| dc.description.abstract | Today's mandate for environmental sustainability demands that manufacturing companies design processes to minimize their environmental ＂footprint,＂ or unit consumption of raw materials and energy and unit production of waste or valueless by-products. One effective approach has been to convert process waste into a byproduct that effectively regenerates another natural resource. Once implemented, these processes must be periodically refreshed with innovations to keep them environmentally acceptable and economically viable. The objective of this study is to help ＂Company A＂ increase its regeneration effectiveness while reducing cost.
Company A currently produces a co-product, man-made aggregate, from its slurry by-product stream containing 75% liquid and 25% solid (slag). In order to neutralize its acidic content and achieve desired co-product quality, large quantities of cement are added to the slurry before casting into a solid sheet for curing. This study explores the alternative of separating most of the acidic water from the solids before neutralization, resulting in separate liquid and solid co-product streams with different regenerative applications. The liquid stream has potential application as coagulant The solid stream can be blended with natural sand for fabricating non steel-reinforced concrete blocks. Prototype production of these blocks for use as sidewalk bricks have been evaluated for aging, dimensional stability, and quality with ultrasonic pulse inspection. Test results show no significant difference from those made with 100% natural sand.
This new process could reduce cement and waste treatment costs for Company A by up to 70%. The solid co-product, if sold at half the cost of natural sand, could reduce variable cost of brick manufacturers by 6-10%. More importantly, the effective regeneration of industrial slag will help reduce the consumption of natural resources. | en_US |