12 steps to exploring your beneficial reuse option.

Follow these steps to determine if external reuse of your spent sand and other by-products is both economically and environmentally viable.

The beneficial reuse of "spent foundry sands," or sands that have outlived their usefulness in the foundry, certainly seems to make sense. Sand and clay come from natural sources, and many of the so-called "impurities" are burned out in the casting process. Reuse of foundry by-products offers foundries an opportunity to reduce the materials that must be landfilled - a definite environmental benefit - as well as the associated costs. With this in mind, today's foundries should have a real asset on their hands.

However, even though reuse options look promising to foundries, potential users typically do not see things the same way. They have a genuine fear of the "unknown" and are often wary about using different materials in the production of asphalt or concrete. In addition, they may have concerns about possible liabilities in the use of spent sand and other by-products.

You may feel that you should get paid for this "asset," but, in reality, most end users want to be paid to reuse your spent foundry sands and other residual materials.

As you can see, beneficial reuse may not be easy, but it can be accomplished. What should you do if you're interested in the beneficial reuse of your materials? The following article represents some basic steps in determining beneficial reuse feasibility and viability.

1 Determine what materials are presently, going to the landfill - Many foundries dump all of their materials for disposal into one area or one container. Each of these materials may have different chemical and physical characteristics, so it's important to isolate each one on an individual basis. Excess green sand, for example, would have different characteristics than scrap chemical-bonded cores. If you use different core processes, these residual materials also must be isolated [ILLUSTRATION FOR FIGURE 1 OMITTED].

During this material isolation stage, you must determine if it will cost more to separate these materials (extra trucking, extra storage hoppers, etc.)

Some examples of isolated materials going to the landfill include:

* excess green sand and core butts from the sand system;

* scrap cores from the coreroom (isolate further if different cores are used);

* other-foundry related materials such as slag.

2 Determine the volume and/or weight of each of these materials after isolation - The example in Table 1 breaks down possible sources of the largest amounts of residual materials and prioritizes these materials for beneficial reuse possibilities. These volumes and/or weights are typically broken down on a per day, per week, per month or per year basis. As the residual materials are isolated, they should be weighed out individually, or the general volumes should be estimated using a known size container.

Initial priority should be given to the excess green sand and slag because of the large amounts going to the landfill.

3 Determine the present cost to landfill these materials - You should review your invoices from the landfill, breaking down transportation and landfill tipping fees separately. Also, verify the remaining capacity of the landfill and whether or not it may be closing in the near future. This information should affect future cost considerations. These costs are typically broken down on a per ton or per yard basis.

It's also important to determine other costs involved, such as material handling (equipment and labor), within the plant prior to the transportation to the landfill. Typical landfill costs run approximately $20/ton (gate fee and transportation costs). These can vary greatly, depending on the location of a foundry within the U.S.

For example, a foundry may use a rolloff box, and the material in the box may weigh approximately 30 ton. The cost for the rolloff box, transportation to the landfill and landfill gate fee is $600/rolloff box. The overall cost per ton is $20/ton. Using the example of 8000 ton/year of excess green sand, it will cost $160,000/year to send the excess green sand to the landfill (8000 ton/year x $20/ton). This does not include internal costs prior to the 30-ton rolloff box. The cost for slag sent to the landfill is $70,000/year (3500 ton/year x $20/ton).

This can be a significant annual cost to a foundry. Before proceeding further with beneficial reuse, each foundry should try to minimize its residual materials generated and recycle internally. Once you accomplish this and determine that these landfill costs still appear significant, you should proceed to Step 4.

4 Verify your state environmental agency's stance on beneficial reuse of spent foundry sands and other residual materials - Many states have developed policies on reuse of these materials. Before a foundry goes further, it's important to understand what this policy requires and whether a policy even exists.

As an example, the Indiana Dept. of Environmental Management (IDEM) has established Foundry Waste Classification Guidelines that include a well-planned, representative sampling program. The classification process involves two phases: a Hazardous Waste Determination and a Waste Classification. The first phase is meant to ascertain whether the waste streams are hazardous or nonhazardous. The second phase determines disposal requirements and legitimate beneficial reuse applications.

When completing this step, it's important to obtain the most recent policy from the state. In addition, be aware of pending changes to the policy as well as what these changes will mean to your reuse options.

Once you review your state policy and determine that it is reasonable and cost effective for your foundry to comply, you should proceed to the next step.

5 Perform preliminary environmental testing on the priority materials selected - These analytical tests should verify that the residual materials are not hazardous. If you are presently landfilling these materials, many of these tests may already have been completed. Keep in mind that these are preliminary tests. Each state may require additional testing.

As part of IDEM's First Phase Hazardous Waste Determination, each residual material selected must be tested for all parameters listed under the Toxicity Characteristic Leaching Procedure (TCLP) requirement shown in Table 2.

The TCLP organic compounds do not require testing if they are not introduced or created during any part of the process. However, the generator must provide written certification or supporting documentation to that effect. Additional parameters may be required, if there is reason to believe that the waste contains significant concentrations of other contaminants, such as phenolic resins.

If the analytical results show that the materials are below the Type I criteria, then you can proceed to the next step. Be aware that the IDEM guidelines give more detail on how sampling should be conducted and additional waste classification guidelines.

6 Perform preliminary physical testing on the priority residual materials selected - Physical tests are required to determine how these residual materials can be used in areas such as concrete, asphalt, etc. These initial tests may include grain size analysis, modified Proctor, permeability and visual engineering classifications. The residual materials must be processed into aggregate size particles prior to the physical testing procedures.

The results of these preliminary physical tests will give you some options for beneficial reuse applications. They also will point out what options are not feasible based on the physical characteristics of the residual materials.

7 Perform additional environmental testing required by your state environmental agency - If the physical tests in Step 6 show promise and the economics still look good, then it's viable to continue. As indicated in Step 4, many states have certain testing procedures to classify a material as inert, spent and non-toxic, or other individual classifications.

Table 1. Example of Landfilled Material Weights

Excess Green Sand                     8000 ton/year
Hot Shell Materials                   1000 ton/year
Phenolic Urethane Materials           1500 ton/year
Furan Materials                        500 ton/year
Slag                                  3500 ton/year
Total                               14,500 ton/year

[TABULAR DATA FOR TABLE 2 OMITTED]

IDEM requires additional analytical testing to have foundry residual materials certified for legitimate beneficial reuse. After the materials have tested as non-hazardous, additional sampling using a neutral leachate analysis is required to classify the waste (Table 3). Foundry sand materials that meet Type III or lower leaching concentrations may be legitimately reused in accordance with IDEM regulations [ILLUSTRATION FOR FIGURE 2 OMITTED].

The IDEM guidelines also indicate methods of sampling, numbers of samples required and classification guidelines. It's important to thoroughly understand these state guidelines to properly classify your foundry waste materials.

8 Develop options for the materials selected for potential beneficial reuse - If the environmental tests from Step 7 are favorable and costs for testing are not prohibitive, you may begin looking for reuse options, such as landfill cover or in asphalt [ILLUSTRATION FOR FIGURE 3 OMITTED]. At this point, try to obtain some advice from others familiar with construction applications and materials. It's important that you "talk the talk" with potential end users of this material. They will have to be "sold" on using this material. They will not come to you - you must go to them.

When discussing your foundry byproducts with potential end users, call these materials "spent foundry sands" in lieu of "waste foundry materials," because the word "waste" often scares off a number of potential users. Also, don't expect these potential end users to pay you for this material. This is extremely rare and typically you'll have to pay them to take it from your plant.

Based on the environmental and physical test results, you should be able to make a list of your beneficial reuse options. Some of these options may include:

* cement kiln;

* concrete additive;

* asphalt additive;

* brick/tile additive;

* flowable fill additive;

* geotechnical fill;

* daily landfill cover;

* material for closure of old landfill.

Table 3. IDEM Second Phase Reuse Waste Determination Using the
Neutral Leachate Test(**)

PARAMETER              TYPE I      TYPE II    TYPE III    TYPE IV

Chlorides                 *        6250       2500        250
Copper                    *           6.25       2.5        0.25
Cyanide (Total)           *           5.0        2.0        0.2
Fluoride                  *          35         14          1.4
Iron                      *            *        15          1.5
Manganese                 *            *         0.5        0.05
Nickel                    *           5.0        2.0        0.2
Phenols                   *           7.5        3.0        0.3
Sodium                    *        6250       2500        250
Sulfate                   *        6250       2500        250
Sulfide (Total)           *          12.5        5.0        1.0
Total Dissolved Solid     *      12,500       5000        500
Zinc                      *          62.5       25          2.5
PH (Standard Units)       *        4 - 11     5 - 10       6 - 9

* Testing is not required.

** Concentrations (mg/I)

It is also important to note that the foundry may have to purchase special equipment to break up and screen these materials prior to beneficial reuse. Magnetic separation equipment also may be needed. These costs must be factored into your overall analysis.

9 Determine the most likely option and contact an end user - This is probably the toughest step to complete because a potential user may be leery of using your by-products. If, for example, an asphalt option looks like the best opportunity, then you should contact an asphalt company. You might also contact a state asphalt association to get names of open-minded asphalt companies. It's important to let these asphalt companies know up-front the results of the environmental and physical testing, and that this material meets the applicable state's environmental requirements. Be willing to offer a financial incentive to convince a company to switch from the materials it is currently using. An asphalt company also will require additional testing that incorporates foundry residual materials into their mix design.

It is important to select the right option, because each foundry retains future liability for its material. By law, a waste generator is responsible for the material from generation point to final resting point - forever.

A group of foundries may band together to explore reuse options. A Michigan group, Resource Recovery Corp. of West Michigan, received a state grant to develop its own asphalt plant and used the grant money to purchase asphalt processing equipment and equipment to break up and screen the foundry materials. This group of foundries basically followed Steps 1-8 and also performed its own testing with asphalt using foundry materials in a laboratory. The foundry materials are stored throughout the year and processed from April-November through the group's asphalt plant.

Spent foundry sand also has been used successfully as a cover to close a landfill. This is a one-time solution, but it involves several thousand tons of foundry residual materials.

Still another successful use for spent sand is daily cover for a municipal landfill. This option could be a quick "cost saver" for a foundry, serving as an interim beneficial reuse option while other options are pursued.

10 Perform a cost analysis - After selecting the most viable option, an overall cost justification review must be completed. The present cost of landfilling must be compared to the beneficial reuse costs. This analysis is meant to determine the economic feasibility of beneficial reuse.

Landfill costs may include:

* material handling within plant (equipment and labor);

* container rental (if applicable);

* transportation to landfill;

* landfill tipping fees;

* laboratory costs.

Beneficial reuse costs may include:

* laboratory analyses;

* laboratory physical testing;

* equipment, labor and utilities to prepare materials for reuse;

* reuse fees requested by an end user;

* consulting fees to process state paperwork;

* material handling within plant (equipment and labor);

* applicable regulatory permits;

* transportation to end user;

* storage (if applicable).

11 Coordinate activities with the applicable state agencies - Once you determine that a beneficial reuse option is viable, you may need to contact the state to obtain overall approval. Some states require application petitions outlining the proposed beneficial use. Much of this information can be predetermined in Step 4.

12 Begin beneficial reuse application - Many states require annual analytical retesting of the materials proposed for reuse. It's also important to be on the lookout for other more cost-effective beneficial reuse applications.

If there is a significant capital cost for equipment or other needs, it's important to enter into a long-term contract with an end user.

Some of the steps may best be done in a different order, depending on each individual foundry's situation, and after these steps are completed, it's still important to monitor the beneficial reuse activities.