COMMERCIALIZATION OF HIGH-CARBON FLY ASH IN CEMENT MANUFACTURE

COMMERCIALIZATION OF HIGH-CARBON FLY ASH IN CEMENT MANUFACTURE

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Bhatty

Construction Technology Laboratories

Power plants using Illinois coal (fly ash producers) generate large volumes of high carbon fly ash. This fly ash is not acceptable for use in concrete, and is typically landfilled. This non-beneficial use of fly ash places an economic burden on the power generating plants.

Similarly, Illinois cement manufacturers have a need for cost-effective alternative raw materials and process improvements. High-carbon fly ashes from Illinois coal are rich in silica, alumina, iron oxide and carbon. These components make high carbon fly ash an attractive alternate raw material for cement manufacturers.

During our 1999 work for ICCI, we demonstrated the feasibility of utilizing high carbon fly ash in the manufacture of portland cement. This work focused on the laboratory and pilot scales. In 2000 with the support of ICCI, CTL demonstrated on commercial scale that high carbon fly ash from Illinois coal could successfully be utilized in the manufacture of portland cement. During this large-scale demonstration, the high carbonfly ash was used to replace shale/clay in the raw feed of a cement plant while providing added fuel savings from the residual high carbon. During the demonstration, measurable improvements in the cement production and quality, and a significant energy saving due to the carbon content of the fly ash were realized. Additionally, the cement produced during the demonstration met the applicable standards, and had superior characteristics, compared to that of their normal cement.

As an extension to our lab-, pilot- and a proven commercial-scale demonstration of the technology, the current efforts involved CTL working with the four Illinois cement manufacturers and numerous fly ash producers that burn Illinois coal with the objective of promoting the technology to utilize large volumes of high carbon fly ash in the manufacture of portland cement.

Group Meetings with Key Personnel

To achieve this objective, CTL organized a series of technical forums and focused group meetings by bringing together key personnel from Illinois cement manufacturers and fly ash producers that utilize Illinois coal. The goal was to foster and strengthen relationships, and to encourage the commercialization of technology. At these meetings, the needs, constraints, and expectations of the cement manufacturers and fly ash producers were discussed with the sole objective of promoting the technology. The underlying issues of reliable fly ash, compatibility with cement plant raw material, transportability, delivery, and other logistic constrains were also addressed.

Group meetings were held at CTL's facilities in Skokie, IL, Illinois Cement in LaSalle, IL, Ameren's Coffeen Power Station in Coffeen, IL, and at Cinergy's Gibson Power Station near Mount Carmel, IL. The meetings at the participant facilities enabled the participants (cement manufacturers and fly ash producers) to understand each other's operations, needs, and facilities. Additionally, during the second meeting at Illinois Cement, a second commercial demonstration of the technology was performed. The demonstration was as successful as the 2000 commercial demonstration.

The meetings brought together key industry personnel within and outside Illinois. The meetings were open to all fly ash producers that utilize Illinois coal and cement manufacturers with plants in Illinois. One additional non-Illinois cement manufacturer was included because of their ongoing business relationship with a fly ash producer that utilizes large volumes of Illinois coal.

Participating cement manufacturers involved in the meetings included:

• Lone Star Industries, Oglesby, IL
• Illinois Cement Company, LaSalle, IL
• Dixon-Marquette Cement Company, Dixon, IL
• Lafarge Corporation, Grand Chain, IL
• Holnam Corporation, Mason City, IA

Participating fly ash producers with plants in Illinois included:

• Dynegy Midwest Generation
• Ameren Energy Fuels & Services
• City Water, Light and Power (CWLP)

The non-Illinois fly ash producers included:

• Cinergy Corporation (Indiana)
• Dairyland Power (Wisconsin)
• TECO (Florida)
• Tennessee Valley Authority
• Seminole Electric (Florida)
• City Utilities of Springfield (Missouri)
• Northern Indiana Public Service

Technical Assistance to Promote the Technology

To encourage the commercialization of the technology, CTL offered onsite and offsite technical assistance to the program participants. Assistance was designed to aid in the implementation of the technology. Assistance was provided on an "as-requested" basis.

Offsite assistance was utilized more frequently than the onsite assistance. Onsite assistance was requested and provided twice. In both cases, the onsite assistance consisted of short visits and meetings at cement plants to discuss the technology and factors affecting its commercialization.

Offsite assistance was sought by the both cement manufacturers and fly ash producers.
Requests were related to:

• Dryability of ponded fly ash
• Compositional characterization of fly ash and cement plant raw materials
• Compatibility of high carbon fly ash with a particular cement plant operation
• Thermal behavior and fuel value of high carbon fly ashes
• Potential emissions and organic species characterization of various fly ashes
• Applicability of the technology in non-preheater cement plants

All requests for offsite assistance were fulfilled.

11/1/2000

10/31/2001

2000

Francois Botha

Bhatty, J.I., J. Gajda, and F.M. Miller, "A Commercial Demonstration on the Use of High-Carbon Fly Ash in Cement Manufacture", Presented at the Eighteenth Annual International Pittsburgh Coal Conference, Pittsburgh, Pennsylvania, U.S.A., May 2001.