.

Research Highlight: Technology for Extracting Alumina from Fly Ash and Research on Acid/alkali Double Circulation

- Beijing, China

During Coal Ash Asia 2017 this past July, there was substantial discussion surrounding alumina extraction from coal/coal ash and strategies for making the processes practically adapted. Professor Jiang Xun Xiong of Beijing General Research Institute of Mining & Metallurgy posited research concerning the processing and separation of the alumina from fly ash. Below is the abstract of the research provided at CAA2017. Beijing General Research Institute of Mining & Metallurgy have continued to be loyal participants in our annual events, and are committed to efficient technology integration and environmental protection.

BGRIMM is analyzing development and current status about alumina extracted from high-aluminum powder fly ash, and taking subjective analysis for current typical processes in China. Processes include energy consumption, material consumption, three-wastes, product quality. Discussing bottlenecking and development trends for extracting alumina from fly ash, and proposing fly ash conversion using sulfur acid. Will explore the process’ reactions and decomposition, low-temperature alkaline sink and two circulations for alumina extraction. The study results confirm two circulations for acid and alkaline are needed.

To find out more about this research, and research like it, join us at Coal Ash Asia 2018, and join the ongoing discussion and seminars surrounding the topics of metal extraction and alumina extraction specifically.

Transforming Real Estate Sector: Sustainable Construction Techniques

-Beijing, China

Urban housing models are now more of a destiny than a trend for the average person in the most populated parts of Asia, China and India. In the developing world, people increasingly flock to high-density living areas as they have easier access to commerce, healthcare and other amenities. The building materials industry’s infrastructure in Asia for trade and manufacturing has only reached a reasonable application of green building materials model within the past decade or so. The shift in lifestyle and housing infrastructure has led to concerns over energy, and carbon footprint. Researchers are concerned that the concrete, cement, etc, used in the making of modern high density living apartments is to blame for a large part of the pollution produced by these regions.

Almost a quarter of India’s CO2 emissions come from residential and commercial real estate construction. Increased growth in China and India, two industry giants, contribute greatly to the global carbon footprint. In India, 20% of water and 30% of natural materials are used in the construction and building materials industries.

Mr. Jack Yuan from the Institute of Technical Information for the Building Materials Industry in Beijing says that contamination and erosion of earth and air caused by dust and asbestos are hazardous byproducts of construction activities.  The team at ITIBMI, operating under the China Building Materials Academy, researches sustainable and progressively green infrastructure, while keeping in mind the cost and benefits of efficiency. “Nowadays the economic benefits can be seen through water and energy efficiency, with most green technologies focusing on the conservation of water, power and natural materials. ”

Yuan goes on to site specific technologies on the market, focusing on city specific construction. “ Pre-cast, reinforced hollow concrete blocks/ paneling made from fly ash, or Glass fiber Reinforced Gypsum (GFRG) walling, are a few examples of modern housing construction technologies. Efficiency in time, energy, cost and supplies will continue to propel the industry through innovation. “

Construction companies are increasingly embracing technologies consisting of fly ash and gypsum. These bi-products can be locally sourced and inexpensive because transportation costs are low.  Coal fired power stations and factories are selling them at a low cost to keep up with landfilling and other environmental regulations, making exporting/importing of fly ash another viable options for companies without local sources.

Issues arise logistically when construction and building material manufacturers are far from these resources or do not have the infrastructure in place to get the product from power station to manufacturing facility. As the world transitions to green energy, including solar and wind technologies, some countries have been forced to import bulk ash from producing countries. To read more about this logistical issues and trends, please be sure to read our upcoming newsletter, due out at the end of 2017. To be put on our newsletter mailing list, please click the link on the main page.

 

China Coal Combustion Product Conference: Technological Innovation to Promote Green Development

- Shuozhou City, Shanxi Province, China

The Asian Coal Ash Association would like to thank all who participated in CICCPC 2017, the most recent international exchange in Shuozhou. This year’s topics focused on fly ash and desulfurized gypsum, with the theme "Technological Innovation to Promote Green Development". During the two day event participants engaged in technical exchanges on comprehensive utilization of fly ash and gypsum and discuss the latest scientific research.

One goal of the conference was to further strengthen international and domestic cooperation to promote technological progress and industrial development. Experts from the U.S.A, Germany, Australia, Canada, Ukraine and Japan were among the 700 participants at this year’s event.

The conference was jointly organized by AsianCAA, the National Institute of Building Materials Industry Information, Shuozhou Municipal People's Government, and the Shanxi Economic and Information Commission.  Mr. David Harris, the chairman of the Asian Coal Ash Association gave keynote and regular session speeches during the proceedings. Mr. Harris outlined coal ash and other solid waste utilization technologies, international trade status’ and industry development prospects.

In conjunction with the regular plenary session, was a product/technology exhibition and academic poster display. A variety of specialized meetings also took place at CICCPC. The meeting of the National Coal-based Solid Waste Resource Industry Technology Innovation Strategic Alliance took place for the first time during proceedings. There was a Fly Ash Intelligent Sales Control System meeting as well as a special Green Building Materials and Construction Technology exchange. The Ceramic Association business forum convened during the 23rd of September and  Shuozhou City Investment Promotion and Tourism Promotion gave a special inside look into regional operations. Guests were also able to enjoy an afternoon of horse racing at Youyo County and many other networking opportunities.

Discussing Free CaO in CFB Ash and it’s Stability: Research Highlight from Coal Ash Asia 2017


- Beijing, China

Professor Qiao Xiu Chen from East China University of Science and Technology joined the discussion at Coal Ash Asia this past July 21-24 in Beijing, China. Prof Chen presented among industry leaders during the Fly Ash and Coal Gangue Track at the most recent AsianCAA event. The below abstract has been translated from its original submission to our proceedings.

Abstract: Circulating fluidized bed (CFB) boilers discharge 2 to 3 times as much ash per 1 kWh as pulverized coal-fired boilers. Overall, the amount of discarded CFB ash has drastically increased in China. However, there is no bulk utilization due to the different physiochemical properties of coal fly ash (CFA) from pulverized coal-fired boilers. One of the key issues is the amount of CaO left after burning, as CaO has negative effects on the soundness of cement. The national standard requires the maximum free CaO of 1% for F CFA and 4% for C CFA. The amount of lime in CFB ash is usually higher than 5% due to the desulfurization process. The utilization of CFB ash becomes harder when ash contains higher amounts of CaO. Presentation Abstracts

This conference we will show the chemical reaction variations of lime prepared at 800, 850, 900, 950, 1000, 1050, 1150, 1250, 1350°C. The calorimetry, precise measurement of lattice parameter and selected area microdiffraction of TEM were used for evaluation. The results showed that the calcite with a fineness of D100<76μm decomposed by 80% after the treatment at 800 or 850°C for 20 min. Complete decomposition occurred from the treatment at 900°C for 10 min. The maximum amount of CaO was 0.53% after the treatment at 1050°C. The amount of CaO started to be higher than 1% from the treatment at 1150°C and was more than 30% after the treatment at 1350°C for 20 min.

The CFB ash does not show a negative effect on the soundness of cement when the highest combustion temperature in the boiler is lower than 1050°C.