Best Management Practices + CarbonCure Reclaimed Water = ROI
If you’re a concrete producer who has invested in a reclaimer, you enjoy the benefits of a cleaner job site, recovering aggregates, and knowing you are protecting the local groundwater and streams. Your investment also demonstrates your environmental responsibility to like-minded customers as well as regulators.
It’s no small investment. A concrete reclaimer with an agitated tank can run into six figures for the purchase and installation alone, never mind its operation and maintenance. You are, no doubt, saving by recycling aggregates from your returned concrete, but are you getting full value from your reclaimer?
Optimizing Your Reclaimer
You can optimize your concrete reclaimer by making improvements to your equipment, practices, and process flow. Some optimizations are harder to achieve than others, but all are worth a review. In an industry with tight margins and rising material costs, even small improvements can make a significant impact.
1. Retrofit Your Reclaimer
If you have an agitated tank, the most cost-effective way to optimize your reclaimer is to retrofit it with CarbonCure Reclaimed Water. This award-winning technology is installed on top of your existing agitated tank. The technology enables you to reuse the reclaimed water in mixes without negatively impacting your concrete’s fresh or hardened properties. Any reclaimed water you use in mixes is water you don’t have to pay to treat and haul away for disposal. You can save up to 20% of your virgin water use and reduce virgin cement by an average of 4%. The technology is provided through a subscription service, so there is no capital cost for the equipment. Even with modest production volumes, you can generate a return on investment. In short, it can revolutionize your reclaimer operation.
How it works: CarbonCure Reclaimed Water injects captured carbon dioxide (CO2) into the slurry. The CO2 reacts with the cement, changing the CO2 into a mineral that strengthens concrete when the reclaimed water slurry is used in new concrete mixes. The added strength from the mineral and stabilization of the slurry means you can reduce your virgin cement in the new batches. The results are predictable and reliable, providing a high quality, low carbon concrete. When combined with CarbonCure Ready Mix, you can get up to a 7% reduction in cement, producing an even more sustainable concrete.
Note: The following ways to optimize your reclaimer are based on the Best Management Practice for Ready Mix Concrete Process Water recently published by CalCIMA. Some of these improvements to equipment and practices may not even be needed if you use CarbonCure.
2. Avoid Reclaiming Large Batches
CalCIMA recommends only putting large batches into your reclaimer as a last resort. Use the returned concrete in other ways if you can, such as pouring the concrete into forms for blocks or bolos, or using hydration stabilizers and re-batching for the next load. Avoiding reclaiming large loads will help keep down the concentration of suspended particles in your reclaimed water. This reduces how much you need to dilute traditional reclaimed water for use in new mixes. Minimizing water use for reclaiming the aggregates and for washout also reduces the volume of reclaimed water you’ll need to store for reuse, or treatment and disposal.
3. Keep Up With Minor Maintenance to Avoid Major Maintenance
According to CalCIMA, best practices are to clean the reclaimer hoppers daily and to power-wash the holding tank pumps weekly. This will reduce downtime for more involved maintenance or repairs. Another tip for reducing unnecessary maintenance is to avoid putting concrete with lots of fiber into the reclaimer. Fiber content can quickly clog the separators for aggregates and solids. This is another case where you may be better off making blocks or using the concrete for other purposes.
If you’re using CarbonCure, you may also find that manual maintenance is reduced since it uses telemetry to monitor the tank 24 hours a day, 7 days a week for proper functioning and capacity.
4. Optimize Mixes
If you use traditional reclaimed water, you’ll need to develop mixes that work well with reclaimed water. Typically, reclaimed water and flatwork aren’t compatible. Whatever your mix, you will need to watch the specific gravity of your reclaimed water and dilute it to the ideal concentration. This can be done through an in-line system that measures the specific gravity of the water as it flows through, automatically adjusting water weights up or down during batching.
If you use CarbonCure Reclaimed Water as well, it identifies the composition and density of the slurry and makes automatic adjustments to account for the cementitious fines. The overall yield and particle densities remain the same, whether you used the reclaimed water or not. Because CarbonCure integrates seamlessly with your batching software, there’s no manual adjustment needed by your batching staff.
5. Right-size Your Reclaimer & Tank
If this advice is “too little, too late,” consider it for your next purchase if expanding or building a new plant. Reclaimers can only handle so much returned concrete at a time. Ideally, the hopper is big enough that drivers can unload quickly without creating a bottleneck. Likewise, the tank should be large enough so you’re minimizing the frequency of disposal. With CarbonCure Reclaimed Water, the size of your agitated tank is less crucial because you are able to consistently reuse your slurry in a more reliable manner.
6. Optimize Your Process Flow
Like any component of your operation, your reclaimer must be part of an integrated system that considers the process flow of your plant. It must be convenient for drivers to use and follow a logical order without backtracking or bottlenecks. CalCIMA also recommends having the returned concrete removal, the water source for truck washout and the location of the process water discharge (in this case, the tank), all close to each other. The farther they are apart, the less efficient your operations will be and your operating costs will increase. While it’s a big endeavor to rethink your plant layout and flow, the efficiency gained may be worth it in the long run.
Installing a reclaimer is an investment that provides a number of benefits. Optimizing it can save you time and money, improve your product, and solve your reclaimed water challenges once and for all.