m is gradually becoming accepted as a better choice since it also provides other benefits that are not achieved with cullet.
"The increased batch costs are typically recovered through a higher glass yield; thus the unit cost of bottles remains largely unchanged or lower, depending on the location and the costs of other raw materials and fuel," Sheth said.
Why Isn't Everyone on Board?Despite the success stories from manufacturing facilities around the world, many glass manufacturers have been reluctant to consider the use of lithium as an energy-saving solution. A number of the manufacturers that ran lithium trials early on have gone out of business or been acquired by other companies, and today's companies don't appear to be eager to change their product formulations. "[The U.S. industry] seems fixated on the ‘hardware' of glass and ceramic manufacturing and so far has shown no inclination to consider energy reduction improvements through batch adjustments," said Merivale.
Part of the problem is the cost-and perceived cost-of lithium. When many of the early trials were conducted, lithium was considered too costly to implement on a regular basis. However, suppliers have noted that the price of lithium carbonate has dropped considerably over the past several years, and other lithium-bearing ores have also become more affordable. Additionally, data from a number of plant trials have indicated that the energy savings and other benefits that can be achieved with the lithium additions often more than make up for any added material cost.
Another concern for many glass producers is the effect of lithium additions on the refractories inside the furnace. However, a European glass research lab has shown that small additions of lithium-up to 0.3 wt% Li2O-in glass does not corrode refractories at same furnace load or temperature used previously, and in fact can enhance refractory life when it is used to replace soda or potash in the glass batch. Additionally, lithium does not volatilize and therefore poses no threat to the furnace crown.
As global competition continues to place pressure on manufacturers, companies will be forced to look for more ways to reduce costs without compromising productivity and product quality. While a number of advances will continue to be made in terms of equipment, manufacturers shouldn't overlook raw materials such as lithium as a potential part of the overall solution.
"For our industry to remain competitive, it is going to have to consider these other approaches," Merivale said.
Editor's note: This article is an updated version of a previous article published in Ceramic Industry (July 2002), which was compiled with the assistance of Jim Angelo, Chemetall Foote Corp.(contact Gary Otwell, (704) 739-2501, email@example.com ); Derek McCracken, American Minerals, Inc., (724) 695-7820, DMccrac814@aol.com ; Anand Sheth, Sons of Gwalia Ltd., (61) 8-9263-5555, firstname.lastname@example.org ; and Charles Merivale, Amalgamet Canada, (416) 366-3954, ext. 224, email@example.com (on behalf of Tantalum Mining Corp. [TANCO], Manitoba, Canada).