Photograph as originally submitted to this page in the Historical Marker Database www.HMdb.org. Click on photo to resize in browser. Scroll down to see metadata.

Photographer: Barry Swackhamer
Taken: March 9, 2018
Caption: One Whale of a Pot
Additional Description: The earliest processing of cinnabar ore at New Almaden Mine was crude but effective due to the richness of the ore (sometimes more than 60% mercury). In spite of loosing almost as much mercury as they collected, huge metal "whale pots,: once used for rendering whale blubber, could produce 300 pounds of mercury a day.
Small batches of mercury can be extracted by heating ore in a retort; a device similar to a moonshiner's still. When tons of mercury ore must be roasted, however, mercury extraction becomes much more difficult. Engineers at New Almaden Mines were continually challenged to devise faster, more efficient ways of coaxing mercury from cinnabar. As larger furnaces and improved condensers evolved, more mercury was recovered from each ton (roughly one cubic yard) of ore. Existing "batch process" furnaces has to be cooled periodically to remove the accumulation of roasted ore, ash, and soot.
Before the reduction process could continue, a fresh batch of ore had to be loaded, new fuel added and the furnace reheated to operating temperature -- a cumbersome, time-consuming, labor-intensive process.
There had to be a better way.
Submitted: March 13, 2018, by Barry Swackhamer of Brentwood, California.
Database Locator Identification Number: p419104
File Size: 0.773 Megabytes

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