Carrie Everson Story Part II

Left alone to manage the family’s affairs, Carrie began to wonder if something might be saved from the mining investment. She reasoned that if more gold could be extracted from the ore then perhaps the mining might at least break even and she could get some money back. 

She went to work grinding ore samples with mortar and pestle and examined them under a microscope. This type of activity wasn’t unexpected for Carrie. She had always been an explorer of sorts. She graduated from college, which was unusual for a woman in the 19th century, and continued to educate herself. When she married William in 1864, she learned all she could about science and medicine and became proficient in chemistry. It was this knowledge and skill she applied to the study of mineralogy.

Carrie experimented with a wide range of methods to separate gold from the other materials in the rock. The main processes already in use were mechanical ones of smashing and using water to bring lighter materials to the top to be skimmed off with heavier substances like gold and silver settling in the bottom. Some gold is always lost in this mechanical process. The finer flakes are often carried away stuck to pebbles or larger rocks.  Carrie’s challenge was to find a way to keep from losing these small particles of gold.

Carrie kept no notebooks so it is not known how she decided to use oils and fatty substances as potential materials to separate the gold from the mixture. Some accounts say she used the well-known fact that when miner’s clothes were laundered, mineral flecks came to the surface. However, there is no way of knowing if this information influenced her.

Carrie experimented with various combinations of oils, acids and minerals in her work to create a process for separating minerals from ores. She found a relationship between certain oils and minerals. With the correct conditions, oil and water mixed into powdered ore allowed certain minerals to stick to the oil bubbles and rise to the surface. When the minerals were skimmed off the surface, the gold remained at the bottom. By adjusting the kind of oil and kind of acids that were added, many kinds of minerals could be “floated” to the surface and skimmed away.

Dr. Everson returned home from Mexico and was impressed by Carrie’s discoveries. He quit his medical practice and helped her perfect the process. By late 1886, she was ready to apply for a patent for “The Flotation Process.” After many attempts to secure the patent and many revisions of the technical writing of the details, Carrie was eventually awarded U.S. Patent # 348, 157.

Miners panning gold. Photo from http://www.phoenixgoldmine.com/justpanning.html

Unfortunately, some gold is always lost in this process.  The finer flakes are often carried away stuck to pebbles or larger rocks.   Carrie’s challenge was to find a way to remove minerals from the mixture without losing the gold.

How Carrie landed on oils and fatty substances as potential materials to separate the mixtures is not known.  It was well known at the time that when miner’s clothes were laundered mineral flecks came to the surface.  Perhaps Carrie used this information to begin her analysis.  

Carrie experimented with various combinations of oils, acids and minerals and began to formulate a process for separation gold from surrounding minerals. What she found was an interesting relationship between certain oils and minerals.  Given the correct circumstances, adding oil and water into a  powdered ore allowed certain minerals to stick to the oil bubbles and rise to the surface. By skimming the mineral off the surface the gold would remain at the bottom.  By adjusting the kind of oil and kind of acids that were added, many kinds of minerals could be “floated” to the surface and skimmed away.

Carrie Everson. 

Photo:  http://pages.suddenlink.net/mishikal/jack/Appendices/Appendix_A/appendix_A.html

Postscript to the story

Carrie and William moved to Denver to try to get mining companies interested in using oil flotation. Few were interested and most believed that there was little promise in the process.

Three years after the celebrated patent and after repeated efforts to get support, Dr. Everson died. With the family fortune nearly evaporated from bad investments and the costs of acquiring patents, Carrie had to find work to support her five children. Having college preparation and medical experience, Carrie became an obstetrical nurse in Denver.

For the next two years Carrie continued to work on the process. Forming partnerships with others, she continued to build demonstration models to try to sell the idea to miners.

With the help of her son John and from Thomas Criley, she directed plans for a large-scale demonstration of the process in Baker City, Oregon. The ore was crushed in an old stamping mill and then added to a large tank where the mixture was agitated and screened to concentrate the ore.

Although the process showed promise, mining engineers were not willing to change from their old methods. Mining gold from high concentration areas was cheaper than trying to concentrate low grade ores. There was no need to use something crazy like oil. And, although unsaid, the thought that a woman might have good ideas for mining was beyond some men’s grasp and ridiculed by others. Carrie’s work went unrecognized and unused.

The turn of the century brought new rules for mining. Gold deposits became less and less common as all the richest sites had been found and mined. The economics of gold mining and extraction changed. Miners now started to consider using deposits that were once overlooked because of their low yields. Mines that were once considered finished were revisited. New methods were needed to extract as much gold as possible from each ton of ore. Now, Carrie’s flotation process was needed.

By this time, however, 17 years had passed and the patent had run out. Anyone could use Carrie’s process without paying her royalties. She received no financial benefit from a process that made a large impact on modern mining and ore separation. 

In 1909, Carrie moved in California to be with her only surviving child, her son John. Carrie lived her last five years without fame or fortune knowing that her process had helped to make others wealthy. She said she was glad to know that someone was able to derive benefits from her work. She was inducted into the Mining Hall of Fame in 2008.