January 2002
Market
Watch
Recycled Paint Pigments Being Used in Asphalt Pavements
Market Watch
Recycled Paint Pigments Being Used in Asphalt Pavements
By Sandy Lender
If new technology in the Motor City takes hold, aggregate producers may have a new competitor in the fines arena. Workers at Phillips Services Co. (PSC), Detroit, have found a way to recycle paint pigments from an automotive company in Detroit, for use in asphalt mixes. And according to a recycling contractor in Missouri, the product looks promising.
The product stems from the paint overspray issue automobile painting facilities face. “When you’re painting a vehicle, not all the paint goes on the vehicle,” said Kevin Catterfeld, technical manager for PSC.
Bob Spink, director of engineering and technical support at PSC, reports that about 30 percent of the paint sprayed at the cars in assembly plants misses its target. “So it has to be scrubbed out of the air with a liquid solution,” said Spink. “PSC has developed a process that dissolves and disperses the paint components, so that we can recover the paint solids in a powder form.”
The grey powder produced is comparable in size to sand, according to Spink.
“It takes about 250 gallons of paint overspray to result in a cubic yard of the powder out of our recycling plant.” With automotive companies painting approximately 1,000 vehicles a day, at 2 gallons of paint per unit, factories are seeing about 600 gallons of overspray a day. That translates to 2.4 cu. yds. of the powder per day. At 235 production days per year, a contractor could obtain up to 564 cu. yds. of powder from a single factory’s recycling vendor.
“By removing the paint solids and recycling them into products like asphalt,” said Spink, “we keep them out of their traditional disposal site—a landfill.”
“Our whole goal of the program is two-phased,” said Catterfeld, “to recover our chemicals and to recycle the paint pigment that was left over.”
The good news for the roadbuilding industry is that the powdery product is classified as non-hazardous. “Think of paint as a mix of solvents, inerts and resins,” said Spink. “The product coming off of our dryer that goes to be recycled is a combination of these inerts and cured resins.”
The product coming off the dryer garnered approval from the Missouri Department of Natural Resources (DNR). “The information from DNR is that they tested it and say that it’s unregulated material,” said Charlie Bell, vice president of Columbia Curb and Gutter, Columbia, Mo. “It’s completely safe to do whatever we want to with it.”
Bell explains that his company sought permission to mix the product into hot or cold mix asphalt. The response was positive, from more than one source. Sharp Materials Inc., St. Charles, Mo., holds the permit from DNR Waste Management to recycle the product, according to Bob Wallis, proprietor of Sharp Materials.
“The recycling is through Columbia Curb and Gutter,” he said. “And the Missouri Highway Department is supporting Columbia Curb and Gutter to use it in recycled asphalt.”
Although the product offers Bell a substitute for sand, he sees a bigger picture. “I’m not cutting back on my sand,” he states. “I’m adding this in addition to the sand. What I’m hoping is that we’ll have less voids in our mix.”
Another reason Columbia Curb and Gutter crews will use the product in their recycle mixes is to provide an “end result” for the original producer of a hazardous waste. “The EPA likes to have an end to close it out,” he said.
In other words, automotive companies need to track the waste product resulting from overspray at their automobile assembly facilities. “If anybody comes back 10 years from now and asks (the company) what happened to all their waste, they can say it’s in the road,” said Bell. “It’s no longer a hazardous waste. In fact, it’s unregulated altogether, once it’s been treated. It’s just like normal sand.”
And like normal sand, the product is subject to the same conditions as any other aggregate source at the asphalt plant. “Right now it’s just piled up in a pile,” explains Bell. “It’s a fine powder, like a dust, but it’s really heavy. It’s contained very well.”
It appears that the automobile makers have an outlet for their overspray paint pigments now. From the paint booth, to a recycling center, to the contractor producing mix for his roadway projects, paint pigment has found its way into the road. It’s not just for striping anymore.
Sandy Lender is a contributing editor for AggMan.
It’s a Small (Aggregate) World After All
International Seminar Reveals Common Threads in Aggregate Issues
By Valentin V. Tepordei
A seminar held in Brazil reviewed the status of the aggregate industry in South America, North America and Europe, as well as the latest developments in technologies and practices of mining, processing and transportation on the three continents.
We are not alone. This was the prevailing conclusion of attendees of the international seminar entitled The Future of the Aggregates Industry, organized by The National Association of Aggregates Producers for Civil Construction (ANEPAC). The seminar was held between Oct. 23-25, 2001, in Campinas, SP, Brazil, and was sponsored by Caterpillar Brazil.
The main purpose of this seminar was to review the status of the aggregate industry in South America, North America and Europe, as well as the latest developments in the technologies and practices of mining, processing and transportation on the three continents. Environmental and regulatory issues regarding the aggregate industry in several countries were also reviewed.
The exchange of views among producers from North America, Europe and Brazil showed that nearly all countries face the same critical issues. Analyzing how aggregate producers in other countries are handling and coping with these issues provides insight, and perhaps even foresight, into what could likely happen in North American markets.
Before viewing any aggregate market as a “crystal ball” into U.S. trends, it is important to account for differences, too. Brazilian producers, for instance, have space to grow because Brazilian consumption of aggregates is low compared to developed countries. Common worldwide threats to the aggregate industry, however, such as ever-increasing environmental restrictions, justify the value of international information sharing.
Despite worldwide industry challenges, optimism pervaded throughout the seminar: speakers unanimously agreed that the industry will survive.
Per capita consumption statistics and forecasts presented by Cipriano Gómez Carrión, president of the European Aggregates Producers Association (UEPG—Union Européene des Produceurs de Granulats) offered strong evidence of the aggregate industry’s health in Europe.
Gómez described UEPG as consisting of 16 national associations, 13 of which come from countries that belong to the European Union. In these 16 countries, aggregates production in 1999 reached the amount of 3 billion tons, without crushed limestone used in the cement and lime industry. That equates to a per capita consumption of 7 tons/year.
Germany consumed 736 million tons and, although the construction industry is not in good shape, room for growth exists due to the need of former East Germany to invest in housing and infrastructure.
Italy consumed 550 million tons and had the biggest per capita consumption among UEPG countries (9.6 ton).
Per capita consumption in Spain is about 5.5 tons, but in the last five years, the construction industry has been booming. Between year 2000 and 2006, the Spanish government is expected to invest more than U.S.$100 billion in housing. Infrastructure is in dire need of improvement, and tourism is also booming, attracting big investments. Goméz said that he believes that the consumption of aggregates in Spain is more than the official statistic of 353 million tons, and it can possibly reach in the 550-million range.
In France, mergers among aggregate companies are growing. The consumption is now 350 million tons, but was more than 400 millions in the 1980s.
In the United Kingdom, consumption is abnormally low, and only five groups produce 80 percent of total production. But after two decades without investment on infrastructure, the country needs to invest, and the future seems not so bleak.
Sweden, Norway, Finland and Denmark together total 250 million tons production, with a high per capita consumption of 11 tons/year.
The aggregate industry in the UEPG countries is a business of U.S.$20 billion per year, and it employs 200,000 people. Operations vary from big quarries of more than 5 million tons/year to small operations of 50,000 tons/year.
Caterpillar Brazil sponsored the three-day seminar that was attended by 300 representatives of the aggregate industry.
Goméz said that, in the European Summit in Lisbon, it was decided that the mining industry, with the exception of coal, will undergo severe scrutiny regarding environmental practices and sustainable development. To oversee its implementation, the summit members created a Mining Industry and the Sustainable Development Committee. Goméz is very concerned about “not-in-my-backyard” agendas unjustly harming the industry, so the UEPG is participating in the Raw Material Supply Group.
The first goal for the aggregate industry in Europe is summed in a phrase: Do things well. So the industry is defining standards for companies. Rehabilitation of mined-out sites is a high priority. Awards for reclamation projects are now common in many European countries, and the UEPG supports an awards program, too.
Another challenge for aggregate producers in Europe is changing public perception of the industry. Goméz stated that the industry has such a low public perception because we have not done the right thing. Bad public perception has made it increasingly difficult to access reserves. As an example, said Goméz, a region where 6 million people live consumes 35 million tons of construction aggregates. Strict environmental regulations have restricted resources in the region to fulfill local needs for only three years. As a result, in the next two years, 50 percent of the region’s consumption will most likely be produced outside the region; afterward, 75 percent. The average distance of a new source will be 93 miles. Aside from the affect it will have on aggregate costs, the situation will put 2,000 more large haul trucks on the road, costing the region even more in subsequent infrastructure upkeep and environmental impacts.
Goméz said he believes that the industry will be forced to adopt better working practices and modern business techniques. This will make the industry more capital intensive, accelerating mergers and making it inevitable that large entities will control markets.
Speaking on behalf of the National, Stone, Sand & Gravel Association and the United States industry, Gregory J. Bush, NSSGA chairman and president of Linwood Mining & Minerals Corp., in Davenport, Iowa, presented a comprehensive and historic overview the U.S. aggregate market.
Included here is the overview offered by Bush of opportunities facing U. S. aggregate producers:
Automated Plants: A definite trend exists toward more efficient, computer-controlled processing plants. As new plants are built, producers are seeking innovative ways to make their operations more cost efficient and capable of producing a greater variety of product. This is because customers need materials at new, more precise gradations and particulate shape.
Automation also allows plants to operate at night, so that highway repair projects can move forward at the least inconvenience to the motoring public.
The computer, more than any other tool, is helping management achieve these goals, and today many plants are operated by fewer but more highly trained individuals. Currently, processing plants exist that can be set to run without any plant personnel at the site. In case of a problem, the plant automatically shuts down and notifies the appropriate personnel. In many of these cases, the problem can be analyzed and solved by the plant manager from an off-site location.
During the NSSGA’s 2000 Automation Conference in Miami, Fla., an NSSGA member actually showed, during his technical presentation, how he could run his plant in Pennsylvania from an Internet-linked lap-top computer located in the Florida conference room.
Marketing and delivery methods have also benefited from automation technology. Many plants use automated loadout facilities that permit customers to obtain material even after hours, when no one is working at the plant. Typically, the customer will have an identification card or access code that provides entry to a computerized system that gathers the information needed, much like the way bank ATMs work. Some plants have interactive computer programs that allow customers to place orders and schedule deliveries over the Internet. There will be more developments in the area of computer-controlled operations in the future.
Improved Quarry Operations: The second trend is one toward improved quarry operations. One might think that quarry operations already have been refined as much as possible. After all, quarrying consists of simply drilling and blasting rock, and then moving it to the processing plant. How can that be improved?
In recent years, the quarry process has seen the development of highly mobile crushing plants that move into the quarry to crush and screen the material at its source. These mobile crushers are actually processing plants mounted on crawler tracks, rubber tires or walking pads that can carry them close to the quarry wall as material is removed from it. Some of these plants can process up to 4,500 metric tons per hour.
Mobile, in-pit crushers are not for all quarry operations. The units are big and expensive, and quarry conditions have to be just right for the unit to be profitable. However, those producers—-and so far there are only a few—who are moving to mobile, in-pit operations are doing so to eliminate truck haulage and to produce more material faster and cheaper than by any other existing technique.
Generally, those producers who have installed mobile crushing plants tie them into a string of movable conveyors that carry the material from the quarry to the main processing plant where the stone is further sized to specification.
Improved Sand and Gravel Production Techniques: Larger dredges, larger drag lines, more efficient pumps, more efficient water circulation and longer lasting screen decks have contributed to far more proficient sand production. Some of the new dredges permit U.S. producers to extract materials from depths twice as deep as they could with older equipment.
Manufactured Sand: The third trend is the one toward the manufacture of sand by crushed stone producers. In some parts of the country natural, coarse sand is in short supply, but the crushed stone industry is filling this void with a product it calls manufactured sand. Manufactured sand is, of course, produced by “fine grinding” blasted stone.
Superpave: In the United States in the early 1990s, federal and state governments worked together with academic and research institutions to develop a new system of hot-mix asphalt pavement design called Superpave. Superpave is an acronym for “Superior Performing Pavements” and represents an entirely new paradigm in hot mix asphalt design. Superpave was created in response to governments’ and consumers’ demands that user-fee paid roads last longer and be more efficient in their use of materials.
Even though the advent of Superpave required many producers to adjust their processes to provide the type of aggregates required by this new system, the aggregates industry has responded to this challenge by doing what it does best: serving the public interest by meeting our customers needs.
The U.S. aggregate industry also continues to help the government improve the Superpave system by sponsoring materials research at the International Center for Aggregates Research (ICAR) housed at the University of Texas and Texas A&M University. ICAR researchers investigate the aggregate specifications of Superpave to verify that the specifications really relate to pavement performance. Already this research has helped provide the technical basis to help improve some of these specifications.
Improved Blasting Techniques: The fourth trend is a continued movement toward improved blasting techniques and procedures to prevent fly rock (flying rock fragments from a quarry blast) and vibration damage to nearby buildings. Aggregate producers today consider it a normal part of the blasting operation to install seismic equipment to monitor vibrations to nearby structures. This equipment is monitored regularly and provides both resident and quarry operator with an accepted and authoritative report on any quarry-generated sound or vibration.
Damage from fly rock is no longer the threat it once was perceived to be by a quarry operator’s neighbors. Improved loading patterns, careful spacing of blast holes, improved explosives and the retention of professional explosive experts have virtually eliminated blasting-related problems. The industry also applies computer technology to this process. Many operators use computers to accurately map blast holes and loading patterns in order to provide a more efficient use of explosives.
Nevertheless, this remains one of the most significant community relations issues the U.S. aggregate industry faces, and it continues to be cited by people opposed to quarries or sand and gravel operations in their neighborhoods.
Public Awareness: For some time, there has been a definite a trend on the part of aggregate operators to be far more sensitive to, and aware of, the needs and wishes of the public. As our population has grown and suburbs have expanded, the public has moved closer to what used to be “out of town” aggregate operations. Today’s aggregate producers are extremely concerned about public opinion. Many companies have worked hard to win the trust and support of their residential and commercial neighbors, and the files of those producers who have been good corporate citizens are filled with the positive results of carefully developed community relations programs.
Noise, dust and truck traffic are three areas where industry and government are working to develop measures that are more effective for workers and neighbors. Plant operators are seeking new ways to reduce the visual impact of their operations. In many communities, plant operators have won the respect of their neighbors for the improvements they have made in minimizing any type of impact their plant or equipment makes on the environment.
Some of the techniques—such as the use of water trucks and wheel washers, the planting of trees on berms and around the perimeter, installing attractive landscaping at entrances and scalehouses—are simple and relatively inexpensive. Others are more elaborate and, consequently, more costly.
Land Reclamation of Aggregate Operations: Of all the trends affecting the aggregate industry, the most dramatic is the trend toward the recycling—or reclamation—of mined-out aggregate operations into useful and profitable secondary uses. No other single development carried out by the aggregate industry in the past 90 years has brought it greater acclaim. Today, mined-out pits and quarries are being used as sites for both dramatic new projects and for mundane but highly useful applications.
In Indianapolis, Ind., and Rochester, N.Y., developers have filled mined-out sites with water and built luxury condominiums and townhouses around the perimeter. In Virginia, owners of a working quarry are converting a major portion of a mined-out section into a 16-acre shopping center.
Quarry owners and shopping center developers have worked hand-in-hand to reduce quarry noise and dust to a level that businesses in the shopping center have found acceptable. This quarry will be separated from the shopping center by an attractively planted earth berm.
In Penfield, N.Y., Crystal River, Fla., and Austin, Texas, far-sighted land planners have turned old limestone quarries into innovative settings for golf courses, wildlife habitats and even an amusement park. Reclamation is now a booming business, and nobody is happier to see worked-out mining sites turned into viable, profitable second uses than the people who mined the sand and stone in the first place.
The United States’ northern neighbor, Canada—especially Ontario—has an aggressive program for dealing with abandoned aggregate excavation sites.
Other commentary by Bush, along with a list of other seminar papers covering an array of aggregate issues will be featured in future issues of AggMan.
The seminar, which provided live translations in English, French and Portugese, was attended by 300 people. ANEPAC is considering organizing a similar event in 2004.
Valentin V. Tepordei is the crushed stone specialist for Minerals Information at the U.S. Geological Survey.