Dear E,
1. COAL SLAG IN GENERAL
Coal slag is currently an accepted alternative to common silicate sand. Coal slag is the remnant of burning coal in various steel and other processes, and coal mining country is full of the stuff in great heaps -- West Virginia, Pennsylvania, Montana and North Dakota, and (as it happens) the countryside near St Andrews, Fife, where golf was born. For coal slag in general, see these links:
MATERIAL SAFETY DATA SHEET - Coal Slag,
http://www.universalminerals.com/MSDSCoalSlag.htm
American Coke and Coal Chemicals Institute (ACCCI),
http://www.accci.org/ [trade lobby group]
Scotland.com - Travel,
http://travel.scotland.com/regions/lothian/
"Slag in the Park - A History of Nine Mile Run" [Pittsburgh] by Andrew S. McElwaine,
http://slaggarden.cfa.cmu.edu/history/
COMMUNITY AND ECOLOGY: SLAG, SOIL, PLANTS AND WILDLIFE (PDF),
http://slaggarden.cfa.cmu.edu/publications/content/ampleopp/4a-cebg.pdf
2. COAL SLAG AS ARTIFICIAL GREEN FILL
Here are some web resources from synthetic greens companies about using coal slag as an infill -- what size, how much per square foot, and the costs:
All Pro Greens Putting Greens,
http://www.allprogreens.com/pressroom-faqs.htm
All Pro Putting Greens - Synthetic putting greens do-it-yourself kit,
http://backyard.1syntheticgreen.com/coinfo.asp
Great Lakes Landscaping - All pro Putting Greens - Tools and Materials,
http://www.greatlakeslandscaping.net/greentools.htm
Greens To Go: Putting Greens,
http://www.greenstogo.com/FAQs.htm
Greens to Go - Coal slag infill requirements and costs,
http://www.greenstogo.com/PopTools_materials.htm
GTG Advantage - coal slag infill and green speed,
http://www.storesonline.com/site/487269/page/89611
Charlotte Golf Putting Greens - Coal slag application formula and costs,
http://www.greenstogo.com/PopTools_materials.htm
This article also discusses coal slag as an artificial putting green fill:
Par for the course Lawns with leisure built in: For dedicated duffers, artificial-turf putting greens are providing a low-maintenance alternative to grass -- and a way to practice their favorite game., By DEBORAH GEERING For the Atlanta Journal-Constitution, 26 Dec 2002,
http://www.accessatlanta.com/ajc/living/homeandgarden/1202/26golf.html
The green installation process is described as follows:
GREENS TO GO: The installation process of our synthetic turf green is similar to the installation of a natural grass green. During this process coal slag in-fill is spread across the top of the turf, then brushed in with a broom to get between the turf fibers.
Once the in-fill is in place, it will cause the fibers of the turf to stand straight up or vertical. When you stroke the ball, it will roll on the tips of the fibers making for a true roll to the cup.
The coal slag in-fill also controls the speed of the green. The more i-fill you add the faster the green. The less you have, the slower the green. When you install your GTG green according to both the written and video installation instructions, it will register a 9 to 10 on a USGA stimp meter.
Coal slag infill
This should be 35 grit or medium. The infill grades are scaled with 20 grit being large or course grit, 30 to 35 grit is medium, and 40 to 60 grit is fine. The large 20grit coal slag will not sweep properly into the fibers of the turf. This infill product can be purchased as any local sandblasting supply store. Check your Yellow Page listings for locations. Cost is approximately $3-5 per 100lb. bag. You will need 3.5 pounds of infill per square foot on the green.
The formula to determine the amount of infill you will need is:
Total square feet X 3.5 = number of pounds of sand required.
For example, you will need, 7 one hundred pound bags for the 12 by 16, 11 one hundred pound bags for the 12 by 24, and so on
*****
ALL PRO PUTTING GREENS: Because you're buying manufacturer direct, we want to provide you with accurate and factual information so you can make an educated and informed decision before you purchase. We provide the most advanced synthetic turf and infill process in the industry. Some companies use silica sand or sand blasting sand that will pack down and harden over time and is known to be hazardous. Others don't use sand in their process that results in the fibers of the material matting down over time. Still others want to sell you their own "unique bend" of infill that you must purchase from them.
We use coal slag infill in our putting greens. The coal slag is not hazardous, will not pack down over time thus always providing you with a sponge-like feel of a real green, and can be purchased locally in your area.
*****
GREAT LAKES LANDSCAPING - ALL PRO PUTTING GREENS: Coal slag infill -- This should be 35 grit or medium. The infill grades are scaled with 20 grit being large or course grit, 30 to 35 grit is medium, and 40 to 60 grit is fine. The large 20grit coal slag will not sweep properly into the fibers of the turf. This infill product can be purchased at any local sandblasting supply store. Check your Yellow Page listings for locations. Cost is approximately $3-5 per 100lb. bag. You will need 3.5 pounds of infill per square foot on the green.
The formula to determine the amount of infill you will need is:
Total square feet X 3.5 = number of pounds of sand required.
For example, you will need, 7 one hundred pound bags for the 12 by 16, 11 one hundred pound bags for the 12 by 24, and so on.
*****
CHARLOTTE GOLF PUTTING GREENS -- PRO GOLF GREENS: Formulas: Coal slag/back beauty - sand blasting sand 3.5 lbs. / sq. ft. (100 # bags) i.e. 12'x12' green = 504 sq. ft divided by 100 = 5-6 bags 50%
Material Costs: Coal slag/back beauty - sand blasting sand Approx. $5 - 10/bag
3. GOLF COURSES AND COAL SLAG
In recent years, golf courses in the Great Plains states have used coal slag as a bunker material. Jack Nicklaus helped reclaim the Anaconda mine lands in Anaconda, Montana, using coal slag as a bunker material for the Anaconda Old Works Golf Club:
Federal Reserve Bank of Minneapolis - fedgaze - Jack Nicklaus' Anaconda Old Works GC - black coal slag bunkers,
http://minneapolisfed.org/pubs/fedgaz/97-10/mt.cfm
High Country News -- WESTERN ROUNDUP - September 5, 1994 Busted town pursues industrial recreation, by Jim Robbins, ANACONDA, Mont. - Jack Nicklaus' Anaconda Old Works GC - black coal slag better than any bunker sand in the Ohio Valley,
http://www.hcn.org/servlets/hcn.Article?article_id=523
James Engh, golf course architect, has used black coal slag for bunkers in the Bismarck, ND, Hawktree Golf Club, and this material is less susceptible to erosion than common bunker sand from the strong and steady Plains winds:
Hawktree GC, Bismarck ND - IN THE NEWS,
http://www.hawktree.com/NewsInfo/Articles.htm
Golf Course News Magazine - Hawktree GC (May 2000),
http://www.hawktree.com/NewsInfo/Golf%20course%20news.htm
USATODAY.com - A golf odyssey: Best of the Midwest - Hawktree GC, Bismark ND - feauturing black coal slag bunkers,
http://www.usatoday.com/travel/vacations/2001/2001-07-10-golf-odyssey.htm
Another similar use is at the Butte, Montana, course Ponderosa:
Ponderosa Butte GC - coal slag traps,
http://www.colstripparks.com/comments_dec5_02.htm
4. COAL SLAG AS INDUSTRAIL SANDBLASTING ABRASIVE
Coal slag is most commonly used as an abrasive for industrial sand blasting of iron, steel, and other corroding metal surfaces as part of anti-corrosive protective coating or painting. Because of this, the material is commonly available from companies supplying sand and other abrasives. Also because of this, coal slag has been studied as an industrial occupational health issue and especially has been compared to silicate sand for its risks to health.
Commonly called "Black Beauty" or similar names, coal slag as an industrial abrasive for sand blasting is typically available at sources like the following:
Reed Minerals - Product Information - Abrasives - Black Beauty (coal slag),
http://www.reedmin.com/products/abrasives.html
Reed Minerals - Product Information - Black Beauty abrasive materials specifications sheet,
http://www.reedmin.com/products/html/a15.html
Black Beauty Abrasive from READE / Reed,
http://www.reade.com/Products/Abrasives/black_beauty.html
Marco Abrasives-Coal Slag & Sand - Black Lightning,
http://www.marcousa.com/coalslagsand.html
Abrasive Blasting with Coal Slag - Black Blast,
http://www.sandblaster.com/products/Abrasives/coal_slag.htm
Industrial Supply - Black Beauty (coal slag),
http://www.aaa-industrialsupply.com/other_sandblasting_medias.html
Sil Industrial Minerals,
http://www.silindustrialminerals.com/products.htm
All Purpose Sand Company: Bridgeton, Missouri,
http://www.stcharlessand.com/allpurposesand.htm
Target Products Ltd. SANDS,
http://www.targetproducts.com/catalog/sands.htm
These sources also allow you to compare other alternatives to silicon and compare costs. Coal slag is cheapest. You can probably find a supplier for sandblasting abrasives in your phone book, but be sure you get the correct size.
5. COAL SLAG AND INDUSTRIAL / ENVIRONMENTAL HEALTH
The safety of coal slag has been studied in terms of the environment and worker exposure during sand blasting operations. Coal slag typically has under 1 percent of "free silicate," which is recognized as a cause of silicosis. Silicosis results from the inhalation of "respirable" silicate particles into the lungs, which scar over the silicate as a defensive reaction, and extensive scarring can lead to loss of lung function and/or death. other related lung diseases or conditions are attributed to excess breathing of silicates. A "respirable" particle is one small enough to pass through the nose and throat's filtering system and reach the deep tissues of the lung, and this is now considered to be 10 microns or smaller in diameter (1x10^-5 meters, which is 1/1000th of a centimeter, or 1/100th of a millimeter).
While coal slag is generally considered less toxic than sand silicates, the matter is not without some doubt. Some information suggests that coal slag is more toxic than common sand, that there is an issue of radon gas emission, and that toxic heavy metals such as arsenic are present in the slag and may leach out. Each of these toxic hazards, whatever may be the real level of risk, is partly dependent upon the actual environment where the slag is located, how it is used, the degree of exposure, and the susceptibility of the persons exposed.
Here are some science studies related to the health risks associated with sand silicate and coal slag:
Canadian Health Safety Bulletin CH059 - silicosis,
http://www3.gov.ab.ca/hre/whs/publications/pdf/ch059.pdf
NJ Environmental & Health Service, Div of Epidemiology - Stop Silicosis in Sandblasters Use Silica Substitutes,
http://www.osha.gov/SLTC/silica_advisor/protect_against/stopsandblasters/body_stopsandblasters.html
Center for Disease Control, NIOSH Abrasive Study,
http://www.cdc.gov/niosh/silsand.html
NIOSH Abrasive Study,
http://www.sspc.org/site/compliance/96_1/NIOSHtoStudy.html
NASA - Evaluation of Various Abrasive Grits for Replacement of Silica Sand in Sandblasting Operations,
http://technology.ksc.nasa.gov/WWWaccess/techreports/95report/msf/ms11.html
European Union - ERRICCA - Workshop -- List of Accepted Abstracts (07-02-1999) - Measurements of dose rate and radon gas concentration in schools and kindergartens constructed using coal-slag as building material,
http://arcas.nuclear.ntua.gr/~erricca/workshop/list_abstr.html
Society of Toxicology Abstract - Sandblasting Materials - Persistent Pulmonary Inflammation After Intratracheal Instillation of Abrasive Blasting Agents (March 1999),
http://www.sandblaster.com/toxicology_abstract.htm
Chesapeake Specialty Products - Recyclable Metallic Abrasives: The Economical Way to Protect the Environment,
http://www.chesprod.com/html/protect.html
CONCLUSIONS AND RECOMMENDATIONS
I of course cannot state that coal slag is safe or not, but I would say that your use of the coal slag inside a confined enclosure raises the risks, whatever they are. The dust in applying the coal slag will infiltrate your room and, if there is any reason to fear breathing the dust or coming in close contact with it or it giving off toxins or presenting special dangers to children and the elderly, I would imagine that each of these risks is amplified somewhat by using the artificial green inside, without a lot of ventilation. The green will need to be refreshed periodically and the slag broomed into the fabric. There are dust suppressant substances available, mostly as a light oil, that may be advisable, and you might consider using a nose-mouth filter that spray painters use when applying or brooming the fill. You might also want a radon detector; I don't think they cost much, and you can never be too safe.
Whatever you decide, you have the information above to become educated about the concerns, and to compare coal slag to other fill substances in terms of safety and cost. My main concern is using this inside the house.
I hope this helps you make a safe and intelligent decision.
--
Cheers!
Geoff Mangum
Putting Theorist and Instructor
The PuttingZone.com
http://puttingzone.com
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