## Breakout Sessions

Six breakout discussion sessions were held during the Coal Quality: Global Priorities conference. Meeting participants attended the session of their choice depending upon the individual's interest. Each group was asked to discuss any idea of interest within the general outlines of each topical session, but with the underlying idea of whether or not new coal characterization protocols were needed. A facilitator attended each session and directed the discussion. The six breakout sessions were as follows:

1. Global or Regional Coal Characterization Protocols. Are coals from different regions of the world sufficiently unique to warrant different systems of characterization? What are the unique aspects? How do they affect performance.
   Facilitator: James Addington, Quality Associates International, LLC.
2. Development of Modern Coal Quality Databases. What are the parameters and methodology necessary for a coal quality database that addresses current and future issues? What is the best way to provide visualization of the data?
   Facilitator: Gretchen Hoffman, New Mexico Bureau of Geology
3. Coal Reserve Characterization and Beneficiation. What types of geologic and coal quality characterization would be desirable to develop efficient coal blending, selective mining, and beneficiation practices?
   Facilitator: Cortland Eble, Kentucky Geological Survey
4. Environmental Aspects, Including Air Quality and Water Quality Issues. What factors need to be determined to assess the emissions of SO2, NOx, trace elements (e.g. Hg), CO2, etc.? What methods should be used to identify deleterious components (trace elements, acids, organic compounds) leached from coal, coal cleaning, and coal combustion byproducts?
   Facilitator: James Hower, Center for Applied Energy Research
5. Characterization of Coal for Technological Performance. What parameters are needed to determine the behavior of coal in modern and future coal combustion systems?
   Facilitator: David O'Connor, Electric Power Research Institute
6. Characterization of Coal for Byproduct Use and Disposal. What are the parameters necessary to evaluate the use of coal for coke production and byproduct generation? What parameters are necessary to anticipate the characteristics, use, and disposal behavior of coal combustion byproducts?
   Facilitator: David Hassett, American Coal Ash Association

Discussion results from each breakout session follow.

### 1. Global or Regional Coal Characterization Protocols

Is there a need for protocols specific to a region? One example of this might be ash fusion temperature procedures.

Many standards are empirical and not related to the actual use of coals. Many countries have developed their own standards and are reluctant to drop their methods to go to a global standard.

One example of both of the above (test methods specific to one region and a country developing their own method) is ash yield testing of Indian coals. The coals in India have very high ash yields. Their method consists of rating the ash yield in categories (specifically from A to H) for buying and selling coal in India. However, international trading of coal in India is done by ASTM methods and therefore there is a need to standardize within ASTM so that the rating system is globally relevant.

ASTM will need participation and funding in order to do this. Currently, membership is mainly from the U.S., with some Canadian participation. No one outside of the U.S. is on Committee D05, for example. In addition, even U.S. participation in D05 is decreasing because coal utilization is shrinking.

Another example of additional testing needs includes the need for ash fusion temperatures to be supplemented with mineralogical analyses. For example, currently SO3 in ash is expressed simply as the SO3 amount, not within the context of the mineral association. It was suggested that mineralogical analyses be performed as part of the slagging and fouling tests.

ASTM needs coal samples from other countries in order to develop and test standards that are relevant to coals outside of the U.S. There was discussion on how many samples from each mine needs to be analyzed in order to be representative for the entire coal deposit. However, once the samples are obtained, there is a question of who can/will analyze the samples. Human resources and facilities to run the tests is a large problem. In committee D05, there are approximately 250 members, with 125 usually attending the meetings, and these numbers are dwindling.

Another concern raised was the fact that if standards are highly technically instrumented, can other countries afford these instruments in order to run the tests?

There is a huge challenge to get labs to participate in this international testing and to modify procedures to be consistent. It is also difficult to get enough laboratories to participate and use the same method to meet ISO-type ASTM standardization. For example, INAA is done by different laboratories in many different ways, but all give similar results.

Another concern is the testing instrument manufacturers - how does the user community get the manufacturers to share the types of information needed for standardization and how they measure and quantify those specifications.

Unless a consumer wants a particular type of information, it will be difficult to get the backing of laboratories, human resources, or funding to develop new standards. One of the major questions is do we want reproducible composition for a huge quantity of coal to burn at a power plant OR do we want to know how variable the coal is within a mine. In other words, do we want to know the accuracy of the analytical results or the variability of the samples or both.

One concern is with the utility industry - the breakout session participants believed that many of the utilities do not understand that coal quality plays a vital role in combustion problems, rather, utilities believe it is an engineering problem. One way to solve this problem is to go to the utilities and question them on their specific combustion problems, then determine what standards are needed to quantify those assets.

The group suggested using industry to develop methods when available and work with industry to bring forth new lab tests and specifications.

There was discussion on the need to have more types of coal for standards. However, it was pointed out that while one needs a standard sample of coal to develop standard tests, coal is not stable by nature. It is also expensive to maintain sample standards, but perhaps the cost can by justified by lost expense at a utility.

How should coals be classified? Currently, the system of classification is market-based. Perhaps the standards should be geology-based. For example, compare Paleocene vs Miocene lignites. However, the industry, which is the reason for so many standards, is money driven.

Defined Needs by the Group:

- need for ASTM global test methods
- need for global participation
- need for global coal sample bank (need to make an effort to get samples from developing countries)
- need for comprehensive base of coal standard materials (standard coals are needed to do full scale testing)
- need to supplement ash analyses with mineralogical analyses
- need to educate people who mine, sell, and burn coal, because they do not understand simple standards
- need reproducible data
- need for proactive role of utilities (proactive position of producer can better characterize coal and how it will behave)

### 2. Development of Modern Coal Quality Databases

For Whom Are We Collecting the Data?
Data should be collected for all aspects of the coal industry coal combustion, coal combustion byproduct utilization, coalbed methane production, metallurgical uses, and research purposes. Committees consisting of people from the different industry and research groups should be formed to decide what analyses or information would be most beneficial to have in the database. To meet the needs of all these related industries, it may be necessary to have several databases or a relational database with tables for different areas of interest.

For What Elements Do We Look?
The main focus of discussion was meeting the needs of environmental and health issues and also looking at those elements that become concentrated in the ash.

Sampling protocol was the main topic of discussion and the standardization of sampling. Although there are standard sampling techniques in place, there is a real need to make sure all parties submitting samples to the program use these techniques. The handling and storage of the sample should also follow a prescribed method and be documented. Documentation of the location, who took the sample, coalbed name, depths, etc., was considered very important.

The need for a sample storage bank was thought to be a necessary part of a round-robin program to validate the analyses.

There was some discussion of the life of the data. As an example, the data in the U.S. Geological Survey's CoalQual database has many samples from the 1970's. Many of the coals associated with these analyses may be mined out and so the data is of historical signficance, but may not be applicable to today's coal resources. It was felt that a reasonable "life span" should be assigned to databases to give the users a sense of how long these data might be valid for available coal resources.

Finally, the database or databases should be in a format that could easily be accessible or can easily export data to other formats. It would be ideal if the coal data has location data that is in an x-y format so it could be put into a GIS and be associated with other themes. This increases the usefulness of the information because it can be related to cultural and geographic data in a visual manner.

### 3. Coal Reserve Characterization and Beneficiation

Opening Remarks by Facilitator to Start the Discussion

Coal reserve characterization and beneficiation involves many things, including:

- thickness and extent of the reserve
- quality characteristics of the coal, including trace element content
- beneficiation characteristics
- mineability characteristics (such as roof control)
- end-use - this is becoming extremely important as new technologies (for example, intengrated gasification combined cycle and circulating fluidized bed combustors) utilize coal with marginal to poor quality characteristics (for example high ash and sulfur); the same is true for conventional power plants that install flue gas desulfurization technology
- sample point density - how many samples are required to reliably characterize a reserve?
- environmental impacts of mining (for example, acid mine drainage prevention and mitigation)
- post-mining land use

Subsequent Discussion

The role of public databases was discussed at some length. Summary points are as follows:

- The principle reason to develop a CQ database is to provide information to educate and inform not only potential consumers of coal, but also governments and the general public.
- A participant raised the question as to the role of the USGS in a data collection effort (size, scope). The moderator pointed out that many coal companies in Kentucky, especially smaller companies, no longer have geologists on staff and routinely visit the state geological survey for exploration assistance.
- However, it was noted that the U.S. system is unique compared with other countries (such as Australia), in that company data remain proprietary. Other countries, especially those that export most of their coal, publish their CQ data as a marketing tool. In this light, the value of a publicly available CQ database was questioned, the point being that some countries already make their coal data available. One participant mentioned that a compendium of coal quality data for many, mainly exporting, countries is already published and available for purchase. Another participant pointed out that publicly available databases are needed because they represent sources of neutral, unbiased information. They are also a source for comparison with proprietary data.
- The need for expanded combustion testing was introduced, so that more information regarding such parameters as slagging, fouling, and electrostatic precipitator performance would be available. It was also noted that a "test-burn"of potentially mineable coals in the country of origin would be helpful to countries that import coal (for example, Israel). A case was mentioned where one country had received a fairly large shipment of coal from another country, only to learn that the coal could not be used in their combustion furnaces. Problems associated with combustion behavior in furnaces of different designs and sizes were subsequently discussed.

Proposed Regulations on Mercury Emissions from Coal Combusion

- Publicly available databases on mercury in coal are limited.
- There are few data on mercury removal by convention coal beneficiation. EIA indicated interest in developing a database on U.S. preparation facilities. The role of "non conventional" beneficiation was also brought up. One method that was described involved magnetic separation of pyrite from pulverized coal prior to injection into the furnace.
- Company data would be helpful, but presently is inaccessible. It was noted that this is a "U.S." problem, and stems from America consuming most of the coal it produces. Coal-producing companies consider coal quality data as proprietary. Countries that export most of their coal (for example Australia) are more open with coal quality information, as it helps market their product.
- There is a need for selective sampling in new programs to gather data. Collections and analyses should be targeted at potentially mineable coal beds. It was noted that the on going NACQI program is adopting this approach.

Advanced Combustion Technologies

- Australia has an abundance of low sulfur coal and therefore sulfur emissions are presently not an issue.
- In China, expanded use of coal will require a better knowledge of coal properties, especially sulfur content. Because most of the coal is not beneficiated prior to combustion, more data on the nature of sulfur on Chinese coal are needed.

Beneficiation

- The need for more U.S. preparation plant data was emphasized.
- Use of "waste material" from preparation plants was also discussed. One example of this is briquetting, with a potential synfuels tax credit.
- In Kentucky, 2150 mW of new capacity is being proposed and will use waste coal (such as from old tailings ponds) or coal of poor quality. This scenario changes Kentucky's resource picture rather significantly. As a result, better characterization of prep plant refuse is needed.

Concluding Remarks

- Better characterization of world coal resources would be beneficial for some countries, while others already rely on published data sets. The former seems to apply mainly to countries that consume most of their coal domestically, while the latter mainly applies to countries that export most of their coal.
- Coal data issues in the U.S. apply only to the U.S. in many cases.
- Critique of USGS coal data products (for example, coal quality CD's, coal assessment CD's) would ultimately benefit a world coal iniative and subsequent products.

### 4. Environmental Aspects, Including Air Quality and Water Quality Issues

The discussion was started with the creation of a matrix, plotting "land," "water," and "air" along one axis, and "mining and post mining," "preparation," and "utilization" along the other axis. Participants placed items of concerns, such as "hazardous trace elements," in the appropriate block. Some items, such as hazardous trace elements, actually cross the spectrum, affecting land, water, or air for each of the points of coal handling.

Elemental issues did emerge as a topic of concern to many of the participants. Elements of concern include SO2, NOx, As, He, Se, and other HAPs. Organic compounds were mentioned as a topic of concern. At pulverized coal combustion temperatures, however, organics would not be as great of a concern as at lower combustion temperatures. It was noted that there are human health impacts associated with all the elements mentioned, although the degree of the impact is going to be highly variable. A major consideration with respect to trace elements is the point of control of the element. It was agreed that, if possible, it is cheaper to control the elements at the mine site or preparation plant rather than as a gaseous emission from a power plant stack. Interestingly, greenhouse gases were not mentioned, perhaps because so much discussion has been conducted that the audience felt that other issues deserved more attention in the time allotted for discussion.

The need for better and more timely data on coal quality and quantity was discussed. Although it was admitted that the USGS coal quality reports are comprehensive, the mines sampled are in general no longer in operation. In any case, the mining has moved beyond the point of sampling. The integration of government and company efforts in an economy such as the U.S., where coal companies are not state owned, is a problem. It was admitted that some of the most detailed quantity information, at least within the time frame of mine planning, is held by companies and is not available in the public domain.

Acid mine drainage (AMD) continues to be a problem in many parts of the U.S., as well as in other countries. Environmental problems associated with AMD are pH, Mn, and Fe issues. Also, the effectiveness of reclamation regulations and activities were questioned. It was noted that attention needs to be paid to the biologic restoration of damaged streams.

Mined land reclamation continues to be an issue in mining. It was stressed that there is not one simple approach to restoration. A return to the best land use, not necessarily the pre-mining configuration and use, may be the best approach in some countries.

A final issue spontaneous combustion arose late in the session. Discussion was not as lengthy as with some of the previous issues, but it was noted that uncontrolled mine fires pose a health and safety problem due to the fire and the emissions from the fire.

### 5. Characterization of Coal for Technological Performance

Basic Questions:

- What information would process developers require to make conceptual designs?
- What information would operators require to effectively manage their systems?
  - Detailed information likely to be gathered before spending billions on capital investment, but answering these questions could provide a template for information gathering.

Define All Information Requirements For:

- All coals, regardless of rank or potential end-use
- Some information is only required for coals of a certain rank
- Other information is required only if a coal is to be used for certain applications

Information Requirements for All Coals:

- ASTM ultimate/proximate
- ash chemistry
- trace elements
- ash fusion
- grindability (may not need for low rank coals)
- mineralogy (associations via fractionation, SEM) important missing link
- maceral composition
- abrasiveness (test to follow?)
- swelling index
- angle of repose
- coal cleanability (may not need for low rank coal)
- sulfur forms
- indication of delivered quality -- important missing link
- flag unusual coals, or commentary by experts -- important missing link
- drop tube results (test to follow?) -- important missing link
- blending

Rank-Specific Information Requirements:

Anthracite

- conductivity
- calcining yield test
- ignition test (test to follow?)
- Thamman furnace

Bituminous

- carbon product test suite (test to follow?)

Low-rank coals

- spontaneous combustion (test to follow - porosity?)
- grindability vs moisture
- drying (lignite upgrade - test to follow?)

Application-Specific Information Requirements

Combustion

- SO2 release rate
- ion exchangeable cations
- drop tube results

Gasification

- gas/solid reaction rates (test to follow?)
- porosity/surface area
- drop tube results

Industrial

- coking index
- swelling
- suite for coking

### 6. Characterization of Coal for Byproduct Use and Disposal

The session began with general discussion of ash characteristics, including a discussion that coal quality data do not necessarily lead to prediction of ash quality for reuse or disposal. General characteristics can be predicted such as rank or ash and possible occurrence and potential concentrations of trace elements, but overall performance including environmental impacts still must be determined in the laboratory or measured in the field. It is possible to predict some boiler effects such as slagging and ash fouling.

Ash characterization methods were discussed. These included standard methods of bulk analysis such as atomic absorption, inductively coupled argon plasma spectroscopy, and x-ray fluorescence. Leaching protocols were discussed and included a discussion of lack of appropriateness of the U.S. Environmental Agency (EPA) toxicity characteristic leaching procedure (TCLP). Reasons for the unsuitability for the TCLP were discussed and included inappropriateness of the acidic leaching solution and short (18-hour) equilibration time. Potential suitable procedures were discussed, such as the American Society for Testing and Materials (ASTM) shake leach test and the EPA synthetic precipitation leaching procedure (Method 1312). The use of long-term leaching for reactive ash was also discussed. Long-term leaching can and often should be carried out. It was also mentioned that environmental groups and others not versed in ash science were developing and recommending leaching tests that were perhaps more inappropriate than TCLP. The need for a complete understanding of ash chemistry and ash properties including hydration reactions is essential for recommending leaching tests. All seemed to agree that duplicating as closely as possible what would happen in the environment was essential for laboratory leaching.

The issue of coke and coke byproducts was briefly touched upon. It was decided that for this material, special and specific testing procedures were required.

The issue of using performanced-based testing rather than some of the standard ASTM testing was discussed. There was no disagreement on the value of performance testing. It was agreed that it is possible for current non-specification ashes to be used if performance-based specifications were in place.

People in the session agreed that additional sources of coal and coal ash banks were a good idea, but the people could not decide on who would fund or maintain them.

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