Olivine sand offers better physical properties than silica for aluminum sand casters. Because of the interlocking nature of its angular grains, olivine green sand molds develop higher molding properties at higher compaction pressures. The angularity of the olivine sand grains allows the molding aggregate to be more permeable than comparable silica sands. This allows for the usage of extremely fine olivine sand grains to improve as-cast surface finishes. The thermal expansion characteristics of olivine sand is extremely favorable, permitting near-net shape castings and decreasing casting defects such as rattails, buckles and scabs. For the aluminum foundry industry, the advantages of olivine green sand molding systems are offset by the fact that olivine sand is alkaline. Most organic binder systems are not compatible with alkaline molding aggregates. Aluminum casters are forced to use fine grain silica sand cores to create cored passageways and internal cavities. As the silica sand cores are recycled back into the olivine green sand, this leads into another serious process control problem. Silica sand reacts with olivine sand depending on temperature conditions. Aluminum foundries will notice a significant decrease in green sand molding properties when the silica content exceeds 20 % by weight. To counteract this detrimental effect, aluminum foundries will remove a portion of the system sand and replace it with new, clean olivine sand on a regular basis. The removed sand containing good olivine sand is then sent to landfills for disposal. There are several binder systems used by the aluminum foundry industry. The Shell process is attractive because of the excellent surface quality attained and, since the process produces hollow cores, lower addition rates of silica sand is introduced into the olivine green sand. The drawback with this binder process is the relatively large amount of resin used for bonding, increasing the potential for gas related casting defects. The furan binder system is widely used owing to their attractive shakeout characteristics. However, solid silica sand cores are required that degrades the green sand molding system rapidly. Phenolic urethane cores are popular because of the ease in manufacturing and process control. Again, solid silica sand cores are required and poor collapsibility properties of phenolic urethane add to the cost for secondary removal. Considering the unique bonding attributes of the protein based biopolymer binder, a significant impact can be realized for aluminum foundries using olivine sand in their green sand molding operations. The excellent collapsibility property of the binder eliminates the need for post cleaning operations. Cores that are difficult to remove can be dissolved in water. A unique attribute, particularly for aluminum shops running an olivine green sand molding operation, is the neutral bonding nature of the biopolymer binder. Unlike most organic binder system, the chemistry of the molding aggregate does not affect the bonding mechanism of the protein-based binder system. The economic potential of using olivine cores with olivine green sand molding systems can be realized with the protein based biopolymer binder process. This translates to extended usage of olivine green sand in aluminum casting operations. An applied research study was undertaken to assess the influence of protein based biopolymer coated, olivine sand cores on olivine green sand molding properties. Green sand molds were made to assess the green sand properties as used biopolymer cores were continually introduced into the molding system. Aluminum castings were poured to observe the casting quality after each cycle diluted with the biopolymer coated cores. The research work showed an increase in water capacity but stabilized toward the end of the experiment as the amount of returned olivine core sand increased. The green sand properties exhibited an initial decrease but stabilized as the olivine green sand matured with the addition of biopolymer coated cores. The changes in the green sand properties from the addition of decomposed and composed biopolymer binder do not appear to have any adverse effect on casting quality. The cored surface using biopolymer coated olivine sand cores exhibited excellent surface finish with excellent shakeout characteristics. The research work demonstrated the potential of producing olivine cores using the protein based biopolymer to extend the life of olivine green sand for aluminum casting operations. Using olivine sand cores coated with the biopolymer binder reduces periodic disposal of green sand to re-condition an olivine green sand molding system. An indirect result of the feasibility study was the reduction of free silica in the workplace and exposure to hazardous air pollutants associated with organic binder processes. (VDG)