After more than three years of testing and numerous plant trials, the company found its answer-and more. Today, the new additive* is helping brick manufacturers produce lighter, stronger brick, with increased throughput and associated reductions in fuel consumption, transportation costs and bat losses.
"The additive weighs just 35 pounds per cubic foot [lbs/ft3] and is typically two to three times lighter than the additives it replaces, such as grog, fly ash and granite, which often weigh somewhere between 85 to 112 lbs/ft3," Rutherford explains. The additive can also be used to replace some base body materials, particularly heavy clays.
While many factors-including material cost, its role in the mix, etc.-affect which ingredient the additive should replace, weight is usually the key driver. "So many benefits are derived from weight savings that it usually pays to substitute the additive for heavier materials," Rutherford says.
The weight reduction also reduces transportation costs. With a 4-9% weight savings per brick, plants can often get another thousand brick equivalent (MBE) per load on a truck and still stay within weight restrictions. This, in turn, can enable them to cost-effectively expand their sales territories to other regional markets.
Lighter brick might also permit brick manufacturers to increase their throughput while remaining under the 10-ton emission limit required under state and federal Maximum Achievable Control Technology (MACT) standards. "Since less material (by weight) is going through the kiln, plants that are already under the limit might be able to produce more brick while remaining under that limit," Rutherford explains.
"Just about every manufacturer has experienced some bat loss on the bottom of their kiln cars due to inadequate green strength. These losses can be quite high because of the enormous weight of the load," says Rutherford. "The additive acts as a moisture manager in wet clays, firming up the extruded column and improving green strength. Plant tests have shown increases in green strength between 10-21%. As a result, reductions in bat losses range from 2-5%-particularly in the lower portions of the car-both because of the increased green strength, and because the load is composed of lighter brick."
Additionally, unlike many byproduct additives, the new additive is consistent from load to load. As a result, "brick manufacturers won't have to compensate for material variability," Rutherford notes.
"Each situation really needs to be evaluated on a case-by-case basis," Rutherford explains. "For example, this isn't a magic bullet to reduce energy consumption. Plants that are already using a lightweight body material and are firing with fuels other than natural gas probably won't see enough energy savings to justify the additional cost of using the additive."
Likewise, plants that are primarily looking for higher throughput might find other solutions that meet their needs. Oil-Dri Corp. has partnered with Mission Clay Products in Kansas City, Mo., to carefully evaluate each potential application and determine the suitability of the product based on a plant's individual goals. However, for many plants, Rutherford believes the combination of weight reduction, reduced bat losses and increased throughput provided by the new additive will be more than enough to justiify using it in production.
"A number of today's plants are using heavy raw materials and are looking for ways to save on fuel and transportation costs. With this new additive, companies can realize substantial savings in these areas while also improving their overall brick quality," he says.
For more information about the new additive, contact Oil-Dri Corp. of America, 410 N. Michigan Ave., Ste. 400, Chicago, IL 60611; (800) 851-2399; e-mail email@example.com ; or visit http://www.oil-dri.com .
*BA-1000, patented and supplied by Oil-Dri Corp., Chicago, IL.